( "T"he Journal of ARACHNOLOGY OFFICIAL ORGAN OF THE AMERICAN ARACHNOLOGICAL SOCIETY VOLUME 33 2005 NUMBER 1 THE JOURNAL OF ARACHNOLOGY EDITOR-IN-CHIEF: Daniel J. Mott, Texas A&M International University MANAGING EDITOR: Paula Cushing, Denver Museum of Nature & Science SUBJECT EDITORS: EcologySQYen Toft, University of Aarhus; Systematics — Mark Harvey, Western Australian Museum; Behavior and Physiology — Gail Stratton, University of Mississippi EDITORIAL BOARD: Alan Cady, Miami University (Ohio); James Carrel, University of Missouri; Jonathan Coddington, Smithsonian Institution; William Eberhard, Universidad de Costa Rica; Rosemary Gillespie, University of California, Berkeley; Charles Griswold, California Academy of Sciences; Marshal Hedin, San Diego State University; Herbert Levi, Harvard University; Brent Opell, Virginia Polytechnic Institute & State University; Norman Platnick, American Museum of Natural History; Ann Rypstra, Miami University (Ohio); Paul Selden, University of Manchester (UK.); Matthias Schaefer, Universitset Goettingen (Germany); William Shear, Hampden- Sydney College; Petra Sierwald, Field Museum; I-Min Tso, Tunghai University (Taiwan). 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PRESIDENT-ELECT: Elizabeth Jakob (2003-2005), Department of Psychology, University of Massachusetts, Amherst, MA 01003 USA. MEMBERSHIP SECRETARY: Jeffrey W. Shultz (appointed). Department of Entomology, University of Maryland, College Park, MD 20742 USA. TREASURER: Karen Cangialosi, Department of Biology, Keene State College, Keene, NH 03435-2001 USA. SECRETARY: Alan Cady, Dept, of Zoology, Miami University, Middletown, Ohio 45042 USA. ARCHIVIST: Lenny Vincent, Fullerton College, Fullerton, California 92634 USA. DIRECTORS: James Carrel (2001-2003), Rosemary G. Gillespie (2002-2004), Brent D. Opell (2003-2005). PAST DIRECTOR AND PARLIAMENTARIAN: H. Don Cameron (appointed), Ann Arbor, Michigan 48105 USA. HONORARY MEMBERS: C.D. Dondale, H.W. Levi, A.F. Millidge, W. Whit- comb. Cover photo: Brown recluse spider, Loxosceles reclusa Gertsch & Mulaik, from Tennessee. Photo by Rick Vetter. Publication date: 6 June 2005 @ This paper meets the requirements of ANSI/NISO Z39.48-1992 (Permanence of Paper). 2005. The Journal of Arachnology 33:1-6 BEHAVIOR OF WEB-INVADING SPIDERS ARGYRODES ARGENTATUS (THERIDIIDAE) IN ARGIOPE APPENSA (ARANEIDAE) HOST WEBS IN GUAM Alexander M. Kerr': Marine Laboratory, University of Guam, Mangilao GU 96923 USA ABSTRACT. Most Argyrodes live in the webs of other spiders, stealing food from the host, scavenging small prey from the web or killing and eating the host. I observed the behavior of A. argentatus from Guam, where it is a frequent inhabitant of the large orb webs of Argiope appensa. I examined the pro- portion of time spent in different activities, whether behavior differed between the sexes and if population density of Argyrodes on a host web affects Argyrodes behavior. Argyrodes spent 55% of the time hanging immobile and inverted in the support strands at the webs’ margin. This was significantly more time than that spent in stationary activity, forward movement at the web’s margin, feeding, foraging on the sticky spiral or in aggressive interaction. Females foraged significantly more often than did males, though the sexes spent about the same amount of time feeding and in other activities. Females also engaged in more bouts of feeding and 21% of these bouts were at prey bundles prepared by the host. In contrast, males invariably foraged for small insects unnoticed by the host. Keywords: Kleptoparasite, Mariana Islands, Micronesia, Araneae Most members of the large, cosmopolitan genus of Argyrodes Simon 1864 live in the webs of other spiders. They feed on small in- sects that have gone unnoticed by the host (Whitehouse 1986), prey stolen from the host (Robinson & Olazarri 1971), the host itself (Trail 1980; Tanaka 1984; Larcher & Wise 1985) or host- web silk (Shinkai 1988; Tso & Severinghaus 1998). Argyrodes may also cap- ture prey themselves using an abandoned host web (Larcher & Wise 1985) or use their own small web (Whitehouse 1986). Despite a growing literature on the ecology of this interesting spider genus (e.g., Henaut 2000; Miyashita 2001, 2002) and the prospect of powerful comparative phylogenetic ap- proaches (Agnarsson 2002; Whitehouse et al. 2002), the behavior of most species is still poorly known. One little studied species is Ar- gyrodes argentatus O.R Cambridge 1880, a small (adult female body length c. 5 mm) spi- der with a tall, conical, silvered abdomen that is reported from Madagascar eastward through southeast Asia to South America (Cambridge ' Current address: Department of Ecology, Evolu- tion and Marine Biology, University of California, Santa Barbara CA 93601 USA. E-mail: alexander. kerr@ aya.yale.edu 1880; Exline & Levi 1962; photo in Koh 2000). General observations of this species have been made on host webs of Argiope ar- gentata (Fabricius 1775) in Panama (Robin- son & Olazarri 1971) and Nephila maculata (Fabricius 1793) from New Guinea (Robinson & Robinson 1973). Argyrodes argentatus on the island of Guam in western Micronesia is a frequent inhabitant of the large orb webs of several species. Kerr and Quenga (2003) re- port on population variation in different host species and habitats for Guamanian Argyro- des, including A. argentatus. The most com- mon orb-weaving spider on Guam hosting A. argentatus in their webs is Argiope appensa (Walckenaer 1841) (Araneidae) (25 mm), which occurs from New Caledonia and across the tropical western Pacific to Hawaii (Levi 1983). It builds a nearly vertical planar orb web with sticky spiral strands, occasionally with cruciate or diagonal strips of white silk near the center (Kerr 1993). In this paper, I record further aspects of the behavior of Ar- gyrodes argentatus from Guam. Specifically, I asked: (1) What is the proportion of time spent in different activities? (2) How does be- havior differ between the sexes? (3) Does population density on a host web affect Ar- gyrodes behavior? 1 2 THE JOURNAL OF ARACHNOLOGY METHODS Surveys. — The surveys were performed in Mangilao and Ukudu (Dededo), Guam, 6-31 August 1989 in native forest, beach strand or disturbed vegetation. Guam (13° N, 145° E; 540 km^) is a volcanic and tectonically up- lifted limestone arc island in the western Pa- cific Ocean. Voucher specimens of Argyrodes argentatus (adult males and females) and its host Argiope appensa (adult females) are de- posited at the Department of Zoology, South- ern Illinois University at Carbondale and the University of Guam Herbarium. Censusing of haphazardly encountered webs was conducted during periods of no rain between 0900-2100 h, since a preliminary survey (A. Kerr pers. obs.) suggested that the spiders were most ac- tive during this time. A dim red light was used during nocturnal observations to avoid dis- turbing the spiders or attracting insects to the host web. The density of Argyrodes was mea- sured as number of spiders per unit area of host web. The area of Argiope host webs, as defined by the outermost spiral strands, was computed as an ellipse based on horizontal and vertical web diameters. To determine the behavior of Argyrodes, I recorded for 20 Ar- giope appensa host webs the activities of each Argyrodes found, after which the web was no longer used. In these webs, a total of forty- eight Argyrodes argentatus (23 females, 21 males and 4 juveniles) were each observed re- peatedly for ca. 15 s at 5-min intervals (sensu Vollrath 1976) over a period of 1.5-4 h per web for a total of 1 ,286 separate observations in 107.2 spider hours. These same host webs and spiders, and their recorded behaviors, were used in all analyses. Twelve webs (60%) were from beach-strand vegetation, six (30%) were from disturbed vegetation and two (10%) occurred in native forest. I categorized behavior as quiescence (immobile and invert- ed), foraging (moving forward on prey-catch- ing spiral while rotating leg pair I sensu Whitehouse 1986), forward movement on oth- er silks at the web’s margin, feeding (contact between mouthparts and prey), stationary ac- tivity (grooming, modifying silk, mating), or as agonism-avoidance (rushing towards or re- treating from other spiders). Statistical analyses. — The proportion of time a spider spent performing an activity was computed as the number of observations for that activity divided by the total number of observations on that spider. Intersexual differ- ences in time spent in a behavior were ex- amined with one-way anovas or Kruskal-Wal- lis procedures. I examined the relationship between the density of Argyrodes argentatus and behavior using simple linear regressions. Recently hatched spiderlings were sometimes extremely numerous on a web, but such ag- gregations dispersed quickly. To prevent them from inflating estimates of population density on webs, spiderlings were excluded from the analyses. To meet assumptions of parametric procedures, densities of adult Argyrodes were square-root or log transformed and propor- tions were arc-sine-square root transformed when necessary. Statistical outliers were de- tected using Dixon’s tests (Sokal & Rohlf 1981). Tests of association with categorical variables were done with a G test with Wil- liams’ correction for small sample size. Then homogeneity of variances was checked with Bartlett’s tests and normality confirmed with Rankit plots (Sokal & Rohlf 1981). Otherwise analogous nonparametric procedures were used. RESULTS General observations. — Argyrodes argen- tatus would sometimes glean small insects from the host web. These were sometimes eat- en where found or wrapped and taken to the margin of the host web and eaten there. Ar- gyrodes would also remove and eat spiral catching silk from a host web, sometimes re- moving large sections. The host Argiope ap- pensa would sometimes leave wrapped small prey at the capture site. These prey bundles were sometimes removed by Argyrodes ar- gentatus, who would cut them from the web and hoist them to the host web’s barrier strands. At other times, A. argentatus would feed together on prey bundles held in the host’s mouth as the host rested at the web’s hub. I also observed one possible instance of predation on the host by A. argentatus. In this case, several A. argentatus were feeding at the web hub on a dead adult female Argiope ap- pensa host that had been alive the previous day. Proportion of time in activities. — Propor- tional time differed significantly between ac- tivities via a Kruskal-Wallis procedure {H = 121.62, P < 0.001). The 48 Argyrodes (fe- KERR— A/?GF^OD£5 BEHAVIOR 3 Figure 1. — Time budget of adult male and female Argyrodes argentatus. Males denoted by striped bars. Asterisk indicates a significant difference via a one-way anova. males, males and juveniles combined) in the 20 host webs spent significantly more time hanging immobile and inverted in the support strands at the webs’ margin than in stationary activity, forward movement at the web’s mar- gin, foraging, feeding or agonism (minimum pairwise G — 11.02, P < 0.001 adjusted for multiple comparisons). Other activities on av- erage occupied no more than 9% of the time. Instances of agonism were least frequent, oc- curring 0.7% of the time. Sex related differences.— When sexes were considered separately, there was one no- table significant difference in behavior. Fe- males foraged significantly more often than did males (females: mean proportion ± 1 SE - 0.172 ± 0.039; males: 0.019 ± 0.010; = 19.776, P < 0.001) (Fig. 1). Other behav- iors were not significantly different (P > 0.05) between the sexes: quiescence (females: 0.506 ± 0.066; males: 0.625 ± 0.065; H - 0.798, P = 0.372), stationary activities (females: 0.079 ± 0.014; males: 0.113 ± 0.026; H = 2.19, P “ 0.138), movement on support strands (females: 0.138 ± 0.039; males: 0.160 ± 0.010; H = 1.57, P = 0.210), or agonism (females: 0.011 ± 0.010; males: 0.005 ± 0.005; H = 0.89, P - 0.344). Of the 50 bouts of feeding (continuous feeding through mul- tiple observations), 38 were by females and 12 were by males. Females more often fed on large prey bundles prepared by the host (21% of feeding events) than did males, who were never observed feeding on prey bundles, but rather fed on small prey (tiny dipterans and homopterans) caught on the spiral strands, but unnoticed by the host. This intersexual differ- ences in type of prey used was not significant (G,,j - 3.01; P - 0.0829). Effects of density. — The density of A. ar- gentatus on host webs varied by about an or- der of magnitude, from a minimum of 0.027/ 100 cm^ to 0.26/100 cm^ or 1-8 individuals per web. The proportion of time that adult A. argentatus spent feeding on prey was weakly but significantly and inversely related with the density of this species on Argiope webs {n — 44; P - 0.0462; P - 0.142; y - -0.776 x + 0.430) (Fig. 2). I observed only six instances of agonism between Argyrodes individuals or 4 THE JOURNAL OF ARACHNOLOGY Figure 2. — Proportion of time spent feeding by adult Argyrodes argentatiis versus its population density on host webs of Argiope appensa. 0.12 r S' 0.1 - I 0.08 - I 0.06 - ro 0.04 “ 0 S 0.02 - 0 ■ mmt m >— « » 0 0.1 0.2 0.3 Density of A. argentatus (N/100 cm^) Figure 3. — The rate of agonism and avoidance of hosts and other Argyrodes versus adult Argyrodes argentatus population density on host webs of Ar- giope appensa. between Argyrodes and their host. In three of these encounters, the aggression resulted in one of the pair of Argyrodes leaving the web. Pooled inira- Argyrodes and Argyrodes-\\os,{ agonism was not significantly correlated with Argyrodes density (r- = 0.005; n = 44; P > 0.05) (Fig. 3). Other behaviors were also not significantly correlated with the density of adult A. argentatus: quiescence (r- = 0.009), stationary activities {r- = 0.051), movement on support strands (r- = 0.051), or foraging {P- = -0.021). DISCUSSION Of the Argyrodes species that take food in the webs of larger spiders, sometimes foraging is for small prey unnoticed by the host (Whitehouse 1986; Pasquet et al. 1997), while at other times Argyrodes concentrates on shar- ing large prey captured by the host (Vollrath 1979; Whitehouse 1997). There may also be species-specific differences in the use of these strategies (Tso & Severinghaus 2000). Inter- sexual differences in foraging mode have also been noted. Cangialosi (1990) found that male Argyrodes ululans O.P. Cambridge 1880 in webs of Anelosimus eximius (Keyserling 1884) spend more time foraging than do fe- males. This is apparently because females wait until alerted by the hosts to steal freshly captured prey, while males more often search for previously caught prey for which it pre- sumably spends more time in locating. Con- versely, in this study, female A. argentatus spent more time foraging than males. I also did not find an intersexual difference in pro- portional feeding times (Fig. 1) (contra Can- gialosi 1990). However, females engaged in over three times as many bouts of feeding as did males (38 versus 12, respectively). Hence feeding in females is spent in more, but short- er feedings. This difference might occur if some of the feeding events by females were shorter because of higher food quality. Fe- males spent 21% of feeding events at large prey bundles, while males were never ob- served doing so. One possibility that might account for these differences between the sex- es is if females possess a larger energy and nutrient budget, such as needed for egg de- velopment and egg-sac construction (Toft 1999). Food availability can affect a spider’s growth rate, adult size, fecundity (Miyashita 1990, 1991) and web-site tenacity (Caraco & Gillespie 1986; but see Smallwood 1993), as well as influence the degree of intra- and in- terspecific competition (Spiller 1984). Argy- rodes antipodianus are known to aggressively compete for food (Whitehouse 1997), sug- gesting that food is a limiting resource. In this study, the time adult Argyrodes argentatus spent feeding was inversely proportional to their density on host webs (Fig. 2). One pos- sible explanation for this pattern is that as Ar- gyrodes density increases, so does competi- tion for food because of increased intraspecific agonism among Argyrodes and aggression by hosts which limits access to food. However, aggressive interactions were very few and uncorrelated with Argyrodes density (Fig. 3). Another possibility is that time spent feeding is positively correlated with an unmeasured variable, such as food quality, which itself negatively correlates with Argyrodes density. Webs may be densely pop- ulated with Argyrodes because of better food KERR— Ai?GF/?ODE5 BEHAVIOR 5 that requires less time to consume. For ex- ample, feeding bouts (defined as a putatively continuous term of feeding through consecu- tive observations made five minutes apart) are shorter when feeding with the host on large predigested prey bundles. This has also been observed by Whitehouse (1997) in another species, A. antipodianus O.P. Cambridge, 1880. There is growing interest in the evolution of behavior in Argyrodes (Whitehouse et al. 2002). Several researchers are generating a phylogeny of the genus to use, for example, in ancestral state analyses of the correlated evolution of kleptoparasitism and araneopha- gy. The success of this promising approach will depend not only on the quality of the phy- logenetic estimates, but also in large measure on natural history information from a behav- iorally diverse suite of Argyrodes. Robinson and Olazarri (1971) listed several observa- tions on the behavior of A. argentatus in Ar- giope argentatus host webs from Panama. Most of the behaviors of Panamanian Argy- rodes appeared to parallel those of popula- tions in Argiope appensa host webs from Guam in the western Pacific. Guamanian pop- ulations also gleaned insects from the host web, stole host food bundles, fed with the host and appeared to occasionally attack, kill and feed on the host. However, I did not find, as reported for Panamanian populations, that Ar- gyrodes removed host-wrapped prey bundles from the host web. Despite this possible dif- ference, there is apparently little intraspecific variation in these behaviors within the nearly pantropical species A. argentatus. ACKNOWLEDGMENTS I thank J. Beatty for advice, for providing literature and for identifying the spiders. I also thank A. Rypstra, C. Craig, and the students of Craig’s behavioral ecology seminar for comments, as well as I. Schreiner for trans- lating Vollrath (1976). LITERATURE CITED Agnarsson, I. 2002. Sharing a web — on the relation of sociality and kleptoparasitism in theridiid spi- ders (Theridiidae, Araneae). Journal of Arach- nology 30:181-188 Cambridge, O.P. 1880. On some new and little- known spiders of the genus Argyrodes. Proceed- ings of the Zoological Society, London 1880: 320-342. Cangialosi, K.R. 1990. Life cycle and behavior of the kleptoparasitic spider, Argyrodes ululans (Ar- aneae, Theridiidae). Journal of Arachnology 18: 347-358. Caraco, T.W. & R.G. Gillspie. 1986. Risk sensitiv- ity: foraging mode in an ambush predator. Ecol- ogy 67:1180-1185. Exline, H. & H.W. Levi. 1962. American spiders of the genus Argyrodes (Araneae, Theridiidae). Bul- letin of the Museum of Comparative Zoology 127:75-202. Henaut, Y. 2000. Host selection by a kleptoparasitic spider. Journal of Natural History 34:747-753. Kerr, A.M. 1993. Low frequency of stabilimenta in orb webs of Argiope appensa (Araneae: Aranei- dae) from Guam: an indirect effect of an intro- duced avian predator? Pacific Science 47:328- 337. Ken; A.M. and A.S. Quenga. 2003. Population var- iation of web-invading spiders (Theridiidae: Ar- gyrodes spp.) on host webs in Guam, Mariana Islands, Micronesia. Journal of Natural History. In press. Koh, J.K.H. 2000. A Guide to Common Singapore Spiders. Singapore Science Centre, Singapore. Larcher, S.E & D.H. Wise. 1985. Experimental studies of the interactions between a web-invad- ing spider and two host species. Journal of Ar- achnology 13:43-59. Levi, H.W. 1983. The orb- weaver genera Argiope, Gea, and Neogea from the Pacific region (Ara- neae: Araneidae: Argiopinae). Bulletin of the Museum of Comparative Zoology 150:247-338. Miyasita, T. 1990. Decreased reproductive rates of the spider, Nephila clavipes, inhabiting small woodlands in urban areas. Ecological Research 5:341-351. Miyasita, T. 1991. Direct evidence of food limita- tion for growth rate and body size in the spider Nephila clavipes. Acta Arachnologica 40:17-21. Miyasita, T. 2001. Competition for a limited space in kleptoparasitic Argyrodes spiders revealed by field experiments. Population Ecology 43:97- 103 Miyasita, T. 2002. Population dynamics of two spe- cies of kleptoparasitic spiders under different host availabilities. Journal of Arachnology 30: 31-38. Pasquet, A, R. Leborge & T. Canterral. 1997. Op- portunistic egg feeding in the kleptoparasitic spi- der A Ethology 103:160-170. Robinson, M.H. & J. Olazarri. 1971. Units of be- havior and complex sequences in the predatory behavior of Argiope argentata (Fabricius) (Ara- neae: Araneidae). Smithsonian Contributions to Zoology 65:1-36. Robinson, M.H. and B. Robinson. 1973. Ecology and behavior of the giant wood spider Nephila 6 THE JOURNAL OF ARACHNOLOGY maculata (Fabricius) in New Guinea. Smithson- ian Contributions to Zoology 149:1-76. Shinkai, A. 1988. A note on the web silk theft by Argyrodes cylindratus (Thorell) (Araneae: Ther- idiidae). Acta Arachnologica 38:116-119. Smallwood, RD. 1993. Web-site tenure in the long- jawed spider: is it risk-sensitive foraging, or con- specific interactions? Ecology 74:1826-1835. Sokal, R.R. & FJ. Rohlf. 1981. Biometry. Freeman and Company, San Francisco. Spiller, D.A. 1984. Competition between two spider species: experimental field study. Ecology 65: 909-919. Tanaka, K. 1984. Rate of predation by a kleptopar- asitic spider, Argyrodes fissifrons, upon a large host spider, Agelena limbata. Journal of Arach- nology 12:363-367. Toft, S. 1999. Prey choice and spider fitness. Jour- nal of Arachnology 27:301-307. Trail, D.S. 1980. Predation by Argyrodes (Theridi- idae) on solitary and communal spiders. Psyche 87:349-355. Tso, I-M. & L.L. Severinghaus. 1998. Silk stealing by Argyrodes lanyuensis (Araneae: Theiriidae): A unique form of kleptoparasitism. Animal Be- haviour 56:219-225. Tso, I-M. & L.L. Severinghaus. 2000. Argyrodes fissifrons inhabiting webs of Cyrtophora hosts: Prey size distribution and population character- istics. Zoological Studies 39:236-242. Vollrath, F. 1976. Konkurrenzvermeidung bei tro- pischen kleptoparasitischen Haubennetzspinnen der Gattung Argyrodes (Arachnida: Araneae: Theridiidae). Entomologica Germanica 3:104- 108. Vollrath, F 1979. Behaviour of the kleptoparasitic spider Argyrodes elevatus (Araneae, Theridi- idae). Animal Behaviour 27:515-521. Whitehouse, M.A. 1986. The foraging behaviours of Argyrodes antipodiana (Theridiidae), a klep- toparasitic spider from New Zealand. New Zea- land Journal of Zoology 13:151-168. Whitehouse, M.A. 1993. Group structure and time budgets of Argyrodes antipodiana (Araneae, Theridiidae), a kleptoparasitic spider from New Zealand. New Zealand Journal of Zoology 20: 201-206. Whitehouse, M.E.A. 1997. The benefits of stealing from a predator: Foraging rates, predation risk, and intraspecific aggression in the kleptoparasitic spider Argyrodes antipodiana. Behavioral Ecol- ogy 8:663-667. Whitehouse, M.A., 1. Agnarsson, T. Miyashita, D. Smith, K, Cangialosi, T Masumoto, D. Li and Y. Henaut. 2002. Argyrodes: phylogeny, sociality and interspecific interactions-a report on the Ar- gyrodes symposium, Badplaas 2001. Journal of Arachnology 30:238-245. Manuscript received 3 June 2002, revised 27 May 2003. 2005. The Journal of Arachnology 33:7-15 SCYTODES VS. SCHIZOCOSA: PREDATORY TECHNIQUES AND THEIR MORPHOLOGICAL CORRELATES Robert B. Suter; Department of Biology, Vassar College, 124 Raymond Avenue, Poughkeepsie, New York 12604 USA. E-mail: suter@vassar.edu Gail E. Stratton: Department of Biology, University of Mississippi, University, Mississippi 38677 USA, E-mail: byges@olemiss.edu ABSTRACT. Wolf spiders (Lycosidae) typically subdue prey using their legs for capture and their fangs for the injection of venom. Spitting spiders (Scytodidae), in contrast, subdue prey by entangling them, at a distance, in a spitted mixture of silk, glue, and venom that immobilizes and may also kill them. We selected individuals of Schizocosa duplex (Lycosidae) and Scytodes sp. (Scytodidae) of approximately the same mass and carapace width to provide a quantitative assessment of their relative allocations of biomass to morphological features that might be expected to vary with prey-capture technique. As expected, the wolf spiders allocated significantly more to legs, chelicerae, and fangs, and significantly less to the venom glands, than did the spitting spiders. Further comparisons of the legs and chelicerae of the two species provided surprises. First, the legs of Scytodes were 42% longer than those of Schizocosa despite smaller overall allocation to the legs in Scytodes. And second, although the relative sizes of the chelicerae differ greatly, the shapes of the chelicerae of Schizocosa and Scytodes were not significantly different despite the radically different tasks those structures must fulfill. Keywords: Spitting spider, wolf spider, resource allocation, allometry Spitting spiders (Araneae, Scytodidae) are renowned for their eponymous method of sub- duing prey and, at least occasionally, deterring predators (Gilbert & Ray or 1985; Jackson & Pollard 2001). They eject a glutinous mixture of silk, adhesive, and toxin, all from their en- larged venom glands (Monterosso 1928; Mil- lot 1929, 1930; Bristowe 1931; Dabelow 1958; MacAlister 1960; Kovoor 1987; Foelix 1996), that rapidly immobilizes the insects and spiders that typically constitute their diet (Nentwig 1985). What distinguishes this peculiar way of subduing prey from other methods used by spiders is not the use of glue-adorned fibers. Such a combination of materials typifies the prey capture spirals of araneid orb-weavers (e.g., Peters 1987; Foelix 1996; Opell 1997) and the webs of other spiders that produce sticky silk from their opisthosomal spinnerets. Rather, the uniqueness of the method is attrib- utable both to the prosomal source of the ma- terials, the venom glands (Kovoor 1987; Ko- voor & Zylberberg 1972), and to the forceful and directed ejection of the mixture (Millot 1930; Bristowe 1931). Our interest in spitting spiders began with a quest to quantify their expectorant capabilities, but quickly turned to the suite of morphologi- cal characteristics that, together, appear to con- tribute to the overall effectiveness of spitting as a predatory method. These characteristics in- clude (a) venom glands large enough to secrete and store quantities of silk, glue and venom sufficient for multiple predation attempts, (b) ducts and nozzles large enough to accommo- date rapid flows of glutinous material and (c) sensory structures capable of conveying ade- quately accurate targeting information. We know from earlier work that scytodid spiders have disproportionately large venom glands (e.g. Millot 1929), that the secretory epithelia of these glands extend into the chelicerae (Ko- voor & Zylberberg 1972), and that the orifice through which the spit is ejected is located near the base of the fang (Kovoor & Zylberberg 1972) rather than at its usual location near the fang’s distal end (Foelix 1996). We also know that these spiders are primarily nocturnal hunt- ers that appear to use their legs in sensory ex- ploration of their environment, detecting prey via either vibrations or viadirect tactile sensa- tions (Nentwig 1985). The structure and ori- entations of their eyes, then, may be of little 7 8 THE JOURNAL OF ARACHNOLOGY consequence for the triggering and the accu- racy of their spitting, but the structure of the legs may be crucial. To assess quantitatively the morphological correlates of the predatory specialization seen in spitting spiders, we compared Scytodes thoracica (Latreille 1802) and S. fusca WaL ckenaer 1837 with a comparable sized wolf spider, Schizocosa duplex Chamberlin 1925 (Araneae, Lycosidae). Like scytodids, the wolf spiders are often nocturnal hunters that generally do not use webs in prey capture. Un- like the spitting spiders, however, the wolf spiders lunge and grab prey with their legs and bite the prey immediately. We knew at the outset that these differences in predatory tech- nique are strongly reflected in the directly sup- porting morphology-the wolf spider's legs, chelicerae, and fangs are more robust than those of the spitting spider, and the spitting spider’s venom glands are substantially larger than those of the wolf spider (Monterosso 1928; Millot 1929, 1930; Foelix 1996)-al- though those specific comparisons have not previously been made in the literature. These differences, we assumed, also reflect a history of selective pressures that have mod- ified the allocation of resources (Huxley 1932; Calder 1984) within developing spiders. For example, physiological and metabolic resourc- es that could have been devoted to the pro- duction of eggs in an adult female wolf spider are, instead, devoted to the production and maintenance of stout legs and chelicerae. Our adaptionist assumption was that the differenc- es we would detect between these two kinds of spiders mark differences in natural selec- tion that moved each lineage toward an opti- mal allocation of physiological resources. At the same time, we recognized that the very disparate lineages of the lycosids and the scy- todids could contribute substantively to the differences we would detect. For example, the upright, cursorial habit of wolf spiders differs fundamently from the usually supine, seden- tary habit of spitting spiders, and the conse- quent disparity in morphology need not be di- rectly related to differences in predatory techniques. METHODS Spiders. — We used 12 adults (8 females, and 4 males) of the wolf spider, Schizocosa duplex, drawn from the collection of R Miller and G. Stratton, maintained in 80% alcohol, at the Department of Biology, University of Mississippi. All were originally collected in Mississippi (MS., Panola County, nr Sardis Dam, Sandstone Nature Trail 34° 23.616 N, 89° 47.496 W, 5 May 2002). Our specimens of the spitting spiders were provided, live, by James Carrel and Hank Guarisco (9 adult fe- male S. thoracica) from Florida (FL, High- lands County, 10 km S. of Lake Placid, Arch- bold Biological Station; FL, Santa Rosa County, Pensacola), and by Gerald Baker (1 adult female S. fusca) from Mississippi (MS., Oktibbeha County, in Starkville). Subsequent to their use in biomechanics studies, the spit- ting spiders were preserved in 80% alcohol until we used them in this study. We have de- posited voucher specimens in the Mississippi Entomological Museum. Our use of both sexes in the wolf spider species S. duplex and of two species in the spitting spider genus Scytodes could, in the- ory, have complicated our analyses and skewed our results. Most spider species are sexually dimorphic, and this is the case even among the Lycosidae (Walker & Rypstra 2001, 2002) in which the dimorphism is less striking than in many other families of spiders (Foelix 1996). Similarly, species within the same genus can differ both in overall size and in the relative sizes of individual parts. These differences notwithstanding, we pooled the two wolf spider sexes and pooled the two spit- ting spider species, electing to increase our sample size despite the small expected in- crease in variance that might result from the pooling. Morphometry. — -Spiders preserved in al- cohol lose mass due to evaporation when ex- posed to air. To minimize the consequent in- accuracies, we weighed the spiders and their parts, to the nearest 0.1 mg, during < 2 min exposure to air after initially removing surface moisture by blotting with dry filter paper. Be- cause very small objects, such as the chelic- erae and venom glands, are especially suscep- tible to rapid drying and thus to spurious mass measurements, we also made digital images of the structures in which we were interested. In one series of images, we devoted a single frame (6.1 MP, Nikon DlOO) to an entire but dismembered spider. These images showed dorsal views of the separated prosoma and op- isthosoma and lateral views of the legs and SUTER & STRATTON— MORPHOLOGY AND PREDATORY TECHNIQUES 9 Figures 1-4. — Image-derived morphometry methods illustrated for Schizocosa duplex. Lengths, widths, and areas are represented by their italic initials. The first subscript represents the structure (e.g., prosoma, chelicera, fang) and the second subscript designates the view (e.g., dorsal, lateral, caudal). The position of the horizontal line (3), which delimited one end of was determined by the location of the bottom margin of the hinge Qi) around which the jaws rotate. Volumes were calculated as described in the text. pedipalps. In another series of images collect- ed via dissecting microscope (Olympus SZX12) and dedicated digital camera (Olym- pus 750), we devoted a single frame (0.32 MP) each to dorsal, lateral and frontal views of the prosoma (including chelicerae), caudal and lateral views of the chelicerae (after de- tachment from the prosoma), and dorsal and lateral views of the venom glands. We mea- sured lengths, widths, and areas of the struc- tures in these images using NIH Image (NIH shareware) and MetaMorph (Universal Imag- ing Corporation). We used a scanning electron microscope (Amray 1200C) to visualize details on the an- terior surface of two spiders that had been freeze-dried and sputter coated with gold and palladium (80:20). The image-based measurements allowed us to estimate the volume of each prosoma, che- licera, venom gland and leg. For example, we estimated the volume of the prosoma of a Schizocosa duplex (Figs. 1 2) as the product of the area of the prosoma’s dorsal view (Op^) and the average height of the prosoma, cal- culated as the area of the prosoma’s lateral view (flpi) divided by the length of the pro- soma (/pd)- Thus the estimated volume of the prosoma (Vp) is Vp = «p^d • («p,//p,d)- If the prosoma were rectangular in three planes, this measure of Vp would accurately reflect the structure’s true volume. The fact that the prosoma is not rectangular means that Vp overestimates its true volume. We applied the same method in estimating the volumes of the prosoma and chelicerae of all of the spiders and the venom glands of the spitting spiders (Figs. 1-4). To estimate the volume of the legs of all of the spiders and the venom glands of the wolf spiders, we as- sumed these structures to be approximately cylindrical. Thus we estimated the volume of a leg (v,), for example, by taking its area (a^) divided by its length (/j) as double its average radius (rj), and then calculating volume as V, = /, • TT r?. One of the wolf spiders in the study was 10 THE JOURNAL OF ARACHNOLOGY missing one of its chelicerae and four of the spitting spiders were missing a single leg each. In each of these cases we assumed that the missing structure had the same dimensions as its contralateral mate. Although we mea- sured opisthosomal volumes and masses, we have ignored these measurements in the pres- ent study. This is because, as the part of the body that is most extensible (Foelix 1996), it is most subject to the volume and mass fluc- tuations that accompany changes in feeding history and reproductive state and thus is less likely to provide reliable comparative data. RESULTS Morphometry. — The representatives of the two families of spiders were not significantly different in size as measured by the width of the carapace (Scytodes: 2.78 ± 0.17 mm, mean ± SE; Schizocosa: 2.43 ± 0.057 mm; t = 2.06, P = 0.053), the mass of the body not including the opisthosoma {Scytodes: 17.5 ± L93 mg; Schizocosa: 19.2 ± 1.26 mg; t = —0.77, P = 0.448), and the volume of the body not including the opisthosoma {Scyto- des: 22.26 ± 2.76 mm^; Schizocosa: 21.63 ± 1.02 mm^; t = —0.23, P = 0.822). These data confirmed our initial assumption that the two groups of spiders were grossly similar in size. For some structures (e.g., the legs and the prosoma), we had measures of both mass and volume. Not surprisingly, these measures were closely correlated but not identical, with higher correlations in the spitting spiders than in the wolf spiders (Fig. 5). These highly sig- nificant correlations suggest that the use of volume measurements as proxies for mass measurements is justified. As noted above, this substitution is also necessitated by the dif- ficulties encountered in accurately weighing very small structures such as the chelicerae of the spitting spiders and the venom glands of the wolf spiders. Despite the similarity in the overall sizes of the spitting and wolf spiders, we found strik- ing differences in the sizes of their component parts (Table 1). The average spitting spider had a 36% larger prosoma and had venom glands that were 32 times as voluminous than those of the average wolf spider. The venom glands of Scytodes were also, as noted in the literature, conspicuously more complex in shape than those of Schizocosa (Fig. 6). At the same time, the legs and chelicerae of Scytodes were 42% and 83% smaller, as measured by volume, than those of Schizocosa, respective- ly. The linear dimensions of the legs and che- licerae, of interest in part because they have implications for biomechanical strength, also revealed major differences (Table 1). The legs of the spitting spiders were 42% longer, but 38% less wide in the dorso-ventral direction, than those of the wolf spiders. The chelicerae of Scytodes had about the same ratio of length to width (1.84: 1) as the chelicerae of Schi- zocosa (1.79: 1), but were 46% shorter and 41% narrower. Finally, the fangs of the spit- ting spiders were only 21% as long as the fangs of the wolf spiders (compare Figs. 3 & 8, showing Schizocosa, with Figs. 10 & 11, showing Scytodes). Resource allocation. — Several of the con- spicuous differences in the allocation of re- sources by these spiders are readily visible (Figs. 7-11). A wolf spider’s chelicerae, for example, are proportionately much more mas- sive relative to the rest of its “face” than are the chelicerae of the spitting spider. In fact, the legs and jaws, together, in the spitting spi- ders comprise only 22% of the total volume of the measured structures while in the wolf spider they comprise 44% (Fig. 12). In con- trast, and as expected from the data in Table 1, the venom glands in Schizocosa comprise only 0.3% of the total (0.6% of prosomal vol- ume) while in Scytodes they comprise nearly 10% (15% of prosomal volume). Another component of the resource alloca- tion differences can be seen in a comparison of the anterior four legs to the posterior four legs (Table 1). With respect to leg lengths, the spitting spiders have, on average, 37% longer forelegs than hind legs while the wolf spiders’ forelegs are 25% shorter than the hind legs. With respect to leg widths, these relationships are reversed: the spitting spiders’ forelegs are 9% narrower than their hind legs while the wolf spiders have forelegs that are, on aver- age, 15% broader (in the dorsal-ventral direc- tion) than the hind legs. DISCUSSION When capturing prey, the wolf spider, Schi- zocosa, grabs and bites, often using all eight legs in the grab and enveloping the prey in a leggy basket, or it may hang on to a prey item and hold it at a safe distance using the sco- pular hairs found on the tarsi and metatarsi, SUTER & STRATTON— MORPHOLOGY AND PREDATORY TECHNIQUES 11 Mass (mg) Mass (mg) Figure 5. — Relationships between volumes (source: images) and masses (source: balance) for the pro- soma and legs of Scytodes (filled symbols) and Schizocosa (open circles). For the spitting spiders, masses and volumes of both body parts were strongly correlated (prosoma: r = 0.991, P < 0.0001; legs: r = 0.960, P < 0.0001). The correlations were also highly significant but less strong for the wolf spiders (prosoma: r = 0.827, P = 0.0009; legs: r = 0.730, P = 0.007). Data from the single Scytodes fusca specimen (solid square) were included in the two calculations of r for Scytodes. as demonstrated experimentally by Rovner (1978, 1980). The first pair of legs is partic- ularly important for these tasks. The spitting spider, Scytodes, enmeshes its prey in a toxic and gummy silk ejected from the spider’s fangs, then bites after the prey is immobile. Not surprisingly, these contrasting prey cap- ture techniques are associated with different supporting morphology (Table 1, Figs. 6-11). Consider the legs. Strength in these ap- pendages is crucial for the wolf spiders where- as sensitivity to position and to the character- istics of what is touched are crucial for the spitting spiders. Strength (resistance to bend- ing) of a tubular structure such as a spider’s femur is directly proportional to the fourth power of the radius, inversely proportional to the length and, of course, varies with the prop- erties of the constituent material (Vogel 1988). Thus it is not surprising that Schizocosa's legs are substantially more voluminous than those of Scytodes, that their average width (in the direction most crucial for resisting dorso-ven- tral loading) is 61% greater, and that they are shorter (Table 1). Given that the first pairs of legs are often the ones most used in holding 12 THE JOURNAL OF ARACHNOLOGY Table 1 . — Volumes and linear dimensions of the component parts of the bodies (excluding the opistho- soma) of spitting spiders and wolf spiders. The widths (*) of legs represent mean width, from the dorsal to the ventral surface. The widths (*) of chelicerae represent mean width, from the lateral to the medial surface. We used 2-tailed t tests unless we knew from preliminary observation or from the literature to expect a difference in a particular direction. Component Measure Scytodes Mean ± S.E. Schiz Mean ocosa Comparison ± S.E. t P Type Prosoma + legs (8) volume 22.26 -+- 2.76 mm^ 21.63 -H 1.02 mm^ 0.228 0.8218 2-tailed Prosoma volume 16.88 -+■ 2.09 mm^ 12.42 -h 0.68 mm^ 2.186 0.0409 2-tailed Legs (8) volume 5.37 0.74 mm^ 9.21 -+- 0.46 mm^ 4.544 <0.0001 1 -tailed Chelicerae (2) volume 0.12 0.01 mm^ 0.69 0.06 mm"* 8.035 <0.0001 2-tailed Venom glands (2) volume 2.45 -1- 0.35 mm^ 0.08 -+- 0.01 mm^ 7.483 <0.0001 1 -tailed Prosoma width 2.78 0.17 mm 2.43 0.06 mm 2.06 0.0527 2-tailed Chelicera length 0.59 -H 0.03 mm 1.09 -1- 0.02 mm 14.24 <0.0001 1 -tailed Chelicera width* 0.32 -1- 0.01 mm 0.55 0.02 mm 7.972 <0.0001 2-tailed Fang length 0.13 -h 0.01 mm 0.63 + 0.02 mm 22.392 <0.0001 1 -tailed Legs (mean) length 19.61 -+- 1.77 mm 13.80 + 0.65 mm 3.306 0.0035 2-tailed Legs (mean) width* 0.18 0.01 mm 0.29 + 0.01 mm 9.332 <0.0001 1 -tailed Leg ratio (fore/hind) length 1.377 + 0.24 0.752 -1- 0.02 22.385 <0.0001 2-tailed Leg ratio (fore/hind) width* 0.912 -1- 0.01 1.153 -1- 0.02 10.680 <0.0001 2-tailed prey (Rovner 1980), it is likewise not surpris- ing that in S. duplex the first legs are 25% more stout than the hind legs. Chemical and tactile sensitivity, on the other hand, does not depend on structural strength, but length does confer a greater radius of discovery for the sensory organs on the legs. Thus, for the pred- atory technique used by spitting spiders, long legs that need not be robust are suitable. All of this, even the tendency of Scytodes to have longer forelegs than hind legs (but not the converse tendency in Schizocosa), supports the assertion that leg properties constitute part of an adaptive suite of morphological char- acters that enhance the effectiveness of pre- dation for both groups of spiders. Chelicerae, and the fangs they bear, can be considered in the same way, although here the role of morphological size in the spitting spi- ders is less clear. Given the predatory tech- nique of the wolf spiders, mechanically strong chelicerae equipped with teeth and bearing long fangs clearly contribute to a wolf spider’s ability to restrain prey until venom is deliv- ered via the fangs (Rovner 1980). But why are the chelicerae of Scytodes small but not deli- cate (they have about the same ratio of length to breadth, 1.84:1, as those of Schizocosa, Figure 6. — A pair each of venom glands from Scytodes (left) and Schizocosa (right) shown to scale. The spitting spider glands are shown in lateral (top) and dorsal (bottom) views. The venom glands of the wolf spider are nearly cylindrical. The mass of opaque material occupying much of the lateral view of the Scytodes gland is the glandular contents (Kovoor & Zylberberg 1972). SUTER & STRATTON— MORPHOLOGY AND PREDATORY TECHNIQUES 13 Figures 7-11. — SEM images of Schizocosa (7, 8) and Scytodes (9-11). The chelicerae and fangs are conspicuous components of the frontal view of the wolf spider but are relatively smaller in spitting spider — the fangs of Scytodes are nearly invisible when the spider is not about to spit (9) and can only clearly be seen when viewed from below (10, 11). The scale bar applies only to Figs. 7 & 9. 1.98:1), and why are the fangs so dispropor- tionately small (Table 1)? Although further study will be required to answer these ques- tions, we offer two hypotheses. First, the width of the spitting spider’s chelicera prob- ably serves to accommodate the larger than normal venom duct that must conduct a vis- cous mixture of silk, glue, and venom at high velocity. And second, that the diminutive fang facilitates its very rapid oscillation and, in turn, makes possible the characteristic zigzag pattern (Gilbert & Ray or 1985; Foelix 1996) of silk deposition. If this second hypothesis were correct, fang length would then be a good example of evolutionary compromise, in this case between selection for shortness (fa- cilitating oscillation through a reduction in an- gular momentum) and selection for increased length (facilitating chitin penetration and, ul- timately, venom delivery to the interior of prey items). The resolution of the compromise at a fang length too short for effective pene- tration of thick chitin may have abbreviated the menu of acceptable prey types for spitting spiders (Nentwig 1985). Resource allocation. — Scytodes allocates much less of its total resource pool to overtly predatory structures (chelicerae, venom glands) than does Schizocosa (chelicerae, ven- om glands, and legs) (Fig. 12). When we in- clude the legs of Scytodes in this comparison, perhaps legitimate both because they serve a sensory role in predation and because they may be lost relatively frequently during pre- dation (Ades & Ramires 2002), the disparity between the two patterns of allocation de- 14 THE JOURNAL OF ARACHNOLOGY Schizocosa Figure 12. — Mean allocation of resources (as % of non-opisthosoma volume) in spitting spiders (above) and wolf spiders (below). The volume of the grouping of tissues on the left in each chart was estimated by subtraction from the mean volume (excluding the opisthosoma) of the spiders in each species. creases but remains conspicuous. Moreover, much of the volume of the venom glands of spitting spiders is occupied by secreted prod- ucts, is not biomass per se, and may be lost to the spider (if recycling does not occur) dur- ing predation attempts. Thus spitting spiders employ a predatory technique that appears not to rely on the production and maintenance of large structures. On the other hand, both spitting and wolf spiders use their legs in locomotion, in mat- ing, and in other activities, so it is not clear that the allocation of resources to legs should be considered as an allocation to predation even when, as in Schizocosa, those append- ages are entirely necessary for prey capture. If legs are excluded from our consideration, then the fundamental difference between spit- ting and wolf spiders’ allocation patterns is that the former favors the production of ven- om gland secretions and the latter favors mas- sive chelicerae. These two views of allocation cannot be reconciled without evaluating them in the con- text of the phytogeny of the two spider groups, a task that will require further study. For the moment, however, we note the follow- ing. First, none of the spider families that are close relatives of the Scytodidae have mem- bers that capture prey by spitting, but they do contain members with body plans that resem- ble those of the spitting spiders (e.g., Pholci- dae: Nentwig 1985). And second, many of the spider families that are close relatives of the Lycosidae have members that capture prey by grabbing and biting, and most have body plans that closely resemble that of Schizocosa. Further study, then, could reveal that part of the allocation pattern we have described for the spitting spiders is not so much a conse- SUTER & STRATTON— MORPHOLOGY AND PREDATORY TECHNIQUES 15 quence of their predatory technique as it is a consequence of phylogenetic inertia (Orzack & Sober 2001). ACKNOWLEDGMENTS We are particularly indebted to Andrew Douglas for his generous donation of time and the use of his fine microscopy suite. We also thank Patricia R. Miller, Hank Guarisco, James Carrel and Gerald Baker for providing us with some of the spiders used in this study and Jerry Calvin for his help with the scan- ning electron microscope. The study was sup- ported in part by Vassar College's Class of ’42 Faculty Research Fund. LITERATURE CITED Ades, C. & E.N. Ramires. 2002. Asymmetry of leg use during prey handling in the spider Scytodes globula (Scytodidae). Journal of Insect Behavior 15:563-570. Bristowe, W.S. 1931. Notes on the biology of spi- ders, IV. Annals & Magazine of Natural History 8:469-471. Calder, W.A. 1984. Size, Function, and Life His- tory. Harvard University Press, Cambridge, 431 PP= Dabelow, S. 1958. Zur Biologic der Leimschleu- derspinne Scytodes thoracica (Latreille). Zoolo- gische Jahrbucher, Abteilung fur Systematik, Okologie und Geographic der Tiere 86:85-126. Foelix, R.F. 1996. Biology of Spiders (2"^^ ed.). Ox- ford University Press, Oxford. 330 pp. Gilbert, C. & L.S. Ray or. 1985. Predatory behavior of spitting spiders (Araneae: Scytodidae) and the evolution of prey wrapping. Journal of Arach- nology 13:231-241. Huxley, J.S. 1932. Problems of relative growth. Dial Press, New York, 276 pp. Jackson, R.R. & S. D. Pollard. 2001. How to stalk a spitting spider. Natural History 110:16-18. Kovoor, J. 1987. Comparative structure and histo- chemistry of silk-producing organs in arachnids. Pp. 160-186. In Ecophysiology of Spiders. (W. Nentwig. ed.) Springer- Verlag, New York, 448 pp. Kovoor, J. & L. Zylberberg. 1972. Histologic et in- frastructure de la glande chelicerienne de Scyto- des delicutula Sim. (Araneidae, Scytodidae). An- nales des Sciences Naturelles, Zoologie, Paris 14:333-388. MacAlister, W.H. 1960. The spitting habit of the spider Scytodes intricata Banks (Scytodidae). Texas Journal of Science 12:17-20. Millot, J. 1929. Sur la glande cephalothoracique d’une Araignee {Scytodes thoracica Latr.). Comptes Rendus de L Academic des Sciences 119:189. Millot, J. 1930. Glandes venimeuses et glandes ser- icigenes chez les Sicariides. Bulletin de la Socie- te Zoologique de France 55:150-175. Monterosso, B. 1928. Note arachnologiche. — Sulla biologia degli Scitodidi e la ghiandola glutinifera di essi. Archivio Zoologico Italiano 12:63-122. Nentwig, W. 1985. Feeding ecology of the tropical spitting spider Scytodes longipes (Ara- neae,Scytodidae). Oecologia 65:284-288. Opell, B.D. 1997. A comparison of capture thread and architectural features of Deinopoid and Ar- aneoid orb- webs. Journal of Arachnology 25: 295-306. Orzack, S.H. & E. Sober. 2001. Adaptationism and optimality. Cambridge University Press, New York, 416 pp. Peters, J.M. 1987. Fine structure and function of capture threads. Pp. 187-202. In Ecophysiology of Spiders. (W. Nentwig. ed.) Springer- Verlag, New York, 448 pp. Rovner, J.S. 1978. Adhesive hairs in spiders: be- havioral functions and hydraulically mediated movement. Symposium Zoological Society of London 42:99-108. Rovner, J.S. 1980. Morphological and ethological adaptations for prey capture in wolf spiders (Ar- aneae, Lycosidae). Journal of Arachnology 8: 201-215. Vogel, S. 1988. Life’s devices: the physical world of animals and plants. Princeton University Press, Princeton, 367 pp. Walker, S.E. & A.L. Rypstra. 2001. Sexual dimor- phism in functional response and trophic mor- phology in Rabidosa rabida (Araneae: Lycosi- dae). American Midland Naturalist 146:161-170. Walker, S.E. & A.L. Rypstra. 2002. Sexual dimor- phism in trophic morphology and feeding behav- ior of wolf spiders (Araneae: Lycosidae) as a re- sult of differences in reproductive roles. Canadian Journal of Zoology 80:679-688. Manuscript received 14 April 2003, revised 18 Feb- ruary 2004. 2005. The Journal of Arachnology 33:16-24 MATING FREQUENCY IN SCHIZOCOSA OCREATA (HENTZ) WOLF SPIDERS: EVIDENCE FOR A MATING SYSTEM WITH FEMALE MONANDRY AND MALE POLYGYNY Stephanie Norton and George W. Uetz*: Dept, of Biological Sciences, University of Cincinnati, RO. Box 210006, Cincinnati, Ohio 45221-0006 ABSTRACT. Courtship behavior has been studied extensively in the wolf spider Schizocosa ocreata (Hentz) (Araneae, Lycosidae). While much research has tested predictions of sexual selection theory regarding male traits and female mate choice, some critical assumptions about female behavior remain untested. To determine if females mate more than once, and to what degree copulation influences subse- quent female mating, a multiple mating experiment was conducted. Virgin females were paired randomly with males in laboratory containers. If mating occurred, females were paired with a second male within 24 hr, after 3 days, or after 30 days (enough time for an egg sac to be produced). Of the 101 females tested, 83 (82%) mated with the first male they encountered. The probability of a female mating the first time was not influenced by female size, male size, or male age, but varied significantly with female age post-maturity. Of the 18 males that failed to mate, 3 were cannibalized. Of the 83 males that did mate, 12 were cannibalized after mating. There was no difference between re-mating treatments (1 d, 3 d and 30 d), and analysis of pooled data showed a highly significant difference in the proportion of virgin and mated females accepting males; most females mated only once (93%). In contrast, males appeared to court and attempt mating with every female encountered (virgin and mated), and a majority of males paired with more than one virgin female mated more than once (64.5%). Results suggest that female S. ocreata are essentially monandrous, while males are polygynous, and are discussed in the context of potential conflicts-of-interest between the sexes. Keywords: Lycosidae, Schizocosa, mating systems, monandry, polgyny Female mate choice may be expected to vary depending on the mating system of the species (Arnold 1994; Arnold & Duvall 1994; Lorch 2002). Spider mating systems, like all mating systems, are constrained by several factors: (1) whether males are able to mate multiply; (2) whether females will mate with more than one male; and (3) the nature of sperm storage and fertilization (Austad 1984; Eberhard 1985, 1996; Elgar 1998). Numerous studies suggest that the evolution of male and female mating behavior (male competition, mate guarding, cohabitation, multiple mating) may be influenced by sperm precedence pat- terns arising from the morphology of the re- productive tract of the female (Austad 1984; Eberhard 1985), although recent studies have revealed exceptions (Eberhard et al. 1993; Watson 1993; Eberhard & Cordero 1995; El- gar 1998; Uhl 1994, 1998; Schaefer & Uhl 2002). Studies of linyphiid spiders, for ex- ‘ Corresponding author. ample, demonstrate that most females mate more than once and multiple paternity broods are common (Martyniuk & Jaenicke 1982; Austad 1982; Watson 1990, 1991a, b). While many studies have shown varying degrees of polygyny and polyandry in spiders (Austad 1984; Eberhard 1985, 1996; Elgar 1998), Singer & Riechert (1995) found a primarily monogamous mating system in a desert age- lenid spider, as a consequence of high travel costs to males and a significant decline in fe- male receptivity after the first mating. The mating strategies and courtship com- munication of jumping spiders and wolf spi- ders have been studied extensively (see re- views in Richman 1982; Richman & Jackson 1992; Jackson & Pollard 1997; Hebets & Uetz 1999, 2000; Uetz 2000; Uetz & Roberts 2002). Male salticids and lycosids often per- form elaborate visual and/or vibratory court- ship displays to elicit female receptivity, and male color patterns, leg decorations and vi- bration displays often serve as condition-in- 16 NORTON & UETZ— MATING FREQUENCY IN WOLF SPIDERS 17 dicating traits subject to female mate choice (Jackson 1980, 1981, 1986; Clark & Uetz 1992, 1993; Mappes et aL 1996; Parri et ah 1997; Kotiaho et aL 1998; Uetz 2000). The courtship behaviors of wolf spiders in the ge- nus Schizocosa have been studied in detail (Mongomery 1903; Uetz & Denterlein 1979; Stratton & Uetz 1981, 1983, 1986; Stratton 1997; Miller et al. 1998; Hebets & Uetz 1999, 2000). Males within this genus display con- siderable variation in foreleg ornamentation as well as courtship communication, and there is evidence of co-evolution between male sig- nals and female sensory design (Hebets & Uetz 1999, 2000). Male courtship behavior and female mate choice have been studied extensively in the brush-legged wolf spider Schizocosa ocreata (Hentz 1844) (see reviews in Uetz 2000; Uetz & Roberts 2002). Several studies have fo- cused on visual cues provided by the presence of male foreleg tufts in this species, and their role in female mate recognition and preference (Scheffer et al. 1996; Uetz et al. 1996; Mc- Clintock & Uetz 1996). The role of tufts in male-male competition is unclear, as studies have produced mixed results. One study has shown that both naturally-occuring and ex- perimental asymmetry in tufts affects the out- come of male-male contests (Uetz et al. 1996), while another study of males competing for females (triad mating experiments) has dem- onstrated that removal of tufts has no influ- ence on mating success (Scheffer et al. 1996). Other studies suggest that tufts and leg waving displays may exploit a pre-existing sensory bias of female Schizocosa (McClintock & Uetz 1996), or serve as amplifiers (Hasson 1989, 1991; Taylor et al. 2000) of condition- indicating male behaviors or traits (Hebets & Uetz 2000). Recent studies have suggested that the relative size of male tufts may serve as a condition-indicating trait (Uetz et al. 2002). Despite intense interest in sexual selection and especially female mate preference in ly- cosids, much empirical work has focused on male traits; i.e., differences in expression and the mating advantages of males with increased ornamentation via female mate choice (Hebets & Uetz 2000; Uetz et al. 2002). Perhaps be- cause attention has been focused more on male traits and less on female preference, some critical assumptions regarding reproduc- tive behavior in this lycosid model system re- main untested. For example, while often as- sumed, it is currently unknown whether female S. ocreata mate with more than one male. Given high densities and a high rate of male-female encounter in the field (Aspey 1976; Cady 1984) as well as the presence of elaborate male secondary sexual characteris- tics (and their role in mate choice), theory would predict a promiscuous mating system in this species (i.e., both males and females mate multiply). In this study, we address this gap in our knowledge and test this hypothesis by conducting experiments to investigate whether female S. ocreata mate with more than one male and what variables affect fe- male reproductive behavior. METHODS Immature Schizocosa ocreata were collect- ed from the Cincinnati Nature Center Rowe Woods site (N39°09.904'; W84°15.377') in Clermont County Ohio, through April and May 2000. Spiders were brought back to the lab and housed individually under identical, controlled conditions ( 1 3hrs : 1 1 hrs light/dark cycle, temperature 23-25 °C and stable hu- midity). Spiders were raised to maturity in in- dividual opaque plastic deli dish containers (11.5 cm diameter, 6.2 cm height). Constant moisture was provided via a cotton dental wick inserted through a hole on the bottom of the container and immersed in a dish of water below. Spiders were fed 2-3 subadult crickets (Acheta domestica L.) twice a week. Daily checks for molting determined the exact date of maturity, which was recorded for every spi- der. To determine if females mate more than once, and to what degree copulation influenc- es subsequent female mating, a multiple mat- ing experiment was conducted. Virgin females (n = 101) were paired randomly with males, and if mating occurred, females were assigned to one of three re-mating treatments: (1) paired within 24 hr; (2) paired after 3 days; (3) paired after approx. 30 days (by which time 50% of females had produced egg sacs). These time intervals were chosen to account for a high rate of male-female encounter in the field (and the possibility of refractory pe- riods in female propensity to re-mate), and/or the possibility that females may re-mate to ob- tain sperm for a second egg sac. If females 18 THE JOURNAL OF ARACHNOLOGY produced egg sacs, these were taken away be- fore any re-mating attempt. Females that did not mate with the first male encountered were paired the next day with a different male. If a female did not mate after three pairings, that female was excluded from the experiment. Fe- males were placed individually in a plastic box with filter paper lining the bottom (12cm X 17cm floor x 5cm walls) for one hour, after which a male was introduced. This allowed the females to acclimate and lay down silk and/or pheromones prior to the introduction of a male. All pairings were videotaped from above. While pairings were random, approxi- mately one-third of males {n = 31) were paired with more than one female to test for multiple mating by males. Data were analyzed using a contingency test with re-mating treatment (1 d, 3 d and 30 d) as the factor, and mating outcomes (mated once, mated twice) as the response, to deter- mine if mating a second time was dependent on the mating treatment. These data were then analyzed using a McNemar’s chi-square test for significance of changes, which is appro- priate for paired samples (Zar 1999). Specifi- cally, we tested the null hypothesis that the proportion of females mating with a second male is the same as the proportion of virgin females that mate with the first male they are paired with. At the end of the experimental studies, spi- ders were humanely sacrificed using COj an- esthesia and preserved in 70% ethanol. After preservation, all individuals were digitally photographed with a Pixera 1.2 mega-pixel digital camera through a Wild M5 microscope. Measurements of individuals were then taken using the UTHSCSA ImageTool program (de- veloped at the University of Texas Health Sci- ence Center at San Antonio, Texas and avail- able from http://www.maxrad6.uthscsa.edu). Prosoma width, a widely used measure of body size, was determined for both males and females. Male tuft area and leg length were also measured. All egg sacs produced were preserved in 70% ethanol and dissected open using fine point scissors. All eggs were count- ed under a dissecting microscope (Wild M5). The data set consisted of the following in- dividual and pairing variables; age at time of pairings, whether the female ate the first male after mating, size measurements (prosoma width of females and males, male tuft area and leg length), duration of first copulation (if mating occurred), date of egg sac production and number of eggs produced. A preliminary analysis revealed that male prosoma width, tuft size and leg length were highly inter-cor- related (Pearson correlations: prosoma width*tuft area, r = 0.723, P < 0.001; pro- soma width*leg length, r = 0.713, P < 0.001; tuft area*leg length, r = 0.729, P < 0.001). As intercorrelation of so many independent variables violates a basic assumption of mul- tiple-factor regression models, we chose pro- soma width for male size measurement in all subsequent analyses, and scaled male tuft size relative to prosoma width. We used stepwise logistic regression analyses (Hardy & Field 1998) to test the effects of these variables on the: (1) probability of mating with the first male; (2) probability of re-mating; and (3) probability of cannibalism, as in Singer & Riechert (1995). We present the significance level of predictors at the point when they were eliminated from the stepwise regression. Final models only contain significant predictors, thereby providing the most economic combi- nation of initial predictors (Hardy & Field 1998). We also present Tack of fit’ (‘LOF’) statistics, which test for inappropriate model form. A significant LOF indicates an inappro- priate model form. We also used multiple stepwise linear regression analyses to test the effect of the variables on (1) copulation du- ration; and (2) the number of eggs produced. RESULTS Of the 101 females tested, 83 (82%) mated with the first male with which they were paired (Table 1). The probability of a female mating the first time was not significantly in- fluenced by female size, male size, male rel- ative tuft size or male age, but decreased sig- nificantly with female age (Table 2). Of the 18 males that failed to mate, three were canni- balized by the female. Of the 83 males that did mate, 12 were cannibalized by the female after mating. Damage to the cannibalized males made accurate measurement impossible and so further analysis of these data was not possible. These rates of cannibalism are sim- ilar to results of another study (Persons & Uetz, unpub. data). Copulations lasted 80-550 minutes {n = 84, median = 155 min) and were not normally distributed (Shapiro-Wilk test, W = 0.813, P NORTON & UETZ-— MATING FREQUENCY IN WOLF SPIDERS 19 Table L — Mating and re-mating frequencies of female and male S. ocreata. n Mate (%) Not Virgin females: 101 83 (82.18) 18 Previously-mated females: 1) after 1 day 27 3 (11.11) 24 2) after 3 days 24 2 (8.33) 22 3) after 30 days: w/egg sac 16 0 (0.0) 16 no sac 16 0 (0.0) 16 Pooled 83 5 (6.02) 78 Virgin males: 64 49 (76.56) 15 Previously mated males: 31 20 (64.52) 11 < 0.001)= The duration of copulation (In trans- formed) was not significantly influenced by male age {F < 0.001, P = 0.995), male size (F = 0305, P = 0.583), female age (F - 0.002, P = 0.965), or female size (F = 1.043, P - 0310). Most females mated only once; only a small percentage (7%) of females mated twice (Ta- ble 1). The data from the re-mating treatments (1 d, 3 d and 30 d) were analyzed with a con- tingency test revealed no significant difference bci^c.eri mating treatments {IP = 3.89, P < 0.284), and prowlc-rd lastificatioe for pooling the data (Table 1). Results from the McNemar’s chi-square test of pooled data showed a highly significant difference in the proportion of virgins and mated females ac- cepting males (A^ = 51.429, P < 0.001). In contrast, all males observed {n = 95) appeared to court and attempt mating with every female encountered (virgin and mated). Of males paired only once {n = 64), a majority (76.56%) successfully mated (Table 1). For those males paired with more than one virgin female {n = 31), almost two-thirds (64.5%) mated more than once (Table 1). The probability of a female re-mating did not vary with treatment, size or relative tuft size of her first mate, her size or age, or sec- ond male tuft size, bet did increase with the size of the second male (Table 3). Three of the five females that re-mated did not show receptivity displays before being mounted, as is usually the case (Montgomery 1903; Schef- fer et al. 1996). All of these re-mated females had shown receptivity displays before accept- ing their first mate. Of the five females that re-mated, none Table 2.- — Results of stepwise logistic regression elimination analysis of the probability of virgin fe- male S. ocreata mating with the first male. Variables df x" P Eliminated predictors Female size 1 0.095 0.758 Male tuft size 1 0.447 0.506 Male size 1 1.242 0.265 Male age 1 2.440 0.118 Final model Female age 1 8.400 0.004 Lack-of-fit 28 31.643 0.326 cannibalized the male after mating. Of the 78 females that refused to mate a second time, seven (8%) cannibalized the male. The prob- ability that the female cannibalized the male was not influenced by the second male’s age, the second m_ale’s size, latency between first and second male encounters or female size, but did increase with age of the female at her first mating (Table 4). Of the 83 females that mated, 50 (60.2%) produced egg sacs, similar to previous obser- vations (Stratton & Uetz 1983; Uetz, unpubL). Number of eggs produced ranged from zero (no developed eggs) to 82 {n = 50, mean = 37.78, SD = 18.59) and was normally distrib- uted (Shapiro-Wilk test, W = 0.978, P = 0.653). The number of eggs in the egg sac was not related to female age, male size, whether the female had mated once or twice or age of first mate but approached a significant positive relationship with female size (Table 5). Table 3.“-Results of stepwise logistic regression analysis of the probability of previously-mated fe- male S. ocreata mating a second time. Variables df x" P Eliminated predictors Size of first mate 1 0.088 0.766 Tuft size of first mate 1 0.145 0.703 Male age 1 0.043 0.836 Male tuft size 1 0.088 0.766 Female age 1 0.334 0.563 Female size 1 1.486 0.222 Final model Male size 1 5.414 0.027 Lack-of-fit 45 38.498 0.742 20 THE JOURNAL OF ARACHNOLOGY Table 4. — Results of stepwise logistic regression analysis of the probability of a previously-mated female Y ocreata cannibalizing the second male. Variables df x" P Eliminated predictors Second male age 1 0.001 0.989 Second male size 1 0.180 0.671 Latency between first and second male encounters 1 0.570 0.450 Female size 1 0.856 0.355 Final model Female age at first mating 1 4.620 0.032 Lack-of-fit 21 13.97 0.871 DISCUSSION While more data are needed on the potential for multiple mating in the field, this laboratory study has demonstrated that female S. ocreata appear to be essentially monandrous. Males, on the other hand, are capable of mating mul- tiple times, and are potentially polygynous. Sexual conflict over multiple mating may therefore be inevitable, given differences in the reproductive investment by each of the sexes (Trivers 1972). If a female receives enough sperm from a single copulation to fer- tilize her eggs, there may be no motivation for a female to mate a second time. Additionally, mating may be a costly activity for females since copulation duration is relatively long, and could lead to loss of foraging opportuni- ties and possibly increased risk of predation and parasite transmission (Scheffer 1992). Fe- males would therefore be expected to exercise a higher degree of mate discrimination than males, and there is some evidence that fe- males of this species exhibit mate choice (McClintock & Uetz 1996; Uetz & Smith 1999; Uetz 2000). However, because males Table 5. — Results of linear regression analysis of the relationship between number of eggs and female and male independent variables. Variables df F P Eliminated predictors Female age 1 0.032 0.859 Male size 1 0.378 0.543 Female mated more than once 1 0.543 0.466 Female age at first mating 1 1.170 0.287 Final model Female size 1 3.630 0.063 have so much to gain from additional matings, selection would favor mating with highly-re- sistant previously-mated females, even if it is against the female’s interests. There is some evidence in spiders that fe- males may be able to improve the proportion of surviving offspring by choosing a high- quality mate, or by mating with multiple males (Watson 1998). On the other hand, if females are primarily monandrous, males will fertilize most or all of the eggs of each female they copulate with. Female S. ocreata most often produce a single egg sac with 30-50 eggs (additional egg sacs are sometimes pro- duced; Uetz persl. obs.), which for the sake of argument might represent an estimate of max- imum lifetime reproductive potential. As a consequence, for every female mated, male reproductive potential grows by an amount equivalent to that female’s entire reproductive potential, as suggested by Bateman (1948). However, as this species appears to have a 1: 1 sex ratio (based on results of lab rearing studies and adult population surveys in the field during the breeding season; Uetz unpubl. data), it then follows that for every male that mates more than once, others will fail to mate at all, or perhaps be cannibalized in the at- tempt. Variation among females in reproduc- tive success may or may not be smaller than that among males (Bateman 1948; Arnold & Duvall 1994; Lorch 2002); however from a functional perspective this does not make it any less important. Female monandry would be expected to se- lect for a high degree of choosiness, but in this study 83% of females mated with ran- domly paired males, and the only significant predictor of mating probability was female NORTON & UETZ— MATING FREQUENCY IN WOLF SPIDERS 21 age posL maturity. This result may seem par- adoxical, given previous studies of female choice in S, ocreata (McClietock & Uetz 1996; Uetz 2000; Uetz & Roberts 2002), but might be explained by several possibilities. This was a “no choice” experiment in labo- ratory containers where females received both visual and vibratory cues from male courtship. These conditions are unlikely in the field, and females exercising mate choice based on male traits like tuft size or courtship vigor could easily avoid further contact with less favored mules. Additionally, as these spiders were col- lected as sub-adults and maintained under lab- oratory conditions for several weeks, it is probable that laboratory-housed males were in better condition than their counterparts in the field. Even so, female discrimination based on male characteristics not measured in this study cannot be excluded. In any case, these find- ings suggest that if the male meets some threshold criterion and a female is physiolog- ically ready, mating will most likely occur. If mating a second time is not in the best interest of the female, selection would favor resistance and/or avoidance of mating at- tempts by males, leading to a mating system with female monandry. Water striders provide an example in which sexual selection on mat- ing behavior and morphology is a result of females seeking to avoid matings that may be costly in terms of predation risk or energy ex- penditure (Rowe et aL 1994; Arnqvist 1997). The importance of coercive matings in a va- riety of groups, especially arachnids and in- sects, is becoming increasing clear (Choe & Crespi 1997). While it was not possible to col- lect accurate data on male copulation attempts for our entire dataset, there is evidence that at least some males may attempt to force reluc- tant females to copulate. Although our sample size is small, results of the re-mating analysis revealed that second male size was the only significant predictor of mating with a mated female. Of the five previously-mated females that mated a second time, three did not show receptivity displays, and mated only after males “pinned” them down. Male size was a significant predictor in the analysis, suggest- ing that the largest males may use size to their advantage in mating with resistant females. It is also possible that reduction in female receptivity after mating is the result of some form of chemically-mediated mechanism on the part of one sex or the other, although this explanation remains highly speculative at this time. There are studies in spiders and other arthropods documenting male manipulation of female reproductive behavior through seminal product transfer during copulation (Riemann et al. 1967; Chapman et al. 1995; Eberhard & Cordero 1995). Males that successfully render a female uereceptive to other males will have fitness benefits through exclusive paternity. This could be considered a form of “post-cop- ulatory mate guarding”, and might be medi- ated by male seminal fluids interacting with the physiology of the female reproductive tract (Eberhard & Cordero 1995). Addition- ally, since S. ocreata are entelegyee spiders, the first male to copulate with a female may be the principal sire of the offspring produced. Testing male preferences between mated and virgin females may give some insight into whether or not males prefer virgin females and/or actively avoid mated females. An al- ternative might be that mated females produce an 'anti-aphrodisiac’, like the compound pro- duced by mated female Drosophila to adver- tise their status and thereby avoid male court- ship (Scott & Jackson 1990). Such an adaptation may be advantageous if male courtship decreased the amount of time a fe- male can speed feeding or if mule displays attract predators. Since all the males in this study appeared to court, this possibility seems doubtful, but given that males did not have the opportunity to escape, courtship may be a last ditch’ effort to avoid cannibalism. In most species, there appears to be some conflict between the sexes over the outcome of mating events (Brown et al. 1997), and re- sults of this study indicate that potential for conflict in Schizocosa ocreata wolf spiders as well. While much is yet to be learned about the reproductive biology of A ocreata, results presented here suggest that female monandry and male polygyny, characteristics of only a few spider mating systems studied so far (Eberhard 1985, 1996; Elgar 1998), may ap- ply to this species. These results must be in- terpreted with caution, however, as they rep- resent outcomes of laboratory studies in simple enclosed containers, and conditions are obviously different in the complex leaf litter environment of the natural habitat. Even so, confirmation of assumed mating systems will 22 THE JOURNAL OF ARACHNOLOGY allow more robust predictions in future studies of mate choice. ACKNOWLEDGMENTS This work represents a portion of a thesis submitted by SN in partial fulfillment of the requirements for the Master of Science degree from the Department of Biological Sciences at the University of Cincinnati. This research was supported by grant IBN 9906446 from the National Science Foundation (to GWU). Voucher specimens from this population of S. ocreata (Hentz) are deposited in the collection at the U.S. National Museum of Natural His- tory, Smithsonian Institution and the Cincin- nati Museum of Natural History. We are grate- ful to the Cincinnati Nature Center, Milford, Ohio, for allowing us to collect spiders at their Rowe Woods facility. We would also like to acknowledge the assistance of J.A. Roberts, L. Pfeiffer, S. Morgan, A. Fenhoff, J. Best, A. Manter, C. Kluener and M. Salpietra in col- lecting and maintaining spiders for this re- search project. We also appreciate statistical consulting and comments on the manuscript from B. Jayne, M. Polak, J.A. Roberts, RW. Taylor, C. Harris, G.E. Stratton and two anon- ymous reviewers. LITERATURE CITED Arnold, SJ. 1994. Bateman’s principle and the measurement of sexual selection in plants and animals. American Naturalist 144(SuppL):S126- S149. Arnold, S J. & D. Duvall. 1994. Animal mating sys- tems: a synthesis based on selection theory. American Naturalist 143:317-348. Arnqvist, G. 1997. The evolution of water strider mating systems: causes and consequences of sex- ual conflicts. Pp. 146-163. In The Evolution of Mating Systems in Insects and Arachnids. (Choe, J.C. & B.J. Crespi, Eds.). Cambridge University Press, Cambridge, Aspey, W.P, 1976. Behavioral ecology of the “edge effect” in Schizocosa crassipes (Araneae: Lycos- idae). Psyche 83:42-50. Austad, S.N. 1982. First male sperm priority in the bowl and doily spider, Frontinella pyramitela (Walckenaer). Evolution 36:777-785. Austad, S.N. 1984. Evolution of sperm priority pat- terns in spiders. Pp. 233-249. In Sperm Com- petition and the Evolution of Animal Mating Systems. (R.L. Smith, Ed.) Academic Press, London. Bateman, A.J. 1948. Intrasexual selection in Dro- sophila. Heredity 2:349-368. Brown, W.D., J.C. Choe & B.J. Crespi. 1997. Sex- ual conflict and the evolution of mating systems. Pp. 352-377. In The Evolution of Mating Sys- tems in Insects and Arachnids. (Choe, J.C. & B.J. Crespi, Eds.). Cambridge University Press, Cam- bridge. Cady, A.B, 1984. Microhabitat selection and loco- motor activity of Schizocosa ocreata (Walcken- aer) (Araneae, Lycosidae). Journal of Arachnol- ogy. 11:297-307. Chapman, T, L. Liddle, J. Kalb, M. Wolfner & L. Partridge. 1995. Cost of mating in Drosophila melanogaster females is mediated by male ac- cessory gland products. Nature 373:241-244. Choe, J.C. & B.J, Crespi. 1997. The Evolution of Mating Systems in Insects and Arachnids, Cam- bridge University Press, Cambridge. Clark, D.L. & G.W. Uetz. 1992, Morph-indepen- dent mate selection in a dimorphic jumping spi- der— demonstration of movement bias in female choice using video- controlled courtship behav- ior. Animal Behaviour 43:247-254. Clark, D.L, & G.W. Uetz. 1993. Signal efficacy and the evolution of male dimorphism in the jumping spider, Maevia inclemens. Proceedings of the Na- tional Academy of Sciences of the United States of America 90:11954-11957. Eberhard, W.G. 1985. Sexual Selection and Animal Genitalia. Harvard University Press, Cambridge, Massachusetts. Eberhard, W.G. 1996. Female Control: Sexual Se- lection by Cryptic Female Choice, Princeton University Press, Princeton, New Jersey. Eberhard, W.G. & C. Cordero. 1995. Sexual selec- tion by cryptic female choice on male seminal products — a new bridge between sexual selection and reproductive physiology. Trends in Ecology & Evolution 10:493-496. Eberhard, W.G., S. Guzman-Gomez & K.M. Catley. 1993. Correlation between spermathecal mor- phology and mating systems in spiders. Biolog- ical Journal of the Linnean Society 50:197-209. Elgar, M.A. 1998. Sperm competition and sexual selection in spiders and other arachnids. Pp. 307- 339. In Sperm Competition and Sexual Selec- tion. (T.R. Birkhead & A.P. M0ller, eds.) Aca- demic Press, San Diego, CA. Hardy, LC.W. & S.A. Field. 1998. Logistic analysis of animal contests. Animal Behaviour 56:787- 792. Hasson, O. 1989. Amplifiers and the handicap prin- ciple in sexual selection: a different emphasis. Proceedings of the Royal Society of London Se- ries B: Biological Sciences 235:383-406. Hasson, O. 1991. Sexual displays as amplifiers: practical examples with an emphasis on feather decorations. Behavioral Ecology 2:189-197. Hebets, E.A, & G.W. Uetz. 1999. Female responses to isolated signals from multimodal male court- ship displays in the wolf spider genus Schizocosa NORTON & UETZ— MATING FREQUENCY IN WOLF SPIDERS 23 (Araneae: Lycosidae). Animal Behaviour 57: 865-872. Hebets, E.A. & G.W. Uetz. 2000. Leg ornamenta- tion and the efficacy of courtship display in four species of wolf spider (Araneae: Lycosidae). Be- havioral Ecology & Sociobiology 47:280-286. Hentz, N.M. 1844. Descriptions and figures of the Araneides of the United States. Boston Journal of Natural History 4:386-396. Jackson, R.R. 1980. The mating strategy of Phidip- pus johnsoni (Araneae, Salticidae): IT Sperm competition and the function of copulation. Jour- nal of Arachnology 8:217-240. Jackson R.R. 1981. Relationship between reproduc- tive security and intersexual selection in a jump- ing spider Phidippus johnsoni (Araneae: Saltici- dae). Evolution 35:601-604. Jackson, R.R. 1986. Cohabitation of males and ju- venile females; a prevalent mating tactic of spi- ders. Journal of Natural History 20:1193-1210. Jackson, R.R. & S.D. Pollard. 1997. Jumping spider mating strategies: sex among cannibals in and out of webs. Pp. 340-351. In The Evolution of Mating Systems in Insects and Arachnids. (Choe, J.C. & B.J. Crespi, Eds.). Cambridge University Press, Cambridge. Kotiaho, J.S., R.V. Alatalo, J. Mappes, M.G. Niel- sen, S. Parri & A. Rivero. 1998. Energetic costs of size and sexual signaling in a wolf spider. Pro- ceedings of the Royal Society of London Series B: Biological Sciences 265:2203-2209. Lorch, P.D. 2002. Understanding reversals in the relative strength of sexual selection on males and females: a role for sperm competition? American Naturalist 159:645-657. Mappes, J., R.V. Alatalo, J. Kotiaho & J. Parri. 1996. Viability costs of condition-dependent sex- ual male display in a drumming wolf spider. Pro- ceedings of the Royal Society of London Series B: Biological Sciences 263:785-789. Martyniuk, J & J. Jaenicke. 1982. Multiple mating and sperm usage patterns in natural populations of Prolinyphia marginata (Araneae: Linyphi- idae). Annals of the Entomological Society of America 75:516-518. McClintock, W.J. & G.W. Uetz. 1996. Female choice and pre-existing bias: visual cues during courtship in two Schizocosa wolf spiders (Ara- neae: Lycosidae). Animal Behaviour 52:167- 181. Miller, G.L., G.E. Stratton, RE. Miller & E.A. He- bets. 1998. Geographic variation in male court- ship behavior and sexual isolation in wolf spiders of the genus Schizocosa. Animal Behaviour 56: 937-951. Montgomery, T.H. 1903. Studies on the habits of spiders, particularly those of mating spiders. Pro- ceedings of the National Academy of Sciences of the United States of America 55:59-149. Parri S., R.V. Alatalo, J. Kotiaho, & J. Mappes. 1997. Female choice for male drumming in the wolf spider Hygrolycosa rubrofasciata. Animal Behaviour 53:305-312. Richman, D. 1982. Epigamic display in jumping spiders (Araneae, Salticidae) and its use in sys- tematics. Journal of Arachnology 10:47-67. Richman, D. & R.R. Jackson. 1992. A review of the ethology of jumping spiders. Bulletin of the British Arachnological Society 9:33-37. Riemann, J., D. Moen & B. Thorson. 1967. Female monogamy and its control in houseflies. Insect Physiology 13:407-418. Rowe, L., G. Arnqvist, A. Sih & J. Krupa. 1994. Sexual conflict and the evolutionary ecology of mating patterns — water striders as a model sys- tem. Trends in Ecology & Evolution 9:289-293. Schaefer, M.A. & G. Uhl. 2002. Determinants of paternity success in the spider Pholcus phalan- goides (Pholcidae: Araneae): the role of male and female mating behaviour. Behavavioral Ecology & Sociobiology 51:368-377. Scheffer, S.J. 1992. Transfer of a larval mantispid during copulation of its spider host. Insect Be- havior 5:797-800. Scheffer, S.J., G.W. Uetz & G.E. Stratton. 1996. Sexual selection, male morphology, and the ef- ficacy of courtship signalling in two wolf spiders (Araneae: Lycosidae). Behavioral Ecology & So- ciobiology 38:17-23. Scott, D. & L. Jackson. 1990. The basis of control of post-mating sexual attractiveness by Drosphi- la melanogaster females. Animal Behaviour 40: 891-900. Singer, F. & S.E. Riechert. 1995. Mating system and mating success of the desert spider Agelenopsis aperta. Behavioral Ecology & Sociobiology 36: 313-322. Stratton, G.E. 1997. Investigation of species diver- gence and reproductive isolation of Schizocosa stridulans (Araneae, Lycosidae) from Illinois. Bulletin British Arachnological Society 10:313- 321. Stratton, G.E. & G.W. Uetz. 1981. Acoustic com- munication and reproductive isolation in two species of wolf spiders (Araneae: Lycosidae). Science 214:575-577. Stratton, G.E. & G.W. Uetz. 1983. Communication via substratum-coupled stridulation and repro- ductive isolation in wolf spiders (Araneae: Ly- cosidae). Animal Behaviour 31:164-172. Stratton, G.E. & G.W. Uetz. 1986. The inheritance of courtship behavior and its role as a reproduc- tive isolating mechanism in two species of Schi- zocosa wolf spiders (Araneae, Lycosidae), Evo- lution 40:129-141. Taylor, P.W., O. Hasson, & D.L. Clark. 2000. Body postures and patterns as amplifiers of physical condition. Proceedings of the Royal Society of 24 THE JOURNAL OF ARACHNOLOGY London Series B: Biological Sciences 267:917- 922. Trivers, R.L. 1972. Parental Investment and Sexual Selection. Chicago, Aldine. Uetz, G.W. 2000. Signals and multi-modal signal- ling in spider communication. Pp. 387-405. In Animal Signals. Signalling and Signal Design in Animal Communication. (Espmark, Y, Amund- sen,T. & Rosenqvist,G., eds.) Proceedings of the Fifth International Kongsvoll Symposium. Tapir Publishers,Trondheim, Norway. Uetz, G.W. & G. Denterlein. 1979. Courtship be- havior, habitat and reproductive isolation in Schi- zocosa rovneri. Journal of Arachnology 7:86-88. Uetz, G.W., W.J. McClintock, D. Miller, E.I. Smith & K.K. Cook. 1996. Limb regeneration and sub- sequent asymmetry in a male secondary sexual character influences sexual selection in wolf spi- ders. Behavioral Ecology & Sociobiology 38: 253-257. Uetz, G.W. & E.I. Smith. 1999. Asymmetry in a visual signaling character and sexual selection in a wolf spider. Behavioral Ecology and Sociobi- ology 45:87-93. Uetz, G.W. & J.A Roberts. 2002. Multi-sensory cues and multi-modal communication in spiders: insights from video/audio playback studies. Brain Behavior & Evolution 59:222-230. Uetz, G.W, R. Papke & B. Kilinc. 2002. Influence of feeding regime on body condition and a male secondary sexual character in Schizocosa ocreata (Hentz) wolf spiders (Araneae, Lycosidae): con- dition-dependence in a visual signaling trait. Journal of Arachnology 30:461-469. Uhl, G. 1994. Genital morphology and sperm stor- age in Pholcus phalangoides (Fuesslin, 1775) (Pholcidae: Araneae). Acta Zoologica 75:1-12. Uhl, G. 1998. Mating behaviour in the cellar spider, Pholcus phalangoides, indicates sperm mixing. Animal Behaviour 56:1155-1159. Watson, P.J. 1990. Female-enhanced male compe- tition determines the first mate and principal sire in the spider Linyphia litigiosa (Linyphiidae). Behavioral Ecology & Sociobiology 26:77-90. Watson, P.J. 1991a. Multiple paternity and first mate sperm precedence in the sierra dome spider, Lin- yphia litigiosa Keyserling (Linyphiidae). Animal Behaviour 41:135-148. Watson, P.J. 1991b. Multiple paternity as genetic bet-hedging in female sierra dome spiders, Lin- yphia litigiosa (Linyphiidae). Animal Behaviour 41:343-360. Watson, P.J. 1993. Foraging advantage of polyandry for female sierra dome spiders {Linyphia litigio- sa'. Linyphiidae) and assessment of alternative direct benefits. American Naturalist 141:440- 465. Watson, P.J. 1998. Multi-male mating and female choice increase offspring growth in the spider Neriene litigiosa (Linyphiidae). Animal Behav- iour 55:387-403. Zar, J.H. 1999. Biostatistical Analysis. Prentice- Hall, Inc., Upper Saddle River, New Jersey. Manuscript received 26 December 2002, revised 27 June 2003. 2005. The Journal of Arachnology 33:25-32 DAY VS* NIGHT SAMPLING FOR SPIDERS IN GRAPE VINEYARDS Michael J. Costello^ and Kent M* Daaee: Center for Biological Control, Division of Insect Biology, Department of Environmental Science, Policy and Management, University of California, Berkeley, California 94720 USA ABSTRACT. We compared day sampling (between 0700 and 1100) and night sampling (between 1900 and 2300) of spiders on grapevines in a California vineyard in 1993 and 1994, shaking spiders from the vines onto a drop cloth and vacuuming them up. Pooled density of the seven most abundant spider species did not differ significantly between day and night sampling, nor did density of Cheiracanthium inclusum (Miturgidae), Trachelas pacificus (Corrinidae), Oxyopes spp. (Oxyopidae) or Neoscona oaxacensis (Ara- neidae). Under day sampling Metaphidippus vitis (Salticidae) was 60% more abundant and Hololena nedra (Agelenidae) more than 2.5 fold more abundant than under night sampling. Daytime sampling generally resulted in a higher percentage of capture for each spider taxa analyzed, but neither of the diversity indices (Shannon- Wiener, Simpson or Bray-Curtis) showed any difference between day and night sampling. Pa- rameters generated by Taylor’s power law indicate a uniform distribution for most spider taxa, which was not affected by sampling time with the exception of H. nedra. We suggest that at vineyard sites in California with a similar spider community, sampling can be limited to daylight hours if a sampling method is used which is sufficiently vigorous to ( Keywords’ Sampling, night, vineyards, grapes It is well recognized that many spiders ex- hibit diel activity patterns (Williams 1962), and therefore, the time of day at which sam- pling for spiders takes place has been consid- ered by many researchers (e.g., Howell & Pienkowski 1971; Le Sar & Unzicker 1978; Nyffeler et al. 1987; Green 1999). Many spe- cies of the “wandering spider” families (e.g., Clubionidae, Miturgidae, Corrinidae) are noc- turnal or exhibit periods of nocturnal activity (Marc 1990), which is true for many other spi- der families as well (e.g., most Araneidae and many Lycosidae) (Foelix 1982). Some fami- lies, such as the Salticidae, are almost exclu- sively diurnal. Others are active during the day as well as night (e.g., Oxyopidae). Should researchers or pest management practitioners sample at night to obtain accu- rate estimates of spider density or diversity on vegetation in a given ecosystem? In recent studies, sampling time of day made little dif- ference in spider density, but did affect diver- ^ Present address: Horticulture and Crop Science Department, California Polytechnic State Universi- ty, San Luis Obispo, California 93407 USA, E-mail: mcostell@calpoly.edu spiders from their resting places. sity (Coddington et al. 1996; Dobyns 1997; Green 1999; Sorensen et al. 2002). However, sampling method will almost certainly play a role in determining the need to sample at night. For example, visual inspection that is undertaken exclusively in the day will likely miss the nocturnal spiders which rest in cryp- tic locations, and therefore a host of research- ers using this method have included night as well as day sampling (e.g. Nyffeler et al. 1987). Howell & Pienkowski (1971) found that sweep netting, which primarily collects specimens from the distal end of shoots, fa- vored diurnal hunters such as Salticidae and Thomisidae, when used during the day to sample spiders from alfalfa. If the sampling method is efficient at col- lecting active spiders as well as extracting spi- ders from their resting places, then sampling might be done exclusively in the day, as di- urnally active spiders will be easily caught and nocturnal spiders will be dislodged from their resting places. Vacuum sampling meth- ods may achieve this, depending on the suc- tion power and whether the spiders rest on relatively exposed locations on the plant. Us- ing a D-vac, Le Sar and Unzicker (1978) 25 26 THE JOURNAL OF ARACHNOLOGY found significant temporal variation in the vertical distribution of Tetragnathidae, Clu- bionidae, Thomisidae and Salticidae on soy- beans and Green (1999) found that spider di- versity in citrus orchards differed significantly when a D-vac sampling took place in the day compared to the night. These findings suggest that some spiders rested off of the vegetation sampled or that the D-vac suction was not suf- ficient to dislodge resting spiders from their resting places on the plants. Beat or shake samples are designed to dis- lodge arthropods from vegetation; therefore, assuming that spiders are resting on the veg- etation, all spiders, whether active or resting, should be sampled equally. McCaffrey et al. (1984), using the limb beat method on apples, found no differences in day vs. night sampling for Thomisidae, Dictynidae or Theridiidae and mixed results for Clubionidae and Salticidae. Unfortunately, their data set relied on just two sampling dates. In a southern hardwood forest using a foliage beating method, Coddington et al. (1996) found no difference in spider den- sity between diurnal and nocturnal sampling. At the same study site Dobyns (1997) found no time of day difference using an intensive sampling strategy (a two-hour sampling effort applied three times per 24-hour period), but found slightly more spiders during the day than night using a less intensive strategy (the two-hour sampling just once per 24-hour pe- riod). Another sampling method which might be effectively used to sample diurnal and noctur- nal spiders without the need for round the clock sampling is the use of time-sorting pit- fall traps (Alderweireldt 1994), but this meth- od has limitations, as pitfall traps are not a very good estimator of density, and would be more useful for ground dwelling rather than arboreal spiders. Spiders are the dominant predators on cul- tivated grapes in California’s San Joaquin Val- ley (Costello & Daane 1999). Two studies have been published which compared sam- pling methods to estimate spider density on the vines (Costello & Daane 1997; Roltsch et al. 1998), but there have been no comparisons made of day sampling vs. night sampling to determine their effects on estimates of density or diversity. The intent of this study was to compare day vs. night sampling using a single sampling method, the drop cloth, to determine if night sampling is important for estimating spider density or diversity in the grape agroe- cosystem. We focused on seven spider species which dominated our study site. Of these, Me- taphidippus vitis (Cockerell 1895) (Salticidae) is diurnal; Trachelas pacificus (Chamberlin & Ivie 1935) (Corinnidae), Cheiracanthium in- clusum (Hentz 1847) (Miturgidae) and Neos- cona oaxacensis (Keyserling 1864) (Aranei- dae) are considered nocturnal; and Hololena nedra Chamberlin & Ivie 1942 (Agelenidae), Oxyopes scalaris Hentz 1845 and Oxyopes salticus Hentz 1845 (Oxyopidae) are consid- ered active both day and night. METHODS Study site and sampling methods. — Day vs. night sampling comparisons were part of a larger study of spider densities on grape- vines with and without ground cover (Costello & Daane 1998). The study site was a table grape vineyard (cv. Ruby Seedless) near Reedley, Fresno County, California. The ex- perimental design was a randomized complete block, with two treatments (ground cover present during the grape growing season vs. clean cultivation) and five replicates of each block. Each treatment plot was 1.4 ha (8 rows wide by 80 vines long). Ground cover had no effect on spider density on the vines overall, and little effect on individual spider species density (Costello & Daane 1998). Because there was no ground cover X sampling time interaction {P > 0.05), the data were analyzed for sampling time without regard to ground cover treatment. To test the hypothesis that sampling time of day made a significant dif- ference in the estimate of population density, we took two daytime samples (0700-1100 hours) and two nighttime samples (2000- 2400 hours) from each plot (i.e., across ground cover treatments) monthly from May- September in 1993 and 1994 (total of 40 sam- ples). We sampled spiders from the vines as a two-person team and used the drop cloth method, which involved laying a 9 x 3 m mus- lin sheet on the ground underneath the area covered by the trunk, canes, and foliage of two adjacent vines. For —30 sec. we shook the foliage and beat the vine trunks with mal- lets to dislodge spiders onto the muslin sheet, and collected the spiders with battery-pow- ered vacuums. To sample at night, we used battery powered headlamps. COSTELLO & DAANE— DAY VS. NIGHT SAMPLING FOR SPIDERS 27 In the study vineyard, the vines were trained to a bilateral cordon, and trellised on a 0.9 m crossarm with 2 catch wires. Rows were spaced 3.6 m wide and vines were spaced 2.4 m within the row. Pesticides used during the 2 year period included the fungi- cides sulfur, copper and myclobutanil for con- trol of grape powdery mildew, Uncinula ne- cata Burrill, and the insecticide sodium fluroaluminate for control of lepidopteran pests. Statistical analysis. — We analyzed the density of the seven most abundant spider spe- cies, grouped into six taxa, each of which comprised at least 3% of the total number of spiders collected. These were T. pacificus, C. inclusum, M. vitis, H. nedra, N. oaxacensis, and Oxyopes spp. Oxyopes scalaris and O. salticus are grouped together as Oxyopes spp. for purposes of the analysis because they can- not be easily distinguished as immatures. In addition, we analyzed the pooled abundance of these seven species. We log transformed the data and analyzed them by repeated measures ANOVA (SAS Institute 2000), using date as the repeated measures variable. Because there was no interaction between sampling time and year for spider density nor diversity {P > 0.05), the two year period was analyzed as a complete data set, and sampling dates are pre- sented as the mean Julian date of the two sam- pling years. Spider species diversity in day vs. night sampling was estimated in several ways. A similarity index was created using the Bray- Curtis measure (Bray & Curtis 1957; Krebs 1989): E \X - xJ E (Xj + X,,) where B ~ the Bray-Curtis measure of dissim- ilarity and Xy, = percentage of species / in each sample j (day sample) or sample k (night sample). We have chosen to use this index as a measure of similarity by using the comple- ment of B (i.e., 1™-B), as suggested by Wolda (1981). Values of the index range from 0 (completely dissimilar) to 1.0 (completely similar). The Shannon- Wiener index (South- wood 1978), which is sensitive to rare species, was calculated as: H = -E P/log p, where p, is the proportion of the total number of species or genera identified. The Simpson index (Southwood 1978), which is more sen- sitive to common species, was calculated as: D = l/E where again, is the proportion of the total number of species or genera identified. To determine the effect of sampling time on spider dispersion, the mean and variance of spider abundance for each sample date (nat- ural log) were used to generate dispersion pa- rameters using Taylor’s power law (Taylor 1961): s'^ = where s'^ is the variance, a is a sampling pa- rameter, p, is the mean, and b is an aggregation parameter. The aggregation parameter {b) de- scribes species dispersion: Values of b > I indicate a clumped distribution, of Z? = 1 a random distribution, and of Z? < 1 a uniform distribution (Taylor 1961). RESULTS The spider community on grapes in this vineyard consisted of at least 15 families, comprising 22 identified species, with seven species making up 95% of the community. Over the two year period, a total of 6,410 spi- ders was collected: 3668 during the day, and 2742 during the night (Table 1). Spider den- sity per vine (the seven most abundant species pooled) did not differ significantly between day and night (Table 2). In addition to the overall counts, the absolute number of spiders collected was higher for every spider taxon during the day (Table 1), but there was no significant difference in spider density with day vs. night sampling of the spiders C in- clusum, T. pacificus, Oxyopes spp. or N. oax- acensis (Fig. 1, Table 2). However, for two species there were significant differences {P < 0.01) between treatments: M. vitis was 60% more abundant under day sampling, and H. nedra was more abundant under day sampling by more than 2.5 fold (Fig. 1, Table 2). For each spider taxon a higher percentage overall was collected in the day than during the night (Table 1). However, this did not have a significant impact on the diversity indices. There was a trend toward higher overall spider diversity early in the season, but there were no significant differences in diversity for ei- 28 THE JOURNAL OF ARACHNOLOGY Table 1 . — Total number of spiders collected and percentage of spiders collected by sampling time and spider taxon, 1993 and 1994 seasons combined. Spider taxon Total number of spiders collected Percentage of all spiders collected Day Night Day Night Trachelas pacificus 1424 1214 22.2 18.9 Cheiracanthium inclusum 690 576 10.8 9.0 Oxyopes spp. 630 373 9.8 5.8 Metaphidippiis vitis 402 244 6.3 3.8 Neoscona oaxacensis 165 123 2.6 1.9 Hololena nedra 174 63 2.7 1.0 Theridion spp. 63 41 1.0 0.6 Linyphiidae 49 38 0.8 0.6 Salticidae 27 13 0.4 0.2 Thomisidae 19 10 0.3 0.2 Lycosidae 8 19 0.1 0.3 Gnaphosidae 9 16 0.1 0.2 Anyphaenidae 6 9 0.1 0.1 Total spiders 3668 2742 57.22 42.77 ther the Shannon-Wiener index {P = 0.98) or the Simpson index (P = 0.73) between day and night sampling (Table 3). In addition, the Bray-Curtis similarity index was 0.89, which is considered quite high. No spider taxon was found exclusively during either sampling pe- riod. The spider seasonal abundance pattern (i.e., spider density over time) was not significantly altered by time of day sampling for any spider species except T. pacificus (sampling by date interaction: F = 9.56, df = 4, 124, P < 0.001). For this spider, night sampling showed a small early season peak and larger late season peak in density, but only one late season peak for day sampling (Fig. 1). Day and night sampling densities peaked earliest for N. oaxacensis and peaked on the last sampling date for C. inclu- sum, H. nedra and Oxyopes spp. Peak density for M. vitis was mid to late season for both day and night sampling (Fig. 1). Regressions of against p. were signifi- cantly different from zero for every spider taxon and sampling time {P < 0.002, Table 4). With one exception, values of b were <1, indicating a uniform distribution for all spi- ders, which was not changed by sampling time. The one exception was night sampling of H. nedra, which produced a value of 1.17 for b, indicating a random distribution. DISCUSSION Although the sum total of spiders (all spider taxa combined) was higher under day sam- pling, we found no overall statistically signif- icant difference in spider density nor diversity Table 2. — Mean spiders per vine and summary statistics from the analysis of variance, 1993 and 1994 seasons combined. Mean spiders per vine ANOVA Day Night F df P T. pacificus 6.47 ± 0.77 5.67 ± 0.44 0.40 1, 31 0.533 C. inclusum 3.13 ± 0.54 2.69 ± 0.44 0.07 1, 31 0.794 Oxyopes spp. 2.86 ± 0.65 1.74 ± 0.34 0.92 1, 31 0.344 M. vitis 1.82 ± 0.18 1.14 ± 0.11 9.36 1, 31 0.004 N. oaxacensis 0.75 ±0.11 0.54 ± 0.06 2.03 1, 33 0.163 H. nedra 0.79 ± 0.10 0.29 ± 0.04 8.97 1, 31 0.005 Total spiders 15.84 ± 1.86 12.09 ± 1.01 0.67 1, 34 0.420 COSTELLO & DAANE— DAY VS. NIGHT SAMPLING FOR SPIDERS 29 OJ 8.0 6.0 m S 4.0 ^ 0.0 15.0 10.0 5.0 0.0 12.0 d 10.0 - C inclmum Oxyopes spp, 1 OLdiLjdiL til 50 100 150 200 250 Mean Mian Day 300 2J 2.0 1.5 1.0 0.5 0.0 K oaxacemis ifi illifkfili 50 100 150 200 250 Mean Mian Day 300 Figure 1.- — Spider density per vine of the six most common taxa, 1993 and 1994 data combined, with the julian dates of the two study years averaged. Open bars represent day sampling, and closed bars night sampling. Metaphidippus vitis and H. nedra showed significantly higher density with day sampling (P < 0.01). No significant differences were found in spider density for any of the other taxa. Table 3. — Shannon-Wiener (H) and Simpson (D) diversity indices, 1993 and 1994 data combined, with corresponding F- values. Mean Julian H D Day Day Night Day Night 112 0.83 0.76 5.88 4.52 147 0.93 0.75 6.94 3.89 173 0.79 0.67 4.61 2.94 202 0.71 0.74 3.22 4.09 222 0.61 0.64 2.82 2.94 247 0.68 0.67 3.80 3.46 272 0.65 P 0.63 = 0.98 3.69 P 3.28 = 0.73 between diurnal and nocturnal sampling. Our findings are similar to other studies v/Mch used beating or shaking of vegetation as a sampling method (McCaffrey et al. 1984; Coddington et al. 1996; Dobyns 1997), in that few differences in overall spider density were found with day vs. night sampling. Dobyns (1997) found that spider density was signifi- cantly different (more spiders were found dur- ing the day) but only for a low intensity sam- pling method, and concluded that sampling method was more important than sampling time of day. Sorensen (2002) found an inter- action between sampling time of day and sam- pling method, with some methods producing 30 THE JOURNAL OF ARACHNOLOGY Table 4. — Regression statistics of In s'^ against In /x for generation of Taylor’s power law parameters. Spider Sampling time a b R2 P T. pacificus Day 0.472 0.502 0.834 0.0001 Night 0.729 0.447 0.831 0.0001 C. inclusum Day 0.256 0.720 0.987 0.0001 Night 0.325 0.599 0.908 0.0001 Oxyopes spp. Day 0.296 0.434 0.917 0.0001 Night 0.359 0.399 0.923 0.0001 M. vitis Day 0.481 0.440 0.666 0.0013 Night 0.278 0.599 0.795 0.0001 H. nedra Day 0.285 0.458 0.778 0.0002 Night 0.056 1.165 0.743 0.0004 N. oaxacensis Day 0.300 0.393 0.705 0.0007 Night 0.160 0.743 0.866 0.0001 All spiders Day 0.902 0.451 0.821 0.0001 Night 1.131 0.427 0.825 0.001 higher abundance of spiders at night. Other studies have concluded that sampling method can lead to very different estimates of spider density and diversity (Costello & Daane 1997; Roltsch et al. 1998). When analyzed by taxon, we found two species, M. vitis and H. nedra, significantly different in density with respect to time of day sampling, and both of these were more abun- dant with day sampling. Metaphidippus vitis, like most other salticids, is an active diurnal hunter that searches for prey out on the leaves and shoots and can quite easily be shaken off during the day. Could it be that M. vitis, and perhaps other salticids, rest during the night in relatively deep crevices, and are therefore more difficult to shake out? For H. nedra, finding a logical explanation is more difficult. This agelenid sits and waits for prey to land on the flat, sheet like portion of its funnel shaped web, and presumably, will respond to prey during the day or night. Because H. ned- ra does not leave its web to rest, the expla- nation for this difference cannot be that it is not as accessible during the night. However, it is possible that behaviorally, its response to disturbance at night is to retreat rather than to flee. We wonder if this might not be related to lower temperatures at night: //, nedra is a very quick and agile spider, and perhaps be- cause lower temperatures do not allow it to flee as fast at night, it switches to a retreat response. Given that the diurnally active hunting spi- der M. vitis was sampled at a higher density during the day, why did we not find parallel results with the nocturnal spiders T. pacificus, C. inclusum and N. oaxacensisl There are two possibilities, the first being that their resting places are on the foliage, rather than in re- cesses or crevices on the bark of the trunk, or in the leaf litter or soil underneath the vine. This possibility is most plausible for C. inclu- sum and N. oaxacensis than for T. pacificus. The silken bivouacs of C. inclusum are com- monly encountered on the foliage of grape- vines, and N. oaxacensis is well known for stringing its orb web between the rows of grapevines and resting on the foliage during the day. However, this explanation does not fit well with T. pacificus. Few bivouacs of this species have been observed on grape foliage, as this spider has a penchant for hiding under the bark of the trunk. This brings us to the second possibility, that T. pacificus is not as nocturnal as we thought, and may be just as active during the day as during the night. Our results do not indicate that estimates of spider diversity are affected by time of day of sampling, in contrast to findings of other re- searchers. Green (1999) found that generic richness differed significantly with sampling time in over 40% of samples. Coddington et al. (1996) and Dobyns (1997) found some spi- der species and even entire families only at night, and Sorensen et al. (2002) found spe- cies unique to both day and night. The impli- cation is that night sampling was necessary to achieve a more accurate estimate of species richness and a more complete picture of the COSTELLO & DAANE— DAY VS. NIGHT SAMPLING FOR SPIDERS 31 spider fauna. The reasons our results differed may have to do with the ecosystem studied: our grape agroecosystem was much lower in species richness than the southern hardwood forest (Coddington et al. 1996), subtropical citrus orchard (Green 1999) or afromontane (Sorensen et al. 2002) ecosystems. We suggest that in California vineyards with similar spider communities, if a method is used which is sufficiently vigorous to dis- lodge spiders from their resting places, sam- pling can be limited to daylight hours. Al- though we found no difference in spider species diversity between day and night sam- pling, it is possible that at sites with higher species richness than ours, sampling time of day could influence estimates of diversity. As for species density, there was no under rep- resentation of nocturnal spiders, which is the main concern when limiting sampling to day- light hours; each of the two spider species (M. vitis and H. nedrd) which differed between day and night sampling was more abundant with day sampling. ACKNOWLEDGMENTS Field and laboratory assistance for this study was provided by Amanda Bird, Eric Davidian, Ross Jones and Glenn Yokota. We are grateful for the support of the California Table Grape Commission, UC Sustainable Agriculture Research and Education Program, UC Statewide IPM Project, and USDA Na- tional Research Initiative Competitive Grants Program. Voucher specimens are stored in 70% EtOH at the Kearney Agricultural Center, Parlier, California. LITERATURE CITED Alderweireldt, M. 1994. Day /night activity rhythms of spiders occurring in crop-rotated fields. Eu- ropean Journal of Soil Biology. 30:55-61. Bray, J.R. & J.T Curtis. 1957. An ordination of the upland forest communities of southern Wiscon- sin. Ecological Monographs 27:325-349. Coddington, J.A., L.H. Young & EA. Coyle. 1996. Estimating spider species richness in a southern Appalachian cove hardwood forest. Journal of Arachnology. 24:1 1 1-128. Costello, M.J. & K.M. Daane. 1997. Comparison of sampling methods used to estimate spider (Ara- neae) species abundance and composition in grape vineyards. Environmental Entomology 26: 142-149. Costello, M.J. & K.M. Daane. 1998. Influence of ground cover on spiders in a table grape vine- yard. Ecological Entomology 23:33-40. Costello, M.J. & K.M. Daane. 1999. Abundance of spiders and insect predators on grapes in cen- tral California. Journal of Arachnology 27:531- 538. Dobyns, J.R. 1997. Effects of sampling intensity on the collection of spider (Araneae) species and the estimation of species richness. Environmental Entomology 26:150-162. Foelix, R. 1982. Biology of Spiders. Harvard Uni- versity Press, Cambridge, Massachusetts. Green, J. 1999. Sampling method and time deter- mines composition of spider collections. Journal of Arachnology 27:176-182. Howell, J.O. & R.L. Pienkowski. 1971. Spider pop- ulations in alfalfa, with notes on spider prey and effect of harvest. Journal of Economic Entomol- ogy 64:163-168. Krebs, C.J. 1989. Ecological Methodology. Harper Collins Publishers, New York. LeSar, C.D. & J.D. Unzicker. 1978. Soybean spi- ders: species composition, population densities and vertical distribution. Illinois Natural History Survey Biological Notes 107:14 p. Marc, P. 1989. Nycthermal activity rhythm of adult Clubiona corticalis (Walckenaer, 1802) (Ara- neae, Clubionidae). Acta Zoologica Fennica, 190:279-285. McCaffrey, J. R, M. P. Parrella, & R. L. Horsburgh. 1984. Evaluation of the limb-beating sampling method for estimating spider (Araneae) popula- tions on apple trees. Journal of Arachnology 11: 363-368. Nyffeler, M., D.A. Dean & W.L. Sterling. 1987. Evaluation of the importance of the striped lynx spider, Oxyopes salticus (Araneae: Oxyopidae), as a predator in Texas cotton. Environmental En- tomology 16:1114-1123. Roltsch, W.R., R. Hanna, H. Shorey, M. Mayse & E Zalom. 1998. Spiders and vineyard habitat re- lationships in central California. Pp. 311-338. In Enhancing Biological Control: Habitat Manage- ment to Promote Natural Enemies of Agricultural Pests (C.H. Pickett & R.L. Bugg, eds.). Univ. of California Press, Berkeley, California. SAS Institute. 2000. SAS/STAT User’s Guide: Sta- tistics. Version 8.1, SAS Institute, Cary, North Carolina, USA. Sorensen, L.L., Coddington, J.A. & N. Scharff. 2002. Inventorying and estimating subcanopy spider diversity using semiquantitative sampling methods in an afromontane forest. Environmen- tal Entomology, 31:319-330 32 THE JOURNAL OF ARACHNOLOGY Southwood, T.R.E. 1978. Ecological Methods with Particular Reference to the Study of Insect Pop- ulations. Wiley, New York. Taylor, L.R. 1961. Aggregation, variance, and the mean. Nature (Lond.) 189:732-735. Williams, G. 1962. Seasonal and diurnal activity of harvestmen (Phalangida) and spiders (Araneida) in contrasted habitats. Journal of Animal Ecolo- gy 31:23-42 Wolda, H. 1981. Similarity indices, sample size and diversity. Oecologia, 50:296-302. Manuscript received 23 September 2002, revised 17 October 2003. 2005. The Journal of Aracheology 33:33^2 DETERMINING A COMBINED SAMPLING PROCEDURE FOR A RELIABLE ESTIMATION OF ARANEIDAE AND THOMISIDAE ASSEMBLAGES (ARACHNIDA, ARANEAE) Alberto Jimenez- Valverde & Jorge M. Lobo: Departamento Biodiversidad y Biologia Evoiutiva, Museo Nacional de Cieecias Naturales (CSIC), c/ Jose Gutierrez Abascal 2, 28006 Madrid, Spain. E-mail: mcnaj651@mncn.csic.es ABSTRACT. As the disappearance of species accelerates, it becomes extremely urgent to develop sam- pling protocols based on efficient sampling methods. As knowledge of the Iberian spider fauna is extremely incomplete, it is becoming necessary to facilitate reliable and complete species richness inventory collec- tion. In this work the results from six sampling methods (sweeping, beating, pitfall traps, hand collecting at two different heights and leaf litter analysis) in three habitats with different vegetation structure are compared for the inventory of Araneidae and Thomisidae in 1 km^ sampling plots. A combination of sweeping, beating and pitfall trapping prove to be necessary to achieve a reliable inventory of these two spider families. Hand collecting above knee level contributes to the improvement of the protocol in certain habitats where araneids, concentrated in patches of suitable vegetation, are easy to find. RESUMEN. A medida que se acelera la desaparicion de las especies se hace mas urgente el desarrollo de protocolos de muestreo basados en metodos eficientes. El conocimiento de la aracnofauna iberica es bastante escaso, por lo que es necesario desarrollar inventarios fiables y tan completes como sea posible, de una rnanera rapida y sencilla. En el presente trabajo se comparan seis metodos diferentes de muestreo (mangueo, batido, trampas de interceptacion, captura directa a dos alturas distintas y analisis de hojarasca) para el inventariado de las familias Araneidae y Thomisidae en parcelas de 1 km^, estudiando su com- portamieeto en tres habitats con diferente complejidad estructural de la vegetacion, Los resultados mues- tran que para conseguir inventarios fiables de estas dos familias es necesaria la combinacion del mangueo, batido y de las trampas de caida. En los habitats en los que la localizacion de los araneidos es sencilla debido a que se concentran en parches de vegetacion concretes, la captura directa a una altura por encima de las rodillas contribuye a mejorar el protocolo. Keywords! Species richness inventory, sampling methods, efficiency, complementarity Loss of biodiversity, one of the greatest en- vironmental problems (Wilson 1988; May et al. 1995), the outcome of the accelerating de- struction of ecosystems, means that many spe- cies will be eradicated while still undiscov- ered or unstudied. Protecting biodiversity implies protecting terrestrial arthropods, a group poorly known but comprising around 80% of the Earth’s species and including those denominated as hyperdiverse (Hammond 1992). These groups are the least understood, yet contribute most to the planet’s biotic di- versity. Conservation of biological diversity requires detailed information on the geograph- ic distribution of organisms. In the case of ar- thropods, as this information is almost impos- sible to acquire in the medium-term by means of field sampling (Ehrlich & Wilson 1991; Williams & Gaston 1994), the utilization of predictive model techniques may be the only possible way to estimate the distribution of biodiversity attributes (Margules et al. 1987; Iverson & Prasad 1998; Guisan & Zimmer- mane 2000; Lobo & Martm-Piera 2002; etc). However, application of these predictive methods requires reliable biological informa- tion; when this is lacking, the design of spe- cific sampling protocols for each taxonomic group that gather the maximum information, most cost-effectively, becomes essential. About 36,000 species of the order Araneae have been described, while the total number is estimated at between 60,000 and 170,000 (Coddingtoe & Levi 1991; Platnick 1999). This is one of the most diversified orders (Coddington & Levi 1991) and offers the greatest potential to help regulate terrestrial arthropod populations (Marc et al. 1999). Ara- 33 34 THE JOURNAL OF ARACHNOLOGY neids, one of the most successful spider fam- ilies (approximately 2,600 species; Foelix 1996), are relatively easy to detect due to their size, coloration and their orb webs. Vegetation structure seems to be the most important pa- rameter in determining their presence (Wise 1993). Unlike the araneids, thomisids (crab spiders) do not use webs to capture prey; in- stead they ambush prey from flowers or leaves (Wise 1993), where their cryptic coloration al- lows them to go unnoticed. Some genera, like Xysticus and Ozyptila, are eminently edaphic, capturing prey among leaf litter and herba- ceous vegetation. Arachnological tradition is sorely lacking in the Iberian Peninsula, and spider distribution is extremely poorly understood (1,180 record- ed species; Morano 2002). Only in the prov- ince of Aragon is there a recent catalogue of arachnological fauna (Melic 2000); the rest of the Iberian catalogues include out-dated rec- ords, most of doubtful quality and with erro- neous data (Melic 2001). So, it is necessary to augment taxonomic and distributional data on Iberian spiders by using effective and stan- dardized sampling protocols, the design of which involves overcoming some difficulties. As spiders’ life history, behavior and morpho- logic, physiological and ecological adaptation vary widely (Turnbull 1973), sampling meth- od effectiveness depends on the nature of the taxonomic group (Canard 1981; Churchill 1993; Coddington et al. 1996; Costello & Daane 1997; Churchill & Arthur 1999). Fur- thermore, it must be kept in mind that the ef- fectiveness of the method also depends on the environment (Canard 1981). Thus, in order to inventory reliably and completely, the design of the sampling protocol should combine var- ious sampling methods, selecting the methods promising maximum information and comple- mentarity for each environment and taxonom- ic group (Coddington et al. 1996; Green 1999; Sprensen et al. 2002). In this work, several sampling methods for Araneidae and Thomi- sidae species are compared, in habitats with distinct vegetation complexity, in order to de- termine which combination captures the max- imum number of species with the minimum number of sampling techniques. METHODS Study site. — The study was carried out from 2 May- 14 June 2002 in three localities in the Comunidad de Madrid (central Spain), with vegetation differing in structural com- plexity as follows: 1) A grassland zone sub- jected to intense pasturing pressure, with small shrub patches, at 980 m elevation in the municipality of Colmenar Viejo (latitude 40.69, longitude —3.77). Its potential vegeta- tion is the holm-oak forest (supra-mesomedi- terranean-siliceous series of Quercus ilex ro- tundifolia; Rivas-Martinez, 1987). 2) An extensive and dense zone of shrub located in El Berrueco (latitude 39.97, longitude —3.53), at 940 m elevation. The area belongs to the same vegetation series as the former (Rivas- Martinez, 1987); nevertheless, human activity has caused the original vegetation to be re- placed by the Cistus ladanifer series, with patches of Lavandula pedunculata and Thy- mus spp. 3) A Holm-oak forest zone in Can- toblanco (latitude 40.51, longitude —3.65) at an elevation of 700 m, composed of some tall (6-8 m) specimens of Quercus ballota, though the majority of the trees are between 3-4 m tall. An old plantation of Pinus pinea, which dates from the 1930s, occupies one part of the forest. Sampling methods. — In each habitat a I km^ sampling plot divided into 2,500 subplots of 400 m^ was established; 20 of these sub- plots were chosen at random, and a sampling effort unit carried out in each. For the capture of species in these two families, six cheap, easy and widely used sampling methods were employed: sweeping, beating, pitfall traps, above-knee-level visual search, below-knee- level visual search, and leaf litter analysis. A sampling effort unit was defined as one of the following: 1) A one-person sweep of the her- baceous vegetation and shrub during 15 min- utes. The opening of the sweep net was 37 cm in diameter, and it was emptied at regular in- tervals to avoid loss and destruction of the specimens. 2) A one-person beating of bushes and small trees and branches during 15 min- utes with a heavy stick; the specimens fell on a 1.25 X 1.25 m white sheet. In cases where the structure of the vegetation made the use of the sheet difficult a 41 X 29 cm plastic pail was employed. 3) A one-person visual search from knee level to as high as one can reach (above visual search, AVS) during 15 minutes. 4) A one-person visual search from ground to knee level (below visual search, BVS) during 15 min. Stones were lifted up because tho- JIMENEZ-VALVERDE & LOBO— INVENTORYING SPIDER SPECIES RICHNESS 35 misids, especially females after laying eggs (Levy 1975; Hidalgo 1986), from the genera Xysticus and Ozyptila usually dwell under them. 5) Analysis during 15 min. of leaf litter poured in a white pail, justifiable because this is the habitat of the genus Ozyptila (Thomi- sidae) (Urones 1998). 6) The running of 4 open pitfall traps during 48 hours. These traps were 11.5 cm wide and 1 liter in volume, each 10 m apart from the others in order to avoid interference effects and to maximize the effi- cacy of each trap (Samu & Lovei 1995). Traps were filled with water, and a few drops of de- tergent added to break the surface tension so as to prevent the spiders from escaping. Spiders were sucked up with an aspirator to reduce damage and were transferred to 70% alcohol. Sampling was always done by the same person in order to avoid possible differ- ences due to the effect of the collector (Norris 1999); rainy and windy days were avoided in order to prevent a reduction in the efficiency of the sampling methods (see Gyenge et al. 1997; Churchill & Arthur 1999). All speci- mens are deposited in the Museo Nacional de Ciencias Naturales collection (Madrid, Spain). All together, sampling involved running 240 pitfall traps (3 sampling plots X 20 subplots X 4 pitfall traps) and one-person fieldwork during 75 hours (0.25 hours X 5 methods X 3 sampling plots X 20 subplots). Data analysis. — The cumulative number of species found by different sampling efforts (species accumulation curves) was studied to evaluate the accuracy of the species invento- ries obtained in each of the three sampling plots (see Gotelli & Colwell 2001). The num- ber of sampling effort units (i.e. the number of subplots) was used as the measure of sam- pling effort, and the order in which sampling unit inventories were added was randomized 500 times to build smoothed curves using the Estimates 5.0.1 software (Colwell 1997). The asymptotic value of the accumulation curves obtained was estimated using the Clench equation (Soberon & Llorente 1993; Colwell & Coddington 1994). This score, together with the species richness estimations produced by three nonparametric methods, was used to test if the total number of species caught in each sampling plot underestimated the true species richness. The nonparametric species richness estimators used are the first-order jackknife, the abundance-based coverage (ACE), and the incidence-based coverage es- timator (ICE). Detailed descriptions of the es- timators can be found in Colwell (1997) and Colwell & Coddington (1994). In order to study the effects of sampling method and the interaction of method and habitat on the number of species and individ- uals collected per sampling effort unit, a fac- torial ANOVA was performed. As data were not normally distributed, they were trans- formed by log(nTl), and a Tukey test (HDS) was used to determine pairwise significant differences (P < 0.05). STATISTICA package (1999) was used for all statistical computa- tions. Other methodological considerations. — As Norris (1999) pointed out, the inclusion of immature specimens is the factor which has the most significant effect on community trends. It cannot be assumed that the abun- dance distribution of juveniles is the same as that for adults, and the relative abundance of species in a community can be highly altered if juveniles are considered. However, since our objective was to find all the species in- habiting the sampling plots, juveniles that could be identified to the species level were included in the analysis. Sometimes genera represented only by immature states did ap- pear, in which case, they were also included. Rejecting juveniles would have involved re- jecting valuable information, and as they in- creased sample sizes significantly, their inclu- sion allowed statistical analysis. In araneids and thomisids, unlike in most other spider families, color and morphology facilitate the identification of some juveniles. All together, 942 individuals were captured, 56% of them juveniles; almost half (247 individuals) have been used in the analysis. RESULTS In 80 sampling effort units, a total of 661 individuals were captured, representing 26 species, 11 araneids and 15 thomisids. Completeness of the inventories. — The Clench model function fits the accumulation curves well in each of the three sampling plots, with percentages of explained variation higher than 99% (Table 1 & Fig. 1). The pre- dicted asymptote score does not differ too much from the observed species richness, the percentages of collected species oscillating around 80%. The nonparametric estimators 36 THE JOURNAL OF ARACHNOLOGY Table 1. — Observed species richness and results of four species richness estimators for each habitat. The relationship between the number of sampling effort units and the number of species was fitted to the asymptotic Clench equation (Colwell & Coddington 1994) where alb is the asymptote and the percentage of explained variance. Jackknife 1 (first-order jackknife), ACE (abundance base coverage) and ICE (incidence-based coverage) are nonparametric estimators of species richness (Colwell 1997). Forest Shrub Grassland ^obs 17 20 15 Clench alb = 21.6; R2 = 99.9 alb = 25.0; = 99.4 alb = 18.8; R^ = 99.9 Jackknife 1 19.85 26.65 17.85 ICE 18.49 27.18 16.73 ACE 17.85 25.07 17.26 used indicate that the collected species rich= ness varies from 86%-95% for the forest plot, 74%-80% for the shrub plot, and 84%-90% for the grassland plot. These results suggest that the exhaustiveness of the sampling in each of the three habitats is similar, so sam- pling plot composition and richness figures are comparable. However, still more intensive sampling should be necessary to obtain an ac- curate inventory in each habitat. Sampling method performance. — From the three sampling plots, only one individual of Mangora acalypha (Walckenaer 1802) was captured by leaf litter analysis method (in the shrub plot). As this species was collected plentifully with the other sampling methods, Sampling units Figure 1. — Species accumulation curves for the three sampling plots with Clench function fitted: □ grassland; O shrub; A forest. The cumulative number of species found at different numbers of sampling effort units was randomized 500 times using the Estimates 5.0.1 software (Colwell 1997): JIMENEZ-VALVERDE & LOBO— INVENTORYING SPIDER SPECIES RICHNESS 37 Table 2, — Total number of individuals (/i), mean number of individuals (± SE) per sampling unit (Nmean)^ total number of species (S), mean number of species (± SE) per sampling unit (Smean)^ ^^d number of unique species (Suni) for each sampling plot and each sampling method. Sampling Plot Forest Shrub Grassland n 205 348 108 Nmean 2.07 ± 0.36 3.48 ± 0.56 1.57 ± 0.5 S 17 20 15 Smean 0.92 ± 0.14 1.5 ± 0.17 0.72 ± 0.1 Sampling Method Pitfall Sweeping Beating BVS AVS n 25 442 90 13 91 Nmean 0.41 ± 0.14 8.08 ± 1.06 1.6 ± 0.23 0.22 ± 0.09 1.55 ± 0.28 S 5 17 15 7 9 SmEAN 0.3 ± 0.08 2.7 ± 0.24 1.08 ± 0.14 0.18 ± 0.07 0.98 ± 0.14 SuNI 2 5 3 0 0 the results of this technique are not consid- ered. Both the mean number of collected spe- cies (F(4285) = 58.5; P < 0.0001) and the mean number of individuals (F(4,285) = 79.9; P < 0.0001) differ statistically from one sampling method to another. Both in the case of species richness and for the number of individuals, all pairwise comparisons between sampling methods are significant by a posteriori Tukey HSD test, except in the case of pitfall traps and BVS, and beating and AVS (see Table 2). Sweeping, the technique which captured the greatest number of species and individuals, with araneids making up 47% of the species and 68% of the individuals collected, is also the method that captured more species not captured by any other sampling method (unique species, two araneids and three tho- misids). Pitfall traps and BVS are the methods that captured the smallest number of species and individuals, but while BVS did not yield unique species, pitfall traps did capture two unique species. With pitfall traps, only tho- misids of the genera Xysticus and Ozyptila were captured. In the case of the BVS, ara- neids make up 57% of the species and 62% of the individuals. With regard to the other sampling methods, beating and AVS yield the same number of individuals, though the total number of species is larger for the former. In beating, araneids make up 47% of the species and 43% of the individuals; using AVS ara- neid, captures were more frequent, accounting for 78% of species and 89% of individuals. AVS did not yield any unique species, while beating produced three unique thomisids. By an iterative procedure the sampling methods were ranked sequentially, for each habitat, according to contribution to total spe- cies richness in this habitat. Both in the forest and shrub, sweeping is the method that yield- ed more species, followed by beating and pit- fall traps. Together, these three methods cap- tured all the observed species in these habitats. In grassland, where a broader com- bination of methods is necessary to obtain a reliable inventory (Table 3), beating captured more species, while sweeping, AVS and pitfall traps or BVS seem to be indispensable. Sampling method-habitat interaction. — The mean number of species per sampling unit (7^(2,285) ^ 15.14; P < 0.001), as well as the mean number of individuals (F(2285) ~ 15.73; P < 0.001), differs significantly be- tween sampling plots. According to a poste- riori Tukey HDS test, only in the shrub sam- pling plot is the species richness and number of individuals significantly greater than in the other two sampling plots (Table 2). However, sampling method and habitat interaction sig- nificantly affect both the mean number of spe- cies (7^(8,285) “ 6.6; P < 0.0001) and the mean number of individuals per sampling unit (F(8,285) — 9.6; P < 0.0001), indicating that the performance of the various sampling methods depends on the habitat. The results of a posteriori Tukey HSD test highlight the significantly different interaction 38 THE JOURNAL OF ARACHNOLOGY Table 3. — Results of a complementarity procedure in which the inventories of each sampling method were sequentially selected for each habitat according to its contribution to the species richness. Habitat Iteration Sampling method Number of species Accumulated species Forest 1 Sweeping 12 12 2 Beating 4 16 3 Pitfall 1 17 Shrub 1 Sweeping 13 13 2 Beating 4 17 3 Pitfall 3 20 Grassland 1 Beating 8 8 2 Sweeping 4 12 3 AVS 2 14 4 Pitfall or BVS 1 15 terms. The scheme generated for the mean number of species and individuals is quite similar (Fig. 2). There is not a significant be- tween-habitat variation in the number of in- dividuals or species collected by pitfall-traps, BVS or beating. The AVS method collected a significantly greater number of species and in- dividuals in shrub and grassland than in forest (Fig. 2), only in the grasslands did it capture more species and individuals than BVS and pitfall traps; its captures equalled those of beating in the three habitats. Likewise, sweep- ing method captures also varied with habitat; the mean number of species and individuals captured in grasslands was significantly small- er than in the other two habitats (Fig. 2). In- deed, the sweeping method captured more species and individuals in forest and shrub, while in grassland its performance was similar to that of beating or AVS. DISCUSSION Methods differ greatly in the number of species and individuals caught, and collecting method performance depends on vegetation structure. Sweeping is a standard item in an arachnologists fieldwork due to its ease of use and effectiveness (Buffington & Redak 1998). It was the most efficient sampling method in forest and shrub sampling plots, and sweeping yielded more species and individuals. How- ever, in the grassland sampling plot, the ex- treme shortness of the grass and the presence of thorny shrub patches limited its use; AVS and beating there produced equal value of mean individuals and species richness. While other authors have also noticed the reduced usefulness of sweeping in certain habitats (Churchill & Arthur 1999), as sweeping was found here to yield unique species in the three sampling plots, it must continue to be funda- mental to sampling protocol. Because beating and AVS work on similar vegetation habitats, they sample the same part of the spider community. However, while beating yielded unique species in the three habitats, AVS only did so in the grassland sampling plot, where araneids were concen- trated in shrub patches and therefore easily spotted. Furthermore, AVS, a sampling meth- od biased towards big and flashy spiders, yielded a greater proportion of araneids. It can be noticed that where vegetation structure makes visual search difficult, i.e. in the forest sampling plot, AVS is less efficient and beat- ing yielded more (although not statiscally sig- nificant) species and individuals. Beating must be added to the sampling protocol, along with AVS in habitats with such a vegetation struc- ture that the visual detection of individuals is easy. Although its efficiency was quite low in our study, pitfall trapping, one of the most fre- quently used methods to sample surface-ac- tive terrestrial arthropod communities, is es- sential for sampling that part of the community (i.e., genera Xysticus and Ozyptila, which comprise more than the 70% of the Ibe- rian thomisid fauna). Indeed, all the pitfall captures in the three sampling plots belong to these two genera. As already noted by other authors (Churchill 1993; Standen 2000), the captures of this sampling method were biased in favor of adult individuals, facilitating the identification of the specimens and helping in JIMENEZ-VALVERDE & LOBO— INVENTORYING SPIDER SPECIES RICHNESS 39 Figure 2. — Variation in the mean number of individuals (log of N + 1; ± 95% confidence interval) per sample (A) and mean number of species (log of S + 1; ± 95% confidence interval) per sample (B) between the three studied habitats or sampling plots. □ = sweeping; # = beating; A = AVS; ■ = BVS; O = pitfall trapping. 40 THE JOURNAL OF ARACHNOLOGY the inventory work. As BVS samples the same part of the community as pitfall traps do and does not contribute unique species, it can be done without. Thus, only pitfall trapping must be included in the sampling protocol. Because the aim of this sampling protocol is the estimation of species richness, visual search could be more efficient if centered on new species, ignoring the common ones (Dobyns 1997; Churchill & Arthur 1999). The paucity of species and individuals captured by pitfall trapping suggests that the inventory would have been more effective if greater sampling effort were allocated to this method. Brennan et al. (1999) found that the larger the pitfall trap diameter, the greater the number of species captured. Work et al. (2002) pointed out that larger traps were more effective in the characterization of rare elements of an epigeal fauna. They also recommended combining large traps with smaller ones in order to sam- ple a greater range of microhabitats. However, it is difficult to judge if the protocol would have been improved by changing the pitfall trap design or by trying another method that samples this epigeal fauna more accurately. For none of the three sampling sites does the observed species accumulation curve reach an asymptote, although it seems that the simpler the vegetation structure, the smaller the curve-asymptote separation, and the smaller the difference between ^ohs and the Clench model estimation from the nonpara- metric estimator values. Tight clustering of these three nonparametric estimators was also found by Toti et al. (2000), suggesting that they either estimate the same real value or are biased similarly. Other researchers working with the entire spider fauna (Coddington et al. 1996; Dobyns 1997; Toti et al. 2000; Sprensen et al. 2002) have also failed to produce as- ymptotic species accumulation curves. How- ever, according to the estimations obtained, the three inventories sampled around 80% of spider fauna, indicating that it is possible to estimate the probable number of species in a 1 km^ plot. The percentages of completeness are quite similar to those found by other au- thors in temperate forests (Dobyns 1997, 89%; Sprensen et al. 2002, 86-89%). Our study is just a spring “snapshot” of the entire annual spider species richness of three sampling plots in different habitats. Spider as- semblages, dynamic during the season, change in species composition. Thus, results depend on the tim.e of sampling (Churchill & Arthur 1999; Riecken 1999). Nevertheless, estimat- ing species richness accurately at a given time carries weight because sampling designs for annual studies depend on it (Coddington et al. 1996; Sprensen et al. 2002). Determining the proportion of the entire annual spider fauna that is represented in the spring sample is an objective of work currently being carried out. Spider life history and behavioral diversity pose a challenge to the development of a pre- cise and cost-effective sampling program (Costello & Daane 1997). Studies that have tried to take in the entire range of spider fauna have found that even intensive sampling does not reflect the whole of species richness (Cod- dington et al. 1996; Toti et al. 2000; Sprensen et al. 2002). So, Sprensen et al. (2002) suggest that long-term monitoring programs should focus on single, or few, families, or a single feeding guild, and use a few standardized and practical sampling methods. Our study has fo- cused on two abundant spider families, Ara- neidae and Thomisidae, and has shown that a particular combination of sampling methods in each habitat is required to optimize efficacy and minimize effort. Sweeping, beating, pit- fall traps and AVS in specific locations yield a reliable inventory of these two spider taxa in a 1 km^ plot. Given how imperative a more detailed knowledge of Iberian spiders is, ad- ditional studies should be carried out in order to develop standardized sampling protocols for other spider families and/or guilds. ACKNOWLEDGMENTS This paper has been supported by the proj- ect “Faunistica Predictiva: Analisis compara- do de la efectividad de distintas metodologias y su aplicacion para la seleccion de reservas naturales” (grant: REN 2001 = 1 136/GLO), and also by a PhD Museo Nacional de Cien- cias Naturales/C.S.LC./Comunidad de Madrid grant. LITERATURE CITED Brennan, K.E.C., J.D. Majer & N. Reygaert. 1999. Determination of an optimal pitfall trap size for sampling spiders in Western Australian Jarrah forest. Journal of Insect Conservation 3:297- 307. Buffington, M.L. & R.A. Redak. 1998. A compar- ison of vacuum sampling versus sweep-netting for arthropod biodiversity measurements in Cal- JIMENEZ-VALVERDE & LOBO— INVENTORYING SPIDER SPECIES RICHNESS 41 ifornia coastal sage scrub. Journal of Insect Con- servation 2:99-106. Canard, A. 1981. Utilisation comparee de quelques methodes dechantillonnage pour letude de la dis- tribution des araignees en landes. Atti della So- cieta Toscana di Scienze Natural!. Serie B. Me- morie 88, suppl.:84-94. Churchill, TB. 1993. Effects of sampling method on composition of a Tasmanian coastal heathland spider assemblage. Memoirs of the Queensland Museum 33(2):475-481. Churchill, T.B. & J.M. Arthur. 1999. Measuring spi- der richness: effects of different sampling meth- ods and spatial and temporal scales. Journal of Insect Conservation 3:287-295. Coddington, J.A. & H.W. Levi. 1991. Systematics and evolution of spiders. Annual Review of Ecology and Systematics 22:565-592. Coddington, J.A., L.H. Young & F.A. Coyle. 1996. Estimating spider species richness in a southern Appalachian cove hardwood forest. Journal of Arachnology 24:111-128. Colwell, R.K. 1997. Estimates: Statistical Estimation of Species Richness and Shared Species from Samples (Software and Users Guide), Version 5.0.1, in http://viceroy.eeb.uconn.edu/estimates Colwell, R.K. & J.A. Coddington. 1994. Estimating terrestrial biodiversity through extrapolation. Philosophical Transactions of the Royal Society (series B) 345:101-118. Costello, M.J. & K.M. Daane. 1997. Comparison of sampling methods used to estimate spider (Ara- neae) species abundance and composition in grape vineyards. Environmental Entomology 26(2): 142-149. Dobyns, J.R. 1997. Effects of sampling intensity on the collection of spider (Araneae) species and the estimation of species richness. Environmental Entomology 26(2): 150-162. Ehrlich, PR. & E.O. Wilson. 1991. Biodiversity studies: science and policy. Science 253:750- 752. Foelix, R.F. 1996. Biology of Spiders. Oxford Uni- versity Press, New York. Gotelli, N.J. & R.K. Collwell. 2001. Quantifying biodiversity: procedures and pitfalls in the mea- surement and comparison of species richness. Ecology Letters 4:379-391. Green, J. 1999. Sampling method and time deter- mines composition of spider collections. Journal of Arachnology 27:176-182. Guisan, A. & N.E. Zimmermann. 2000. Predictive habitat distribution models in ecology. Ecologi- cal Modelling 135:147-186. Gyenge, J.E., J.D. Edelstein & E.V. Trumper. 1997. Comparacion de tecnicas de muestreo de artro- podos depredadores en alfalfa y efecto de fac- tores ambientales sobre sus estimaciones de abundancia. Ceiba 38(1): 13-18. Hammond, P.M. 1992. Species inventory. Pp. 17- 39. In Global Biodiversity, Status of the Earths Living Resources. Groombridge, B. (ed.). Chap- man & Hall, London. Hidalgo, I.L. 1986. Estudio de los tomisidos de la provincia de Leon (Araneae: Thomisidae & Phi- lodromidae). Excma. Diputacion Provincial de Leon. Inst. “Fray Bernardino de Sahagun”. Iverson, L.R. & A.M. Prasad. 1998. Predicting abundance of 80 tree species following climate change in the eastern United States. Ecological Monographs 68:465-485. Levy, G. 1975. The spider genera Synaema and Ozyptila in Israel (Araneae: Thomisidae). Israel Journal of Zoology 24:155-175. Lobo, J.M. & F. Martm-Piera. 2002. Searching for a predictive model for Iberian dung beetle spe- cies richness (Col., Scarabaeinae) using spatial and environmental variables. Conservation Bi- ology 16:158-173. Marc, R, A. Canard & F. Ysnel. 1999. Spiders (Ara- neae) useful for pest limitation and bioindication. Agriculture, Ecosystems and Environment 74: 229-273. Margules, C.R., A.O. Nicholls & M.P. Austin. 1987. Diversity of Eucalyptus species predicted by a multi-variable environment gradient. Oecologia 71:229-232. May, R.M., J.H. Lawton & N.E. Stork. 1995. As- sessing extinction rates. Pp. 1-24. In Extinction Rates. Lawton, J. H. & R. M. May (eds.). Oxford University Press, Oxford. Melic, A. 2000. Aranas de Aragon (Arachnida: Ara- neae). Catalogus de la Entomofauna Aragonesa 22:3-40. Melic, A. 2001. Aranas endemicas de la Peninsula Iberica e Islas Baleares (Arachnida: Araneae). Revista Iberica de Aracnologia 4:35-92. Morano, E. 2002. Catalogo Iberico de Aranas, in http: //entomologia.rediris.es/gia/catalogo/index.htm Norris, K.C. 1999. Quantifying change through time in spider assemblages: sampling methods, indices and sources of error. Journal of Insect Conservation 3:309-325. Platnick, N.I. 1999. Dimensions of biodiversity: Targeting megadi verse groups. Pp. 33-52. In The Living Planet in Crisis: Biodiversity Science and Policy. Cracraft, J. & F. T. Grifo (eds.). Columbia Univ. Press, New York. Riecken, U. 1999. Effects of short-term sampling on ecological characterization and evaluation of epigeic spider communities and their habitats for site assessment studies. Journal of Arachnology 27:189-195. Rivas-Martmez, S. 1987. Memoria del mapa de se- ries de vegetacion de Espana 1:400.000. ICONA, Madrid. Samu, F. & G.L. Lovei. 1995. Species richness of a spider community (Araneae): extrapolation 42 THE JOURNAL OF ARACHNOLOGY from simulated increasing sampling effort. Eu- ropean Journal of Entomology 92:633-638. Soberon, J. & BJ. Llorente. 1993. The use of spe- cies accumulation functions for the prediction of species richness. Conservation Biology 7:480- 488. Sprensen, L.L., J.A. Coddington & N. Scharff. 2002. Inventorying and estimating subcanopy spider diversity using semiquantitative sampling methods in an afromontane forest. Environmen- tal Entomology 31:319-330. Standen, V. 2000. The adequacy of collecting tech- niques for estimating species richness of grass- land invertebrates. Journal of Applied Ecology 37:884-893. STATISTICA for Windows. 1999. Computer pro- gram manual. StatSoft, Inc. Tulsa, Oklahoma. Toti, D.S., F.A Coyle & J.A. Miller. 2000. A struc- tured inventory of Appalachian grass bald and heath bald spider assemblages and a test of spe- cies richness estimator performance. Journal of Arachnology 28:329-345. Turnbull, A.L. 1973. Ecology of true spiders (Ara- neomorphae). Annual Review of Entomology 18: 305-348. Urones, C. 1998. Descripcion de Oxyptila bejarana n. sp. de la Sierra de Bejar (Salamanca, Espana) (Araneae, Thomisidae). Revue Arachnologique, 12(8):79-88. Williams, RH. & K.J. Gaston. 1994. Measuring more of biodiversity: can higher-taxon richness predict wholesale species richness? Biological Conservation 67:211-217, Wilson, E.O. 1988. The current state of biological diversity. Pp. 3-17. In Biodiversity. Wilson, E. O. (ed.). National Academic Press, Washington, D. C. Wise, D.H. 1993. Spiders in Ecological Webs. Cam- bridge University Press, New York. Work, TT, C.M. Buddie, L.M. Korinus & J.R. Spence. 2002. Pitfall trap size and capture of three taxa of litter-dwelling arthropods: implica- tions for biodiversity studies. Environmental En- tomology 31(3):438-448. Manuscript received 19 February 2003, revised 18 November 2003. 2005. The Journal of Arachnology 33:43-49 SURFACE ULTRASTRUCTURE OF LABIAL AND MAXILLARY CUSPULES IN EIGHT SPECIES OE THERAPHOSIDAE (ARANEAE) Fernando Perez-Miles and Laura Montes de Oca: Seccion Entomologi'a, Facultad de Ciencias, Igua 4225, 1 1400 Montevideo, Uruguay. E-mail: myga@fcien.edu. uy ABSTRACT. Surface ultrastructure of labial and maxillary cuspules was studied in eight species of seven different genera of Theraphosidae. Cuspule ornamentation was observed through SEM images and comparisons were made among labial and maxillary cuspules of different species and different zones of each cuspule. Ornamentation patterns were different on the anterior face of the cuspule with respect to the posterior face. A significant correlation analysis between cuspule size and body size was found. The systematic use and the probable functions of the cuspules are discussed. Keywords: Oral cuspules, cuspule ultrastructure, theraphosids Labial and maxillary cuspules are globular to conical sclerotized features on the inner ventral corner of the maxillae and on the me- dian-anterior side of the labium. They are ex- clusively found in mygalomorph spiders (Ra- ven 1980, 1985). The number and distribution of cuspules has been used in mygalomorph systematics by several authors including Ra- ven (1978, 1980, 1985, 1994), Griswold (1985), Snazell & Allison (1989), Goloboff (1993), Griswold & Ledford (2001), Perez- Miles (1992, 2000) and Perez-Miles et al. (1996), but studies on cuspule microstructure are scarce. Maxillary cuspule microstructure has been studied in Microstigmatidae (Gris- wold 1985), Barychelidae (Raven 1994) and in the theraphosid Aphonopelma seemanni (F.O.P.-Cambridge 1897) by Cutler & Vuil- liomenet (2001). There are no explicit descrip- tions of the microstructure of labial cuspules although Raven (1994) suggested that they are similar to maxillary ones. In the present study, the surface ultrastructure of labial and maxil- lary cuspules were examined by SEM in eight theraphosid species corresponding to seven different genera and three different subfami- lies (Aviculariinae, Ischnocolinae and Thera- phosinae). This is a first approach to test the systematic value of such features in Thera- phosidae. The possible mechanical, glandular and sensorial functions of the cuspules are dis- cussed. METHODS Males of eight theraphosid species repre- senting three subfamilies were studied includ- ing the Aviculariinae: Iridopelma hirsutum Pocock 1901; the Ischnocolinae: Oligoxystre argentinense (Mello-Leitao 1941) and the Theraphosinae: Acanthoscurria suina Pocock 1903, Eupalaestrus weijenberghi (Thorell 1894), Grammostola iheringi (Keyserling 1891), Grammostola mollicoma (Ausserer 1875), Homoeomma uruguayense (Mello-Lei- tao 1946), Plesiopelma longisternale (Schia- pelli & Gerschmao 1942). Seven individuals of A. suina and five of E. weijenberghi were additionally studied to estimate intraspecific variation. Body size was estimated from the carapace length of each individual measured dorsally with an ocular micrometer. One max- illa and the labium of each individual were removed for the observation of cuspules in a scanning electron microscope (SEM). Cuspule maximum width was measured from SEM im- ages. Cuspules were counted using a stereo- scopic microscope with an ocular reticule in fields of 1 mm^ taken randomly from the la- bium and maxilla with at least 6 fields counted from each piece. Mean cuspule density was used as an estimator of the total number of cuspules. Nonparametric correlations were done using Spearman R test, means were compared by the Student's t test with restric- tions for the variance. All individuals studied, including voucher specimens, were deposited 43 44 THE JOURNAL OF ARACHNOLOGY in the Arachnological collection of the Facul- tad de Ciencias, Montevideo, Uruguay. RESULTS Shape, size and density. — Cuspules are placed in groups on the anterior median zone of the labium and on the inner ventral corner of the maxillae (Figs. 1-7). They are implant- ed approximately perpendicular with respect to body surface (venter of labium and maxil- lae). Labial and maxillary cuspules are similar (Figs. 8-11), globular-conical, short or more elongated, thick and reddish brown. Some cuspules showed a slight constriction in the middle of their length. Two faces could be recognized: anterior (oral, Fig. 8) and poste- rior (Fig. 9). Cuspules are inserted in circular sockets where the anterior edge is higher than the posterior edge (Fig. 9). General shape shows a similar pattern in most species with only slight differences (Figs. 8-23). No pores were found on the cuspule surface on any of the species studied. Cuspule size ranged from 39.6-1 07. 8p.m Table 1. A significant correla- tion between cuspule maximum diameter and body size was found in the labium (r = 0.89; P < 0.05) and also in the maxillae (r = 0.97; P < 0.05). We did not find significant corre- lation between body size and the number of labial and maxillary cuspules (r =-0.60, P = 0.48; r =—0.32, P = 0.48, respectively). Intra-specific variation in cuspule width was less than 10% in A. suina (mean 46.01 ± 3.46 SD, n — 1) and in E. weijenberghi (mean 50.7 ± 3.22 SD, n = 5) and no significant differences were found between sexes in these species (t = 1.017, P > 0.30; t = 0.246, P > 0.80, respectively). We found significant dif- ferences in cuspule width between these spe- cies (t = 3.52, P < 0.01). Cuspule ornamentation. — The surface of the labial cuspules is completely covered by ridges. The general pattern of ridges resem- bles the shape of a finger print in most spe- cies. Ornamentation of the anterior face dif- fers from the posterior face. The disposition of ridges also differs in different zones of each face, comparing basal, median and apical zones. The general morphology and ornamen- tation of the cuspule is similar in all species studied, with the exception of dimensions. Slight variations among cuspule morphology and ornamentation in the same individual are similar to intra-specific and interspecific var- iations in the species studied. In a general pattern, the anterior face (Figs. 8, 10, 12, 14, 16, 18, 22) has parallel longi- tudinal ridges on the basal half and parallel transverse ridges on the apical half (which are continued by the circular ridges in the poste- rior face). In this face the longitudinal ridges are fused to the transversal ridges in several points of contact. The posterior face of the cuspules show longitudinal and diagonal ridg- es in the basal half; the central zone shows small loose ridges that resemble a whirl or more or less parallel ridges (Figs. 9, 11, 13, 15, 17, 19, 20, 21, 23). The periphery of the apical zone has circular to oval concentric par- allel ridges. The intra-specific study shown that in A. suina, the interdistances between two ridges were approximately 1.2 pm in la- bial cuspules and 1.7 pm ± 0.29 SD in max- illary cuspules. No significant differences were found in the interdistances between sex- es (t = 1.76, P > 0.10). Eupalaestrus weijen- herghi has both faces of cuspules similar to A. suina. The interdistances between two ridg- es were 1.2 pm in labial cuspules and 1.6 pm ± 0.27 SD in maxillary cuspules. No signifi- cant differences were found in the interdis- tances between sexes (t = 1.07, P > 0.30). When we compared the interdistances of ridg- es between A. suina and E. weijenberghi, no significant differences were found (t = 0.30, P > 0.70). Interdistances between two ridges (in labial and maxillary cuspules respectively) in the other species studied were as follows: in G. iheringhi 2.4 pm and 1.8 pm; in G. mollicoma 2.3 pm and 2.5 pm; in H. uruguayense 1.3 pm and 1.5 pm; in P. longisternale 1 pm and 1.3 pm; in /. hirsutum 1.6 pm and 1 pm. Oli~ goxystre argentinense lacks labial cuspules, on coxal cuspules the interdistance between two ridges was 1.2 pm. DISCUSSION Raven (1994) found that maxillary cuspule size is independent on adult size in Barychel- idae. He found several discrete cuspule sizes related to the number of cuspules (in species with numerous cuspules, cuspules are small). In contrast, in the theraphosids studied, we found significant correlations between both maxillary and labial cuspule size with spider PEREZ-MILES & MONTES DE OCA— CUSPULES OF THERAPHOSIDAE 45 Figures 1-7. — Oral region of the species studied showing position of maxillary and labial cuspules. 1. Acanthoscurria suina. 2. Eupalaestrus weijenberghi. 3. Grammostola mollicoma. 4. Homoeomma uru- guayense. 5. Plesiopelma longisternale. 6. Iridopelma hirsutum. 7. Oligoxystre argentinense. (Scale = 0.5 mm). 46 THE JOURNAL OF ARACHNOLOGY Figures 8-11. — Cuspules of Acanthoscurria suina male. 8, 9. Maxillary cuspules. 8. Anterior view. 9. Posterior view. 10, 11. Labial cuspules. 10. Anterior view. 11. Posterior view. Figures 12-13.^ — Maxillary cuspule of Eupalaestrus weijenberghi. 12. Anterior view. 13. Posterior view. Figures 14-15. — Labial cuspule of Grammostola iheringi. 14. Anterior view. 15. Posterior ventral view. PEREZ-MILES & MONTES DE OCA— CUSPULES OF THERAPHOSIDAE 47 Figures 16-17. — Maxillary cuspule of Grammostola mollicoma. 16. Anterior view. 17. Posterior view. Figures 18-19. — Labial cuspule of Plesiopelma longisternale. 18. Anterior view. 19. Posterior view. Figure 20. — Labial cuspule of Homoeomma uruguayense, posterior view. Figure 21. — Maxillary cuspule of Oligoxystre argentinense, posterior view. Figures 22-23. — Labial cuspule of Iridopelma hirsutum. 22. Anterior view. 23. Posterior view. 48 THE JOURNAL OF ARACHNOLOGY Table 1. — Sizes (single cuspules) and density of cuspules in eight species of theraphosid spiders. Width (pm) Density of cuspules Density of ridges (number/ 10pm) Length (fxm) Maxil- (number/mm^) Maxil- Taxa Labial Maxillary Labial lary Labial Maxillary Labial lary Theraphosinae Acanthoscurria suina 58.3 61.3 40.8 38.7 3.0 ± 1.5 4.0 ± 4.2 9 7 Eupalaestrus weijenberghi 71.2 74.3 41.5 39.3 3.8 ± 1.8 6.3 ± 3.9 7-9 10 Grammostola iheringi 98.5 107.8 70.2 69.8 4.5 ± 1.3 4.5 ± 1.1 6 6 Grammostola mollicoma 74.1 72.5 46.2 50.0 2.2 ± 0.9 2.7 ± 1.6 5 5 Homoeomma uruguayense 43.0 40.9 31.1 28.5 7.0 ± 4.3 6.0 ± 4.2 9 10 Plesiopelma longisternale 53.8 71.3 29.1 38.0 10.7 ± 3.0 7.7 ± 7.0 11 8 Aviculariinae Iridopelma hirsutum 53.7 69.7 36.8 33.9 4.5 ± 2.3 4.9 ± 3.2 7 13 Ischnocolinae Oligoxystre argentinense 39.6 27.8 4.8 ± 1.7 10 size. No significant correlation was found be- tween cuspule number and cuspule size. Two models of ornamentation were de- scribed in the maxillary cuspules of the Mi- crostigmatidae (Griswold 1985): one present- ing deep grooves and the other with many hne shallow grooves, the former considered as synapomorphic of clade “c” of Griswold (1985). Raven (1994) suggested the study of cuspule ridge interdistances (0.5-1 |xm or 3-5 |jim) to distinguish between two patterns in Nemesiidae. The interdistances of cuspule ridges found in the theraphosid species stud- ied have intermediate values (0.9-2. 5 pm) be- tween Raven’s groups and their aspect fits with Griswold’s (1985) second model (“many fine shallow groves”). The differences in ornamentation found be- tween the anterior and the posterior faces of the cuspules is here reported for the first time in Theraphosidae. However, these differences in ornamentation are probably also present in Microstigmatidae and Barychelidae consider- ing the figures given by Griswold (1985:6, figs. 17-18) and Raven (1994:303-310, figs. 3-10) respectively. A unique cuspule descrip- tion from a theraphosid species was done by Cutler & Vuilliomenet (2001) in Aphonopel- ma seemani. In our opinion this description corresponds to the posterior face. No strong differences were found in cus- pule morphology or ornamentation among the genera and species studied. This, together with the similarity in other families, could re- flect that cuspules are an early synapomorphy at the level of the Mygalomorphae as was in- dicated by Raven (1980) and could be inter- preted as a conserved feature through the evo- lution of several mygalomorph taxa. We therefore suggest these structures have limited systematic value. The probable functions of the cuspules in theraphosids could be mechanical, sensorial and glandular. Cutler & Vuilliomenet (2001) suggest a glandular or sensory function for the cuspules of A. seemani on the basis of a pore observed on the apical region of the cuspules, that could be interpreted as a sensory pit or secretory gland. We did not observe any pore on labial nor maxillary cuspules. Considering the oral inclination of the cuspules, their or- namentation and their unique presence in my- PEREZ-MILES & MONTES DE OCA— CUSPULES OF THERAPHOSIDAE 49 galomorphs with paraxial chelicerae, a me- chanical function seems probable. Cuspules could help in prey retention by opposing the backward force of the chelicerae. The orna- mentation of the apical half of the anterior face with transverse ridges could be related to particle retention near the mouth. ACKNOWLEDGMENTS We thank Dr. Charles Griswold for the crit- ical reading and valuable comments on the manuscript. We also thank Jorge Troccoli and Alejandro Marquez for the operation of the SEM. LITERATURE CITED Cutler, B. & E Vuilliomenet. 2001. Surface ultra- structure of Aphonopelma seemanni cuspules (Araenae: Theraphosidae). American Arachnol- ogy 62:4. Goloboff, P.A. 1993. A reanalysis of Mygalomorph spider families (Araneae), American Museum Novitates 3056:1-32. Griswold, C.E. 1985. A revision of the African spi- ders of the family Microstigmatidae (Araneae: Mygalomorphae). Annals of the Natal Museum 27(1): 1-37. Griswold, C., & J. Ledford. 2001. A monograph of the migid trap-door spiders of Madagascar with a phylogeny of world genera (Araneae, Myga- lomorphae, Migidae). Occasional Papers of the California Academy of Sciences 151:1-120. Perez-Miles, F. 1992. Analisis cladistico preliminar de la sub familia Theraphosinae (Araneae, Ther- aphosidae). Boletm de la Sociedad Zoologica del Uruguay 7:1 1-12. Perez-Miles, F. 2000. Iracema cabocla new genus and species of a theraphosid spider from Ama- zonic Brazil (Araneae, Theraphosinae). Journal of Arachnology 28:141-148. Perez-Miles, E, S.M. Lucas, P.I. da Silva & R. Ber- tani. 1996. Systematic revision and cladistic analysis of Theraphosinae (Araneae: Theraphos- idae). Mygalomorph 1:33-68. Raven, R.J. 1978. Systematics of the spider subfam- ily Hexathelinae (Dipluridae: Mygalomorphae: Arachnida). Australian Journal of Zoology, sup- plementary series 65:1-75. Raven, R.J. 1980. The evolution and biogeography of the mygalomorph spider family Hexathelidae (Araneae, Chelicerata). Journal of Arachnology 8:251-266. Raven, R.J. 1985. The spider infraorder Mygalo- morphae (Araneae): Cladistics and Systematics. Bulletin of the American Museum of Natural History 182:1-180. Raven, R.J. 1994. Mygalomrph spiders of the Bar- ychelidae in Australia and the western Pacific. Memoirs of the Queensland Museum 35(2):291- 706. Snazell, R. & R. Allison. 1989. The genus Macroth- ele Ausserer (Araneae, Hexathelidae) in Europe. Bulletin of the British Arachnological Society 8(3):65-72. Manuscript received 3 June 2002, revised 10 Oc- tober 2003. 2005. The Journal of Arachnology 33:50-62 NATURAL HISTORY AND KARYOTYPE OF SOME ANT-EATING ZODARIID SPIDERS (ARANEAE, ZODARIIDAE) FROM ISRAEL Stano Pekar: Department of Zoology and Ecology, Faculty of Sciences, Masaryk University, Kotlafska 2, 611 37 Brno, Czech Republic and Research Institute of Crop Production, Drnovska 507, 161 06 Praha 6 — Ruzyne, Czech Republic Jin Krai: Laboratory of Arachnid Cytogenetics, Department of Genetics and Microbiology, Faculty of Sciences, Charles University, Vinicna 5, 128 44 Praha 2, Czech Republic Yael Lubin: Mitrani Department of Desert Ecology, Blaustein Institute for Desert Research, Ben Gurion University, 84990 Sede Boqer Campus, Israel ABSTRACT. Natural history, including phenology, circadian activity, mimicry, reproduction, prey spe- cialization and karyotype was studied in the zodariid spiders Trygettus sexoculatus, Zodarion cyrenaicum, Z lutipes and Z. nitidum (Zodariidae, Zodariinae) found in Israel. The spiders were active throughout the year, with maximum seasonal activity in the summer. Two distinct reproductive periods were found for Z. cyrenaicum and Z. nitidum, one in May and the other in November. Individuals of all species studied were observed hunting only in the morning. Three zodariid species were found to generally mimic ants: Trygettus sexoculatus mimicked tiny yellow-brown ants such as Monomoriiim niloticum, Z. cyrenaicum mimicked large black ants such as Messor arenarius, and Z. lutipes mimicked large yellow-brown ants such as Camponotus fellah. The zodariids observed were able to subdue various ant species, from the subfamilies Formicinae, Myrmicinae and Dolichoderinae. Trygettus sexoculatus appeared to specialize on Monomorium sp., Z. lutipes on Camponotus sp. and Z. cyrenaicum on Messor sp. ants, i.e., the same ant species they imitate. When bitten by zodariids, Formicinae and Dolichoderinae ants were paralyzed much more quickly than Myrmicinae. Female zodariid paralyzed ants faster than juveniles and males. Courtship and mating were observed only in Z. lutipes and were found to be similar to other Zodarion species. The mean fecundity for all three Zodarion species ranged from 38-45 eggs per egg sac, thus being higher than reported in central European species. Females of all three species guarded egg sacs inside of their retreats. Karyotypes of studied Zodarion spiders were similar to the karyotypes of other zodariid spiders in terms of the diploid number (26 in Z. cyrenaicum and 25 in both Z. lutipes and Z. nitidum), sex chromosome systems and morphology of chromosomes. Most of the data indicate that the Zodarion species of this study have a close affinity to a group of Western European Zodarion species. Keywords; Myrmecophagy, specialization, mimicry, Formicidae, chromosomes The family Zodariidae is a species rich group of spiders, which includes more than 570 species in six subfamilies with worldwide distribution, but is most abundant in the sub- tropical region (Platnick 2002). Zodariid spi- ders were neglected on a worldwide scale un- til recently, when Jocque (1991) produced a generic revision. Very little information is re- ported on the natural history of zodariid spi- ders (e.g. Wiehle 1928; Harkness 1976; Cush- ing & Santangelo 2002). In the Mediterranean region, representatives of two subfamilies and more than 110 species have been found. The majority of species be- long to the most advanced subfamily, Zoda- riinae. The diversity of this subfamily seems to decline from west to east in the Mediter- ranean region. In the western and the central area, three genera and about 60 species of Zo- dariinae were found and in the eastern part five genera with only about 30 species. This may be explained, in part, by the lack of col- lecting in the eastern region. In fact, in the eastern Mediterranean only the zodariid spi- ders of Israel have been revised so far. Alto- gether 13 species of the genera Palaestina, 50 PEKAR ET AL.— NATURAL HISTORY OF ZODARIIDS FROM ISRAEL 51 Ranops, Trygettus and Zodarion were report- ed from Israel (Levy 1992). In spite of the lower number of species in the eastern Mediterranean, the zodariid fauna of Israel shows a remarkable diversity perhaps due to the fact that Israel is situated where two biogeographic regions, the Palearctic and the Ethiopian, meet. However, little is known of the natural history of these zodariid spiders. The purpose of this study was to gather data on the natural history and karyotypes of the four most abundant species, Trygettus sexo- culatus (O.P.-Cambridge 1872), Zodarion cy- renaicum Denis 1935, Zodarion lutipes (O.P.- Cambridge 1872), and Zodarion nitidum (Audouin 1826) and to compare them to the European Zodarion species that have been studied (Couvreur 1990a; Pekar & Krai 2001). This study contributes to the understanding of the adaptive radiation within Zodariinae and particularly within the genus Zodarion. Mem- bers of the subfamily Zodariinae are remark- able for their diet specialization on some so- cial insects (ants and termites) and for the frequent occurrence of ant mimicry. Infor- mation on phenology, diet specialization and mimicry as well as the number and morphol- ogy of their chromosomes was compared with similar data reported for the European species (Pekar & Krai 2001). Trygettus sexoculatus, Z. cyrenaicum, and Z. nitidum are found in Israel and in North Africa; Z. lutipes occurs in Crete and north of Israel, in Lebanon and Turkey (Levy 1992). In Israel, T. sexoculatus occurs in the central and southern arid region. Zodarion nitidum, a des- ert spider, occurs mainly in the Negev desert. Zodarion lutipes was found only as far south as the north-western part of the Negev desert (desert edge). Zodarion cyrenaicum occurs in the northern part of the Negev desert. It is occasionally sympatric with Z. nitidum in the desert, while in the northern Negev it occurs syntopically with Z. lutipes (Fig. 1). METHODS Study areas. — Numerous specimens of Z. cyrenaicum and Z. lutipes were collected in the weedy margin of a melon field at the Bi- tronot-Be’eri Nature Reserve (about 40 km NW of Be’er Sheva, 31°26'N, 34°29'E). These two species, together with T. sexoculatus, were collected and observed also on an open slope of a semi-desert steppe character close Figure 1. — The distribution of Zodarion species in Israel reported in this study. Sites mentioned in the text are indicated: 1. Be’eri Nature Reserve, 2. Fura Nature Reserve, 3. Lehavim, 4. Sede Boqer. to Lehavim, at the northern edge of the Negev desert (about 10 km NE of Be’er Sheva, 31°22'N, 34°48'E). Zodarion lutipes was also found in Fura Reserve in semi-desert grass- land habitat (about 20 km N of Be’er Sheva, 31°27'N, 34°45'E). Zodarion nitidum was very abundant in a large-scale spider diversity project of the Negev desert that began in the early 1990’s (Pekar & Lubin 2003). However, in March & April 2001 a three- week intensive search for these spiders in the surroundings of Sede Boqer (Haluqim Ridge, 30°51'N 52 THE JOURNAL OF ARACHNOLOGY 34°45'E) yielded only five specimens. Boeken et al. (2001) noted that a severe drought in 1999 followed by drought in 2000 caused a dramatic decline of plant density in the Negev. It is likely that these droughts considerably reduced the population density of Zodarion species. Material and analyses. — ^Data used to ex- trapolate the seasonal activity and phenology of zodariids came from the large-scale project on the diversity of spiders of the Negev desert (Proszynski & Lubin 1994; Pekar & Lubin 2003). Spiders were sampled at 45 sites in the Negev between September 1990 and July 1993. The spiders were collected using pitfall traps that were opened for 3 consecutive days each month. No preservative was used in the traps (diameter and depth 10 cm) and the spi- ders were collected each morning. Immature Zodarion individuals were identified to spe- cies based on the color. Circadian activity of spiders was observed in 2001 as the number of spiders found during 5 min in the vicinity of ant nests or along ant trails (in the case of Messor ants). As the sites in the northern Negev were not easily acces- sible, the activity of spiders was observed only during the day, between 0900 and 1900. At Sede Boqer, the activity of ants was ob- served for 24 hours on one day in the begin- ning of April. On that day the sunrise was at 0530 and the sunset at 1800. Activity of four ant species (the most frequent in the study sites), namely Camponotus fellah Dalla Torre 1893, Cataglyphis albicans (Roger 1859), Messor arenarius (Fabricius 1787) and Mon- omorium niloticum Emery 1881, was estimat- ed every hour as the number of ants counted per 15 s at four nest entrances. The behavior of the different species was investigated in the laboratory. Twenty-seven individuals of Z. cyrenaicum, 21 of Z. lutipes, 10 of Z. nitidum and four of T. sexoculatus were brought to the laboratory. Spiders were kept singly in glass tubes (60 x 15 mm) in a constant temperature 25 ± 2 °C and L:D = 14:10 and were fed twice a week with various ant species. To observe courtship and mating, adult males were introduced into tubes occu- pied by females. After mating the males were separated from the females. The number of egg sacs produced and the fecundity (total number of eggs) were recorded. In the feeding experiments spiders were put singly to a Petri dish (diameter 40 mm, with a filter paper attached to the bottom) a day before the experiment started. Ten individuals of each Zodarion species and four specimens of Trygettus were used. Four ant species, namely C. albicans (Formicinae), M. arenar- ius, M. niloticum (Myrmicinae) and Tapinoma simrothi Krausse 1911 (Dolichoderinae), were offered to each individual of Zodarion spe- cies. Three ant species, Pheidole pallidula Nylander 1849, M. niloticum (Myrmicinae) and T. simrothi (Dolichoderinae), were of- fered to T. sexoculatus. The ants were offered to spiders randomly over a 4 day interval. All ants were weighed before the experiment, Ca- taglyphis and Messor ants were disabled by removing the distal parts of mandibles before the experiments. Other ant species were not disabled. An ant was released into a dish oc- cupied by a spider; if the spider did not attack the ant within 15 min the experiment was ter- minated. Latency to the first attack, number of attacks and the paralysis latency (time to par- alyze the ant) were observed for each trial. The latency to the first attack was estimated as the time from the first encounter between spider and ant to the first attack. The paralysis latency was estimated as the time between the first attack and complete immobilization, i.e. when an ant could not raise itself after being touched with forceps. Data were analyzed using Generalized Lin- ear Models (GLM) in Statistica (StatSoft 2001). The body mass of an ant was expected to have an effect on the number of attacks and on paralysis latency, therefore ant mass was first regressed (using linear regression) on these dependent variables. However, ant mass had no effect on the number of attacks and therefore could be ignored in the analyses. As the data followed a Poisson error structure, a log-linear analysis was used with three factors (see below). Over-dispersion was resolved by adjusting the scale parameter. The same meth- od was used to analyze data on the latency to the first attack. The paralysis latency was af- fected by ant body mass, which was set as a covariate. The paralysis latency data were log transformed and further analyzed using AN- COVA. In all analyses the factors were (1) Zodarion species (Z. cyrenaicum, Z. lutipes, and Z nitidum), (2) developmental stage or sex of spider (female, male, and juvenile) and (3) ant subfamily (Dolichoderinae, Formicinae PEKAR ET AL.— NATURAL HISTORY OF ZODARIIDS FROM ISRAEL 53 and Myrmicinae). Post=hoc comparisons were made using Tukey’s HSD test. For the karyological analyses three individ- uals of Z, cyrenaicum (locality Bitroeot- Be’eri), five individuals of Z. lutipes (Lehav- im), and 12 individuals (reared from two egg sacs) of Z nitidum (Hatira), representing both sexes and various developmental stages, were used. However, only the testes of subadult males (two in Z cyrenaicum, three both in Z. lutipes and Z nitidum) gave ieterpretable chromosomal figures. The chromosome prep- arations were obtained by a modification of the spreading technique used by Traut (1976). The gonads were dissected from the abdomen in a hypotonic solution (0.075M KCl) and moved to fresh hypotonic solution so that the tissue was hypotonized for 10 min in total. This was followed by 10 min fixation in fresh- ly prepared Carnoy fixative (ethanol: chloro- form: glacial acetic acid 6:3:1) and 25 min fixation in a new Carnoy fixative. Afterwards, the tissue was placed in a drop of 60% acetic acid on a clean slide and quickly shredded as finely as possible with a pair of fine tungsten needles. The slide was quickly moved onto a warm histological plate (surface temperature of 40 °C) and the drop of dispersed tissue was allowed to evaporate while moving it con- stantly using a fine tungsten needle. Slides were air-dried at room temperature overnight and stained with 5% Giemsa solution in So- rensen phosphate buffer (pH = 6.8) for 25- 30 min (Cokendolpher & Brown 1985). Zodariid spiders were identified using Levy (1992) and ants were determined using an un- published key of Kugler (1984). Voucher specimens of spiders and ants are deposited at the Department of Entomology of the Re- search Institute of Crop Production, Prague, the Czech Republic. RESULTS Phenology.— Pitfall-trap sampling at regu- lar intervals allowed us to outline the seasonal activity and phenology of Z cyrenaicum and Z nitidum. Data for Z lutipes and T. sexo- culatus were insufficient to determine any pat- tern. Zodarion cyrenaicum and Z nitidum were active during the whole year (Fig. 2). The maximum seasonal activity (between 27- 44 % of the total annual activity) of both spe- cies was in the summer months, June (Z ni- tidum) and July (Z cyrenaicum). There was Figures 2-4. — Phenology of zodariid spiders col- lected in pitfall traps: data from three years (1991- 3) combined. 2. Seasonal activity of Z. cyrenaicum and Z. nitidum, expressed as a monthly proportion. Total number of individuals: Z. cyrenaicum = 146, Z. nitidum = 2403. 3. Phenology of Z. cyrenaicum and Z. nitidum expressed as the proportion of adult spiders per month. 4. Monthly proportions of males (empty bars) and females (gray bars) of Z. nitidum with a polynomial curve. minimal or no activity in the winter months, December (Z nitidum) and January (Z cyren- aicum). Adults of Z nitidum were found throughout the year (Fig. 3), while no individ- uals of Z. cyrenaicum were trapped during the winter months. Both species had two repro- ductive peaks annually: spiders matured in spring (March) and autumn (November) and reproduced soon after. The proportion of males to females of Z nitidum changed during 54 THE JOURNAL OF ARACHNOLOGY s e m 'S E 3 hour Figures 5-8. — Daily activity of ants expressed as number of ants recorded in 15 s: 5. Messor arenarius; 6. Monomorium niloticum.; 1. Cataglyphis albicans; 8. Camponotus fellah. Bars represent mean + SE. the year (Fig. 4). Whereas males dominated in spring (peak in March), females dominated in autumn (peak in September). In total the M/F ratio of individuals collected in pitfall traps was significantly skewed toward males 1/0.83 (binomial test, P = 0.002). Kctiwity .—Zodarion spiders were collected from igloo-shaped retreats underneath stones where they rest during the day. The retreats were made of sand pebbles or pieces of gas- tropod shells and were proportional to the size of the spider. In females the retreats were up to 2 cm in diameter. Individuals of T. sexo- culatus were found under stones but never in a retreat. Trygettus sexoculatus, Z. cyrenaicum and Z. lutipes were active only in the morning, from 0900-1 100, running among ants or hunt- ing them. No Z. nitidum was observed at all during March-April 2001. In 2002, however, Z nitidum was seen active in the morning hours (males and females) in the vicinity of nests of M. arenarius in sandy habitats. Ac- tivity of the four most abundant ant species, which are the prey of observed zodariid spi- ders, followed different patterns. Messor ants were active in the day as well as at night (Fig. 5), with a decline in activity between 0900 and 1400. Monomorium ants were active only during the day, from 0500-2000, with a de- cline at midday (Fig. 6). Cataglyphis ants were also active during the day only, from 0400-1800, with a slight decline between 1300 and 1400 (Fig. 7). Camponotus ants were active only from the afternoon (1600) and through the night until morning (0700; Fig, 8). The activity of ant species and of the spiders overlaps broadly. Batesian mimicry* — Tentative ant models were found for three spider species. Trygettus sexoculatus imitates tiny yellowish-brown ants, especially Monomorium niloticum. Adult spiders are 2-2.5 mm in length, with yellow- ish prosoma and legs and the opisthosoma is dorsally dark brown with a glossy scutum (Fig. 9). Workers of M. niloticum are 3-3.5 mm in length with head, thorax, antennae and legs yellow to orange and the gaster dark brown. Adult spiders of Z. cyrenaicum mimic larger black ants, e.g. the small workers of Messor arenarius. The spiders are 3.5-8 mm in length with uniform blackish prosoma and opisthosoma. The legs are black, except for the coxae and patellae, which are pale (Fig, 10). Workers of M. arenarius are polymor- PEKAR ET AL.— NATURAL HISTORY OF ZODARIIDS FROM ISRAEL 55 Figures 9-11. — Spider mimics and their ant models. 9. Trygettus sexoculatus (female) and Mon- omorium niloticum; 10. Zodarion cyrenaicum (fe- male) and Messor arenarius; 11. Zodarion lutipes (male) and Camponotus fellah (freshly hatched in- dividual with light gaster). Scale lines = 2 mm. phic, 4-15 mm and are uniformly black. Adult individuals of Z lutipes resemble larger yel- lowish-brown ants, notably small workers of Camponotus fellah. The spiders are 3. 5-6. 5 mm in length, the prosoma is yellow with a brown cephalic part and the opisthosoma is dark brown (Fig. 11). All leg segments are yellow except for the first and second femora, which are brown. The model ants are 6-17 mm, with head and gaster dark brown while the thorax, antennae and legs are yellow to light brown. Individuals of Z. nitidum were observed with M. arenarius ants, which they do not appear to mimic closely. Prey, — A few individuals were observed feeding on ants in the field. Four individuals of Z cyrenaicum were observed feeding on M. arenarius, two individuals of Z lutipes fed on Messor semirufus (Andre 1883) or C. fel- lah and three individuals of T. sexoculatus fed on M. niloticum. Feeding of Z nitidum was not observed in the field. In laboratory exper- iments all Zodarion species were able to sub- due larger ants of the genera Cataglyphis and Messor. Tiny ants were often ignored: only 24% (n = 30) of all Zodarion individuals at- tacked M. niloticum ants and 75% of Z cy- renaicum and Z. lutipes {n — 20) attacked T. simrothi ants while no Z nitidum attacked this ant. All T. sexoculatus (n = 4) attacked M. niloticum and P. pallidula but failed to catch T. simrothi. Trygettus sexoculatus always at- tacked ants only once while Zodarion spiders averaged two attacks per ant. There was no difference in the number of attacks on ants from different subfamilies, nor was there a difference between the Zodarion species. The latency to the first attack was significantly dif- ferent for the three Zodarion species (GLM, P — 0.002). Zodarion cyrenaicum took almost four times longer to attack (119 s, SE = 46) than the other two species (30 s, SE — 5.1). There was also a difference between sexes and developmental stages (GLM, P — 0.0001). Males took about five times longer to attack (150 s, SE — 46) than females and juveniles (31.5 s, SE = 5.2). In T. sexoculatus the la- tency was on average 20 s (SE = 14.2). Myr- micinae ants attacked by T. sexoculatus were paralyzed on average after 3.1 min (SE = 0.34, n = 6) (Table 1). In Zodarion spiders the paralysis latency differed for developmen- tal stages and species (Fig. 12). It was longest in males and shortest in females (GLM, P = 0.003). There was also a significant difference in paralysis latency between ant subfamilies (GLM, P < 0.0001). Myrmicinae ants were paralyzed on average after 64 min while For- micinae and Dolichoderinae after 17-19 min (Table 1). The three Zodarion species did not differ significantly in the paralysis latency for Myrmicinae. However, Z lutipes paralyzed 56 THE JOURNAL OF ARACHNOLOGY Table 1. — Comparison of the number of attacks and the paralysis latency (min) on three ant subfamilies for three zodariid spiders. Zodarion nitidum did not attack dolichoderine ants, presumably because the spiders were large in comparison with the ants. Trygettus sexoculatus was not tested with formicine ants because the ants were too large for this species. All numbers are means ± SE. Spider Ant subfamily No. of attacks Paralysis latency T. sexoculatus Myrmicinae 1.0 ± 0.0 3.6 ± 0.13 Dolichoderinae 0 — Z. cyrenaicum Formicinae 1.9 ± 0.4 26.7 ±11.7 Myrmicinae 2.2 ± 0.4 56.5 ± 11.1 Dolichoderinae 2.1 ± 0.3 28.1 ± 15.3 Z. lutipes Formicinae 2.2 ± 0.4 6.7 ± 1.4 Myrmicinae 1.8 ± 0.2 71.2 ± 15.8 Dolichoderinae 2.0 ± 0.7 3.5 ± 1.1 Z. nitidum Formicinae 3.0 ± 0.6 19.0 ± 5.6 Myrmicinae 2.4 ± 0.5 65.6 ±11.7 2.0 1.8 1.6 TO 1.4 0 Q 1 1.2 'i E 1.0 0.8 0.6 0.4 Figure 12. — Comparison of the mean (±SE) paralysis latency (min) for different Zodarion sexes and developmental stages (pooled for the three Zodarion species) and two ant subfamilies (Formicinae were pooled with Dolichoderinae). Formicinae+Dolichoderinae Myrmicinae PEKAR ET AL.— NATURAL HISTORY OF ZODARIIDS FROM ISRAEL 57 Formicinae ants in a significantly shorter time than Z. nitidum and Z. cyrenaicum (Tukey HSD, P = 0.0002). Enemies. — Of 73 collected specimens, only one subadult male of Z. cyrenaicum, col- lected from an igloo-shaped retreat in Lehav- im, was found to have a larva of Polysphincta sp. (Hymenoptera, Ichneumonidae) attached to the anteriodorsal region of its abdomen. No other Zodarion spider in this study was found with a parasitoid wasp larvae and no other enemies were observed attacking Zodarion. Reproduction. — Courtship was similar in all three Zodarion spiders. Males began to court after a brief contact with the female. The male slowly approached the female from the front with rapidly quivering forelegs, and touched her lightly. If the female was recep- tive she first responded by similar quivering of forelegs, then crouched and allowed the male to climb onto her and copulate. Copu- lation was observed only in Z. lutipes, lasting on average 1.58 min (SE = 0.5, n = 5). Males copulated from both sides inserting the appro- priate palp, and interrupted several times. Af- ter each interruption males quivered the fore- legs, otherwise the female would respond aggressively. In the other two Zodarion spe- cies only several attempted copulations (un- successful insertion of palpal organs) were ob- served, each lasting less than 10 s. Females of Z. cyrenaicum and Z. lutipes produced only one egg sac while females of Z. nitidum pro- duced 1-3 egg sacs in captivity. Females of all species guarded the egg sac inside the re- treat. A new egg sac was produced only after the previous one hatched. Mean fecundity in Z cyrenaicum was 45 eggs/sac (SE = 7.5, n = 5), 39 eggs/sac (SE - 17.9, n - 3) in Z lutipes and 38 eggs/sac (SE ^ 4.3, n = 11) in Z. nitidum. Spiderlings (pooled for all three Zodarion species, as there was no difference between species (ANOVA, P = 0.22)) hatched on average after 36.3 days (SE = 4.8, n = 8). No information on reproduction was obtained for T. sexoculatus. Karyotype. — Both mitotic and meiotic phases were obtained from the testes of sub- adult males. The diploid chromosome num- bers were as follows: Z cyrenaicum 26 (Figs. 13, 15), Z. lutipes 25 (Figs. 16, 18), and Z. nitidum 25 (Figs. 19, 21). No individuals of T. sexoculatus were collected for karyological analysis. Karyotypes of all studied species were formed by acrocentric chromosomes ex- clusively. Chromosome pairs decrease gradu- ally in size except for two shortest pairs in Z lutipes (Fig. 18). Sex chromosome(s) of all species are among the longest chromosomes in the karyotype. Observation of sex chro- mosomes during meiotic division indicated an X1X2O sex chromosome system in Z. cyren- aicum. Sex chromosomes Xj and X2 were sim- ilar in size, the X2 being somewhat shorter than Xj (Fig. 14). Zodarion lutipes and Z ni- tidum have an XO sex chromosome system (Figs. 17, 20). The X chromosome of Z luti- pes and Z nitidum exhibits positive hetero- pycnosis (greater condensation than auto- somes) during the first meiotic division and interkinesis as well as in prophase IT Hetero- pycnosis of sex chromosomes in Z cyrenai- cum continues only to diplotene. However, weak heteropycnosis reappears also during in- terkinesis and prophase IT Sex chromo- some(s) in males of all species lie on the pe- riphery of meiotic figures until metaphase 11. DISCUSSION Aspects of the biology of five species of the genus Zodarion have been reported (Couvreur 1990b; Harkness 1977; Pekar & Krai 2001; Schneider 1971; Wiehle 1928), but only two central European species, Z germanicum (C.L, Koch 1837) and Z rubidum Simon 1914, have been studied in detail (Couvreur 1990b; Pekar & Krai 2001). The latter authors found that these two species differ consider- ably from each other in their circadian activ- ity, reproduction and karyotype. The seasonal activity of the three Zodarion species studied here is similar to the central European species with greater activity in sum- mer. Central European zodariid spiders are ac- tive from April to October. In the winter, be- tween November and March, European species are inactive, obviously overwintering (Pekar & Krai 2001) while the species studied in Israel have low activity levels throughout winter. Central European species are univol- tine and stenochronous with one maturation period in June. Spiderlings hatch in July and reach adulthood the following year, 10-11 months after hatching (Couvreur 1990a; Pekar & Krai 2001). Data on two species, Z. cyren- aicum and Z. nitidum, show that Israeli spe- cies are bivoltiee and eurychronous, with two major maturation periods, one in spring and 58 THE JOURNAL OF ARACHNOLOGY «\-nk ^ 21 AA '' A '*>* X Figures 13-21. — Karyotype of Zodarion males. 13-15. Zodarion cyrenaicum. 13. Mitotic metaphase. 14. Diplotene. 15. Karyogram. 16-18. Zodarion lutipes. 16. Mitotic metaphase. 17. Diplotene. 18. Karyo- gram. 19-21. Zodarion nitidum. 19. Metaphase of the second meiotic division. Arrow identifies X chro- mosome that differs from autosomes by closely aligned chromatids. 20. Diplotene. 21. Karyogram. Karyo- PEKAR ET AL.— NATURAL HISTORY OE ZODARIIDS EROM ISRAEL 59 the other in autumn. Data collected by Levy (1992) and data from this study suggest that T. sexoculatus and Z lutipes have a similar phenological pattern. The tendency to multi- voltinism is known also for other Mediterra- nean arthropods (so called “Mediterranean biotype”). For example, Bodenheimer (1943) found that populations of Coccinella septem- punctata L. (Coleoptera) in Israel are bivoltine with one complete and one partial generation in spring and in autumn. Observations on the desert widow spider, Latrodectus revivensis Shulov 1948 (Theridiidae), indicate that this species has two peaks of maturation in Israel; a major one in spring and a minor one in au- tumn (Lubin et al. 1991). Zodarion species in Israel follow a similar pattern. It is not known how long it takes to complete one generation. Provided the development takes about six months there should be two non-overlapping generations in one year. If the development is about 10 months then there are two overlap- ping generations. For the spring generation it may be possible to mature in 6 months, i.e. by the end of summer, because ants are abun- dant and the temperature, controlling the rate of development, is sufficient. The autumn generation, however, might not be able to reach maturity by May as the temperature is rather low and ants are less active in winter. Thus it is assumed that the autumn generation is only partial, resulting in the eurychronous character of phenology. Observations suggest that the zodariid spi- ders studied are mainly nocturnal (foraging in the morning and in the evening) like other Mediterranean species that have been studied. Zodarion frenatum Simon 1884 was found to have nocturnal activity, hunting ants mainly at dawn and dusk and searching for mates in the night (Harkness & Harkness 1992). The noc- turnal activity may be due to excessive surface temperatures during the day, particularly in summer. Nocturnal activity may be an adap- tation to avoid high densities of ants, which can be dangerous to hunting Zodarion. Cur- rent observations, however, do not support the latter hypothesis because many ants, for ex- ample Messor, are also active at night. Similar to European Zodarion spiders, spe- cies in this study exhibited Batesian mimicry. Central European Zodarion spiders were found to be generalized mimics of ants (Pekar & Krai 2002). They do not bear an exact re- semblance to a specific model as do some cor- rinid spiders, for example Myrmecium (Hill- yard 1997), but have a superficial resemblance to a group of similar ant species. Ant mimicry has been observed also in other species of the subfamily Zodariinae occurring in the Medi- terranean region. Pierre (1959) suggested that Zodariellum (Acanthinozodium) sahariense Denis 1959 and Zodarion bicoloripes (Denis 1959) resemble Messor aegyptiacus (Emery 1878) in Algeria. In this study Z. cyrenaicum was found to resemble larger black {Messor) ants, Z. lutipes to resemble larger yellowish- brown (Camponotus) ants, and Trygettus to resemble tiny yellowish-brown (Monomo- rium) ants. The mimics are found in the same area as the models (Collingwood & Agosti 1996) and all these spiders closely associate with their models in order to feed on them. We failed to find a tentative model for Z ni~ tidum. It appears that males are better mimics than females, owing to the fact that females have larger abdomens. We suggest that more improved mimicry of males may be due to the different behavior of male and female Zoda- rion spiders. When running among ants, fe- males are foraging and they retreat after cap- turing an ant, while males are patrolling for females and are therefore more visible to po- tential predators. This could select for closer mimicry in males, as it does for example in Seothyra henscheli Dippenaar-Schoeman 1991 (Eresidae), in which the males alone are ant mimics, while the sedentary females are not (Dippenaar-Schoeman 1991). Messor ants seem to be the most common ant model as many of these ants are polymorphic and can provide appropriate models for nearly all of the spiders’ developmental stages. Our results showed that Zodarion species are able to subdue several different ant spe- cies, as were European species of Zodarion (Harkness 1976; Pekar & Krai 2001). Spiders ignored ants that were very small in compar- grams were made from depicted metaphases. * identifies the sex chromosome(s) at diplotenes. Note the positive heteropycnosis of the sex chromosome. Scale lines = 10 [xm. 60 THE JOURNAL OF ARACHNOLOGY ison with the spider. It is likely that the Zo- darion spiders studied here can feed naturally on several ant species, as does Z. frenaturn in Greece, which hunts both Cataglyphis and Messor ants (Harkness 1976). In general, all three Zodarion species possess more effective venom for paralyzing Formicinae and Doli= choderinae than for Myrmicinae ants. This is consistent with results of other studies. Hark- ness (1976) observed in the field that Z. fren- atum paralyzed Cataglyphis bicolor (Fabricius 1793) (Formicinae) ants in 15 min. Wiehle (1928) noticed that it requires about two hours for Z. elegans (Simon 1873) to paralyze myr- micine ants, Messor sp. Couvreur (1990b) found in laboratory experiments that Z. rubi- dum paralyzed several species of formicine ants in about 6 min whereas large myrmicine ants were paralyzed in about 45 min. It is be- lieved that such effective venom against for- micine ants is an important adaptation. For- micinae, in contrast to Myrmicinae, are very fast and agile. They can easily harm or even kill the spider (Schneider 1971). The attacked ant becomes aggressive and seeks the attacker but immediately after the attack, the spider re- treats and waits at a distance (Pekar 2004). If the venom were less effective, the attacked ant could harm the spider or the ant could move away from the attack site and be lost to the spider. Moreover, our results suggest a certain degree of specialization in particular species. Zodarion lutipes may be specialized on for- micine ants as it had the shortest latency to paralysis among the species studied. This spe- cies hunts and imitates Camponotus ants, which are very large, requiring effective ven- om. Also T. sexoculatus and Z. cyrenaicum both hunt the same ant species that they imi- tate. The former species imitates and feeds on Monomorium ants and the latter hunts and mimics Messor ants. Zodarion cyrenaicum was the slowest to attack of all the species studied. The explanation may lie in its spe- cialization on myrmicine ants, which are slow moving. This is supported by recent obser- vation when juvenile individuals of this spe- cies were seen in the vicinity of Crematogas- ter nigriceps Emery ants (Myrmicinae) (Lubin, pers. obs.). Zodarion nitidum was ob- served hunting M. arenarius in the field, how- ever, it does not seem to be specialized on this species (having a long paralysis latency). Ob- servations on ant feeding in T. sexoculatus support Jocque’s (1991) hypothesis that all genera of Zodariinae are either myrmecopha- gous or termitophagous. Females of all the species studied were better at paralyzing ants than were juveniles or males. Since it was not possible to observe how much venom was dis- charged at every bite, we do not know wheth- er this difference is due to more efficient bit- ing or to injecting more venom. The females, being larger might have more venom, how- ever, experiments by Cushing & Santangelo (2002) showed that the size of the spider did not influence the paralysis efficiency. Records of predators of zodariid spiders are rare (Pekar & Krai 2002). Ferton (1896) de- scribed a sphecid wasp, Psen (Miscophus) bonifaciensis that parasitized Zodarion ele- gans and Z. nigriceps (Simon 1873). For the first time, an ichneumonid parasitoid attacking Zodarion was recorded. Since these are the only records of parasitoids, we believe that the frequency of parasitism in Zodarion is very low. Batesian mimicry, nocturnal activity and anachoresis, i.e. the habit of hiding in retreats (Pekar & Krai 2002) may explain this low parasitism rate. Polysphincta wasps attack many different spider species, mainly web- building spiders (Araneidae, Dictynidae, Lin- yphiidae, Tetragnathidae and Theridiidae) but also hunting species living in the vegetation (Clubionidae) and occasionally epigeal spe- cies (Lycosidae) (Rollard 1984). Courtship and copulation in Z. lutipes was identical to that observed in other Zodarion spiders (Pekar & Krai 2001). Although Zo- darion females are able to copulate repeatedly (Gerhard 1928), it seems that after a certain period, shortly before producing an egg sac, they do not copulate again. However, another copulation was recorded after the first egg sac had hatched. The copulation time of Z. lutipes was rather short, similar to that observed for Z. rubidum (Pekar & Krai 2001). Females of Z. cyrenaicum and Z. nitidum copulated be- fore they were brought to the laboratory as they refused to mate but produced egg sacs. Like in the central European species Z. ger- manicum, females guard the egg sac inside the retreat until hatching. Fecundity in all three species is higher than that found for the cen- tral European species, a likely consequence of a larger body size. Simpson (1995) found that fecundity (clutch size) is a function of the fe- male body size in spiders and the data on Zo- PEKAR ET AL.— NATURAL HISTORY OF ZODARIIDS FROM ISRAEL 61 darion species from Israel fit his model for cursorial spiders very well. The karyotypes of only three zodariid spe- cies, Storena indica Tikader & Patel 1975 (Datta & Chatterjee 1983), Zodarion german- icum and Z rubidum (Pekar & Krai 2001), have been described. Diploid chromosome numbers of males range from 22-29. Chro- mosome morphology of S. indica was not de- scribed. In the karyotype of the latter two spe- cies acrocentric chromosomes predominate. Storena indica and Z. rubidum employ a sex chromosome system X1X2O that is thought to be an ancestral condition in spiders (White 1973). A derived sex chromosome system XO in Z germanicum, with the acrocentric chro- mosome X, probably originated by tandem fu- sion of chromosomes Xj and X2. The karyo- types of the three Zodarion species from Israel are quite similar to each other, differing how- ever by the length of some chromosome pairs and the type of sex chromosome system. These karyotypes are similar to karyotypes of other zodariid spiders in terms of the diploid number, sex chromosome system and mor- phology of chromosomes. The acrocentric sex chromosome X in the XO system found in Z lutipes and Z nitidum might have originated independently from the one in Z germanicum. ACKNOWLEDGMENTS We wish to thank O. Eitan for a translation of J. Kugler’s key to the ants of Israel, R Wer- ner for identification of some ant species, G. Levy for additional data on fecundity and phe- nology and J. Sedivy for identification of the wasp. SP was funded by ARI (Advanced Re- search Infrastructure of EU) through the Blau- stein Center for Scientific Cooperation (Blau- stein Institute for Desert Research) and the Grant Agency of the Czech Republic (no. 206/ 01/P067). JK was supported by a grant of the Czech Ministry of Education no. 113100003. This is publication # 395 of the Mitrani De- partment for Desert Ecology. LITERATURE CITED Bodenheimer, FS. 1943. Studies on the life-history and ecology of Coccinellidae. I. The life-history of Cocinella septempunctata L. in four different zoogeographical regions. Bulletin de la Societe Fouad ler d’ Entomologie 27:1-28. Boeken, B., Y. Oren & M. Shachak. 2001. The ef- fects of drought on annual plant communities in the northern Negev of Israel. Available at http:/ /WWW. bgu.ac.il/cwst/drought.htm. Cokendolpher, J.C. & J. Brown. 1985. Air-dry method for studying chromosomes of insects and arachnids. Entomological Newsletter 96:114- 118. Collingwood, C.A. & D. Agosti. 1996. Formicidae (Insecta: Hymenoptera) of Saudi Arabia (Part 2). Fauna of Saudi Arabia 15:300-385. Couvreur, J.M. 1990a. Quelques aspects de la biol- ogie de Zodarion rubidum Simon, 1918. Nieuws- brief van de Belgische Arachnologische Veren- iging 5(2):7-15. Couvreur, J.M. 1990b. Quelques aspects de la biol- ogie d’une araignee myrmecophage: Zodarion rubidum (Simon, 1914). MSc. Thesis. Universite fibre de Bruxelles. Cushing, P.E. & R.G. Santangelo. 2002. Notes on the natural history and hunting behavior of an ant eating zodariid spider (Arachnida, Araneae) in Colorado. Journal of Arachnology 30(3):618- 621. Datta, S.N. & K. Chatterjee. 1983. Chromosome number and sex determining mechanism in fifty- two species of spiders from north-east India. Chromosome Information Service 35:6-8. Dippenaar-Schoeman, A.S. 1991. A revision of the African spider genus Seothyra Purcell (Araneae: Eresidae). Cymbebasia 12:135-160. Ferton, C. 1896. Nouveaux Hymenopteres fouis- seurs et observations sur I’instinct de quelques especes. Actes de la Societe Linneenne de Bor- deaux 68:261-272. Gerhardt, U. 1928. Biologische Studien an Grie- chischen, Corsischen und Deutschen Spinnen. Zeitschrift fiir Morphologic und Okologie der Ti- ere 10(4):576-675. Harkness, R.D. 1976. The relation between an ant, Cataglyphis bicolor (F.) (Hymenoptera: Formi- cidae), and a spider, Zodarion frenatum. (Simon) (Araneae: Zodariidae). Entomologist’s Monthly Magazine 111:141-146. Harkness, R.D. 1977. Further observations on the relation between an ant, Cataglyphis bicolor (E) (Hymenoptera: Formicidae) and a spider, Zoda- rion frenatum (Simon) (Araneae: Zodariidae). Entomologist’s Monthly Magazine 1 12:1 1 1-123. Harkness, M.L.R. & R.D. Harkness. 1992. Preda- tion of an ant {Cataglyphis bicolor (F.) Hym., Formicidae) by a spider (Zodarium frenatum (Si- mon) Araneae, Zodariidae) in Greece. Entomol- ogist’s Monthly Magazine 128:147-156. Hilly ard, P. 1997. Spiders Photoguide. Harper Col- lins Publ., Glasgow. Jocque, R. 1991. A generic revision of the spider family Zodariidae (Araneae). Bulletin of the American Museum of Natural History 201:1- 160. Kugler, J. 1984. The key to the subfamilies, genera 62 THE JOURNAL OF ARACHNOLOGY and species of ants (Formicidae) in Israel (based on the worker caste). Available from the author; Department of Zoology, Tel Aviv University, Ra- mat Aviv, 69978, Tel Aviv. (In Hebrew). Levy, G. 1992. The spider genera Palaestina, Try- getus, Zodarion and Rcmops (Araneae, Zodari- idae) in Israel with annotations on species of the Middle East. Israel Journal of Zoology 38:67- 110. Lubin Y., M. Kotzman & S. Ellner. 1991. Ontoge- netic and seasonal changes in webs and websites of a desert widow spider. Journal of Arachnology 19:40-48. Pekar, S. 2004. Predatory behaviour of two Euro- pean specialized ant-eating spiders (Araneae, Zo- dariidae). Journal of Arachnology. Pekar, S. & J. Krai. 2001. A comparative study of the biology and karyotypes of two central Eu- ropean zodariid spiders (Araneae, Zodariidae). Journal of Arachnology 29(3):345-353. Pekar, S. & J. Krai. 2002. Mimicry complex in two central European zodariid spiders (Araneae, Zo- dariidae): how Zodarion deceives ants. Biologi- cal Journal of the Linnean Society 75(4):517- 532. Pekar, S. & Y. Lubin. 2003. Habitats and interspe- cific associations of zodariid spiders in the Negev (Araneae: Zodariidae). Israel Journal of Zoology 49:255-267. Pierre, E 1959. Le mimetisme chez les araignees myrmecomorphes. Annee Biologie 35(5-6): 191- 201. Platnick, N.I. 2002. The world spider catalog, ver- sion 2.0. American Museum of Natural History. Available at http://research.amnh.org/entomolo- gy/spiders/catalog 8 1-87/index. html. Proszyhski, J. & Y. Lubin. 1994. Pitfall trapping of Salticidae (Araneae) in the Negev Desert. C.R. XI Ve Colloque Europeene d’arachnologie, Ca- tania 1993, Bollettino del Accademia Gioenia di scienze natural! Catania 26(345):28 1-292. Rollard, C. 1984. Composition et structure de la biocenose consommatrice des Araneides. Pp. 211-237. In Comptes Rendus du Vlleme Col- loque d’arachnnologie (B. Krafft, R. Leborgne & C. Rollard, eds.). Revue Arachnologique, Nancy. Schneider, P. 1971. Ameisenjagende Spinnen (Zo- dariidae) an Cataglyphis-'HQsiQxn in Afghanistan. Zoologischer Anzeiger 187(1): 199-201. Simpson, M.R. 1995. Covariation of spider egg and clutch size: the influence of foraging and parental care. Ecology 76(3):795-800. StatSoft, Inc. 2001. STATISTICA (data analysis software system), version 6. Available from www.statsoft.com. Traut, W. 1976. Pachytene mapping in the female silkworm Bombyx niori L. (Lepidoptera). Chro- mosoma 58:275-284. White, M.J.D. 1973. Animal Cytology and Evolu- tion. Cambridge University Press, Cambridge. Wiehle, H. 1928. Beitrage zur Biologie der Araneen insbesondere zur Kenntnis des Radnetzbaues. Zeitschrift fiir Morphologie und Okologie der Ti- ere 11:115-151. Manuscript received 24 January 2003, revised 29 September 2003. 2005. The Journal of Arachnology 33:63-75 A NEW SPECIES OF APOSTENUS FROM CALIFORNIA, WITH NOTES ON THE GENUS (ARANEAE, LIOCRANIDAE) Darrell Ubick: Department of Entomology, California Academy of Sciences, 875 Howard Street, San Francisco, California 94103 USA; and Sierra Nevada Field Campus, San Francisco State University, San Francisco, California 94132 USA. E-mail: dubick@calacademy.org Richard S. Vetter: Department of Entomology, University of California, Riverside, California 92521 USA; and Biology Division, San Bernardino County Museum, Redlands, California 92373 USA ABSTRACT. The genus Apostenus is newly recorded from the Nearctic region and a new species, Apostenus californicus, is described from California. Notes are presented on several morphological features of phylogenetic interest. Keywords: Spiders, taxonomy. North America The genus Apostenus currently comprises nine species from the western Palearctic re- gion, including the Canary Islands, and one species each from Mongolia and Sierra Leone [although this latter species is apparently mis- placed (Bosmans 1999, J. Bosselaers pers. comm.)]. Previously, three species from the Nearctic region were assigned to Apostenus {A. cinctipes Banks 1896, A. acutus Emerton 1909 and A. pacificus Gertsch 1935), but all were eventually transferred to other genera (Dirksia Chamberlin & Ivie 1942, Agroeca Westring 1861 and Drassinella Banks 1904, respectively) thus reinforcing the Old World distribution for the genus (Platnick & Ubick 1989). It consequently comes as quite a sur- prise to discover a California species that is clearly congeneric with the type species, Apostenus fuscus Westring 1851, in both so- matic and genitalic features. This species, which we are describing here as A. californicus, resembles A. fuscus in hav- ing the PER slightly recurved (Fig. 1), ante- rior tibiae with 5 and metatarsi with 3 pairs of ventral spines, tarsi with annulations and lacking true claw tufts (Figs. 3-7) and the male abdomen with modified ventral setae (Figs. 15, 16). As for genitalic features, the male of both species has a palp with a simple tapering retrolateral tibial apophysis, a narrow sickle-shaped median apophysis, and a grooved embolus (Figs. 22-24, 27-30), and the female has a median lobe on the epigynum and simple spermathecae with short copula- tory ducts (Figs. 25, 26, 31, 32). Although the California species is clearly an Apostenus on morphological grounds, its geographic isolation from the remaining spe- cies is puzzling. While it is certainly possible that A. californicus is an introduction from the Old World, this seems improbable. Unlike in- troduced species, which are typically found in disturbed marginal habitats and urban settings, this one has been collected from several pris- tine habitats of mountainous forest removed from human habitation and so appears to be a native of California. In addition, several of these mountain ranges are separated by wide stretches of low elevation habitats which ap- pear to be impermeable barriers between the known populations and suggest a relictual presence for the species. Assuming this to be the case, it is tempting to speculate on the biogeographical relation- ship between A. californicus and the remain- ing Apostenus species. Of some interest is the fact that a similar disjunction exists between three closely related liocranid genera. In this case, the California Hesperocranum Ubick & Platnick 1991 was argued to be the sister 63 64 Figure 1. — Apostenus californicus, female, dorsal view. Scale bar = 1 mm. group to the Palearctic Liocranum L. Koch 1866 and Mesiotelus Simon 1897 (Bosselaers & Jocque 2002). Whether the same pattern oc- curs in Apostenus will not be known until its many poorly known species are studied. METHODS Observations were made using a Leica MZ12.5 dissecting microscope, Nikon SL3D compound microscope and Leica M420 dis- secting microscope coupled with a JVC KY- F70B digital camera and a Syncroscopy Auto Montage system. Specimens were prepared for scanning by cleaning in a Branson 1510 Ultrasonicator, dried with a Denton DCPl Critical Point Dryer, coated with AuPd with a Denton Vacuum Desk II Sputter Coater and examined with a Hitachi S-520 Scanning Electron Microscope. Spiders were collected primarily by sifting oak leaf duff, both in the field and in samples brought back to the laboratory, and extracted with a Berlese funnel. Immatures removed live from the sifting were often reared to ma- turity. Oaks, both deciduous and perennial, were targeted as they are the most prevalent montane tree allowing leaf accumulation and subsequent decomposition in which spiders and their prey are found. Because initial Apos- tenus specimens were discovered from 1700- 2100 meter elevations, collections were con- THE JOURNAL OF ARACHNOLOGY centrated above the 1500 meter level. Collec- tions were also concentrated from September through March because the rainless, summer Mediterranean climate desiccates leaf litter sufficiently that collecting is often fruitless. These factors bias the collection data present- ed here and may not indicate the actual avail- ability of Apostenus in southern California mountains. Description largely follows the format of Ubick & Platnick (1991). Leg and palp mea- surements are given as: total length (femur + tibia-patella + metatarsus + tarsus). Measure- ments are in mm. Abbreviations: ALE = anterior lateral eye; ALS anterior lateral spinneret; AME = an- terior median eye; PE = posterior eyes; PER = posterior eye row; PLE = posterior lateral eye; PLS = posterior lateral spinneret; PME = posterior median eye; PMS = posterior me- dian spinneret; RTA = retrolateral tibial apophysis. Specimens are deposited at the California Academy of Sciences (CAS), San Diego Nat- ural History Museum (SDM), University of California at Riverside (UCR) and the collec- tions of T. Prentice (TRP) and D. Ubick (CDU). TAXONOMY Family Liocranidae Apostenus Westring 1851 Apostenus californicus new species Type material. — Male holotype and fe- male allotype from moist Quercus kelloggi duff at intersection of Cedar Springs and Pa- cific Crest Trails off Morris Ranch Road, 33°40'00"N, 116°34'31"W, 2090 m, San Jacin- to Mountains, Riverside County, California, U.S.A., 7 January 2001, R. Vetter (CAS). Paratypes: U.S.A.: California: Kem Coun- ty: 1 (3,1 juvenile, Los Padres National Forest, 100 m S of snow gate on Cuddy Valley Road toward Mount Pinos, (at mile marker 6.01), 1 km S of intersection with Cerro Mil Potrero Hwy, 34°49'51"N, 119°05'03"W, 1895 m, in moist Quercus shrub duff, 12 April 2003, R. Vetter (UCR); 3 juveniles, same road as above but at mile marker 8.95, 34°49'17"N, 119°05'01"W, 2105 m, in moist Quercus kel- loggi duff, 12 April 2003, R. Vetter (UCR); Riverside County: 1 juvenile, San Jacinto Mountains: same locality as holotype, 29 UBICK & VETTER— A NEW APOSTENUS FROM CALIFORNIA 65 Figure 2. — Map of southern California showing the known localities of Apostenus californicus. The northernmost locality (Inyo County) is tentative, be- ing based on juvenile specimens. March 2001; 4 juveniles (3 $ reared to matu- rity), 28 April 2001; 1 juvenile, along Cedar Springs Trail (Trail 4E17), 1950 m, in dry Quercus wisUzenii duff, 7 January 2001; 6 d, 6 $, 9 juveniles (1 $ reared to maturity), on Cedar Springs Trail off Morris Ranch Rd., 33°39'42"N, 116°34'4rW, 1790 m, in moist Quercus chrysolepis duff, 30 September 2001; 4 females, 4 juveniles, near Cedar Springs trail- head, 33°39'26"N, 116°35'01"W, 1720 m, in dry Quercus chrysolepis oak duff near stream- bed, 7 January 2001; 1 juvenile, in moist Quer- cus chrysolepis oak duff under snow, 1 8 March 2001; all above collected by R. Vetter (6 d and 4 $ at CAS, remainder at UCR); 2 d, 2 ?, 1 juvenile, James Reserve, Lake Fulmor, 33°48'31"N, 116°4636"W, 1640 m, in dry Quercus kelloggi oak-pine duff next to wet stream, 8 October 2001, R. Vetter and T Pren- tice (UCR); 1 9, 4.2 km N Lake Fulmor on Hwy 243, trailhead of trail 2E35, 33°49'39"N, 116°47'44"W, 1575 m, in extremely dry Quer- cus leaf duff, 26 September 2003, R. Vetter (UCR); 19,1 juvenile. Spillway Canyon, S of Lake Hemet, 33°39'07"N, 116°4r32"W, 1365 m, probably from oak litter, 29 May 2001, T. Prentice & D. Popko (UCR); San Bemandino County: San Bernardino Mountains: 1 9, 4.8 km W Angelus Oaks general store on Hwy 38, 34°10'N, 116°52'W, 1820 m, in Quercus kel- loggi duff, 6 June 2003, R. Vetter (UCR); 1 9, Forest Falls, Momyer- Alger Trail, 34°05'05"N, 116°55'07"W, 1660 m, 1 April 2001, TR. Pren- tice (TRP); 6 juveniles (1 d, 2 9 reared to maturity), in oak duff, 28 May 2001, T. Pren- tice (UCR); 1 juvenile (9 reared to maturity), 17 April 2002, T Prentice (TRP); 1 9, 2 ju- veniles, Forest Falls, near Vivian Creek trail- head (Trail 1E08), 34°04'58"N, 116°53'35"W, 1850 m, in dry scrub oak duff, 25 March 2001, R. Vetter (UCR); 2 9, 3 juveniles, 1 April 2001, T. Prentice (TRP); 1 juvenile, Forsee Creek and Hwy 38, 0.4 mi E of Camp Cedar Falls turnoff, 34°09'29"N, 116°55'54"W, 1850 m, in Quercus sp. duff, 15 June 2003, R. Vetter (UCR); 19,1 km W Jenks Lake Loop Road East turnoff, 34°10'14"N, 116°50'29"W, 2093 m, in scrub oak duff, 6 May 2001, R. Vetter (UCR); 1 penultimate male, Ponderosa Pines trail (1E19) near W entrance to Jenks Lake Loop Road on Hwy 38, 34°09'56"N, 116°54'46"W, 1950 m, in Quercus sp. duff, 15 June 2003, R. Vetter (UCR); 3 9, 6 juveniles. Mill Creek Canyon, 1.3 km E of Hwy 38 on Valley of the Falls Dr., 34°05'42"N, 116°56'44"W, 1450 m, 2 March 2002, R. Vetter (UCR); 1 juvenile, near Seven Oaks, 1.6 km N of Hwy 38 on Glass Rd, 34°10'29"N, 116°54'00"W, 1820 m, in mixed Quercus kel- loggi and pine duff, 6 May 2001, R. Vetter (UCR); 19,1 juvenile, in Quercus kelloggi and Q. chrysolepis duff, 6 June 2003, R. Vetter (UCR); 1 9,3 juveniles, Skinner Ridge be- tween Skinner Creek and Mountain Home Creek, 34°06'48"N, 116°58'53"W, 1500 m, in oak duff, 29 November 1983-26 January 1984, M. Narog (UCR); 1 d, 23 January 1986, M. Narog (UCR); San Diego County: 1 d, 5 9,1 penultimate d, 3 juveniles, Cleveland National Forest, Julian, 4839 Pine Ridge Ave., 33°02'34"N, 116°37'49"W, 1300 m, in mixed Quercus kelloggi and Quercus sp. leaf duff, 3 1 March 2002, R. Vetter (UCR); 2 penultimate d, Cleveland National Forest, ca. 1.6 km N Cibbets Flat, 32°46^38"N, 116°26'56"W, 1250 m, 12 July 2003, J. Berrian (SDM); 1 d, 1 9, Descanso Junction, 32°50'N, 116°36'W, 1040 m, ex willow duff, 31 March 1961, E. Lind- quist (CDU); 4 juveniles, Laguna Mountain across from fire station, 1/8 mi N Camp Ole Station, 32°53'N, 116°25'W, 1755 m, in duff of black oak, Quercus kelloggi, 20 February 2003, L. Merrill and R. Vetter (UCR); 2 9, Palomar Mountain State Park, Doane Pond trail, 20 m from parking lot, 33°20'29"N, 116°54'05"W, 1415 m, in mixed Quercus oak 66 THE JOURNAL OF ARACHNOLOGY Figures 3-6. — Apostemis califoniicus, lateral views of tarsi: 3, 4. Tarsus I showing leg bristles (B); 5, 6. Tarsus IV; 3, 5. Male; 4, 6. Female. Scale bar = 150 um (3-5), 200 um (6). duff on creek bank next to road, 20 January 2003, R. Vetter (UCR); 1 $ , 0.3 mi W of Ran- chita on Hwy S22, 33°12'37"N, 116°32'30"W, 1193 m, in oak leaf duff, 16 March 2003, R. Vetter (UCR). Non-paratypes (identification tentative): U.S.A.: California: 2 juveniles, Inyo County: Independence: Oak Creek Campground, just beyond Mt. Whitney Fish Hatchery, 36°50'31"N, 118°15'37"W, 1455 m, in black oak duff, 7 May 2003, E.E Drake (UCR). Etymology. — The species name refers to its known distribution. Diagnosis. — This is the only Apostenus known from the Nearctic region. The male is similar to A. annulipedes Wunderlich from UBICK & VETTER— A NEW APOSTENUS FROM CALIFORNIA 67 Figures 7-10. — Apostenus californicus, male leg parts; 7. Tibia IV showing plumose hair; 8-10. Apices of tarsus I; 8. Lateral view; 9. Apical view showing enlarged tenent hairs (TH) and lateral claw (LC); 10. Close-up of apical view showing median claw scar (MC) with lateral ridges (R) and origin of tenent hair laterad of lateral claw (O). which it differs in having the median apoph- ysis longer and originating more basad on the bulb. The female is close to A. grancanarien- sis Wunderlich (male unknown) but has the spermathecae more widely separated, (com- pare Figs. 22-26 with figs. 750e-h and 751- 751a in Wunderlich 1992). Description. — Male (holotype, range of other males in parentheses; n = 8): Total length 2.42 (2.24-2.95). Carapace length 1.10 (0.98-1.15), width 0.88 (0.79-0.94), height 0.34. Clypeus 0.08 (at AME), 0.05 (at ALE). Fovea length 0.18. Abdomen length 1.32, width 0.74. Eye sizes and interdistances: 68 THE JOURNAL OF ARACHNOLOGY Figures 1 1-14. — Apices of tarsus I of various spiders: 1 1, Liocranum sp., apical view showing median claw scar (MC) with lateral ridges (R) and the absence of a tuft or tenent hairs; 12. Drassinella sp., lateral view showing lateral claw (LC) and tuft (T) arising from lateral ridges (R) of median claw scar; 13-14. Titiotiis sp.; 13. Lateral view showing claw tuft analog (TA); 14. Close-up showing reduced median claw (MC) with lateral ridges (R). AME 0.04, ALE 0.08, PME 0.06, PLE 0.06, AME-AME 0.03, AME-ALE 0.02, PME-PME 0.06, PME-PLE 0.04, ALE-PLE 0.04, AER 0.25, PER 0.30. Palpus and leg lengths: Pal= pus: 1.10 (0.38 + 0.34 + 0 P 0.38); Leg I: 3.38 (0.90 + 1.22 + 0.64 + 0.62); Leg II: 2.96 (0.84 + 1.02 + 0.58 + 0.52); Leg III: 2.84 (0.76 + 0.94 + 0.64 + 0.50); Leg IV: 4.06 (1.06 P 1.34 P 0.98 P 0.68). Leg for- mula 4123. Color: Carapace brown, black in eye region and along margin, light brown at fovea. Ab- UBICK & VETTER— A NEW APOSTENUS FROM CALIFORNIA 69 Figures 15-17. — Apostenus californicus, abdomen: 15, 16. Male; 15. Ventral view showing distribution of modified setae along midline; 16. Close-up of modified setae; 17. Female, comparable part of abdomen showing unmodified setae. Scale bar = 500 um (15), 30 um (16, 17). domen dorsum dark brown to black with two short longitudinal pale marks anteriorly, fol- lowed by two pairs of transverse marks, and 2-3 transverse bands posteriorly; venter light brown with dark median maculation. Legs light brown with dark annulations, anterior femora and tibia dark brown, coxae light brown. Sternum brown. Vestiture: Carapace largely glabrous, eye region and clypeus with strong setae and re- cumbent white scales in longitudinal band. Sternum with setae mostly at margins and at posterior projection. Abdomen dorsum dense- ly setose, anteriorly with recumbent white se- tae, venter with modified short setae (Figs. 15, 16); appendages densely clothed with long se- tae, spines, plumose hairs and trichobothria. Carapace piriform in dorsal view, some- what flattened, highest at fovea. AME small- est, about half the diameter of ALE, PE sub- equal slightly smaller than ALE, AER straight, PER slightly recurved in dorsal view. Chelicerae not geniculate, lacking boss, ante- rior face with several setae, no spines, retro- margin with 2 teeth, promargin with 3 teeth. Sternum rounded, anteriorly truncate, with posterior extension between coxae IV, with marginal setae, especially at posterior exten- sion. Precoxal triangles absent. Labium round- ed, wider than long, one half length of endites; endites quadrate, with serrula on anterior margin. Abdomen: lacking dorsal scute; epigastric furrow lacking epiandrous spigots. Spinnerets with colulus represented by two setae; ALS conical, 2-segmented, contiguous, twice the width of the PLS; ALS with 3 spigots (piri- form) and 3 nubbins; PMS with 3 spigots (aciniform) and 2 nubbins; PLS with 3 spigots (aciniform) and 3 nubbins. Tarsi, metatarsi, and tibiae with dorsal tri- chobothria in two rows. Tarsi subsegmented; anterior with lateroventral rows of spatulate bristles (Fig. 3); posterior longer than anterior, bent in apical third (Fig. 5); with two pectinate lateral claws and two broad tenent hairs orig- inating laterad of claws (Figs. 8-10). Leg spines: I: metatarsus v2-2-2, tibia v2-2-2-2- 2, femur d 1-1-0, pO-0-1, vO-0-0-8 (bristles); II: metatarsus v2~2~2, tibia v2-2-2-2, femur dl-1-0, vO-0-0-8 (bristles); III: tibia d2-l, V 1-1-0; IV: metatarsus d2-2-0, v2-2-0, tibia d 1-2-2, V2-2-0. Palpus: Cymbium with dorsoapical scopu- la, lacking trichobothria. Bulb with median apophysis sickle-shaped, conductor absent, embolus broad with apical groove and angular base which forms a lock with the subtegulum. RTA short, curved, thorn-like prong. Femur lacking ventral process. (Figs. 22-24, 27-30) Variation: Penultimate males lack the mod- ified setae on the venter of the abdomen and the recumbent scales on the carapace and ab- domen. Female (allotype, range of other females in parentheses; n = 8): Total length 3.14 (2.30- 3.60). Carapace length 1.14 (1.05-1.32), width 0.94 (0.85-1.05), height 0.47. Clypeus 70 THE JOURNAL OF ARACHNOLOGY Figures 18-2F — Apostenus calif ornicus, female spinnerets: 18. entire spinning field; 19. ALS, showing major ampiilate (MA) and piriform (P) spigots; 20. PMS, showing minor amputate (mA), cylindrical (CY), and aciniform (AC) spigots; 21. PLS, showing cylindrical (CY) and aciniform (AC) spigots. 0.08 (at AME), 0.04 (at ALE). Eovea length 0.14. Abdomen length 1.80, width 1,14. Eye sizes and interdistances: AME 0.04, ALE 0.08, PME 0.07, PEE 0.07, AME-AME 0.03, AME-ALE 0.02, PME-PME 0.05, PME-PLE 0.03, ALE-PLE 0.05, AER 0.34, PER 0.26. Palpus and leg lengths: Palpus: 1.12 (0.40 A 0.38 A 0 + 0.34); Leg E 3.28 (0.98 + 1.20 + 0.64 + 0.46); Leg IE 3.02 (0.90 + 1.10 + 0.60 + 0.42); Leg III: 2.86 (0.78 + 0.98 + 0.60 + 0.50); Leg IV: 3.98 (1.06 + 1.36 + 0.94 + 0.62). Leg formula 4123. Color as in male. Vestiture as in male ex- cept that abdominal venter has long slender UBICK & VETTER— A NEW APOSTENUS FROM CALIFORNIA 71 setae and the carapace and abdomen lack the conspicuous recumbent scales. Form essen- tially as male except that tarsi are shorter and tarsi IV straighter than in male. Epigynum with rounded lateral lobes and triangular median lobe; copulatory openings in median grooves. Vulva with 2 rounded spermathecae, short copulatory ducts, and curved fertilization ducts. Spinnerets as in male; PMS conical, not compressed; ALS with 6 long spigots (4 piriforms and 2 larger major ampulates); PMS with 2 large cylindri- cal spigots, 1 smaller minor ampulate, and 3 small aciniforms; PLS with 2 cylindrical and 5-6 aciniform spigots (Figs. 18-21). Sexual dimorphism: Adult males have a vestiture of short setae on the abdominal ven- ter and recumbent white scales on the cara- pace and abdominal dorsum. Males have tarsi longer, and posterior tarsi more strongly bent, than females. Biology. — This species is widespread in the mountains of southern California and has been collected from several contiguous localities each in San Diego County and the San Jacinto and San Bernardino Mountains. It is also known from two isolated localities to the west in Kern County, and a tentative record, based on juveniles, to the north in Inyo County. The spider occurs in leaf litter (which varies from moist to slightly dry) of various oak species (with two records from oak and pine duff and one from willow) at elevations from 1040- 2100 m. Males have been taken from Septem- ber-April, females from September-June. In the lab, juvenile Apostenus were successfully reared to maturity on a diet of Collembola, Psocoptera, and Lepidoptera larvae. Distribution. — Known only from southern California (Fig. 2). DISCUSSION Our examination of A. californicus has turned up some observations that have not been adequately, if at all, described in the lit- erature. To date, the most complete descrip- tion of Apostenus is in the recent analysis of the clubionoid genera by Bosselaers & Jocque (2002), to which we can add the following: Dimorphic abdominal setae. — The pres- ence of short setae ventrally on the male ab- domen (Figs. 15, 16) was not scored by Bos- selaers & Jocque (2002), but occurs in A. californicus and A. fuscus and appears to be an autapomorphy for Apostenus. Although Wunderlich (1999) refers to the presence of modified setae in some species of Agroeca Westring 1861, of the species we examined, the males have normal setae {A. minuta Banks 1895, A. pratensis Emerton 1890, and A. tri- vittata (Keyserling 1887)), slightly shorter se- tae (A. ornata Banks 1892) or short ones in- terspersed with normal setae (A. brunnea (Blackwall 1833), J. Bosselaers pers. comm.). Claw tufts. — The tip of the tarsus bears two spatulate tenent hairs (Figs. 8-10) which also appear to be an autapomorphy for the ge- nus. Although this was interpreted as a claw tuft by Bosselaers & Jocque (2002: Character 63), it is clearly not homologous to a true tuft, which is generally understood to arise from the transformed median claw (Forster 1970). In Apostenus californicus, the modified hairs originate laterad of the paired claws and the region of the median claw is represented by a vestige consisting of a central protuberance and a series of lateral ridges (Figs. 9, 10). In a true claw tuft, the modified setae originate from the lateral ridge portion of the median claw vestige, as for example in Drassinella (Fig. 12). Such tufts are of a different origin, as are the tufts in 3-clawed spiders. Forster (1970) recorded various forms of claw tuft an- alogs in several 3-clawed desid genera from New Zealand, and similar analog tufts are also found in the 3-clawed Titiotus Simon 1897 and related tengellids from the Nearctic region (Figs. 13, 14). Finally, claws lacking tufts of any sort are found in several liocranid genera, for example, in Liocranum (Fig. 11). Detailed observations of these structures will be nec- essary to determine homology. Bent posterior tarsi. — All tarsi are subseg- mented in both sexes of Apostenus, but tarsi III & IV are much more markedly bent in the male (Figs. 3-6). Subsegmented and bent pos- terior tarsi occur in several Holarctic liocranid genera {Agroeca, Agraecina Simon 1932, Cy- baeodes Simon 1878, Neoanagraphis Gertsch & Mulaik 1936, and Scotina Menge 1873). This character was first noted by Wunderlich (1999) and interpreted as a synapomoiphy by Bosselaers & Jocque (2002: Character 9) for this group of genera. Interestingly, in Apos- tenus the subsegmented tarsi occur in both sexes, but only in males of Agroeca and Neoanagraphis. Tegulum/subtegulum lock. — The locking 72 THE JOURNAL OF ARACHNOLOGY Figures 22-26. — Apostenus californicus, genitalia: 22-24. Male left palpus with embolus in black; 22. Prolateral-ventral view; 23. Ventral view; 24. Retrolateral view; 25, 26. Female epigynum; 25. Ventral view; 26. Dorsal view. mechanism of the tegulum to subtegulum was first observed by Griswold (1993) in the Ly- cosoidea and its basal sister groups. A similar locking structure occurs in Apostenus (Figs. 22, 29), which has a distinct subtegular lobe, but may differ in having the tegular lobe rep- resented by the embolar base. This locking mechanism was also recorded in Agroeca, Scotina, and Phrurotimpus Chamberlin & Ivie 1935 (Bosselaers & Jocque 2002: Characters 130, 131). Cymbial scopula. — A scopula on the dor- soapical part of the cymbium was not noted by Bosselaers & Jocque (2002), but occurs in Apostenus californicus (Fig. 29), at least in some Agroeca (observed in A, pratensis), and is also found in a number of lycosoids and their kin (Griswold 1993). Epigynum with scape. — Bosselaers & Jocque (2002, Character 148) interpreted the middle piece of the epigynum of Apostenus as a scape. But unlike a scape, it is broadly at- tached to the rest of the epigynum (Figs. 25, 31, 32) and more closely resembles the me- dian lobe of amaurobiids, lycosoids, and some other spiders. Embolus insertion. — Although the embo- lus of A. californicus is apical in position, its insertion as seen in prolateral views is clearly at the middle of the bulb (Figs. 22, 29, 30) UBICK & VETTER— A NEW APOSTENUS FROM CALIFORNIA 73 Figures 27-30. — Apostenus californicus, male left palpus: 21, 28. Ventral view with close-up showing embolus (E) and median apophysis (MA); 29, 30. Prolateral view showing cymbial scopula (CS) and tegular-subtegular locking mechanism (TS) and a close-up showing base of embolus (E). and not apical as recorded by Bosselaers & Jocque (2002: Character 140) Abdominal scute. — Bosselaers & Jocque (2002) indicate the presence of a male abdom- inal scute in Apostenus (Character 102); but this was not observed in A. californicus. Plumose hairs, — Bosselaers & Jocque (2002) state that Apostenus lacks plumose hairs (Character 57); in A. californicus they are present on the legs (Fig. 7). Leg bristles. — These bristles have been in- terpreted as diminutive spines (Ubick & Plat- nick 1991) and occur in a wide number of clubionoids. Although they were not recorded for Apostenus by Bosselaers & Jocque (2002, Characters 4 & 5), they are present in Apos- 74 THE JOURNAL OF ARACHNOLOGY Figures 31-32. — Apostenus califoniicus, female epigynum, setae removed: 31. Ventral view showing lateral (L) and median (M) lobes; 32. Ventrolateral view. tenus californicus (Figs. 3, 4), and also occur, at least on anterior tarsi, in other species of Apostenus and in Agroeca and Liocranoeca. The family placement of Apostenus is pres- ently in a state of flux. Although traditionally associated with the Liocranidae, the most re- cent analysis of the clubionoid genera (Bos- selaers & Jocque 2002), argues that the genus belongs neither to the Liocranidae, sensu sthcto, nor to the Phrurolithinae (which they transferred to the Corinnidae) but to an inter- mediate clade which was not assigned to fam- ily. As mentioned above, the genus appears to cluster with the several genera having subseg- mented tarsi. These genera also lack claw tufts and precoxal triangles and show some affini- ties to the lycosoid complex, suggested by the bulbal locking mechanism and cymbial scop- ula, which may be worth exploring further. ACKNOWLEDGMENTS We thank Gordon Pratt (UCR) and John Al- cock (Arizona State University) for their roles in the hike that lead to the initial discovery of Apostenus specimens. Tom Prentice (UCR) collected specimens at several locations, reared immatures and sequestered specimens from the Narog collection. Laura Merrill (United States Forest Service, Riverside) con- tributed in several aspects by providing infor- mation on montane oak woodlands, ferrying duff from the mountains and ferrying RSV to dufhng sites. The following people provided access and/or permits, without which collect- ing would not have been possible: Melody Lardner (US Forest Service, San Bernardino), Sheri Lubin (Univ. Calif. James Reserve, San Jacinto Mountains), Paul Jorgensen (Califor- nia State Parks, Borrego Springs), and Ranger Bradeen (Palomar Mountain State Park). The Entomology Department at CAS pro- vided facilities to DU. Special thanks go to Martin J. Ramirez (while at the American Mu- seum of Natural History) for help in character interpretation and providing some scanning electron micrographs, Jan Bosselaers (Musee Royal de TAfrique Centrale) for invaluable discussion, and Jorg Wunderlich (Strauben- hardt, Germany) for loaning material of Apos- tenus annuUpedes, Suzanne Ubick assisted with the editing and Jan Bosselaers, Mark Harvey, and Robert Ra- ven provided useful comments on an earlier version of the manuscript. LITERATURE CITED Banks, N. 1896. New North American spiders and mites. Transactions of the American Entomolog- ical Society 23:57-77. UBICK & VETTER— A NEW APOSTENUS FROM CALIFORNIA 75 Bosnians, R. 1999. The genera. Agroeca, Agraecina, Apostenus and Scotina in the Maghreb countries (Araneae: Liocranidae). Bulletin de ITnstitut Royal des Sciences Naturelles de Belgique 69: 25-34. Bosselaers, J. & R. Joeque. 2002. Studies in Cor- innidae: cladistic analysis of 38 corinnid and lio- cranid genera, and transfer of Phrurolithinae. Zoologica Scripta 31:241-270. Emerton, J.H. 1909. Supplement to the New Eng- land Spiders. Transactions of the Connecticut Academy of Arts and Sciences 14:171-236. Forster, R.R. 1970. The spiders of New Zealand, Part III; Desidae, Dictynidae, Hahniidae, Amau- robioididae, Nicodamidae. Otago Museum Bul- letin, Number 3:1-184. Gertsch, W.J. 1935. New American spiders with notes on other species. American Museum Nov- itates 805:1-24. Griswold, C.E. 1993. Investigations into the phy- logeny of the lycosoid spiders and their kin (Arachnida: Araneae: Lycosoidea). Smithsonian Contributions to Zoology 539:1-39. Platnick, N.I. & D. Ubick. 1989. A revision of the spider genus Drassinella (Araneae, Liocranidae). American Museum Novitates 2937:1-12. Ubick, D. & N.I. Platnick. 1991. On Hesperocran- um, a new spider genus from western North America (Araneae, Liocranidae). American Mu- seum Novitates 3019:1-12. Westring, N. 1851. Forteckning ofver de till nar- varande tid Kande, i Sverige forekommande Spindlarter, utgorande ett antal af 253, deraf 132 aro nya for svenska Faunan. Handlingar, Gote- borgs Vetenskaps och Vitterhets Samhalle 2:25- 62. Wunderlich, J. 1992. Die Spinnen-Fauna der Mak- aronesischen Inseln: Taxonomic, Okologie, Bio- geographie und Evolution. Beitrage fiir Araneo- logie 1:1-619. Wunderlich, J. 1999. Liocranoeca — eine bisher un- bekannte Gattung der Feldspinnen aus Europa und Nordamerika (Arachnida: Araneae: Liocran- idae). Entomologische Zeitschrift 109(2):67-70. Manuscript received 14 April 2003, revised 18 No- vember 2003. 2005. The Journal of Arachnology 33:76-81 THE EFFECT OF PERCEIVED PREDATION RISK ON MALE COURTSHIP AND COPULATORY BEHAVIOR IN THE WOLF SPIDER PARDOSA MILVINA (ARANEAE, LYCOSIDAE) Abraham R. Taylor and Matthew H. Persons': Biology Department, Susquehanna University, Selinsgrove, PA, 17870, USA. Ann L. Rypstra: Department of Zoology, Miami University, Hamilton, OH, 45011, USA. ABSTRACT. The wolf spider, Pardosa milvina (Hentz 1844), shows effective antipredator responses in the presence of chemotactile cues (silk and excreta) from a larger wolf spider, Hogna helluo (Walckenaer 1837). We examined the influence of these substratum-borne cues on male P. milvina courtship and copulatory behavior. Forty-one pairs of adult virgin male and female P. milvina were placed on substrates with or without silk and excreta from an adult female H. helluo. Using behavioral observation software (Noldus Observer® 4.1), we recorded time until courtship, courtship duration, and intensity (leg raise and body shake rates). We also measured the total number of matings, the duration of each mating, and the number and rate of successful and failed palpal insertions. While we found no difference between treat- ments in mating success, courtship intensity or duration, there were significant increases in time until courtship and significant decreases in palpal insertion rates under predation risk. Males under predation risk also had significantly more failed palpal insertions than males not under risk. Results suggest that predation risk has a relatively minor impact on courtship displays and mating success, but could potentially impact mate searching, sperm transfer efficiency, or copulatory courtship. Keywords: Hogna helluo, kairomone, mate choice, mating, chemical cue Most wolf spider species engage in con- spicuous courtship displays that include leg- waving, stridulating, drumming, tapping or other attention-drawing signals (Kaston 1936; Rovner 1967a, 1968, 1975; Stratton & Uetz 1986; Hebets & Uetz 2000). These visual and vibratory displays often significantly increase mating success of the males (Hebets & Uetz 2000; McClintock & Uetz 1996; Parri et al. 1997, 2002; Rypstra et al. 2003), but may also attract the attention of predators (Kotiaho et al. 1998). Males may mitigate the costs of courtship displays by reducing courtship in- tensity or duration when predation risk is el- evated, however this may compromise species recognition or assessment of male quality by the female and contribute to lower mating suc- cess (Kotiaho et al. 1996, 1998). Male courtship displays may not be the only component of lycosid mating behavior to be compromised by predation risk. Many spe- cies engage in prolonged copulation (Stratton * Corresponding author. et al. 1996) that could lead to reduced vigi- lance or physical impairment of the ability of either the male or female to quickly escape from a predator. During copulation, wolf spi- ders may perform a variety of conspicuous be- haviors including rapid bouncing or vibrating of the abdomen by the male (Kaston 1936) and abdominal rotations by the female to fa- cilitate pedipalp-epigynal coupling (Stratton et al. 1996). In addition to these movements, the male often scrapes, rubs or taps at the epigyn- um with his palps and engages in various re- positioning movements as the male moves from one side of the female to the other (Kas- ton 1936; Rovner 1967b; Stratton et al. 1996). If these overt copulatory behaviors also attract attention from predators, pairs may benefit by minimizing their frequency or abbreviating copulation duration when predation risk is high. Several recent studies have shown that the wolf spider, Pardosa milvina (Hentz 1844), is capable of detecting and responding to silk and excreta deposited by a larger syntopic 76 TAYLOR ET AL.— COPULATION AND PREDATION RISK IN WOLF SPIDERS 77 wolf spider, Hogna helluo (Walckenaer 1837) (Persons & Rypstra 2001; Barnes et aL 2002; Persons et al. 2002). Upon encountering these cues from H. helluo, P. milvina typically greatly reduce their activity level and show increased vertical movement and substratum avoidance (Persons & Rypstra 2001; Persons et al. 2001, 2002). These behavioral shifts have a probable defensive function since P. milvina that reduce activity when encounter- ing H. helluo silk and excreta survive signif- icantly longer when confronted with live H. helluo than individuals that do not have access to these cues (Persons et al. 2001, 2002; Barnes et al. 2002). If P. milvina shows adap- tive reductions in activity when encountering cues from H, helluo, presumably, the presence of these cues may also alter P. milvina court- ship and mating behavior. Here we tested the influence of predation risk on P. milvina courtship and mating behavior by using H. helluo silk and excreta as a proxy for a live predator. METHODS Collection and Maintenance. — Between August and October 2002, we collected 82 in- tact P. milvina from corn, soybean and alfalfa fields near Susquehanna University, Selins- grove, Snyder County, PA. To ensure that all spiders used in our mating experiment were virgins, we collected only antepenultimate and penultimate male and females and reared them to maturity in the laboratory. We also collect- ed adult female H. helluo to be used for the deposition of silk and excreta as the source of predator cues. Both species of spider received food and water weekly. Diets consisted of 3- 5 adult and subadult house crickets (Acheta domesticus) for H. helluo and 5-7 one-week- old cricket nymphs {A. domesticus) and adult fruit flies {Drosophila melanogaster) for P. milvina. Housing for H. helluo consisted of white round plastic containers (8 cm in height X 11 cm in diameter) with two to three cm of moistened peat moss as a substratum. Par- dosa milvina were kept in clear round plastic containers of smaller size (5 cm in height X 8 cm in diameter) with one to two cm of the moist peat moss substrate. Spiders were main- tained at room temperature (23-25 °C) with a 14:10 L:D photoperiod. Stimulus Preparation. — We prepared 41 courtship and mating arenas that either did {n = 20) or did not {n = 21) have silk and ex- creta from a single adult H. helluo. Each arena consisted of a transparent plastic container (Rubbermaid Tortilla Keeper®, 9 cm h X 20 cm diam.). Eorty-eight hours prior to testing, a 20 cm diam. circular sheet of white filter paper was placed on the bottom of each arena along with an inverted 15 dram vial lid con- taining several drops of water. The lid served as a means of providing humidity and a direct source of water to stimulus spiders during cue deposition. A single adult virgin female P. milvina was then introduced into each arena and allowed to move freely for a 24 h period. For the no-predator cues treatment, the female was then removed for an additional 24 h prior to being paired with a male. For the predator cues treatment, the female P. milvina was also removed for an additional 24 h; but immedi- ately after removal, we introduced a single adult female H. helluo into the container where she was allowed to lay down silk and excreta on the filter paper for 24 h. The H. helluo was then removed from the arena im- mediately prior to testing. A different H. hel- luo was used to deposit predatory cues for each male-female P. milvina pair in the pred- ator cue treatment. During stimulus prepara- tion, we satiated both the adult female P. mil- vina and the female H. helluo by providing constant access to appropriately sized A. do- mesticus 24 h before their introduction into the arena to deposit silk and excreta. We also satiated adult male and female P. milvina pairs using the same method before the beginning of the trial. This served to reduce variation in body condition among paired spiders, a pos- sible confounding variable in the female’s mate choice decision or male display rates. All P. milvina tested had been between four and fourteen days post-final molt and all pairs were alternately assigned to either treatment to control for possible temporal effects on mating or copulatory behaviors between treat- ments. Testing Protocol. — Following the removal of H. helluo, females were then reintroduced into their respective containers and allowed to acclimate for fifteen minutes, after which the males were introduced into the center of the arena under a clear plastic vial (15 dram). Males were allowed a two minute acclimation period under the vial after which time they were released and allowed to freely interact 78 THE JOURNAL OF ARACHNOLOGY Table 1. — Male Pardosa milvina behavior with (Predator cues) and without (No predator cues) the presence of silk and excreta from an adult female Hogna helluo. Each behavior was analyzed using a two-sample t-test. Mean ± SE for each behavior is reported. * indicates significant difference after a table- wide adjustment to the alpha level (sequential bonferroni). Behavior n Predator Cues No Predator Cues T-value P-value Leg Raise Rate (/min) 41 13.42 ± 2.84 12.93 ± 2.32 0.135 0.8934 Body Shake Rate (/min) 41 11.14 ± 2.49 12.27 ± 2.14 0.347 0.7305 Time to Court (s) 39 320.72 ± 76.46 117.43 ± 24.98 2.688 0.010* Courtship Duration (s) 41 799.71 ± 152.68 1033.01 ± 163.47 1.334 0.2010 Copulation Duration (s) 18 860.84 ± 134.27 744.10 ± 107.31 0.135 0.8934 with the female for a thirty minute period. During each trial period we recorded two pri- mary courtship behaviors: leg raises and body shakes (see Montgomery 1903 and Kaston 1936 for a complete description of P. milvina courtship behaviors). We also measured (1) time until courtship (the time period from the beginning of the trial to the first body shake or leg raise), (2) courtship duration (the time period from the first body shake or leg raise to a successful mount), (3) time until copu- lation (the time period from the start of the trial to the first palpal insertion) and (4) cop- ulation duration (the time period from the first palpal insertion to a dismount). In addition to courtship behaviors and cop- ulation duration, we also measured more spe- cific copulatory behaviors, including the total number of palpal insertions, the rate of palpal insertion per unit of time mounted on the fe- male, and the total number of attempted palpal insertions that failed (general lycosid palpal insertion behavior described in Rovner 1975). For purposes of our study, palpal insertions were recorded as successful only if the ex- treme proximal end of the hematodocha was observed to visibly expand and the female ab- domen concomitantly inflated with this expan- sion. A palpal insertion was recorded as “failed” only if the pedipalp became decou- pled from the epigynum at the time of infla- tion resulting in the hematodocha expanding external to the female reproductive tract. Be- cause of the difficulty in accurately videotap- ing copulatory behaviors, all data were re- corded live with direct observations using the software package Noldus Observer 4.1®. Each male P. milvina was given 30 minutes to mount and begin mating before the trial was terminated. Pairs that were in copula after 30 minutes were allowed to continue mating until the male dismounted. Males that failed to mount within the 30 minute period were re- corded as unsuccessful. Voucher specimens from this study were deposited in the Museum of Nature and Science, Denver, Colorado. RESULTS Most of the conspicuous behaviors exhib- ited during P. milvina courtship displays were not significantly different between treatments (Table 1). The presence of substratum-borne predator cues did not have a significant effect on courtship duration or either measure of courtship intensity (leg raise rates, or body shake rates) (Table 1) but did significantly af- fect time until courtship (Table 1). In the pres- ence of predator cues, males took more than twice as long to initiate a leg raise or body shake than males without predator cues pres- ent (Table 1). The presence of substratum-borne predator cues did not affect the mating success of P. milvina (X^ = 0.0191; P > 0.90) (Fig. 1). Mating frequency was 42.8% for the no-pred- ator treatment and 45% for the predator cues treatment. There was also no significant dif- ference in copulation duration between treat- ments (Table 1). While most courtship behav- iors were similar across treatments, we did observe some differences in copulatory be- havior. Pedipalp insertion rates were signifi- cantly lower for matings under perceived pre- dation risk (t = 2.620; P — 0.0186; n = 18) (Fig. 2), and the number of failed palpal in- sertions were significantly higher for the pred- ator cues treatment (t = 2.292; P = 0,0358; n = 18) (Fig. 3). The total number of inser- tions during copulation ranged from a mini- mum of nine to a maximum of forty (mean = 25.16 ± 2.17 S.E.; n = 18) with failed inser- tion attempts being considerably more vari- able (range 1-99) (Fig. 3). TAYLOR ET AL.— COPULATION AND PREDATION RISK IN WOLF SPIDERS 79 1. Mating Success Mated Unmated 2. Insertion Rate 3. Missed Insertions 50 40 Figures 1-3. — 1. Male mating success among P. milvina pairs with and without H. helluo cues present {n = 2\ for no predator cues, = 20 for predator cues). 2. Mean successful palpal insertion and hematodocha inflation rates (± S.E.) into the female epigynum {n = 9/treatment); 3. Total number of failed pedipalp insertions and hematodocha inflations when H. helluo cues are present {n = 9/treatment). Asterisks indicate significant differences between predator and no-predator treatments based on a two sample t-test (a = 0.05). Predator Cues No Predator Cues DISCUSSION Among measured courtship behaviors, only time until the onset of courtship showed a sig- nificant difference between treatments. This difference was likely due to a marked reduc- tion in overall activity level by either the male, the female or both when on substrates containing H. helluo cues. During our obser- vation of pairs among control treatments, the male would begin localized searching and 80 THE JOURNAL OF ARACHNOLOGY chemoexploring immediately after detection of female silk. During this experiment, leg raises and body shakes were observed only after the female had either made some overt movement to draw the male’s attention or af- ter the male had made direct physical contact with the female. Males on H. helluo cues showed similar behaviors except they exhib- ited much reduced localized searching and oc- casionally prolonged periods of immobility. Anecdotally, we observed that females also moved much less frequently on H. helluo cues. Although this was not quantified directly in this study, other published studies have consistently documented significant reduc- tions in activity of adult female P. milvina when encountering H. helluo cues (Persons et al. 2001, 2002; Persons & Rypstra, 2001; Barnes et al. 2002). We believe that reduced female movement rendered them vibratorily and visually cryptic to males and therefore impaired the ability of males to initially per- ceive females as has been found in other ly- cosids (Rovner 1996). Male activity could also have been compromised by the presence of H. helluo cues. This, in turn, may impair the ability of males to locate female silk or the female directly and delay the onset of courtship. Since we did not directly measure male and female activity in this study, it is difficult to ascertain the extent to which male or female behavior impacts the timing of courtship. Further, it is possible that males could perceive females while under perceived risk to the same degree as males not under risk, but chose to delay courtship because of the possible presence of a predator. Although the onset of courtship appeared to be affected by H. helluo cues, the intensity of male courtship displays and mating success did not differ among treatments. Recent stud- ies have established that male body shake and leg raise rates significantly affect P. milvina mating success (Rypstra et al. 2003; Brauti- gam & Persons 2003) . Since leg raise and body shake rates were the same among treat- ments, as well as mating success, we can ten- tatively infer that females do not modify their mate choice criteria with respect to male dis- plays while under risk. It seems likely that males weigh the immediate benefits of mating more highly than the possible predation costs of display. Predator chemical cues, by their nature, only indicate a probability of a pred- ator being in the area rather than confirmation of such a predator. Additional visual or vibra- tory information about the presence of a pred- ator may be necessary to induce changes in conspicuous components of display that are known to be used in mate choice criteria. Although predation risk had only a minor impact on courtship behaviors, we found sig- nificant differences in important copulatory behaviors. Insertion rates were significantly reduced while under predation risk. Presum- ably, this was due to a significantly higher number of failed insertions. It remains unclear why failed insertions increased while under risk, however several vertebrate studies indi- cate that efficiency of complex tasks such as foraging, is compromised by increased pred- ator vigilance (Milinski 1984; Dukas & Kamil 2000, 2001). We suggest that increased pred- ator vigilance during predator encounters may reduce attention paid to complex copulatory maneuvers. The fitness consequences, if any, of de- creased palpal insertion rates are unknown. If sperm is transferred at a similar rate through- out intromission, predation risk may signifi- cantly decrease transfer efficiency and possi- bly limit sperm availability to the female. Alternatively, if most sperm are transferred very early during copulation; as suggested by other spider species (Suter & Parkhill 1990), reduced insertion rates and missed insertions may have a minimal impact on male or female fitness. However, even if all sperm is trans- ferred during the first insertion, continued in- sertions may still be adaptive. Prolonged in- tromission by males may serve as a form of copulatory courtship by providing information to the female about body condition, genetic quality, or otherwise serving to convince the female to accept the male’s sperm. Continued intromission may also serve as a form of mate guarding, allowing sufficient time for the sperm to capacitate (reviewed in Eberhard 1996). As suggested by Suter and Parkhill (1990), further copulation may function to transfer substances in the ejaculate that may facilitate oviposition or nourish the offspring. Our results suggest that predation risk may have the greatest impact on mate searching and copulation rather than courtship displays. As such, our study underscores the need to examine not only how conspicuous displays are influenced by predators, but also how cop- TAYLOR ET AL.— COPULATION AND PREDATION RISK IN WOLF SPIDERS 81 ulatory behavior itself is affected. Future stud= ies should address the reproductive conse- quences of modifed copulatory behavior while under predation risk. ACKNOWLEDGMENTS We would like to thank Ashley Shade, Kir- sten Wilbur, Ryan Bell, Katie Hess, Valerie Wolfgang, Helen Petre, and Dan Church for their help collecting and maintaining spiders used for this research. This research was fund- ed in part by NSF grant C-RUI DBI 0'2 16776 for M. Persons and C-RUI DBI 0216947 for A. Rypstra. LITERATURE CITED Barnes, M.C., M.H. Persons, & A.L. Rypstra. 2002. The effect of predator chemical cue age on an- tipredator behavior in the wolf spider Pardosa milvina (Araneae: Lycosidae). Journal of Insect Behavior 15:269=281. Brautigam, S.E. & M.H. Persons. 2003. The effect of limb loss on the courtship and mating behavior of the wolf spider Pardosa milvina (Araneae: Lycos- idae). Journal of Insect Behavior 16:571=587. Dukas, R. & A.C. Kamil. 2000. The cost of limited attention in blue jays. Behavioral Ecology 11: 502=506. Dukas, R. & A.C. Kamil. 2001. Limited attention: the constraint underlying search image. Behav- ioral Ecology 12:192=199. Eberhard, W.G. 1996. Female control: sexual selec- tion by cryptic female choice. Monographs in Behavioral Ecology. Princeton University Press, Princeton: New Jersey Hebets, E.A. & G.W. Uetz. 2000. Leg ornamenta- tion and the efficacy of courtship display in four species of wolf spider (Araneae: Lycosidae). Be- havioral Ecology and Sociobiology 47:280=286. Kaston, B.J. 1936. The senses involved in the court- ship of some vagabond spiders. Entomology Americana XVI:97=167 Kotiaho J., R.V. Alatalo, J. Mappes, &. S. Parri. 1996. Sexual selection in a vt/olf spider: male drumming activity, body size, and viability. Evo- lution 50:1977=1981. Kotiaho J., R.V. Alatalo, J. Mappes, S. Parri, & A. Rivero. 1998. Male mating success and risk of predation in a wolf spider: A balance between sexual and natural selection? Journal of Animal Ecology 67:287=291. McClintock, W.J., & G. W. Uetz. 1996. Female choice and preexisiting bias: visual cues during courtship in two Schizocosa wolf spiders (Ara- neae:Lycosidae). Animal Behaviour 52:167=181. Milinski, M. 1984. A predator’s costs of overcom- ing the confusion-effect of swarming prey. Ani- mal Behaviour 32:1157-1162. Montgomery, T.H. 1903. Studies on the habits of spiders particularly those of the mating period. Proceedings at the Academy of National Science and Philosophy 55:59-149. Parri, S., R.V. Alatalo, J. Kotiaho, & J. Mappes. 1997. Female preference for male drumming rate in the wolf spider Hygrolycosa rub rof as data. Animal Behaviour 53:305-312. Parri, S., R.V. Alatalo, J.S. Kotiaho, J. Mappes A. Rivero. 2002. Sexual selection in the wolf spider Hygrolycosa rubrofasciata: female preference for signal length and pulse rate. Behavioral Ecol- ogy 13:615-621. Persons, M.H. & A.L. Rypstra. 2001. Wolf spiders show graded antipredator behavior in the presence of chemical cues from different sized predators. Journal of Chemical Ecology 27:2493-2504. Persons, M.H., S.E. Walker, A.L. Rypstra, & S.D. Marshall. 2001. Wolf spider predator avoidance tactics and survival in the presence of diet-as- sociated predator cues (Araneae: Lycosidae). An- imal Behaviour 61:43-51. Persons, M.H., S.E. Walker, & A.L Rypstra. 2002. Fitness costs and benefits of antipredator behav- ior mediated by chemotactile cues in the wolf spider Pardosa milvina (Araneae: Lycosidae). Behavioral Ecology 13:386—392. Rovner, J.S. 1967a. Acoustic communication in a lycosid spider (Lycosa rabida Walckenaer). An- imal Behaviour 15:273-281. Rovner, J.S. 1967b. Copulation and sperm induc- tion by normal and palpless male linyphiid spi- ders. Science 157:835. Rovner, J.S. 1968. An analysis of display in the lycosid spider Lycosa rabida Walckenaer. Ani- mal Behaviour 16:358-369. Rovner, J.S. 1975, Sound production by nearctic wolf spiders: a substratum-coupled stridulatory mechanism. Science 190:1309-1310. Rovner, J.S. 1996. Conspecific interactions in the lycosid spider Rabidosa rabida: the roles of dif- ferent senses. Journal of Arachnology 24:16-23. Rypstra, A.L., C. Wieg, S.E. Walker, & M.H. Per- sons. 2003, Mutual mate assessment in wolf spi- ders: Differences in the cues used by males and females. Ethology 109:297-306. Stratton, G.E., E.A. Hebets, P.R. Miller, & G.L. Miller. 1996. Pattern and duration of copulation in wolf spiders (Araneae, Lycosidae). Journal of Arachnology 24:186-200. Stratton, G.E., & G.W, Uetz. 1986. The inheritance of courtship behavior and its role as a reproduc- tive isolating mechanism in two species of Schi- zocosa wolf spiders (Araneae: Lycosidae). Evo- lution 40:129-141. Suter, R.B. & V.S, ParkhilL 1990. Fitness conse- quences of prolonged copulation in the bowl and doily spider. Behavioral Ecology and Sociobiol- ogy 26:369-373. Manuscript received 9 September 2003, revised 11 January 2004. 2005. The Journal of Arachnology 33:82-92 WEB ORIENTATION, STABILIMENTUM STRUCTURE AND PREDATORY BEHAVIOR OF ARGIOPE FLORIDA CHAMBERLIN & IVIE 1944 (ARANEAE, ARANEIDAE, ARGIOPINAE) Michael J. Justice^: Behavioral Sciences Department, Nova Southeastern University Fort Lauderdale, FL, 33314 USA. Teresa C. Justice: Archbold Biological Station, Lake Placid, FL 33862 USA and Department of Biology, East Carolina University, Greenville, NC 27858 USA Regina L* Vesci: Behavioral Sciences Department, Nova Southeastern University, Fort Lauderdale, FL 33314 USA ABSTRACT. This study was undertaken to describe the web orientation, stabilimentum structure and predatory behavior of Argiope florida Chamberlin & Ivie 1944 (Araneae, Araneidae, Argiopinae), a vir- tually unstudied orb-web spider of the southeastern United States. Adult female Argiope florida were sampled from five sandy ridge areas of Florida. Compass orientation of the spider’s dorsum, incline of the web from vertical and hub height were measured. The presence of male A. florida, barrier webs, kleptoparasitic species of Argyrodes Simon 1864 (Araneae, Theridiidae), wrapped prey and large areas of web damage were noted. Predatory behavior was elicited by touching a radius with a 100 Hz tuning fork. The number of stabilimentum arms was measured, along with their arrangement, length and number of silk bands. On average, webs faced 100° E of N, were inclined 19° from vertical and were 1 m from the ground at the hub. Responses to the tuning fork, which closely resembled the responses to actual prey, were more vigorous when Argyrodes spp. were present on the web, but were not different when wrapped prey were present on the web. Most webs had stabilimenta and most stabilimenta had four arms in a cruciate pattern. The upper arms tended to be smaller and spaced further apart than the lower arms. Spider size was related to the angle between the lower arms of the stabilimentum, but not to other measures of the stabilimentum. Keywords; Orb web, prey capture, Florida scrub, tuning fork, Argyrodes kleptoparasites The behavior of orb-web spiders has long been a topic of interest. Much of the research has focused on the building of the web and the variables that affect its final structure, es- pecially its size, asymmetry, number of radii and distance between loops of the sticky spiral (e.g,, Craig 1987; Sandoval 1994; Sherman 1994; McReynolds 2000; Venner et al. 2000). Other behavioral research has been dedicated to web site selection (e.g., Enders 1973, 1976), compass orientation (e.g., Carrel 1978; Tolbert 1979; Biere & Uetz 1981; Caine & Heiber 1987), sexual behavior (e.g., Elgar et al. 2000), thermoregulatory posturing (e.g., Humphreys 1991; Higgins & Ezcurra 1996), ' Current address: Michael Justice, 10949 East Lynchburg-Salem Turnpike, Forest, Virginia, 24551. predatory behavior (e.g., Robinson & Robin- son 1974; Klarner & Barth 1982; Masters & Moffat 1983; Masters 1984) and the effects of kleptoparasitic Argyrodes spp. Simon, 1864 (Araneae, Theridiidae; e.g., Larcher & Wise 1985; Elgar 1989; Cangialosi 1990). Many orb-web spiders add bits of debris, egg cases, or conspicuous tufts or bands of silk to the frame, radii and/or hub of their webs. This web-decorating behavior is seen in a number of Araneidae, spanning 15 genera and occurring in both ecribellate and cribellate spiders (Scharff & Coddington 1997). A phy- logenetic analysis of this family by Scharff & Coddington (1997) suggests that web-decorat- ing behavior has evolved nine separate times in Araneidae. The extent to which web-deco- rating behavior has established itself in the Araneidae suggests that this behavior serves 82 JUSTICE ET AL.— WEBS AND PREDATORY BEHAVIOR OF A. FLORIDA 83 an important function(s) in spiders that build orb webSo Spiders in the genus Argiope Audouin 1 826 often decorate their nearly invisible orb webs with conspicuous zigzags of silk called sta- bilimenta. However, the ecological function of stabilimeetum building is still unresolved (see Herberstein et al. 2000a). Because of its re- flectivity in both the visible and ultraviolet (UV) regions of the spectrum (Craig & Ber- nard 1990, Watanabe 1999, Zschokke 2002), many authors have suggested that the stabili- mentum is used as a visual signaL However, it is much debated whether the primary recip- ients of this signal are predators, prey or megafauna. Arguments that the primary recip- ients are predators suggest the stabilimentum thwarts predators by displacing attacks or changing the apparent size or shape of the spi- der (Hingston 1927; Ewer 1972; Eberhard 1973; Horton 1980; Edmunds 1986; Schoeeer & Spiller 1992). Arguments that the primary recipients are prey center around the UV re- flectivity of the stabilimeetum, which may at- tract insects by simulating flowers or patches of daylight in vegetation (Craig & Bernard 1990; Craig 1991; Tso 1996; Hauber 1998; Tso 1998a, 1998b; Watanabe 1999; Herber- stein 2000; but see Blackledge & Wenzel 1999, 2000). Finally, the stabilimeetum may signal the presence of the orb to megafauna that may otherwise walk or fly through it; this is mutually beneficial because the spider keeps its web intact and the megafauea do not have to groom the sticky spiral (Eisner & Nowicki 1983; Eberhard 1990; Kerr 1993; Blackledge & Wenzel 1999). In any case, the effectiveness of a visual signal is in part a function of the light that strikes it, which in any season would be affected by the web’s compass direction and angle from vertical. However, this basic natural history informa- tion is often missing, even for some of the best-studied species. Indeed, many species are virtually unstudied beyond their description and classification. One of the relatively unknown species is Argiope florida Chamberlin & Ivie 1944. In the most recent description and classification of this species, Levi (1968) summarizes the little that is known of its natural history: adults range from central North Carolina south to the panhandle and peninsula of Flor- ida, mature from July to November and build a cruciate stabilimentum. In Florida, the spe- cies lives in sand scrub and pine flatwoods. The only other study mentioning the species is that of Eisner & Nowicki (1983), who noted that removing the stabilimentum did not seem to affect prey capture or evasive behaviors. The purpose of the present study was to fur- ther characterize the web and stabilimentum of A. florida, to gather baseline data on pred- atory behavior via responses to a tuning fork and examine any interesting relationships that were revealed. METHODS Numerous areas of the Florida panhandle, peninsula and keys were visited during 2000- 2002 and locations where A. florida were found are summarized in Table 1. A search for adult female Argiope was carried out by walking through the habitat during the day- time and scanning the vegetation from the ground to a height of about 2.5 m. Argiope florida hang head down at the hub on the un- derside of their slightly tilted webs all day, like its congenerics (Comstock 1948). Upon locating an individual, the date, time, location, temperature and weather were noted. Next, two measures of the web were taken from a distance of about 1-3 m, with careful effort to avoid disturbing the spider. The com- pass direction its dorsum faced was recorded to the nearest 5°. The angle of the plane of the web was measured with a clinometer and recorded to the nearest 1° from vertical. Some- times the web was significantly flexed at the hub, so that the incline of the web above the hub was quite different from that below the hub. In these situations, the incline of a line connecting the tips of the spider’s 4* legs to the tips of its legs was used. Several measures were then taken from a distance of less than 1 m, again being careful to avoid disturbing the spider. First, it was not- ed whether any large sections of the web were missing or damaged. Then, both sides of the web were inspected for the presence of barrier webs, which are cobweb-like tangles of non- sticky silk placed adjacent to the orb. Next, the orb and barrier webs were carefully searched for male A. florida and the klepto- parasitic Argyrodes spp, (the frame threads and nearby vegetation were not searched for males or Argyrodes spp.). Lastly, the presence of wrapped prey was noted. 84 THE JOURNAL OF ARACHNOLOGY Table 1. — Dates and locations where A. florida were found. SP = State Park, NF = National Forest, SF = State Forest, CO = County. Locality and/or Land- n Ridge mark, County Latitude/Longitude Dates Found 9 Atlantic Coastal Jonathan Dickinson SP, Hobe Sound, Martin CO 27°0r01"N 80°06'37"W 31 Aug 2001 17 Oct 2001 05 Oct 2002 1 Bell Bell, Gilchrist CO 29°47'25"N 82°5ri3"W 15 Oct 2001 38 Lake Wales Archbold Biological Sta- tion, Highlands CO 27°10'55"N 8r2r08"W 15-17 Sep 2001 19 Oct 2001 15 Aug 2002 13 Sep 2002 3 Lake Wales Hickory Lake Scrub, Polk CO 27°41'47"N 8r32'23"W 03 Sep 2001 4 Lake Wales Sun ‘N Lake, Lake Placid, Highlands CO 27°14'55"N 8ri8T2"W 02 Aug 2002 6 Mount Dora Alexander Springs, Ocala NF, Lake CO 29°07'24"N 81°34'40"W 02 Sep 2001 1 Mount Dora Healing Waters, Ocala NF, Lake CO 29°10'14"N 81°38'14"W 02 Sep 2001 1 Unnamed Camel Lake, Appalachicola SF, Liberty CO 30°06'30"N 84°58'51"W 14 Oct 2001 1 Unnamed Pine Log SF, Panama City, Bay CO 30°24'18"N 85°52'06"W 14 Oct 2001 A predatory response was then elicited by touching the web with a 100 Hz tuning fork. In controlled experiments, 100 Hz vibrations increased at the hub of empty Larinioides sclopetarius (Clerck 1757) orbs when flies {Calliphora erythrocephala), mosquitoes (Cm= lex spp.) and bees {Apis melUfora) began buzzing while trying to free themselves (Mas- ters 1984). Tuning forks produce pure tones at an initial amplitude of 100-110 dB (refer- ence 0.0002 dynes/cm^), which rapidly decay (Frings & Frings 1966). Amplitude is thus dif- ficult to control with tuning forks, but natural prey produce a very wide range of amplitudes (Barrows 1915; Landolfa & Barth 1996). Pilot work and previous research (Boys 1880; Wells 1936; Frings & Frings 1966) revealed that striking the tuning fork near the spider can produce a number of behavioral responses without even touching the web, probably due to the significant near-field air vibrations of a tuning fork. For this research, the tuning fork was struck at least 1 m from the spider and not passed near the spider before touching the web. Five seconds after striking the fork, a single tine of the fork was gently pressed onto a radius at a 45° angle. This angle should pro- duce a high amplitude (about 2 mm) combi- nation of transverse and longitudinal vibra- tions, which are believed to be important for prey detection, localization and recognition (Masters & Markl 1981; Klarner & Barth 1982; Masters 1984). The stimulated radius was to the right or left of the hub, approxi- mately halfway from the hub to the edge of the orb (typically 15-25 cm from the hub). The radius was pushed in about 1.5 cm with the tine for about 3 s and then allowed to re- turn to its original position. The fork was left in place about 10-15 s. Pilot testing revealed that tuning fork stim- ulation of other areas of the web was less sat- isfactory. Stimulation above the hub was dif- ficult because this area of web was often small, and the response may be inhibited by having to rotate 180° and climb upward (cf. Masters & Moffat 1983). Stimulation below the hub did not allow for an assessment of rotation of the body toward the stimulus, an important element of the response (Boys 1880), and could potentially confuse an attack with an escape-drop. Stimulation of the frame threads often produces a vigorous response (Boys 1880; pers. obs.), but prey items are not typically caught there. Predatory responses were easily scored JUSTICE ET AL.— WEBS AND PREDATORY BEHAVIOR OF A. FLORIDA 85 from no response at all (=0U) to exhibiting the full range of behaviors that a real prey item would elicit (=5U)= The following are listed from least to most vigorous response, and were scored as numbered: 1) moving a leg, typically to place a tarsus on or near the radius being stimulated, 2) rotating the body so that the axis of the cephalothorax and ab- domen is aligned with the point of stimula- tion, 3) plucking or tugging on radii, 4) ap- proaching the fork and making physical contact with it, usually with the 1®^ and 2”^ tarsi (if the approach were interrupted by stop- ping or returning to the hub, 0.5 points were deducted from the score) and 5) wrapping the tip of one or both tines with silk. Thus, a spi- der that quickly rotated, approached and wrapped the fork with silk scored 5.0. A spi- der that paused during the approach but ulti- mately wrapped the fork with silk scored 4.5. A spider that rotated but never approached scored 2.0. Spiders that bit the fork consis- tently did so after wrapping, but this behavior was not factored into their predatory response score because the 10-15 s that the tuning fork was in the web may not have been sufficient time for a full predatory response if an indi- vidual spent several seconds wrapping a large area of the fork. An avoidance response such as dropping off the web or moving away from the fork was rare. The remaining measures were taken last be- cause they required close proximity to the spi- der and often caused the spider to leave the hub. The height of the hub above ground was measured with an extension rule. The number and pattern of stabilimentum arms was noted, after which three measures were taken on each arm: 1) its length, measured with dial calipers, 2) the number of bands of silk crossing from one radius to another (hereafter “bands”) and 3) the angle it formed with the next arm, mea- sured with a transparent goniometer. Next, dial calipers were used to obtain an index of size from leg #2. Specifically, the chord of the distance from the proximal end of the meta- tarsus to the distal tip of the tarsus was mea- sured. Although there may be some flexion at the tarsometatarsal joint, this chord was very close on average to the sum of Levi's (1968) averages for the tarsal and metatarsal lengths. After these data were collected in the field, the azimuth of the sun at the dawn of the day was obtained to the nearest 0.1° from the U. S. Naval Observatory's Astronomical Appli- cations Department (http://aa.usno.navy.mil/). Statistics involving angles were calculated using the methods described by Mardia (1972), Batschelet (1981) and Zar (1996). Sample sizes vary because some measures were added after some data collection had tak- en place, and not all measures could be taken successfully on all spiders. Voucher speci- mens of A. florida and Argyrodes spp. are de- posited in the arthropod collection at the Archbold Biological Station in Lake Placid, Florida. RESULTS Argiope florida were only found between August and October in the sand scrub and sandhill habitats of the Florida ridges. Specif- ically, A. florida were found on the Atlantic Coastal Ridge {n = 9), the Bell Ridge {n = 1), the Lake Wales Ridge {n — 45), the Mount Dora Ridge {n ” 7) and in unnamed ridge areas in the panhandle (« = 2) (see Table 1). Argiope florida and A. aurantia Lucas 1833 were frequently sympatric on the ridges, even though A. aurantia is often found in wetter habitats such as lake margins and swamps. There was no obvious horizontal or other niche separation between A. florida and A. au- rantia; in fact, their webs were often close to- gether, and occasionally in clusters with both species present. Argiope florida were not found south of Martin County, and thus their distribution did not overlap that of the Argiope argentata (Fabricius 1775) commonly found in southern peninsular Florida and the keys. All Argiope spp. in Florida are easily recog- nizable by shape and color patterns; also, A. florida and A. argentata construct cruciate sta- bilimenta, whereas A. aurantia construct lin- ear stabilimeeta. During data collection, temperature ranged from 21--38°C and was typically about 30- 35°C. Spiders were frequently observed with their abdomens flexed away from the orb or off to the side, presumably to minimize ex- posure to the sue. Webs were never observed to be vertical, but instead were inclined by a mean $ = 18.7°, ^ = 8.9° {n = 63). Twenty percent (« = 13 of 64 webs examined) had large sections of the web missing or damaged. Some of these were excluded from further measures and later analyses as appropriate. Twenty-five percent had barrier webs {n = 12 86 THE JOURNAL OF ARACHNOLOGY of 48 examined); barrier webs were occasion- ally on both sides of the orb, but usually only on the same side as the spider. No male A. florida were found on w = 48 webs searched. Argyrodes spp. were present on 8 (42%) of n = 19 webs searched (range 1-4 individuals per web). Individual Argyrodes were not iden- tified to species. Fourteen of 49 webs searched (29%) had wrapped prey present either in the sticky spiral, at the hub, or at the spider's mouth. The height of the hub above the ground was measured on n = 48 webs and varied from 0.43 m to 1.61 m (x = 1.06, ^ = 0.28). Although genitalia were not inspected, all were likely adults or at least subadults based on size: the chord of the tarsus + meta- tarsus on leg II averaged 10.9 mm (n = 61, .v = 1.1, Min = 7.0, Max = 13.3). The sampled A. florida showed a significant tendency to orient the plane of their webs par- allel to the N-S axis so that their dorsa faced E or W. Using the direction the dorsum faced {mod 180°), the mean ± 5 compass direction was $ = 99.6° ± 52.6° E of N (95% Cl = 83.6°-115.6°). With n = 64, the Rayleigh test for directional preference was significant (mean vector length r == 0.58, P < 0.001). On the days of data collection, the sun’s azimuth at dawn ranged from 69.6°- 10 1.1° E of N. However, the orientation of the web did not correlate with the dawn azimuth (r = 0.24, n = 64, P > 0.40). The lOOHz tuning fork was applied to n = 61 webs. Thirty-seven spiders approached the fork and wrapped it in silk (score = 4.5 for n = 17 that paused on the way and 5.0 for n = 20 that did not). Ten spiders approached but did not wrap the fork (score 3.5 for n — 1 and 4.0 for n = 3). Five spiders moved a leg but nothing more (score = 1.0). Nine spiders did not respond at all (score = 0.0). Overall, the mean ± 5 response to n = 61 stimulations was 3.57 ± 1.84. Mean predatory responses were not different when wrapped prey were present (x = 3.27, s = 1.99, n = 13) V5. absent (x = 3.92, s = 1.62, n = 33; equal variances t = 1.16, df = 44, two-tailed P = 0.25). However, predatory responses were stronger and less variable when Argyrodes were present (x = 4.86, s = 0.24, n = 1) V5. absent (x = 3.40, s ^ 2A6, n = 10); the variance difference was significant (F = 78.21, df =9,6, P < 0.0001) and the mean difference was nearly significant (unequal variances t = 2.11, df = 9, two-tailed P = 0.06). Most webs had a four-arm, cruciate stabi- limentum, but other patterns were observed (Fig. 1). Descriptive statistics on the stabili- mentum measures are given in Table 2. Paired difference tests were used to compare lower arms and upper arms on the same web. Lower arms were closer together than upper arms (Hotelling’s F = 3.66, df = 2, 25, P = 0.040). Lower arms were longer {t = 8.00, df = 46, two-tailed P ^ 0.0001), but there was no dif- ference between lower and upper arms in their length asymmetry {t = 0.37, df = 30, two- tailed P = 0.716). Lower arms had more bands {t = 10.07, df = 46, F ^ 0.0001), but there was no difference between lower and upper arms in the number of bands per cm arm length {t = 0.40, df = 46, two-tailed P = 0.691). Given that length would be added to an arm by adding more bands, the amount of variation in length explained by bands was surprisingly low: for n = 46 upper arms, F = 0.49 and for n = 56 lower arms, F = 0.63 (for these calculations, one arm was chosen at random from stabilimenta with more than one upper or lower arm). This suggests that other factors play a significant role in the spacing between bands. The size index was not related to the total number of bands (r = +0.07, n = 55, P = 0.61), the total length of the arms of the sta- bilimentum (r = +0.12, n = 55, P = 0.38), the bands/cm in the stabilimentum arms (r = -0.19, n = 55, F = 0.16), or the angle be- tween the two lower arms of the stabilimen- tum (r = +0.12, n = 32, P = 0.51). The size index was related, however, to the angle be- tween the two upper arms of the stabilimen- tum (r = +0.41, n = 25, F = 0.04). DISCUSSION Areas where Argiope spp. were found cor- respond fairly well with the distribution maps of Levi (1968) with two exceptions. First, Levi (1968) found A. florida on the Atlantic Coastal Ridge south of Martin County, where- as they were not found in these areas in the present study. This may be due to a reduction in sand scrub habitat in these areas (Myers 1990). Second, based on collecting reports with habitat information, Levi (1968) states that A. aurantia in Florida are found “rarely in sand scrub”, whereas they were easily JUSTICE ET AL.— WEBS AND PREDATORY BEHAVIOR OF A. FLORIDA No Stabilimentum: Q 3,5% 87 One Lower Arm Two Arms: ' f A Three Arms: 1.8% 10.5% 7.0% Four Arms 57.9% 1.8% Five Arms 1.8% Figure 1. — ^Observed patterns of stabilimentum structure and their frequencies. Percentages are based on n = 57 webs. found and quite numerous in sand scrub in the present study. Of course, the collecting reports and present authors may be defining “sand scrub” quite differently. In open habitat with highly reflective sand, at subtropical latitudes, and at the hottest times of the year, A. florida hang at the hub of fairly exposed webs with their dorsa facing due east/west on average. It may be worths while to examine the behavioral and physio- logical responses to the heat load that could result from this combination of temperature, exposure and orientation. Orb-web spiders with webs in open areas can regulate insola- tion (and thus heat load) by retreating to shade at high temperatures, posturing their bodies to adjust exposed surface area (i.e., Pointing 1965; Suter 1981), orienting their webs in a particular compass direction (i.e., Carrel 1978; Biere & Uetz 1981; Caine & Heiber 1987), building reflective silk shields over the hub (Humphreys 1992), and/or reflecting light with hairs on the cephalothorax and abdomen (Robinson & Robinson 1978). Argiope florida orbs are parallel to the N-S axis, which on nearly vertical webs would seem to maximize exposure to the sun. Argiope do not use re- treats (Levi 1968; Tolbert 1979), and their sta- bilimenta do not cross the hub and thus do not provide a sun shield. Thermoregulation in A. 88 THE JOURNAL OF ARACHNOLOGY Table 2. — Descriptive statistics on stabilimentum characteristics. Sample sizes refer to number of spi- ders. If a web had two upper arms, their measures were averaged and the averages were used in the analyses. If a spider had built only one upper arm or only one lower arm, the length of this arm was used but this spider could not contribute to the analyses of asymmetry and angle. Analyses of the angle between upper and lower arms required an upper arm and a lower arm on the same side of the hub. Variable n Mean 5' Min Max Angle Between the Upper Arms 27 68.8° 10.3° 46° 87° Angle Between the Lower Arms 34 60.2° 13.9° 24° 95° Length of the Upper Arms (cm) 47 1.18 0.73 0.41 4.32 Length of the Lower Arms (cm) 56 2.04 1.09 0.54 6.29 Asymmetry in the Length of the Upper Arms (cm) 34 0.47 0.54 0.01 2.71 Asymmetry in the Length of the Lower Arms (cm) 40 0.52 0.47 0.04 1.84 Bands in the Upper Arms 47 4.78 2.23 1 12 Bands in the Lower Arms 56 8.96 4.25 2 18 Bands/cm in the Upper Arms 47 4.77 2.27 0.98 11.43 Bands/cm in the Lower Arms 56 4.72 1.47 1.45 8.38 Angle Between the Upper and Lower Arms Asymmetry in the Angle Between the Upper and 32 112.2° 8.9° 90° 139° Lower Arms 27 10.0° 7.1° 0° 27° florida, therefore, would seem to come from behavioral posturing and silvery reflective hairs covering the dorsal cephalothorax and partially covering the dorsal abdomen (cf. Tol- bert 1979). While heat load may be a cost of the place- ment of their webs, benefits may come from an increase in prey capture and/or a decrease in the frequency of web loss. A large propor- tion (29%) of webs were found with wrapped prey already in the spiral, at the hub, or at the spider’s mouth. Also, a large number of prey impacts probably accounts for the large pro- portion of webs found with sections damaged or missing. As discussed above, the stabili- mentum may increase benefits by attracting prey and/or preventing megafauna from de- stroying the web. Both of these functions re- quire reflection of light from the stabilimen- tum; habitat selection, compass direction of the web, and incline of the web from vertical will influence the maximum amount and tim- ing of insolation. Thus, the E-W direction and the 19° incline may be a combination that op- timizes reflection of light from the stabilimen- tum for prey capture and web protection in this habitat. Barrier webs may not generally be worth their costs for A. florida. After comparing three populations of A. argentata in the Gal- apagos, Lubin (1975) suggested that barrier webs help to mechanically strengthen the web because they were more frequent in areas of high wind. The percentage of webs with a bar- rier web in a low-wind area (28%) closely matched that of the A. florida in the present study (25%); both were much lower than the high-wind areas (68%). It is possible that A. florida webs do not need the mechanical sta- bility of a barrier web. Also, if the stabili- mentum is serving to deter larger animals from walking or flying through the web, the early warning provided by a barrier web may be superfluous enough to not justify the cost of the additional silk. The barrier web also provides a habitat for kleptoparasitic Argyro- des spp. By living in the barrier web, Argy- rodes spp. likely can detect, through vibra- tions, when a prey item has been captured and wrapped; further, by not living on the orb, the threat of being depredated by the host is re- duced (Vollrath 1979). On the other hand, bar- rier webs may benefit the host by deterring or warning of hymenopteran predators or para- sites (Tolbert 1975). The tuning fork stimulation elicited natu- ralistic predatory responses. Specifically, the sequence of observed responses closely fol- low the sequences described by (1) Brings & Frings (1966) for 20-160 Hz stimulation with a modified audio-oscillator in the webs of A. aurantia, (2) Robinson & Olizarri (1971) for heavy prey with sustained vibrations in the web of A. argentata, (3) Harwood (1974) for large, active, non-lepidopteran prey in the web of A. aurantia, (4) Robinson & Robinson JUSTICE ET AL.— WEBS AND PREDATORY BEHAVIOR OF A. FLORIDA 89 (1974) for orthopterans in the webs of Argiope picta L. Koch 1871, Argiope aemula (Wal- ckenaer 1842) and Argiope reinwardti (Do- leschall 1859), and (5) Olive (1980) for slow- ly escaping, large acridid orthopterans in the webs of A. trifasciata. Thus, naturalistic re- sponses can be obtained in the field without having to transport electronic equipment or live prey. Live prey items placed on webs are also likely to be more variable in stimulation than a tuning fork. The response to the tuning fork was usually vigorous. Almost 80% of the tested spiders approached and touched the fork, and over 60% wrapped it in silk. This sequence of pred- atory behavior was unaffected by recent prey capture; the response to the tuning fork was not different when wrapped prey were already present in the web. This is consistent with the arguments set out in Wise (1993) that spiders may be food-limited in general; each addi- tional prey item can further increase survival and fecundity. It may be that spiders with kleptoparasitic Argyrodes spp. in their webs had higher and more consistent predatory re- sponse scores because some proportion of their captured prey is stolen, reducing their to- tal consumption (cf. Rypstra 1981). Argiope florida stabilimenta were remark- able in four ways. First, 13 other species of Argiope are known to add cruciate stabilimen- ta to their webs, but these often comprise only a couple of arms, with full crosses usually be- ing relatively rare (Kingston 1927; Yaginuma 1960; Levi 1968; Marples 1969; Robinson & Robinson 1970, 1974; Lubin 1975; Robinson & Lubin 1979; Robinson & Robinson 1980; Edmunds 1986; Nentwig & Heimer 1987; Nentwig & Rogg 1988; Kerr 1993; Elgar et al. 1996; Hauber 1998; Herberstein et al. 2000b). In comparison, A. florida has a rela- tively high proportion of webs with a com- plete cross (almost 60%). Second, Kingston (1927) remarked that the four arms in the cru- ciate stabilimentum of Argiope pulchella Tho- rell, 1881 were “evenly separated. . . at equi- distant points”. This is a very different arrangement from A. florida stabilimenta, in which the upper and lower pairs of arms are each separated by about 65°. No other studies have quantified the angular arrangement of the arms in Argiope cruciate stabilimenta. Third, there were a substantial number of differences between the upper and lower arms of A. flor- ida stabilimenta. While this may be related to the function of the stabilimentum, it may also be reflective of the asymmetry in the orb it- self: the area above the hub is almost always smaller than the area below the hub. It would be interesting to know how closely stabili- mentum asymmetry is related to the structural asymmetries of the orb itself. It may be rele- vant that size was related to the angle between the upper arms but not to the angle between the lower arms, because size is known to con- tribute to asymmetries in orb webs (Kerber- stein & Keiling 1999). Fourth, the number of bands is sufficiently independent of the length of the stabilimentum arm to continue separate consideration. Arms of the same length can show considerable differences in the number, thickness, spacing, silk density, and even pat- tern of the bands (personal observations). For example, Kingston (1927) counted an average of 6.3 bands/cm on the linear stabilimenta of Argiope sector (ForskM, 1775), over 30% more dense than the bands of A. florida in the present study. Further research into the distribution, nat- ural history and behavior of A. florida could make valuable contributions to conservation and behavioral biology. A phenology of the presence of males and reproductive behavior of the species is needed. Also, the few patches of sand scrub remaining in Palm Beach, Bro- ward and Dade Counties should be checked for the presence of A. florida. Behavioral re- search on A. florida could facilitate and extend comparative work with its more extensively studied congeners. If the stabilimentum is a visual signal, there may well be costs or ben- efits for spiders that deviate from the mean on web orientation from vertical and compass di- rection of the plane of the orb. If variability in these characters can account for variability in prey capture success and/or web destruc- tion, this would speak to general theories of stabilimentum function. Investigations into the influence of Argyrodes kleptoparasitism on Argiope behavior should be pursued. A cost- benefit analysis of barrier web construction that considers Argyrodes kleptoparasitism and hymenopteran attacks could be used to ad- dress the finding that 25% of A. florida built barrier webs. Also, changes in the extent of kleptoparasitism should be related to changes in predatory behavior; the exact nature of this relationship, including Argyrodes depredation 90 THE JOURNAL OF ARACHNOLOGY by Argiope, should be quantified. Lastly, var- iation in the number of arms in the stabili- mentum, the spacing or arrangement of arms and band density within arms could all be re- lated to several proposed functions of the sta- bilimentum and should be considered in future studies of stabilimentum structure and func- tion. ACBUHOWLEDGMENTS The authors are indebted to Mark Deyrup at the Archbold Biological Station for gra- ciously providing thoughts, space, and support facilities while we were working on the Lake Wales Ridge. Todd Blackledge, Mark Deyrup, Marie Herberstein, Alexander Kerr and an anonymous reviewer provided extremely helpful advice and comments on the manu- script. Paul Vos in the Biostatistics Depart- ment at East Carolina University provided training in the statistical analysis of circular data, but any errors in this paper are the re- sponsibility of the authors. The Behavioral Sciences Department of Nova Southeastern University financially supported this research. LITERATURE CITED Barrows, W.M. 1915. The reactions of an orb- weav- ing spider, Epeira sclopetaria Clerck, to rhyth- mic vibrations of its web. Biological Bulletin 29: 316-332. Batschelet, E. 1981. Circular Statistics in Biology. Academic Press, New York. Biere, J.M. & G.W. Uetz. 1981. Web orientation in the spider Micrathena gracilis (Araneae: Aranei- dae). Ecology 62:336-344. Blackledge, T.A. & J.W. Wenzel. 1999. Do stabili- menta in orb webs attract prey or defend spiders? Behavioral Ecology 10:372-376. Blackledge, T.A. & J.W. Wenzel. 2000. The evo- lution of cryptic spider silk: a behavioral test. Behavioral Ecology 11:142-145. Boys, C.V. 1880. The influence of a tuning-fork on the garden spider. Nature 23:149-150. Caine, L.A. & C.S. Hieber. 1987. Web orientation in the spider Mangora gibberosa (Hentz) (Ara- neae, Araneidae). Journal of Arachnology 15: 263-266. Cangialosi, K.R. 1990. Life cycle and behavior of the kleptoparasitic spider, Argyrodes ululans (Ar- aneae, Theridiidae). Journal of Arachnology 18: 347-358. Carrel, J.E. 1978. Behavioral thermoregulation dur- ing winter in an orb-weaving spider. Symposia of the Zoological Society of London 42:41-50. Comstock, J.H. 1948. The Spider Book: A Manual for the Study of the Spiders and Their Near Rel- atives, the Scorpions, Pseudoscorpions, Whip- scorpions, Harvestmen, and Other Members of the Class Arachnida, Found in America North of Mexico, with Analytical Keys for Their Classi- fication and Popular Accounts of Their Habits. Comstock Publishing Company, Ithaca, New York. Craig, C.L. 1987. The ecological and evolutionary interdependence between web architecture and web silk spun by orb web weaving spiders. Bi- ological Journal of the Linnean Society 30:135- 162. Craig, C.L. 1991. Physical constraints on group for- aging and social evolution: observations on web- spinning spiders. Functional Ecology 5:649-654. Craig, C.L. & G.D. Bernard. 1990. Insect attraction to ultraviolet-reflecting spider webs and web dec- orations. Ecology 71:616-623. Eberhard, WG. 1973. Stabilimenta on the webs of Uloborus diversus (Araneae: Uloboridae) and other spiders. Journal of Zoology, London 171: 367-384. Eberhard, W.G. 1990. Function and phytogeny of spider webs. Annual Review of Ecology and Systematics 21:341-372. Edmunds, J. 1986. The stabilimenta of Argiope fla- vipalpis and Argiope trifasciata in west Africa, with a discussion of the function of stabilimenta. Pp. 61-72. In Proceedings of the Ninth Interna- tional Congress of Arachnology, Panama, 1983. (W.G. Eberhard, YD. Lubin, & B.C. Robinson, eds.). Smithsonian Institution Press, Washington, D.C. Eisner, T & S. Nowicki. 1983. Spider web protec- tion through visual advertisement: role of the sta- bilimentum. Science 219:185-187 Elgar, M.A. 1989. Kleptoparasitism: a cost of ag- gregating for an orb-weaving spider. Animal Be- haviour 37:1052-1055. Elgar, M.A., R.A. Allan, & T.A. Evans. 1996. For- aging strategies in orb-spinning spiders: ambient light and silk decorations in Argiope aetherea Walckenaer (Araneae: Araneoidea). Australian Journal of Ecology 21:464-467. Elgar, M.A., J.M. Schneider, & M.E. Herberstein. 2000. Female control of paternity in the sexually cannibalistic spider Argiope keyserlingi. Pro- ceedings of the Royal Society of London B 267: 2439-2443. Enders, E 1973. Selection of habitat by the spider Argiope aurantia Lucas (Araneidae). American Midland Naturalist 90:47-55. Enders, E 1976. Effects of prey capture, web de- struction and habitat physiognomy on web-site tenacity of Argiope spiders (Araneidae). Journal of Arachnology 3:75-82. Ewer, R.E 1972. The devices in the web of the Af- rican spider Argiope flavipalpis. Journal of Nat- ural History 6:159-167. JUSTICE ET AL.— WEBS AND PREDATORY BEHAVIOR OF A. FLORIDA 91 Frings, H. & M. Brings. 1966. Reactions of orb- weaving spiders (Argiopidae) to airborne sounds. Ecology 47:578-588. Harwood, R.H. 1974. Predatory behavior of Argi- ope aurantia Lucas. American Midland Natural- ist 91:130-139. Hauber, M.E. 1998. Web decorations and alterna- tive foraging tactics of the spider Argiope ap- pensa. Ethology, Ecology & Evolution 10:47-54. Herberstein, M.E. 2000. Foraging behaviour in orb- web spiders (Araneidae): do web decorations in- crease prey capture success in Argiope keyserlin- gi Karsch 1978? Australian Journal of Zoology 48:217-223. Herberstein, M.E., C.L. Craig, J.A. Coddington, & M.A. Elgar. 2000a. The functional significance of silk decorations of orb- web spiders: a critical review of the empirical evidence. Biological Re- views 75:649-669. Herberstein, M.E., C.L. Craig, & M.E. Elgar. 2000b. Foraging strategies and feeding regimes: web and decoration investment in Argiope key- serlingi Karsch (Araneae: Araneidae). Evolution and Ecology Research 2:69-80. Herberstein, M.E. & A.M. Heiling. 1999. Asym- metry in spider orb webs: a result of physical constraints? Animal Behaviour 58:1241-1246. Higgins, L.E. & E. Ezcurra. 1996. A mathematical simulation of thermoregulatory behaviour in an orb- weaving spider. Functional Ecology 10:322- 327. Hingston, R.WG. 1927. Protective devices in spi- der’s snares, with a description of seven new spe- cies of orb- weaving spiders. Proceedings of the Zoological Society of London 28:259-293. Horton, C.C. 1980. A defensive function for the stabilimenta of two orb weaving spiders (Ara- neae: Araneidae). Psyche 87:13-20. Humphreys, WE 1991. Thermal behaviour of a small spider (Araneae: Araneidae: Araneinae) on horizontal webs in semi-arid Western Australia. Behavioral Ecology and Sociobiology 28:47-54. Humphreys, W.E 1992. Stabilimenta as parasols: shade construction by Neogea sp. (Araneae: Ar- aneidae, Argiopinae) and its thermal behaviour. Bulletin of the British Arachnological Society 9: 47-52. Kerr, A.M. 1993. Low frequency of stabilimenta in orb webs of Argiope appensa (Araneae: Aranei- dae) from Guam: an indirect effect of an intro- duced avian predator? Pacific Science 47:328- 337. Klarner, D. & EG. Barth. 1982. Vibratory signals and prey capture in orb-weaving spiders {Zygiel- la x-notata, Nephila clavipes; Araneidae). Jour- nal of Comparative Physiology 148:445-455. Landolfa, M.A. & EG. Barth. 1996. Vibrations in the orb web of the spider Nephila clavipes: cues for discrimination and orientation. Journal of Comparative Physiology A 179:493-508. Larcher, S.F. & D.H. Wise. 1985. Experimental studies of the interactions between a web-invad- ing spider and two host species. Journal of Ar- achnology 13:43-59. Levi, H.W. 1968. The spider genera Gea and Ar- giope in America (Araneae: Araneidae). Bulletin of the Museum of Comparative Zoology 136: 319-352. Lubin, Y.D. 1975. Stabilimenta and barrier webs in the orb webs of Argiope argentata (Araneae, Ar- aneidae) on Daphne and Santa Cruz Islands, Gal- apagos. Journal of Arachnology 2:119-126. Mardia, K.V. 1972. Statistics of Directional Data. Academic Press, New York. Marples, B.J. 1969. Observations on decorated webs. Bulletin of the British Arachnological So- ciety 1:13-18. Masters, WM. 1984. Vibrations in the orb webs of Nuctenea sclopetaria (Araneidae) II: Prey and wind signals and the spider’s response threshold. Behavioral Ecology and Sociobiology 15:217- 223. Masters, WM. & H. Markl. 1981. Vibration signal transmission in spider orb webs. Science 213: 363-365. Masters, WM. & A.J.M. Moffat. 1983. A function- al explanation of top-bottom asymmetry in ver- tical orbwebs. Animal Behaviour 31:1043-1046. McReynolds, C.N. 2000. The impact of habitat fea- tures on web features and prey capture of Argio- pe aurantia (Araneae, Araneidae). Journal of Ar- achnology 28:169-179. Myers, R.L. 1990. Scrub and high pine. Pp. 150- 193. In Ecosystems of Florida. (R. L. Myers & J. J. Ewel, eds.). University of Central Florida Press, Orlando, Florida. Nentwig, W. & S. Heimer. 1987. Ecological aspects of spider webs. Pp. 211-225. In Ecophysiology of Spiders. (W Nentwig, ed.). Springer- Verlag, Berlin. Nentwig, W. & H. Rogg. 1988. The cross stabili- mentum of Argiope argentata (Araneae: Aranei- dae)— nonfunctional or a nonspecific stress re- action? Zoologischer Anzeiger 221:248-266. Olive, C.W. 1980. Foraging specializations in orb- weaving spiders. Ecology 61:1133—1144. Pointing, P.J. 1965. Some factors influencing the orientation of the spider, Frontinella communis (Hentz), in its web (Araneae: Linyphiidae). Ca- nadian Entomologist 97:69-78. Robinson, M.H. & Y. Lubin. 1979. Specialists and generalists: the ecology and behavior of some web-building spiders from Papua New Guinea. 1. Herennia ornatissima, Argiope ocyaloides, and Arachnura melanura (Araneae: Araneidae). Pa- cific Insects 21:97-132. Robinson, M.H. & J. Olazarri. 1971. Units of be- 92 THE JOURNAL OF ARACHNOLOGY havior and complex sequences in the predatory behavior of Argiope argentata Fabricius. Smith- sonian Contributions to Zoology 65:1-36. Robinson, M.H. & B. Robinson. 1970. The stabi- limentum of the orb web spider, Argiope argen- tata: an improbable defence against predators. Canadian Entomologist 102:641-655. Robinson, B.C. & Robinson, M.H. 1974. The bi- ology of some Argiope species from New Guin- ea: predatory behaviour and stabilimentum con- struction (Araneae: Araneidae). Zoological Journal of the Linnean Society 54:145-159. Robinson, M.H. & B.C. Robinson. 1978. Thermo- regulation in orb-web spiders: new descriptions of thermoregulatory postures and experiments on the effects of posture and coloration. Zoological Journal of the Linnean Society 64:87-102. Robinson, M.H. & B. Robinson. 1980. Comparative studies of the courtship and mating behavior of tropical araneid spiders. Pacific Insects Mono- graphs 36:1-218. Rypstra, A.L. 1981. The effect of kleptoparasitism on prey consumption and web relocation in a Pe- ruvian population of the spider Nephila clavipes. Oikos 37:179-182. Sandoval, C.P. 1994. Plasticity in web design in the spider Parawixia bistriata: a response to variable prey type. Functional Ecology 8:701-707. Scharff, N. & J.A. Coddington. 1997. A phyloge- netic analysis of the orb-weaving spider family Araneidae (Arachnida, Araneae). Zoological Journal of the Linnean Society 120:355-434. Schoener, TW. & D.A. Spiller. 1992. Stabilimenta characteristics of the spider A argentata on small islands: support of the predator-defense hy- pothesis. Behavioral Ecology and Sociobiology 31:309-318. Sherman, P.M. 1994. The orb-web: an energetic and behavioural estimator of a spider’s dynamic for- aging and reproductive strategies. Animal Be- haviour 48:19-34. Suter, R.B. 1981. Behavioral thermoregulation: so- lar orientation in Frontinella communis (Liny- phiidae), a 6-mg spider. Behavioral Ecology and Sociobiology 8:77-81. Tolbert, W.W. 1975. Predator avoidance and behav- iors and web defensive structures in the orb weavers Argiope aurantia and Argiope trifascia- ta (Araneae: Araneidae). Psyche 82:29-52. Tolbert, W.W. 1979. Thermal stress of the orb- weaving spider Argiope trifasciata (Araneae). Oikos 32:386-392. Tso, LM. 1996. Stabilimentum of the garden spider Argiope trifasciata: a possible prey attractant. Animal Behaviour 52:183-191. Tso, I-M. 1998a. Isolated spider web stabilimentum attracts insects. Behaviour 135:311-319. Tso, I-M. 1998b. Stabilimentum-decorated webs spun by Cyclosa conica (Araneae, Araneidae) trapped more insects than undecorated webs. Journal of Arachnology 26:101-105. Venner, S., A. Pasquet, & R. Leborgne. 2000. Web- building behaviour in the orb-weaving spider Zygiella x-notata: influence of experience. Ani- mal Behaviour 59:603-611. Vollrath, F. 1979. Vibrations: their signal function for a spider kleptoparasite. Science 205:1149- 1151. Watanabe, T. 1999. Prey-attraction as a possible function of the silk decoration of the uloborid spider Octonoba sybotides. Behavioral Ecology 5:607-611. Wells, EL. 1936. Orbweavers’ differential respons- es to a tuning fork. Psyche 43:10-13. Wise, D.H. 1993. Spiders in Ecological Webs. Cam- bridge University Press. Yaginuma, T. 1960. Spiders of Japan in Colour. Hoikusae, Osaka. Zar, J.H. 1996. Biostatistical Analysis, 3*^^^ ed. Pren- tice Hall, Upper Saddle River, New Jersey. Zschokke, S. 2002. Ultraviolet reflectance of spi- ders and their webs. Journal of Arachnology 30: 246-254. Manuscript received 9 September 2003, revised 12 February 2004. 2005. The Journal of Arachnology 33:93-100 FIRST FOSSIL FILISTATIDAEi A NEW SPECIES OF MISIONELLA IN MIOCENE AMBER FROM THE DOMINICAN REPUBLIC Da¥M Penney: Earth Sciences, The University of Manchester, Manchester, Ml 3 9PL, United Kingdom ABSTRACT. Misionella didicostae new species is described from 15-20 Ma Miocene amber from the Dominican Republic as the first fossil record of the family Filistatidae. The biogeography of the extant (Brazil and Argentina) and the new fossil species supports the hypothesis that the developing northern Greater Antilles and northwestern South America were briefly (33-35 Ma) connected by a landspan centered on the ero.ergeiit Aves Ridge. Undiscovered extant species of Misionella may exist on Hispaniola. The autospasized first pair of legs suggest that the spider was engulfed in a flowing resin seep of relatively low viscosity, rather than having wandered onto a sticky exudate, becoming stuck and then covered by a subsequent resin flow. Keywords: Hispaniola, Araneae, spider, biogeography, autospasy The spider family Filistatidae has an almost worldwide distribution in tropical and warm temperate regions, and consists of 107 species and one subspecies in 16 genera (Platnick 2003). These small to medium-sized, cribeh late spiders represent one of the most basal branches of the Haplogynae (Platnick et al. 1991). Filistatidae have not previously been described in the fossil record, although Eskov (1990) mentioned a fossil specimen from the Upper Jurassic of Kazakhstan. The current evolutionary tree (including the new fossil de- scribed in this paper) of the Haplogynae (Fig. 1) predicts the presence of Filistatidae in the fossil record back to the Upper Cretaceous. However, this is a youngest age prediction based on the presence of Ooeopidae and Se- gestriidae in amber from New Jersey (Penney 2002a, 2004). Here, the first fossil Filistatidae is described in the genus Misionella, from Miocene (15-20 Ma; e.g, Iturralde-Vineet & MacPhee 1996) Dominican Republic amber. METHODS Preservation,— The spider is preserved close to the surface of a clear yellow, tear- shaped piece of Dominican Republic amber 4 cm long X 1 .7 cm wide; for details of locality and stratigraphy see Iturraide-Vineet & MacPhee (1996). The spider is best observed in ventral view. There are two partial insect legs and the associated thoracic stereite in the amber as a syninclusion. The holotype and only known specimen is held in the collection of the Museo del Ambar Dominicano, Puerto Plata, Dominican Republic. Measurements and drawings,— All mea- surements were made using an ocular grati- cule and are in mm. Drawings were done un- der incident light with a camera lucida attached to an Olympus SZH stereomicro- scope and photographs were taken with a Ni- kon DIX digital camera attached to a Wild M8 stereomicroscope then manipulated in Adobe Photoshop. Abbreviations used in the text and fig- ures.-— In the leg formula (e.g. 1423), the legs are ranked in order of length (longest first). Abbreviations are as follows: cx = coxa; cy = cymbium; e = embolus; fe = femur; h = haem,olymph; la = labium; mt == metatarsus; op = opisthosoma; pa = patella; pi = paraem- bolic lamina; pom = leg segment present but not measurable; pp = pedipalp; rex = retro- lateral excavation; s = long setae; sp = spine; spr = spinneret region; st = sternum; ta — tarsus; ti = tibia; 1-4 = walking legs 1-4. SYSTEMATIC PALEONTOLOGY Family Filistatidae Ausserer 1867 Subfamily Prithinae Gray 1995 Misionella Ramirez & Grismado 1997 Type species, — Filistata mendensis Mello- Leitao 1920 by original designation. 93 94 THE JOURNAL OF ARACHNOLOGY Age (Ma) ^ < u. O UJ < iuj 5 < S Q y 5 m O UJ % LU < UJ Q ^ LJJ Q < < - X o o ^ E P i h-UJ. O) o Q. 10m) white pines (Pinus strobus) and mixed species of smaller hardwoods, espe- cially red maple {Acer rubrum) and white ash (Fraxinus americana), with an uederstory of saplings and shrubs. This species mix repre- sents an alternative intermediate stage of suc- cession to the assemblage in CG; the relative height of the hardwoods in this stand indicated that PW may be the older of the two, at least 40 years old. The site is located on a flood plain, with relatively most soil. The litter layer is mainly dead needles, but somewhat thicker (>lcm). 5. Upland hardwoods (UH): This site is within the woodlot boundary of the DR site. The overstory is of mixed hardwoods 10- 15m high, especially white ash and tulip poplar {Liriodendron tulipifera), with several species of oaks (Quercus spp.), and red maple in the uederstory. This species mix is typical of the community that replaces coniferous species, i.e., perhaps 10-15 years older than site PW (i.e., 50-55 years old). The soil here is well- drained and rich in organic matter, with a rel- atively deep (3-4cm) leaf litter layer. 6. Lowland hardwoods (LH): This is a ma- ture hardwood forest that has been subjected to little disturbance for at least the past 70 years, with canopy trees (tulip, maple, white ash, and mixed oak) > 30m. This site is deep- ly shaded and is on a floodplain at the bottom of a slope, downward from site UH. The leaf litter is more compacted than and not as thick as at site UH, probably because of the in- creased soil moisture and humidity. Sampling* — We sampled ground-dwelling spiders at each site with six pitfall traps set out in a 2 X 3 array, such that no trap was closer than approximately 1.5m from its near- est neighbor. Trap arrays were at least 10m from the edge of the habitats they sampled. Each trap consisted of a 10cm diameter, 11cm deep polypropylene cup fitted into a perma- nent sleeve that was sunk into the ground flush with the soil surface. A cover for each 104 THE JOURNAL OF ARACHNOLOGY Table 1. — Total numbers of cursorial spiders by habitat type (sampling site): DR = disturbance recovery; OF = old field; CG = cedar grove; PW = pine woods; UH = upland hardwoods; LH = lowland hard- woods. Superscripts denote other studies in which species were found: 1 = Hurd & Fagan (1992); 2 = Buddie et al. (2000); 3 = Aitcheson & Sutherland (2000); 4 = Bonte et al. (2002); 5 = Gajdos & Toft (2000); 6 = Uetz (1975); 7 = Uetz (1976); 8 = Uetz (1977); 9 = Uetz (1979); 10 = Buddie and Rypstra (2003); and 11 = Draney (1997). Nomenclature follows Platnick (2003). Family DR OF CG PW UH LH Species Genus; species Total Total Total Total Total Total Total Agelenidae Koch 1837 Agelenopsis pennsylvanica^ Koch 1843 Antrodiaetidae Gertsch 1940 Antrodiaetus unicolor Hentz 1842 Corinnidae Karsch 1880 Castianeira cingulata^-^’^'^’ Koch 1841 2 1 Castianeira longipalpus^’ “ Hentz 1847 Phrurotimpus alarms'' Hentz 1847 Phrurotimpus borealis^’ ^ Emer- ton 1911 Phrurotimpus minutus'-^ Banks 1892 1 3 4 2 4 16 22 3 2 5 1 1 2 Phrurotimpus sp. Chamberlin & Ivie 1935 Scotinella britcheri Petrunke- 2 1 vitch 1910 Cybaeidae Banks 1892 Dysderidae Koch 1837 Gnaphosidae Pocock 1898 Hahniidae Bertkau 1878 Scotinella formica' Banks 1911 Scotinella sp. Banks 1911 Cybaeus sp. Koch 1868 Dysdera crocata"' Koch 1838 Drassyllus depressus Emerton 1890 Hahnia cinerea^’^ Emerton 1890 Antistea brunnea Emerton 1909 Hahnidae sp. 1 Neoantistea agilis^' Keyserling 1887 Neoantistea magna Keyserling 1887 8 1 1 3 1 9 5 1 1 1 5 6 1 1 2 1 3 4 1 1 2 1111 4 Linyphiidae Blackwall 1859 Drapetisca alteranda Chamber- lin 1909 Subfamily: Linyphiinae Stemonyphantes lineatus Linnae- 1 us 1758 Tenuiphantes zebra Emerton 1882 Lycosidae Sundevall 1833 Allocosa funerea'- " Hentz 1844 2 1 Allopecosa aculeata Clerck 1757 1 Arctosa virgo Chamberlin 1925 Hogna helluo'' Walckenaer 1 1837 Pardosa distincta' Blackwall 2 1 1846 Pardosa milvina'' " Hentz 11 1844 Pardosa saxatilis''^ Hentz 1844 16 Pardosa sp. I Koch 1847 Pardosa sp. 2 Koch 1847 7 Pirata aspirans''^ ChambQvXm 1 2 1 1 1 1 1 1 3 1 1 2 3 11 16 7 1904 MALLIS & HURD— CURSORIAL SPIDER DIVERSITY 105 Table 1. — Continued. DR OF CG PW UH LH Species Family Genus; species Total Total Total Total Total Total Total Pirata imularis^'^'^ Emerton 25 37 1 141 204 1885 Rabidosa rabida^- Walckanaer 5 5 1837 Schizocosa avida^ Walckanaer 3 4 7 1837 Lycosidae Sundevall 1833 Schizocosa bilineata^' “ Emerton 2 2 1885 Schizocosa ocreata^' 7, 8, ii 6 1 5 3 15 Hentz 1844 Trochosa terricola^' ^ Tho- 2 1 3 reli 1856 Trochosa sp Kock 1847 1 1 Oonopidae Simon 1890 Orchestina saltitam Banks 1894 1 1 Oxyopidae Thorell 1870 Oxyopes salticus^'^^ Hentz 1845 2 2 PMlodromidae Thorell 1870 Thanatus forrnicinus^^ Clerck 1 1 1757 Pisauridae Simon 1890 Dolomedes tenebrosus Hentz 1 1 2 1844 Salticidae Blackwall 1841 Habronattus borealis Banks 1 1 1895 Neon neliP PecMiam & Peckham 1 1 2 1888 Theridiidae Sundevall 1833 Euryopsis argentea Emerton 1 1 1882 Thomisidae Sundevall 1833 Ozyptila sp. Simon 1864 1 1 Xysticus ferox^’'^’^’ Hentz 1847 1 1 2 Xysticus punctatus Keyserling 0 1880 Xysticus sp. Koch 1835 1 1 Habitat Total Abundance = 50 35 41 47 31 178 382 trap was constructed using a Petri dish lid with nails to elevate it 3cm above the lip of the trap. These covers kept out rainwater and falling debris. Sampling occurred at weekly intervals from early June to mid-August, and then once at the end of September 2002 (total = 354 trap-days). Each time we sampled, we put approximately 2cm of 70% ethanol into each trap during the afternoon (ca 1600h), and collected the samples 16-18h later. All adult spiders collected from the traps were counted and identified using taxonomic keys (Kaston 1978, 1981; online taxonomic updates http://kastoii.traesy.edu/spiderlist/ Kaston78.htm and http://kastoe.traesy.edu/ spiderlist/kast.htm; Roth 1993). Our nomen- clature follows Plateick (2003). We did not attempt to enumerate or identify to species spiders in the subfamily Erigonieae (family Linyphiidae), which were infrequently cap- tured, and most of which were represented by a single individual. At least one individual of each species collected (a male and female of each, when available) was preserved in Kah- le’s fluid as part of a reference collection. As with any field study in a diverse species assemhlage, sampling efficacy is not likely to be equal among taxa. In the case of pitfall traps, for instance, the most active spiders (e.g., many lycosids) may have a tendency to be disproportionately sampled relative to more sedentary species (e.g., clubionids). There- fore, species richness and relative abundance of captured spiders may not accurately reflect the entire resident assemblage, but can be used for comparisons among sites of those taxa that are susceptible to pitfall trapping. Data analysis.— We compared sampling 106 THE JOURNAL OF ARACHNOLOGY Table 2. — The number of shared cursorial species between habitats, and species diversity (richness = S; J' = evenness; Shannon’s diversity = H') for each habitat based on pit trap samples. Sites arranged in order of increasing successional age from left to right and top to bottom. Site descriptions given in Methods. Sites: DR OF CG PW UH LH DR 14 — — — — — OF 6 18 — — — — CG 0 3 12 — — — PW 1 2 4 9 — — UH 1 1 6 5 18 — LH 2 1 3 4 9 13 H' = 2.06 2.57 1.45 0.94 2.63 0.96 5 = 14 18 12 9 18 13 f = 0.78 0.89 0.58 0.43 0.91 0.37 sites with regard to diversity, measured as (1) the number of species found, or species rich- ness, S, (2) Evenness of distribution of indi- viduals among species, J\ and (3) Shannon’s diversity, H\ which is a measure of the inter- action between evenness and richness (Pielou 1969; Hill 1973). RESULTS We collected a total of 50 species of ground-dwelling spiders from our six sam- pling sites (Table 1). Twenty-six of these were habitat specialists, found at only one site; no species was found at all six sites. The spiders with the broadest distribution, found at four of the six sites, were the lycosids Schizocosa ocreata, Pirata insularis, Pirata arenicola and the hahniid Neoantistea magna. Both S. ocreata and P. insularis were found at all four wooded sites and none was collected at either of the open held sites. However, P. arenicola and TV. magna were found at combinations of wooded and open held sites. Some of the spiders we found appear to have wide geographical distributions. Five species in Table 1 were also reported in four or more other studies from Denmark, Belgium and Manitoba, as well as sites in the U. S. (Delaware, Ohio, Georgia and Virginia). However, there appears to be no reliable re- lationship between how broadly cursorial spi- der species are distributed among geographic sites, how many sites they occupy within a study, or what kind of habitat (e.g., wooded or open) they prefer in those studies that sam- pled more than one habitat type. We found no relationship between succes- sional age and any measure of diversity (Table 2). The pine stand (PW), representing the in- termediate stage of succession, had the lowest spider diversity (Table 2). This site also had the lowest apparent vegetational diversity among the six sites: there was almost no ground cover vegetation, and the tree diversity was limited to white pine and a few small de- ciduous saplings. However, there were no oth- er apparent correlative trends between spider diversity and site structure. The highest H' di- versity and 7’ evenness values we found were in the nearly mature forest (UH), and the old field (OF), our second to youngest site, yield- ing virtually identical rank abundance patterns (Fig. 2). Although species richness was the same (18) for both of these sites, they only shared a single species, TV. magna (Table 2). The climax forest (LH) had the lowest H' val- ue even though species richness was about av- erage among the sites. This was because of the high dominance of a single species {Pirata insularis), which was reflected by the low val- ue of 7’ (Tables 1 & 2), Our most abundant species trapped was P. insularis, accounting for more than half of all spiders trapped (Table 1). The abundance of P. insularis in our traps was highest in mid- June, decreasing to just two individuals caught in August and September. From the beginning of the sample season, the sex ratio of this spe- cies was highly male-biased. As the season progressed it shifted to a female-biased ratio. July appeared to be the month of reproduc- tion: females were caught with egg sacs on 2 July, and with juveniles riding on the dorsa of their abdomens on 10 and 19 July. We also were able to record some repro- MALLIS & HURD— CURSORIAL SPIDER DIVERSITY 107 ductive data for S. ocreata and P. saxatilis. On 1 July we found a female S. ocreata with a new (white) egg case. On 10 July a female with a gray (older) egg case was captured. The case was dissected and almost fully developed eggs were found inside, with fangs evident. On 19 July a female was caught with juveniles on her back. On 20 June we found a female P. saxatilis, with an egg case. On two other occasions (2 and 17 July) we found females with egg cases. On 26 July we found one with spiderlings on her dorsum, and brought it back to the lab for observation. On 29 July spider- lings were seen leaving the mother’s dorsum and by 30 July they had all dispersed. DISCUSSION As with previously reported studies, we found that most ground-dwelling spider spe- cies were habitat specialists, found at one or two sites, and very few were generalists. Be- cause rare species may be present in such low numbers that they may be missed by sam- pling, we cannot conclude that a species that did not show up in our samples was complete- ly absent from a given site, but we can at least score a species as present if we captured it in a sample. This is a problem common among studies that report the presence of rare species, many of which are represented by a single trapped individual (e.g., 31 of 105 species re- ported by Buddie et al. 2000). Both Aitchison & Sutherland (2000) and Hurd & Fagan (1992) found only three species that occupied four or more sites; we found only four species in that category. However, very few of these are the same species. Six of the species we found were also reported from these two studies in Manitoba, one of which {Trochosa terricola) was found in both Man- itoba studies and in our present study (Table 1) and has been reported to occur from as far away as Finland (Aitchison & Sutherland 2000) and Belgium (Bonte et al. 2002). Not surprisingly, there were more spider species (20) in common between our present study and the geographically closer Delaware sites of Hurd & Fagan (1992). The most abundant species in both the present Virginia study and the Delaware study was the lycosid, Pirata in- sularis. The majority of spiders we encountered be- longed to the family Lycosidae. While P. in- sularis preferred wooded sites, the next two most abundant lycosids (Pardosa milvina and P. saxatilis) were confined to the most open site (DR). Buddie & Rypstra (2003) also not- ed that Pardosa species achieve dense popu- lations in barren exposed habitats. Schizocosa ocreata was found in all four wooded sites. This species is commonly found in leaf litter of deciduous forests in eastern North America (Wagner & Wise 1996). Uetz (1977) noted that S. ocreata occurs in simple litter where the leaves are compressed and the ground is relatively moist. The diversity of sampled spiders in our study did not follow a successional gradient, a finding of other studies as well: a forest suc- cessional gradient in Delaware (Hurd & Fagan 1992), and forests in Manitoba (Aitchison & Sutherland 2000; Buddie et al. 2000). Part of the difficulty may lie in the relative scarcity of studies that examine a wide range of suc- cessional seres at a given locale. In any event, attempting to find predictable environmental correlates to spider diversity have proved frus- trating for many researchers. In their 20 year study of coastal dunes Gajdos & Toft (2000) found that temporal changes in community composition were greater than differences oc- curring between habitats. It was impossible for them to determine what ways ecological characteristics changed for those spider spe- cies in which abundance changed over time. Differences in the physical structure of leaf litter and its complexity can influence species composition, spider abundance and diversity generally increasing with increased litter depth in some studies (Uetz 1975, 1977, 1979; Buddie & Rypstra 2003). Uetz (1975) found that weather patterns, which could be tied to prey productivity for spiders, did not correlate significantly to any diversity measure. Instead, he found that richness and evenness were re- lated to litter depth, and moderately well re- lated to successional age and plant cover. However, in our study we found as many spi- der species in the two open habitats with al- most no litter (DR and OF) as we did in the two hardwood forest habitats (UH and LH). Mrzljak & Wiegleb (2000) presented evidence that species richness and abundance are lim- ited by vegetative stratification and height, e.g., tall grass stands had more species than short grass stands. Hurd & Fagan’s (1992) study of spider assemblages in Delaware found the main difference to be between 108 THE JOURNAL OF ARACHNOLOGY woodland and open habitats and not age of the habitats: diversity of cursorial spiders gen- erally was greater in open field habitats than in woodlands. However, in our present study we found no clear difference among sites based on presence, absence, or extent of tree cover. It is apparently not difficult to predict the presence in spider assemblages of some very broad generalists such as Trochosa terricola, but for most habitat speeialists, such predic- tion is problematic. Given the data so far, it is hard to refute the null hypothesis that spider diversity within a site may be more a function of stochastic colonization opportunities of dif- ferent species rather than a set of intra-com- munity assembly rules (sensu Diamond 1975). Other factors that can influence species mem- bership in arthropod assemblages, including spiders, are habitat features such as area, de- gree of isolation, and movement patterns of animals relative to their resouree requirements (Matter 1996, 2000; Hanski 1999; Marshall et al. 2000; Samu et al. 2003). Thus, changing spider community composition over time is not really true succession at all, but rather re- peated colonization by opportunistic species. The success of such colonists, once they in- vade a habitat, may well depend on competi- tive abilities (Marshall et al. 2000) and the changing environmental conditions that ac- company plant succession (Mrzljak & Wie- gleb 2000; Hodkinson et al. 2001), but as yet we are far from being able to predict cursorial spider composition among seres with any de- gree of precision. ACKNOWLEDGMENTS This study is part of ongoing long-term re- search on succession and disturbance recovery in the Science Park of Washington & Lee Uni- versity. Our research was supported by grants from the R. E. Lee (REM) and John M. Glenn (LEH) research programs of the university. LITERATURE CITED Aitchison, C.W. & G.D. Sutherland. 2000. Diversity of forest upland arachnid communities in Mani- toba taiga (Aranae, Opiliones). Canadian Field Naturalist 114:636-651. Bonte, D., L. Baert & J.R Maelfait. 2002. Spider assemblage structure and stability in a hetero- geneous coastal dune system (Belgium). Journal of Arachnology 30:331-343. Buddie, C.M. & A.L. Rypstra. 2003. Factors initi- ating emigration of two wolf spider species (Ar- anae:Lycosidae) in an agroecosystem. Environ- mental Entomology 32:88-95. Buddie, C.M., J.R. Spence & D.W. Langor. 2000. Succession of boreal forest spider assemblages following wildfire and harvesting. Ecography 23: 424-436. Diamond, J.M. 1975. Assembly of species com- munities. Pp. 342-444. In Ecology and Evolu- tion of Communities (M.L. Cody and J.M. Dia- mond, eds.). Belknap Press, Massachusetts. Draney, M.L. 1997. Ground-layer species (Aranae) of a Georgia piedmont flood plain agroecosys- tem: species list, phenology and habitat selection. Journal of Arachnology 25:333-351. Gajdos, P & S. Toft. 2000. A twenty-year compar- ison of epigeic spider communities (Aranae) of Danish coastal heath habitats. Journal of Arach- nology 28:90-96. Hanski, LA. 1999. Metapopulation Ecology. Oxford University Press, Oxford, U.K. Hill, M.O. 1973. Diversity and evenness: a unifying notion and its consequences. Ecology 54:427- 432. Hodkinson, I.D., S.J. Coulson, J. Harrison & N R. Webb. 2001. What a wonderful web they weave: spiders, nutrient capture and early ecosystem de- velopment in the high Arctic — some counter-in- tuitive ideas on community assembly. Oikos 95: 349-352. Hurd, L.E. & R.M. Eisenberg. 1990. Arthropod community responses to manipulation of a bi- trophic predator guild. Ecology 71:2107-2114. Hurd, L.E. & W.E Fagan. 1992. Cursorial spiders and succession: age or habitat structure? OecoL ogia 92:215-221. Kaston, B.J. 1978. How to Know the Spiders. Wm. C. Brown Company Publishers, Dubuque, Iowa. Kaston, B.J. 1981. Spiders of Connecticut. State Geological and Natural History Survey of Con- necticut, Hartford, Connecticut. Lawrence, K.L. & D.H. Wise. 2000. Spider preda- tion on forest-floor Collembola and evidence for indirect effects on decomposition. Pedobiologia 44:33-39. Marshall, S.D., S.E. Walker & A.L. Rypstra. 2000. A test for a differential colonization and com- petitive ability in two generalist predators. Ecol- ogy 81:3341-3349. Matter, S.E 1996. Interpatch movement of the red milkweed beetle, Tetraopes tetraophthalmus: in- dividual responses to patch size and isolation. Oecologia 105:447-453. Matter, S.E 2000. The importance of the relation- ship between population density and habitat area. Oikos 89:613-619. McNabb, D.M., J. Halaj & D.H. Wise. 2001. Infer- ring trophic positions of generalist predators and their linkage to the detrital food web in agroeco- MALLIS & HURD— CURSORIAL SPIDER DIVERSITY 109 systems: a stable isotope analysis. Pedobiologia 45:289-297. Moran, M.D., T.P. Rooney & L.E. Hurd. 1996. Top- down cascade from a bitrophic predator in an old-field community. Ecology 77:2219-2227. Mrzljak, J. & G. Wiegleb. 2000. Spider coloniza- tion of former brown coal mining areas — time or structure dependent? Landscape & Urban Plan- ning 1:131-146. Odum, E.P. 1969. The strategy of ecosystem devel- opment. Science 164:262-270. Pielou, E.C. 1969. An Introduction to Mathematical Ecology. Wiley, New York. Platnick, N.I. 2003. The world spider catalog, ver- sion 4.0. American Museum of Natural History, online at http://research.amnh.org/entomology/ spiders/catalogS 1 -87/index. html. Riechert, S.E. & L. Bishop. 1990. Prey control by an assemblage of generalist predators: spiders in garden test systems. Ecology 71:1441-1450. Roth, V.D. 1993. Spider Genera of North America. American Arachnological Society. Samu, E, A. Sziranyi & B. Kiss. 2003. Foraging in agricultural fields: local 'sit-and-move’ strategy scales up to risk-averse habitat use in a wolf spi- der. Animal Behaviour 66:939-947. Spiller, D.A., J.B. Cosos & T.W. Schoener. 1998. Impact of a catastrophic hurricane on island pop- ulations. Science 281:695-697. Terborgh, J., L. Lopez, P, Nunez, M. Rao, G. Sha- habuddin, G. Orihuela, M. Riveros, R. Ascanio, G. H. Adler, T. D. Lambert & L. Baibas. 2001. Ecological meltdown in predator-free forest frag- ments. Science 294:1923-1926. Uetz, G.W. 1975. Temporal and spatial variation in species diversity of wandering spiders (Aranae) in deciduous forest litter. Environmental Ento- mology 4:719-724. Uetz, G.W. 1976. Pitfall trapping in ecological stud- ies of wandering spiders. Journal of Arachnology 3:101-111. Uetz, G.W. 1977. Coexistence in a guild of wan- dering spiders. Journal of Animal Ecology 46: 531-541. Uetz, G.W. 1979. The influence of variation in litter habitats on spider communities. Oecologia 40: 29-42. Uetz, G.W, J. Halaj & A.B. Cady. 1999. Guild structure of spiders in major crops. Journal of Arachnology 27:270-280. Wagner, J.D. & D.H. Wise. 1996. Cannibalism reg- ulates densities of young wolf spiders: evidence from field and laboratory experiments. Ecology 77:639-652. Weeks, Jr., R.D. & TO. Holtzer. 2000. Habitat and season in structuring ground-dwelling spider (Aranae) communities in a shortgrass steppe eco- system. Environmental Entomology 29:1164- 1172. Wilson, E.O. 1992. The Diversity of Life. Harvard University Press, Cambridge. Wise, D.H. 1993. Spiders in Ecological Webs. Cam- bridge University Press, New York. Wise, D.H., WE. Snyder & P. Tuntilbunpakul. 1999. Spiders in decomposition food webs of agroecosystems: theory and evidence. Journal of Arachnology 27:363-370. Manuscript received 19 May 2003, revised 9 Feb- ruary 2004. 2005. The Journal of Arachnology 33:110-123 SEASONAL HABITAT SHIFT IN AN INTERTIDAL WOLF SPIDER: PROXIMAL CUES ASSOCIATED WITH MIGRATION AND SUBSTRATE PREFERENCE Johanna M. Krans' and Douglass H. Morse^; Department of Ecology and Evolutionary Biology, Box G-W, Brown University, Providence, RI 02912 USA. E-mail: d_morse@brown.edu ABSTRACT. During most of the year, the wolf spider Pardosa lapidicina Emerton 1885 occupies tidal cobble beaches surrounding Narragansett Bay, RI, USA, but in late autumn part of the population moves into adjacent forest litter to overwinter. We monitored these movements with drift fences and pitfall traps from 1996-1999 and evaluated the possible roles of ambient temperature, rainfall, humidity and storm events. We tested substrate choice over the season as a proxy for migratory tendency, both in the laboratory and the field, focusing on the roles of temperature and photoperiod. The timing of peak migration differed among years (S.D. = 15.5 d). Minimum weekly temperature, weekly rainfall, percent relative humidity and storm events did not explain the variation in migratory times. However, significantly more spiders migrated during weeks with below-freezing temperatures than in weeks without them. Leaf litter, which has less variable temperatures than beach cobble, may provide a refuge from extreme temperatures during winter. Spiders maintained at cold temperatures in laboratory experiments chose leaves over beach cobble significantly more often than did those in warm temperatures. The time of year that spiders were collected also influenced their probability of choosing leaf substrate in the laboratory. Photoperiod, on the other hand, did not significantly influence substrate preference. This study helps to uncover how environmental cues influence seasonal movements across a habitat boundary. Keywords: Acclimation period, photoperiod, substrate, temperature Migration is a common behavioral response to seasonal change in temperate-zone organ- isms, providing them with the opportunity to exploit otherwise unavailable seasonal re- sources or escape temporarily inclement con- ditions (Tauber et al. 1986; Dingle 1996). The timing of these movements, often from one habitat type to another, is essential to the sur- vival and reproduction of the migrant. Thus, seasonal migration likely requires both the use of environmental cues to indicate optimal tim- ing of movement and major shifts in behavior, such as substrate choice preference. Two en- vironmental variables, temperature and pho- toperiod, frequently indicate the oncoming habitat deterioration for temperate-zone ter- restrial species and play a major part in their seasonal movements (Schaeffer 1977; Delisle and McNeil 1987; Han and Gatehouse 1991; ' Current address: Department of Biology, Gilmer Hall, University of Virginia, Charlottesville, VA 22904 USA. 2 Corresponding author. Tanaka 1997). These cues help migrants to an- ticipate or respond directly to seasonally del- eterious aspeets of their environment, such as low temperatures and freezing eonditions, by triggering physiological and behavioral changes (Tauber et al. 1986). Although long-distance movements like those of some birds and butterflies capture much of the attention surrounding migration, considerably shorter movements by less mo- bile animals are likely a frequently occurring phenomena. Despite the short distance, these migrants may cross abrupt physical boundar- ies, ineluding such markedly dissimilar habi- tats as marine or freshwater-influenced to ter- restrial locales (Svensson & Janzon 1984; Takada 1995; Madsen & Shine 1996), epilith- ic to benthic habitats (Kornijow 1992) and elevational gradients (Kimura & Beppu 1993). Crossing the boundaries exposes migrants to novel substrate. To survive in a drastically dif- ferent environment, the migrants are often forced to make behavioral changes, potential- ly including a changed preference for sub- 110 KRAUS & MORSE— SEASONAL HABITAT SHIFT IN A WOLF SPIDER 111 strate in the ‘new’ environment. Whether this change in preference occurs, and how it may be related to actual migratory tendency, has not, to our knowledge, yet been tested. We studied the effect of photoperiod, tem- perature, humidity and storm events on the timing of migration by the intertidal wolf spi- der Pardosa lapidicina across a marine inter- tidal-terrestrial boundary. We further asked how substrate choice is associated with sea- sonal movement in the field, and how impor- tant seasonal cues such as temperature and photoperiod influence substrate preference. Populations of P. lapidicina in Bristol County, RI, USA, spend all but the winter months on cobble beaches immediately above the tide line, but in November and December some individuals retreat from the beach to the ad- jacent forest where they overwinter. Though not a lengthy move (5-15 m, Morse 1997), it spans two totally different adjacent ecosys- tems (see Polis & Hurd 1996). The spiders are exposed to substrates of strikingly contrasting texture and conductance (stones and pebbles vs. leaves): one familiar, one novel. Although short-distance movements (<1 m) from veg- etation to ground hibernacula are common in spiders, larger seasonal movements of several meters are rare (Schaeffer 1977). Winters in the study area vary markedly in their severity (Morse 1997). For example, snow and ice covered the beach from January through mid-March in 1994, making it unin- habitable for spiders during that time, whereas the 1995 winter was snowless, allowing a small number of spiders to persist on the up- per beach throughout the winter (Morse 1997). We hypothesized that as a result this beachside species should respond variably to changing seasons (Hopper 1999; Tammaru et al. 1999; Comeau et al. 2002). During cold winters, temperature extremes, storm events and freezing weather the rocky shore may be- come extremely deleterious to the spiders (Morse 1997). Under these conditions, P. lap- idicina should benefit from anticipating the onset of winter and leaving the beach. During mild winters, the spiders may benefit from de- laying migration temporarily or indefinitely and feeding on the beach. We hypothesized that spiders would use photoperiod as an indicator of the onset of winter, but might only respond with move- ment if temperatures reached some minimal threshold. Furthermore, we expected that large winter storm events would force spiders to leave the beach. Humidity has been shown to influence seasonal movements in another spe- cies of wolf spider (Eubanks & Miller 1993), probably due to their high susceptibility to desiccation. Although very dry conditions are unlikely at our study sites because fresh water drains from upslope towards the shore, we ex- pected that humidity could play a role in the seasonal movement of these spiders. In terms of substrate choice, we hypothesized that sub- strate preference would be closely related to predilection to migrate, since migration re- quired moving to a novel substrate. We there- fore predicted that the cues affecting substrate preference would mirror those cues influenc- ing migration in the field and that substrate could be used to examine those patterns ex- perimentally. Preliminary evidence suggested that cold temperatures increase the preference of wolf spiders for leaf substrate (J.M. ICraus, unpubl. data). To test these hypotheses, we used a com- bination of field observations and experiments in the laboratory and field. We monitored the movements of these spiders from cobble beach to forest leaf litter using drift fences and pitfall traps during the autumn over four fall seasons (1996-1999). We then examined the relationship between migration and common seasonal cues or deleterious events that might affect the spiders on the beach (temperature, photoperiod, moisture, storms). To investigate the relationship between migration and sub- strate preference, we ran substrate choice ex- periments in the field and compared the results with migration patterns. We tested for the in- fluence of photoperiod and temperature on substrate preference in the laboratory to estab- lish the role of these common migratory cues on substrate preference. We used temperature probes to measure the thermal conditions in cobble and leaves before, during and after mi- gration, since consistently warmer tempera- tures might convey benefits for migrating into the leaf litter in winter. METHODS Study subjects. — Pardosa lapidicina in Bristol County, RI, USA have a one-year life cycle. During the reproductive seasons of spring and summer, the spiders regularly fol- low the receding tide into the intertidal area 112 THE JOURNAL OF ARACHNOLOGY where they prey primarily upon small Diptera and Collembola (Morse 1997). Spiders dis- appear from the low intertidal in mid-October. Density on the high intertidal and supratidal decreases in late November and December as numbers caught in the forest leaf litter in- crease (Morse 1997). Spider density on the beach remains low from December-March, although a portion of the population overwin- ters on the upper beach. In March and April the density on the beach increases again, as the spiders migrate back to the beach, and then decreases a last time as that cohort dies after reproducing in June and July. These spi- ders were never found in the forest or forest- beach interface until the fall when they made their decision to overwinter in the forest or on the beach (Morse 1997). It appears that they do not contact the forest environment until the late fall, unless a storm event inundates the beach. Like other Pardosa species (Vogel 1971; Lowrie 1973; Fuji! 1974), P. lapidicina are small, cursorial and nomadic. They are dark-colored and 6-9 mm in length, with the females somewhat larger than the males (Kas- ton 1948). By migration time in November, they weigh 15-45 mg (J.M. Kraus, unpubl. data). In the study area individuals overwinter as juveniles, usually in the penultimate or an- tepenultimate stages (Morse 1997). We have no evidence that they overwinter as adults. Morse (1997) estimated about 2000 spiders entered winter in 1993 along a cobble beach 120 m long (17 spiders/m transect). Voucher specimens of P. lapidicina have been depos- ited in the National Museum of Natural His- tory, Smithsonian Institution. Study area. — We studied the spiders at two sites on the Haffenreffer Estate of Brown Uni- versity, Bristol Co., RI. The research area con- sists of a cobble beach and adjacent forest on the west shore of Mt. Hope Bay, a partially sheltered arm of Narragansett Bay. Most cob- ble rocks range from 10-30 cm in diameter, and larger stones and bedrock protrude in some places (Morse 1997). The cobble bed is several rocks deep. The forest consists pre- dominately of hackberry Celtis occidentalism red oak Quercus rubra and red cedar Juni- perus virginiana under 20 m, with bittersweet Celastrus orbiculatus, greenbrier Smilax sp., and poison ivy Rhus radicans often climbing into the canopy. Other than the vines, ground cover is sparse, but a heavy layer of leaf litter persists throughout the year (Morse 1997). Ambient temperatures on the beach within 1- 2 m of the forest may drop from over 20 °C in early November to =”17 °C by late Decem- ber. Study sites were separated by over 100 m, and by boulders and vegetation (see Morse 1997 for details). Seasonal movement. — To monitor spider movement from beach to forest, 15 m drift fences were used at two forest sites 5 m from the cobble beach/forest interface and parallel to it. The fences, ca. 0.5 m high, consisted of heavy clear plastic sheeting that was support- ed by rebars driven into the ground approxi- mately 1 m apart. The bottom of the plastic sheeting was buried under several cm of soil. Pardosa lapidicina are non-burrowing wolf spiders and it is very improbable that they could have moved under the fences. Pitfall traps, 1 liter plastic containers of 12 cm di- ameter, were sunk flush with the ground at approximately 1 m intervals on the beach side of the fences to trap individuals moving di- rectly away from the beach and on the forest side of the fences to measure lateral move- ment around the fences. Leaves and small stones were added to the bottoms of the traps to provide cover and to discourage cannibal- ism. The total number of spiders captured was used as an index of migration over that trap period. The weekly ratio of spiders captured on the forest side to total catch was used as a conservative estimate of nonmigratory spider activity in the forest. Trapping began in late October, based upon preliminary data on the timing of seasonal movements (Morse 1997), which showed no capture of spiders by hand searching in the 5 m strip of forest above the beach and by using pitfall traps 3 m into the forest from early Sep- tember until 14 November in 1993 (Morse 1997). Additionally, an intensive search of the forest from May-November 1994 (0.1-10 m above the beach) turned up no individuals un- til 6 November (Morse 1997). Drift fence traps were monitored weekly from late Octo- ber or early November through mid to late December 1997-1999, and twice weekly in 1996. Spiders were brought to the laboratory, weighed, sexed and then released on the land- ward side of the fences. Rate of recapture in the fences was estimated in 1997 by marking spiders caught in the fences at the beginning KRAUS & MORSE— SEASONAL HABITAT SHIFT IN A WOLF SPIDER 113 and end of November with orange micronite dye (Morse 1997) and noting their recapture. Ambient temperature was recorded at the time of all censuses and field experiments. Daily minimum temperature, maximum and minimum relative humidity, weekly rainfall and storm events of the local region were ob- tained from recorded NOAA (National Ocean- ographic and Atmospheric Administration) weather station data at the T.F. Green Airport in Providence, RI, 17 km to the WNW (NOAA 1996-1999). All statistical analyses were performed using SAS statistical software (SAS Institute, Inc. 1989) unless otherwise noted. The relationship between temperature, rainfall and humidity measurements taken be- tween trapping periods and spider movement at the end of that period was examined using NOAA data to investigate the potential influ- ence of these factors on migration during 1996-1999. The effect of storm events and days below freezing were independently eval- uated using Wilcoxon non-parametric statis- tics to evaluate the one-way hypothesis that larger migrations would occur during weeks of storm events and freezing weather. In 1999, one temperature probe from a HOBO H8 data logger (Onset Computer Corp., Bourne, MA, USA) was placed in each of four habitat types at a central site: ambient in shade 1 m off ground 5 m into the forest, ambient in open 1 m off ground at the beach- forest edge, under leaves 5 m into the forest, and under rocks on the upper part of the beach. The probes recorded ambient temper- ature every 10 min from early November to late December. Daily temperature variation (s^) was compared among microhabitats using a 1-way ANOVA. Differences among means were then tested using the Ryan-Einot-Gabri- el-Welsch multiple range test. Substrate choice in the field. — Substrate choice experiments were performed weekly for 14 weeks in the field during 1997 using spiders hand-collected from the upper beach (20 per trial), and in 1997 and 1999 using those captured in pitfalls that week (7 test pe- riods in 1997, 5 test periods in 1999). The substrate choice arenas were plastic tubs (32 cm X 18 cm X 10 cm), one half lined with beach cobble and the other half with forest leaf litter. Fresh substrate was used for each run. Spiders already in the leaf litter were ex- tremely difficult to locate by hand (Morse 1997), and as a result only spiders caught in forest pitfalls were used for the already-mi- grated spiders in the substrate choice experi- ments. Substrate choice arenas were placed at the intersection of the cobble beach and forest leaf litter perpendicular to the tide line. The con- tainers were alternated so that the cobble faced the forest in half of the arenas and the leaves faced the forest in the other half, thus controlling for the effect of orientation on spi- der movement. Spiders were placed in the containers at the interface of the leaves and the substrate, and their location was recorded after 3 h. Pilot studies indicated that the spi- ders explored the container actively for the first 1 .5 h, after which their rate of movement greatly declined (D.H. Morse pers. obs.). The 3 h acclimation period was used as a conser- vative estimate of the time needed for the spi- ders to explore their habitat thoroughly and make a choice. If the spider escaped before the end of the experiment, it received a “no choice” rating and was removed from the analysis. We used logistic regression to ex- amine whether substrate choice varied over time (both by year and month collected), mi- gration status (1997) or substrate orientation. Substrate choice in the laboratory. — In Fall 1999, we investigated the effects of tem- perature and photoperiod on substrate prefer- ence under controlled laboratory conditions using a 2 X 2 X 5 factorial design: two levels of temperature (cold/warm), two levels of day length (short/long) and five time periods (12- 15 Sept., 5-7 Oct., 4-7 Nov., 21-23 Nov., 13- 15 Dec.). Substrate choice was measured in the same arenas used in the field. Treatments were replicated 30 times for a total of 600 spiders. The collection dates were chosen to reflect dates before, during and after migration in the field. Spiders were collected at each of the four collection dates from the beach and immedi- ately acclimated for 8 d before the experi- ments were run in the experimental arenas. Treatment conditions were maintained in two environmental chambers, one cold (4 — 6 °C), one warm (22 — 28 °C). Within each chamber a lightproof partition separated short (9 h, 40 min) and long (12 h, 40 min) day-length con- ditions. One 20 watt earthlight bulb in each side of the chambers provided appropriate day length. Temperature and photoperiod were not 114 THE JOURNAL OF ARACHNOLOGY alternated among chambers over the duration of the experiment due to mechanical con- straints. The cold/short treatment simulated temperature and light conditions in mid-No- vember, when previous data indicated the peak migration occurred (Morse 1997). The warm/long treatment simulated conditions in mid- September, The cold/long and warm/short treatments served as controls to separate the independent effects of temperature and pho- toperiod on substrate choice. The statistical model included temperature, photoperiod, time, and all interactions and was evaluated using a generalized linear model to perform logistic regression on binomial data (PROC GENMOD). All factors were considered fixed because they were set a priori by the investi- gators to sample different populations. On each collection date we obtained 120 spiders from the beach 50 m or more from the drift fences, and maintained them individually in 15 dram vials (6.0 cm long, 3.5 cm diam- eter) with a 3 cm X 3 cm moistened square of paper toweling. Thirty spiders were ran- domly assigned to each treatment immediately after collection and remained in the chambers for an 8 d acclimatization period. On the third and sixth days of this period, they were all fed one Drosophila melanogaster, and their tow- eling was moistened to maintain uniform hu- midity. Instances of feeding (whether the fly was consumed) and molting were recorded. We analyzed the main effects of the treatment and collection date on whether an individual molted or fed, using logistic regression (PROC GENMOD). On the eighth day, experimental arenas were prepared in the same way as the field experiments and then placed in the environ- mental chambers for 1 h before the spiders were introduced to bring their materials into equilibrium with the air temperature. Spiders were placed, one per container, at the interface of the cobble and leaves (on a rock and under a leaf), and substrate choice was recorded af- ter 3 h. If the spider did not move (which was extremely rare) or if it escaped before the end of the experiment, it received a “no choice” rating and was removed from the analysis. The spiders were released at their original field site during the following week. All substrate choice trials for both field and laboratory were analyzed with a chi-square test for goodness of fit to examine whether the substrates were chosen in equal proportions. Data were summed over the whole season when sample sizes for a week’s trial were not adequate for individual analysis (Sokal & Rohlf 1995). RESULTS Seasonal migration. — Yearly drift fence captures (1996-1999) totaled 59, 66, 38 and 28 individuals, respectively, peaking between early November and early December in dif- ferent years (Fig. 1). Drift fence data were summed over both fences for all analyses due to low sample size. The difference in day length between the two extremes (2 Nov. 1997 and 6 Dec. 1998) was 64 min. The percentage of spiders captured on the side of the fences facing the beach changed over the years, but was consistently more than 2 times as large as the proportion captured behind the fences: 1999, 82% in front; 1998, 71% in front; 1997, 96% in front; 1996, unknown. Also, the over- all rates of recapture behind the fences were low. Of the 33 spiders that were marked after being captured at the fences on 2 Nov. and 30 Nov. in 1997, only one was recaptured (3%) after being released behind the fence. No significant relationship occurred be- tween numbers that migrated and minimum ambient temperature in the week preceding a collection at the pitfall traps (correlation anal- ysis, R = —0.13, n = 44, P > 0.05), but mi- gration did occur significantly more frequently during periods containing episodes of freezing weather (Wilcoxon 2-sample one sided exact f-pof M ^ 1 ^ OQ P = '‘^above freezing '^freezing or below ^ 0.047; Fig. 2). Neither weekly rainfall (cor- relation analysis, R = 0.13, n = 44, P > 0.05), nor percent relative humidity (correlation analysis, available for 1996-1997 only; min R = -0.17, « = 27, P = 0.41; max R - -0.24, n = 27, P > 0.05) correlated significantly with migration, and migration did not occur more frequently during weeks with storm events than those without storms (Wilcoxon 2-sam- ple one sided exact test, = 39, P > 0.05). Although the mean temperature was similar at all microhabitat sites, the vari- ation (s^) in daily temperature within fallen leaves was more than three times less than in the cobble, in the shade above the leaves, or in the sun above the leaves in 1999 (Table 1). Substrate choice in the field. — A total of 280 spiders collected from the beach were KRAUS & MORSE--SEASONAL HABITAT SHIFT IN A WOLF SPIDER 115 Figure 1. — Number of spiders captured at the two drift fences, 1996-1999. Sample sizes were too low to analyze each fence separately. Bars represent number captured during trapping period (ranging from several days to a week). Lines are running average number of spiders captured over two trapping periods. “F” indicates first date of trapping. Traps ran continuously throughout season. Initiation of trapping was dictated by preliminary data. 116 THE JOURNAL OF ARACHNOLOGY Minimum temperature per trapping period (°C) Figure 2. — Comparison of number of spiders (4- S.E.) captured at drift fences during trapping periods with minimum temperatures above freezing (0 °C) versus at freezing and below (1996-1999). Asterisk indicates significant differences between categories at P < 0.05. tested for substrate choice in 1997; 74 escaped before choice was recorded and none failed to make a choice. In 1997 and 1999, a total of 37 and 42 spiders collected from the forest drift fences were tested for substrate choice; 4 escaped before choice was recorded in 1997, no spiders escaped in 1999. No spiders in ei^ ther year failed to make a choice after the 3 h acclimation period. For the field experi- ments on substrate choice in 1997 and 1999, Table 1. — Average daily temperature (°C) and variance in 1999 at four microhabitat sites at the beach-forest interface: under leaves, under cobble, ambient shade, and ambient sun. Microhabitat Daily temperature Variance Leaves 7.2 1.4 Rocks 6.4 9.4 Shade 6.2 8.0 Sun 6.2 7.8 substrate choice was not predicted by month collected, orientation of substrate, or whether the individual had migrated (1997 only), (lo- gistic regression, P > 0.05 in all cases). There was a marginal effect of year on the proba- bility of choosing leaves (x^ = 3.51, df = 1, P = 0.06). The proportion of individuals choosing leaves over cobble varied over the experimental period in both 1997 and 1999. Spiders collected from the forest in 1997 and 1999 showed an increase in leaf choice in the experimental arenas when migration occurred in the field, discounting the 2 Nov. move- ments forced by storm-driven beach inunda- tion (Figs. 3, 4). In 1997, the beach-captured individuals increased their leaf choice in late October, before migration occurred in the field (Fig. 3). Spiders collected from the beach chose cob- ble significantly more often than leaves in ev- ery set of substrate choice experiments (23 to- tal), both in the field and laboratory (x^ test for goodness of fit, Bonferroni-adjusted, k = KRAUS & MORSE— SEASONAL HABITAT SHIFT IN A WOLF SPIDER 117 m m o c “O o 0 "D Q- m 05 C £ ■q. O) Q. 3 m m 1— o i— m 0 0 "D ’a. CO Figure 3. — Results of field substrate choice trials in 1997 showing how substrate choice changes with migratory tendency. Open circles = substrate preference of spiders captured on beach, closed circles = substrate preference of spiders captured at drift fences, and bars = number of spiders captured in drift fences over season. Sample size for substrate choice experiments above each data point: number of spiders captured on beach in brackets, number captured at drift fence in parentheses. m 0 o c ■O H— o © T3 Q C0 D C ■q 05 Q 3 m m o m 0 Q 0 ~o ■q. Figure 4. — Results of field substrate choice trials in 1999 showing how substrate choice changes with migratory tendency. Closed circles = substrate preference of spiders captured in drift fences, and bars = number of spiders captured in drift fences over season. Sample size for substrate choice experiments above each data point. 118 THE JOURNAL OF ARACHNOLOGY Temperature Figure 5. — Laboratory experiments on beach-captured spiders in 1997, showing effect of temperature collected on substrate choice. Sample size for each data point in parentheses. Asterisk indicates significant differences between temperatures at P < 0.05. The interaction between temperature and data collected not significant. 23, P < 0.002 for every week's trial). Weekly sample sizes of the forest-captured individuals often were inadequate for analysis {n = 1-18) because the replicates were limited by the numbers that were caught in pitfall traps that week, but the pooled yearly results showed that the vast majority also selected cobble (29 of 33 in 1997; 41 of 42 in 1999), both highly significantly different from a 50:50 ratio j — 12.5, 20.0; P < 0.001, < 0.001: tests for goodness of fit). Substrate choice in the laboratory. — A total of 604 spiders were tested in the labo- ratory experiment over the 5 sample dates. There were 56 deaths or escapes and 6 inci- dents in which the spider apparently made no choice, 29.4 ± 2 spiders were tested per treat- ment with the exceptions of 4 treatments that contained only 19 or 20 replicates. Those treatments, late November/warm short and long daylength, and September/cold short and long daylength, had reduced replicates due to alternate use of the spiders and an experimen- tal error. The main effects of temperature and collection date on substrate choice were sig- nificant (temperature x^ = 9.24, df = 1, P = 0.002; collection date x^ = 10.6, df = 4, P = 0.03). Preference for leaves peaked in cold conditions and for spiders collected in Oct. (Figs. 4, 5). Post-hoc pairwise contrasts re- vealed that spiders collected in Oct. had a sig- nificantly different substrate preference from those collected in Dec. (Bonferroni adjusted P- value, P < 0.005) and were marginally dif- ferent from those collected in early and late November (P < 0.05). Photoperiod did not significantly affect substrate choice (P > 0.05). The two-way and three-way interac- tions among photoperiod, temperature and collection date were also not significant (P > 0.05). Temperature and date collected significantly affected whether an individual molted or fed (Table 2). The incidence of molting and feed- KRAUS & MORSE— SEASONAL HABITAT SHIFT IN A WOLF SPIDER 19 Table 2. — Proportion of spiders molting and feeding during laboratory experiments in 1999. Molting and feeding are significantly affected by temperature and collection date. Sample sizes in parentheses. Proportion molting Proportion feeding Collection date Cold Warm Cold Warm OCT 5-7 0.02 (66) 0.35 (66) 0.50 (66) LOO (66) NOV 4-7 0.00 (62) 0.02 (64) 0.56 (66) LOO (64) NOV 21-23 0.00 (62) 0.03 (40) 0.21 (42) LOO (40) DEC 12-15 0.00 (63) 0.00 (61) 0.10 (63) 0.66 (61) ieg decreased over the season and occurred more often in warm conditions (for molting: temperature = 46.0, df = I, P < 0.001, datex^ ^ 59.1, £|f= 4, P < 0.001; for feeding: temp = 291.9, df = I, P < 0.001, date x^ - 108.1, df= A,P < 0.001). Photoperiod had no effect (for molting: x^ = 0.4, df = I, P > 0.05, for feeding: x^ = lA,df= 1, P > 0.05). DISCUSSION Seasonal migration. — Photoperiod and temperature: Our use of drift fence captures as a measure of directional migration and not general activity is supported by the lack of drift fence captures in early fall when warm weather increases activity, the large disparity between spiders caught in front and behind the drift fences (greater than 70% captured in front), and the low recapture rate of spiders in fences (3% in 1997). The timing of P. lapp dicina movement and the numbers of spiders moving from the cobble beach to the adjacent forest as measured by the drift fences varied among years (Fig. 1). Date of peak movement occurred between early November and late December (S.D. = 15.5 d) during 1996~-1999, which is at least 1.5 times as variable as the timing of seasonal migration in some fish and birds (S.D. = 2-10 d; Comeau et al. 2002). For most seasonal responses in arthropods, photoperiod is used to cue the physiological changes that determine the timing of major life history events (Tauber et al 1986). Many organisms use absolute day length (Tauber et al. 1986; Delisle & McNeil 1987), change in day length (Beck 1980) or both to differing degrees (Han & Gatehouse 1991), to antici- pate seasonal changes in their environment. The high variance in timing of migration over the years argues against a singular role of pho- toperiod in this system, but it seems unlikely that photoperiod played no role in migration given its seasonal nature. It appears that temperature has an effect on migration: low temperatures may thus in- crease the migratory response of P. iapidicina to seasonal change, while mild temperatures decrease it. Only about half as many spiders were captured at the drift fences during the relatively warm autumns of 1998 and 1999 (the 82”^ and 96* coldest of the past 100 years), as during the relatively cold autumns of 1996 and 1997 (the 19* and 34* coldest; NOAA, 1996-1999). Furthermore, a greater number of spiders migrated during weeks when temperatures dipped below freezing, perhaps to avoid contact with ice on the beach (Schaeffer 1977), although minimum ambient temperature did not correlate with movement. During mild winters, more individuals appar- ently overwinter on the very edge of the cob- ble-forest boundary (< 5 m into forest) or on the beach itself (Morse 1997). Although it is unclear what their relative survival is com- pared to those that migrate, if these spiders continue feeding on the beach it could give them a size advantage at the beginning of the following season. Ultimately, retreating to leaves during colder seasons may afford the spiders protection from extreme conditions because of the less variable temperatures in the microhabitat under leaves. Leaf litter has been previously found to be a preferred mi- crohabitat for spiders in the winter because of its low thermal conductivity and temperature fluctuation (Schaeffer 1977) Other temperate zone arthropods exhibit seasonal responses to low temperatures (De- lisle & McNeil 1987; Han & Gatehouse 1991; Eubanks & Miller 1992). For example, the length of the prereproductive periods of true armyworm moths Pseudaletia unipuncta (De- lisle & McNeil 1987) and oriental armyworm moths Mythimna separata (Han & Gatehouse 1991), which determine their predisposition to 120 THE JOURNAL OF ARACHNOLOGY migrate in the autumn, increase under cold temperature or short photoperiod regimes. These responses suggest that cold temperature may directly determine an animal’s propensity to migrate. The mechanism for temperature driving this propensity may be either direct, by affecting rates of growth and development, or indirect, by inducing a physiological syn- drome that prepares the insect for coming sea- sonal changes (Tauber et al. 1986). Rainfall, humidity and storm events: Sea- sonal change in habitat preference of non-bur- rowing lycosids has been previously docu- mented in temperate forests. Eubanks & Miller (1992, 1993) suggested that the habitat shift of Gladicosa pulchra in the late summer and early fall was affected by rainfall (surro- gate for soil humidity). Rainfall and ambient humidity appeared to have no influence on the habitat preference of P. lapidicina. This dif- ference may be explained by the geographical ranges of the two populations. Gladicosa pul- chra was studied in the southern U.S., where winters are much milder, and desiccation has a larger probability of affecting survival. In addition, the fresh water flowing across por- tions of our study sites would further reduce dessication risk for the spiders. Storm events did not correlate with move- ment in the field. However, the large early peak in 1997 (on 2 Nov., 28 individuals were captured) occurred after a large storm in which the tide inundated the high beach (J.M. Kraus & D.H. Morse, pers. obs.). Substrate choice as a proxy for migra- tion?— We expected that if substrate prefer- ence did play a role in spider migratory de- cisions, that spiders would be more likely to choose leaves after they had migrated. This expectation was not met: in 1997, 4 out of 29 (14%) spiders that had migrated and 24 of 185 (13%) that had not migrated chose leaves. Al- though the overall proportion of individuals choosing leaves was not affected by migratory status, it appears that individuals captured at the drift fences show their highest leaf pref- erence within a week of peak migration, not including storm forced movements in 1997 (Figs. 3,4). On the other hand, beach-captured spiders chose leaves most frequently a month prior to peak migration (1997, Fig. 3). We predicted that spiders that had not yet migrated would exhibit a strong preference for leaf substrate during the fall migration. Al- though being in migratory condition does not necessarily result in preference for leaf litter, since spiders that have already migrated still chose cobble a majority of the time, the peak in preference for leaf litter coincided with high migration rates over two years. This re- sult suggests that migration is somehow as- sociated with substrate preference. Collective- ly, the field-conducted substrate choice experiments, coupled with the pattern of mi- gration, suggests that change in substrate pref- erence is related to seasonal movement from beach cobble to forest leaf litter in the field. To verify this connection, similar comparisons need to be made over more years, using a larger number of replicates. Month of collection and substrate orienta- tion had no effect on spider substrate choice in the field. The marginal effect of year on substrate choice in the field is most likely at- tributable to the small number of replicates in 1999. Substrate choice and environmental cue. — The results of the laboratory substrate choice experiments suggest that temperature, which may affect the number of individuals migrating in the field, also influenced individ- ual substrate preference. Individuals main- tained at cold temperatures selected leaf sub- strate significantly more often than those kept at warm temperatures (Fig. 5). There are two possible explanations for this pattern. Spiders in cold conditions may simply choose the warmer substrate (leaves), especially if they have not yet acclimated to cold temperatures in the field. Alternatively, the spiders may have been physiologically primed, perhaps by photoperiod in the field, to respond to cold temperatures by changing their substrate pref- erence. An additional condition in which the substrate was cooled before being placed with warm spiders or warmed before being placed with cooled spiders, would have allowed us to establish whether the spiders were undergoing a physiological change that affected their pref- erence or if they were simply responding to the tactile cues they were receiving at that mo- ment. Given that the spiders decreased feeding and molting as the season progressed (Table 1), and the main effect of date collected on spider choice (leaf preference peaked in Oct., Fig. 6), we suggest that a physiological change had occurred and the spiders’ choices KRAUS & MORSE— SEASONAL HABITAT SHIFT IN A WOLF SPIDER 121 "O 0) -i—* o 0 0 0 CO 0 > 0 0 H— O c o o Q- 2 CL 0.3 - 0.2 ^ 0.1 - i€ (118) 0.0 Sept 12-15 Oct 5-7 Nov 4-7 Nov 21-23 Dec 13-15 Date collected (1999) Figure 6. — Laboratory experiments on beach-captured spiders in 1999, showing effect of date collected on substrate choice. Sample size for each data point in parentheses. Asterisk indicates significant differ- ences between dates at P < 0.05. were most likely driven by an interaction be- tween physiological and tactile factors. Photoperiod showed no effect on substrate preference in our laboratory experiments. This result was surprising because of the role that photoperiod traditionally has played in trig- gering physiological changes that allow tem- perate organisms to respond to the onset of winter (Tauber et al. 1986; Kumar 1997). It is possible that P. lapidicina do not use photo- period to make substrate choice decisions. Al- ternatively, the experimental design may not have tested an aspect of photoperiod (such as change in day length) to which the spiders re- spond, or the 8 d acclimation period at the beginning of the experiment was inadequate. There is some evidence for the latter expla- nation, since the date at which spiders were collected from the field affected substrate choice in the laboratory (Fig. 6). Spiders col- lected in October were almost twice as likely to choose leaves in the laboratory as those collected at any other time. Apparently the spiders were at least partially making their substrate choice decisions based on conditions in the field. On the failure of some individuals to mi- grate.— The striking difference between the rocky intertidal and adjacent forest litter may inhibit P. lapidicina that encounter the inter- face from moving across the boundary. Since the spiders were born on the beach in the spring and early summer (Morse 1997), they are naive to the forest environment, having previously experienced no more than occa- sional leaves. This background is consistent with leaves never being favored by a majority of individuals in the experiments, even though they provide a less variable temperature re- gime than the beach cobbles. Although we have not quantified costs of migrating to the leaf litter, we have trapped both arachnid and shrew predators at the drift fences (Morse 1997 pers. obs.). In other com- munities prey moving across habitat bound- aries have been shown to enhance the num- 122 THE JOURNAL OF ARACHNOLOGY bers of predators there (Polls & Hurd 1996; Hering & Platcher 1997; Henschel et al. 2001). This cost may inhibit movement for P. lapidicina. Spiders may also continue to reap a benefit from access to food on the beach. Laboratory data suggest, however, that this benefit would be most significant early in the season, since the spiders undergo a two-fold decline in overall feeding rate and cease molL ing as the season progresses, even if main- tained in warm temperatures (Table 1). Fur- ther, individuals captured on the beach during November and December are slightly lighter than ones caught in the forest (J.M. Kraus pers. obs.) and have ceased gaining mass by this time (D.H. Morse pers. obs.). Depending on the year, most of the spiders may eventually cross the beach-forest inter- face, but some do not unless driven to it by physical factors such as ice and high water. Although they might change their choices with experience and time, the performance of the naive individuals is the relevant variable here, since it represents the normal condition for an individual first encountering the habitat boundary. ACKNOWLEDGMENTS We thank J. Gist, A. Kopelman, and E. Leighton for assistance in the field and R.L. Edwards for identifying P. lapidicina. J. Wit- man, M. Tatar, L. Galloway and D. Bell lent useful suggestions and aided in the statistical analyses. L. Aucoin, G. Ruthig and two anon- ymous reviewers made helpful and extensive comments on the manuscript. JMK was sup- ported by a U. S. National Science Foundation Graduate Research Fellowship during part of the writing of the manuscript and analyzing of the data. LITERATURE CITED Beck, S.D. 1980. Insect Photoperiodism. Academic Press, New York. Comeau, L.A., S.E. Campana & G.A. Chouinard. 2002, Timing of Atlantic cod (Gadus morhua L.) seasonal migrations in the southern Gulf of St. Lawrence: interannual variability and proximate control. ICES Journal of Marine Science 59:333- 351. Delisle, J. & J.N. McNeil. 1987. The combined ef- fect of photoperiod and temperature on the call- ing behaviour of the true armyworm, Pseudaletia unipuncta. Physiological Entomology 12:157- 164. Dingle, H. 1996. Migration. Oxford University Press, New York. Eubanks, M.D. & G.L. Miller. 1992, Life cycle and habitat preference of the facultatively arboreal wolf spider, Gladicosa pulchra (Araneae, Lycos- idae). Journal of Arachnology 20:157-164. Eubanks, M.D. & G.L Miller. 1993. Sexual differ- ences in behavioral response to conspecifics and predators in the wolf spider Gladicosa pulchra (Araneae: Lycosidae). Journal of Insect Behavior 6:641-648. Fujii, Y. 1974. Hunting behaviour of the wolf spi- der, Pardosa T-insignita (Boes et. Str.) Bulletin of the Nippon Dental College, General Education 3:134-148. Han, E. & A.G. Gatehouse. 1991. Effect of tem- perature and photoperiod on the calling behav- iour of a migratory insect, the oriental army- worm Mythimna separata. Physiological Entomology 16:419-427. Henschel, J.R., D. Mahsberg, & H. Stumpf. 2001. Allochthonous aquatic insects increase predation and decrease herbivory in river shore food webs. Oikos 93:429-438. Hering D. & H. Plachter. 1997. Riparian ground beetles (Coleoptera, Carabidae) preying on aquatic invertebrates: a feeding strategy in alpine floodplains. Oecologia 111:261-270. Hopper, K. 1999. Risk-spreading and bet hedging in insect population biology. Annual Review of Entomology 44:535-60. Kaston, B.J. 1948. The Spiders of Connecticut. Connecticut State Geologic Natural History Sur- vey Bulletin 70:1-874. Kimura, S.T. & K. Beppu. 1993. Climatic adapta- tions in the Drosophila immigrans species group: seasonal migration and thermal tolerance. Eco- logical Entomology 18:141-149. Kornijow, R, 1992. Seasonal migration by larvae of an epiphytic chironomid. Freshwater Biology 27: 85-89. Kumar, V. 1997. Photoperiodism in higher verte- brates: An adaptive strategy in temporal environ- ment. Indian Journal of Experimental Biology 35:427-437. Lowrie, D.C. 1973. The microhabitats of western wolf spiders of the genus Pardosa. Entomolog- ical News 84:103-116. Madsen, T. & R. Shine, 1996. Seasonal migration of predators and prey: A study of pythons and rats in tropical Australia. Ecology 77:149-156. Morse, D.H. 1997. Distribution, movement, and ac- tivity, patterns of an intertidal wolf spider Par- dosa lapidicina population (Araneae, Lycosidae). Journal of Arachnology 25:1-10. NOAA (National Oceanographic and Atmospheric Administration). 1996-1999. Online data. www. noaa.org Polls, G.A. & S.D. Hurd. 1996. Linking marine and KRAUS & MORSE— SEASONAL HABITAT SHIFT IN A WOLF SPIDER 123 terrestrial food webs: allochthonous input from the ocean supports high secondary productivity on small islands and coastal land communities. American Naturalist 147:396-423. SAS Institute Inc. 1989. SAS/STAT User’s Guide, Version 6, Fourth Edition, Volume 1, Cary, NC: SAS Institute Inc., 943 pp. Schaeffer, M. 1977. Winter ecology of spiders (Ar- aneida). Zeitschrift ftir Angewandte Entomologie 83:113-134. Sokal R.R. & EJ. Rohlf. 1995. Biometry: the Prin- ciples and Practice of Statistics in Biological Re- search. WH. Freeman and Company, New York. Svensson, B.G. & L. Janzon. 1984. Why does the hoverfly Metasyrphus corollae migrate? Ecolog- ical Entomology 9:329-335. Takada, Y. 1995. Seasonal migration promoting as- sortative mating in Littorina brevicula on a boul- der shore in Japan. Hydrobiologia 309:151-159. Tammaru, T, K. Ruohomaki & 1. Saloniemi. 1999. Within-season variability of pupal period in the autumnal moth: a bet-hedging strategy? Ecology 80:1666-1677. Tanaka, K. 1992. Photoperiodic control of diapause and climatic adaptation of the house spider, Achaearanea tepidariorum (Araneae, Theridi- idae). Functional Ecology 6:545-552. Tanaka, K. 1997. Evolutionary relationship between diapause and cold hardiness in the house spider Achaearanea tepidariorum (Araneae: Theridi- idae). Journal of Insect Physiology 43:271-274. Tauber, M.J., C.A. Tauber & S. Masaki. 1986. Sea- sonal Adaptations of Insects. Oxford University Press, New York. Vogel, B.R. 1971. Individual interactions of Par- dosa. Armadillo Papers 5:1-13. Manuscript received 17 March 2003, revised 26 April 2004. 2005. The Journal of Arachnology 33:124-134 SPATIAL DISTRIBUTION AND MICROHABITAT PREFERENCE OF PSECAS CHAPODA (PECKHAM & PECKHAM) (ARANEAE, SALTICIDAE) Gustavo Quevedo Romero and Joao Vasconcellos-Neto: Departamento de Zoologia, Universidade Estadual de Campinas (UNICAMP), C.R 6109, Campinas, SP, 13083= 970, Brazil. E-mail: GQ^omero@ br.yahoo.com ABSTRACT. Although spiders generally do not have a strong association with the plants on which they live, the jumping spider Psecas chapoda inhabits and breeds on Bromelia balansae (Bromeliaceae). To understand the relationship between Psecas chapoda and Bromelia balansae, we investigated whether the type of habitat (forest or grassland), the size of the bromeliad and the inflorescence of the host plants affected the preference and/or density of P. chapoda. We also examined how spiders of different ages and their eggsacs were distributed on the leaf layers of the rosette of host plants and whether P. chapoda used other plants in addition to B. balanasae. Psecas chapoda occurred with higher frequency on bromeliads in grasslands to those in forest. In grassland, larger bromeliads had more spiders, but this was not true of bromeliads in the forest. This spider avoided bromeliads with inflorescence. Most of the spiderlings (70%) occuned in the central layer of the rosette leaves, and their distribution pattern suggested that they sought shelter to protect themselves from desiccation or cannibalism, both of which are commonly observed in this species. Older spiders, as well as females without eggsacs, occurred in the external layers whereas 90% of the females with eggsacs occurred close to the central layers. Deposition of the eggsacs near the center of the rosette can allow the spiderlings to reach their shelter rapidly and to be less exposed to desiccation and cannibalism. The non-detection of P. chapoda on non-bromeliad plants, and the stereo- typed behaviors on the host-plant suggest that this jumping spider was strongly associated with B. bal- ansae. Keywords: Animal-plant interaction, habitat selection, microhabitat, plant architecture, Salticidae In contrast to host-specific herbivorous in- sects (Schoonhoven et al. 1998), spiders gen- erally do not have a strong association with the plants on which they occur. However, some spider species inhabit and breed on spe- cific plants and interact indirectly with their hosts (Louda 1982; Figueira & Vasconcellos- Neto 1991, 1993; Rossa-Feres et al. 2000; Romero & Vasconcellos-Neto 2004). Why some spiders choose specific plants and how the occurrence of such spiders affects the or- ganization of spider communities are impor- tant aspects in understanding the community structure on a given host plant and in eluci- dating the direct and indirect interactions within and among species (Abraham 1983; Uetz 1991). The components of habitat re- ported to influence the numbers and types of spiders include the abundance and richness of prey (Riechert & Tracy 1975; Waldorf 1976; Rypstra 1983; Miller & Drawer 1984; Schmalhofer 2001), the availability of extra- floral nectarines as a food source and as for- aging sites (Ruhren & Handel 1999), the availability or density of sites for constructing webs (Lubin 1978; Rypstra 1983; Greenstone 1984; Herberstein 1997; Figueira & Vascon- cellos-Neto 1991), the availability of foraging sites (Scheidler 1990; Romero 2001; Schmal- hofer 2001; Romero & Vasconcellos-Neto 2003), the spatial distribution of web and for- aging sites (Greenquist & Rovner 1976; Rob- inson 1981; Louda 1982) and the availability of sites for shelter (Riechert & Tracy 1975; Gunnarsson 1990, 1996) and breeding (Smith 2000). The jumping spider Psecas chapoda (Peck- ham & Peckham 1894) (Salticidae), previous- ly identified as P. viridipurpureus Simon 1901 by Rossa-Feres et al. (2000), is commonly found on Bromelia balansae Mez. (Bromeli- aceae) and has an apparently host-specific dis- tribution. This plant does not store rainwater in its rosette. Psecas chapoda spends its entire 124 ROMERO & VASCONCELLOS-NETO— MICROHABITAT OF PSECAS CHAPODA 125 reproductive cycle: courtship, mating, ovisac formation and populational recruitment of the young spiders on this plant (Rossa-Feres et al. 2000). Females produce 1-3 eggsacs on the concave side of the central region of the leaves. The eggsacs are enveloped with a plain silk cover and are spun at the edge of each leaf. Since females remain under this cover and on the eggsacs (Fig. 1) (Rossa- Feres et al. 2000), there may be maternal care of the offspring. In this study, we examined the spatial and microspatial patterns of P. chapoda on B. bal- ansae and investigated the factors affecting this distribution. Specifically, we assessed whether the type of habitat (forest or grass- land) and the size and architecture (absence vs. presence of inflorescences) of the brome- liad affected the density of P. chapoda. We also determined whether spiders of different ages and the eggsacs were randomly distrib- uted among the leaf layers of the rosette, and whether P. chapoda was associated exclusive- ly with B. balansae. METHODS This work was done in a fragment of sem- ideciduous forest (250 m x 60 m) and in an adjacent grassland area along the margin of a river, in the city of Dois Corregos (22° 21' S, 48° 22' W), Sao Paulo state, southwestern Brazil, from July 1998-May 2000 and in March and April 2002. Only Bromelia bal- ansae, a ground-dwelling brorneliad (Figs. 2- 4), occurs in the study area. Habitat preference. — Habitat preference was determined by recording the number of P. chapoda on B. balansae growing in the for- est and in the grassland. Observations were made in the cold-dry season (July 1998), at the beginning of the rainy season (October 1998) , in the hot-rainy season (February 1999) and at the end of the rainy season (April 1999), along two parallel 250 m transects in the forest and grassland (one each). The two transects were at least 20-30 m apart, and 37- 53 stalks of B. balansae in the forest and 75- 103 stalks in the grassland were randomly chosen in each season. The spider density per brorneliad stalk was compared between the forest and grassland transects and among the four seasons using two-way ANOVA. Since the occurrence of the spiders may be skewed by the density of bromeliads, the number of plants growing at 10 m intervals in 100 m x 6 m transects of forest and grassland was es- timated to determine if there were variations in density between sites. Since the preference for bromeliads was affected by the presence of inflorescence, only bromeliads without in- florescence were included in the analysis (see below). Influence of host plant size on the micro- habitat preference. — To examine the prefer- ence of spiders for host plants of different siz- es, the relationship between the brorneliad surface area and the number of P. chapoda was examined for bromeliads in grassland, at the forest margin and within the forest. The bromeliads (50-82 in grassland, 16-27 at the forest margin and 31-53 within the forest) were observed bimonthly from July 1998- July 1999. The bromeliads were randomly chosen in each sample period. Bromeliads growing under tree branches but which re- ceived incident solar light at any time of the day were considered to occur in the forest margin. The total surface area was estimated by multiplying the surface area of one leaf by the total number of green leaves on each bro- meliad. The leaf surface area was estimated using the formula: length (L) x breadth (B) of a leaf from the middle layer of the rosette, chosen at random, x 1/2. Linear regression analysis was used to assess the relationship between surface area and the number of spi- ders. Student t-test was used to compare the brorneliad surface area between grassland and forest. Influence of inflorescence on spider den- sity.— The relationship between B. balansae inflorescence and spider density was exam- ined by comparing the density of spiders on grassland B. balansae with and without inflo- rescence (Figs. 2-4). The observations were made in December 1998 and 1999 because al- most all of the B. balansae at the study sites bloomed in this season. The results were an- alyzed using the G-test. Preference for leaf layers. — Bromelia bal- ansae has several leaf layers in the rosette (Figs. 2, 3). Since preliminary observations showed that P. chapoda was distributed in dif- ferent layers of the rosette according to the spiders’ age, the distribution patterns of spi- ders of different ages were determined by ex- amining 24-64 grassland bromeliads with at least five leaf layers. The observations were 126 THE JOURNAL OF ARACHNOLOGY ROMERO & VASCONCELLOS-NETO— MICROHABITAT OF PSECAS CHAPODA 127 made bimonthly, from November 1999-May 2000. The bimonthly interval of observations was determined to avoid data dependence (i.e., temporal pseudoreplication, Hurlbert 1984), since spiders change instars by molting and the eggsacs are constructed and aban- doned in approximately one month (Rossa= Feres et al. 2000; G.Q. Romero pers. obs.). Age-^specific patterns of spots and coloration were used to classify P. chapoda as spider- lings (3^*^ instar), young (4* and 5* instars), and juvenile males (up to 1.1 cm in body length) or females (6* iestar). Although sex- specific patterns of spots and coloration are also useful for discriminating subadult and adult stages, subadult and adult females with the same spot and coloration patterns and of similar size (up to L6 cm in body length) are difficult to distinguish in the field. In addition, the number of subadult males is extremely small. For these reasons, we created two ad- ditional groups, namely subadult (7* instar) + adult females (8* instar) and adult m.ales (8* instar) (Rossa-Feres et al. 2000; G.Q. Romero pers. obs.). In the subadult and adult female class, the adult females with eggsacs were dis- tinguished from subadult and adult females without eggsacs. The distributions of the five developmental stages above and those of sub- adult and adult females with and without eggsacs were analyzed using the G-test. Selectivity of P. chapoda, for the host plant. — ^The selectivity of P. chapoda for B. balansae was examined in March and April 2002, a period of high spider density, by the following three methods: 1) Direct observa- tion; searching for spiders, silk shelters and abandoned eggsacs on 590 eon-bromeliad plants belonging to the families Asteraceae, Fabaceae, Solaeaceae, Asclepiadaceae, Laur- aceae and several grasses. The plants exam- ined were 10-170 cm tall and grew at least 3 m away from B. balansae. At each observa- tion, we examined the abaxial and adaxial sides of leaves and branches. 2) Beating or shaking the plants with a stick. The spiders were collected on a beating tray, essentially a cloth-covered frame that sloped slightly to- wards the center (Southwood 1978). All of the spiders dropping off noe-bromeliad plants (up to 170 cm tall) were collected. Fifty plants were sampled in grassland, 50 at the forest margin and 50 within the forest. Five beats per sample (plant) were done between 1:00- 4:00 p.m. 3) Pitfall traps; 30 pitfall traps (10 cm in diameter and 15 cm deep) containing 75% ethanol were placed among individuals (0.4-L5 cm) of B. balansae. The spiders were collected five days after the traps were placed. Voucher specimens of P. chapoda were de- posited in the Laboratorio de Artropodes Pe- gonhentos, Institute Butaetae, Sao Paulo. RESULTS Habitat preference, — The average number of P. chapoda on B. balansae was signifi- cantly greater in grassland than in forest (two- way ANOVA, Fi^534 - 123.67, P < 0.0001, Fig. 5). The average number of P. chapoda on B. balansae also changed seasonally (two-way ANOVA, ^3,534 = 2.89, P = 0.035) and was lower in the hot, rainy season (Fig. 5). The interaction between the factors habitat and seasonality was significant = 2.82, P = 0.038). There was no difference between the density of bromeliads in grassland and forest (T-test, t = -0.46, 18 df, P - 0.648). Influence of host plant size on the micro- habitat preference. — There were positive, significant relationships between bromeliad surface area (size) and number of spiders in- habiting the plant, in the grassland and forest margins (Table 1). Despite the bromeliads in the forest being bigger than the bromeliads in the grassland (data from July 1998; forest: 9649.0 cm2 + 1256.2 (SE), grassland: 4609.5 ± 470.6 (SE); t = ~4.53, 154 df, P < 0.001), there were no relationships between plant size and number of spiders in the forest (Table 1). Up to 21 spiders were seen on a single plant in the grassland area, whereas a maximum of 3 spiders was seen on bromeliads in the forest. Influence of inflorescence on spider den- sity.— Among bromeliads with no iefiores- Figures 1-4. — L Female of P. chapoda (arrowhead) under the plain silk cover and on the eggsac produced on a leaf of B. balansae. 2. Individual of B. balansae in vegetative phenophase in the grassland. 3. In the beginning of inflorescence release (note the central leaves folding back). 3. with presence of infratescence. (Photos: G.Q. Romero). 128 THE JOURNAL OF ARACHNOLOGY Table 1 . — Linear regressions of the relationship between the bromeliad size (surface area) and individ- uals number of Psecas chapoda in the grassland, forest margins and into the forest, in different seasons. Places Equations n P F P 1998 Jul Grassland . Y = 0.00033X + 1.44 82 0.51 84.67 <0.001 Margin Y = 0.000102X + 0.94 21 0.27 7.06 0.016 Forest Y = 0.00000 13X + 0.63 53 0.0003 0.02 0.899 Sep Grassland Y = 0.0001 IX + 1.11 76 0.09 7.22 0.009 Margin Y = 0.00003 IX + 0.86 22 0.04 0.77 0.390 Forest Y = 0.0000006X + 0.28 53 0.0001 0.001 0.932 Nov Grassland Y = 0.00045X + 1.27 74 0.08 6.70 0.012 Margin Y = 0.000084X + 0.74 27 0.06 1.51 0.231 Forest Y = 0.000002X + 0.31 48 0.001 0.06 0.806 1999 Jan Grassland Y = 0.00055X + 0.89 67 0.22 18.64 <0.001 Margin Y = 0.000047X + 1.92 18 0.01 0.25 0.623 Forest Y = 0.000002X - 0.56 43 0.0009 0.04 0.849 Mar Grassland Y = 0.0002 IX + 1.40 62 0.07 4.28 0.043 Margin Y = 0.00024X + 0.34 20 0.28 7.07 0.016 Forest Y = 0.000013X + 0.33 36 0.04 1.29 0.264 May Grassland Y = 0.00067X L 0.38 50 0.47 43.05 <0.001 Margin Y = 0.00021X + 0.19 24 0.37 12.77 0.002 Forest Y = 0.000029X + 0.20 36 0.11 4.22 0.048 Jul Grassland Y = 0.00017X + 1.50 53 0.08 4.16 0.047 Margin Y = 0.0001 IX + 0.25 16 0.31 6.17 0.026 Forest Y = 0.000005X + 0.35 31 0.003 0.08 0.783 cence, 79% and 90% were occupied by P. chapoda in 1998 and 1999, respectively. In contrast, for bromeliads with inflorescences, only 17% and 13% were used by P. chapoda in 1998 and 1999, respectively. The percent- age of bromeliads used by P. chapoda was significantly different between stalks with and without inflorescences (Fig. 6). Preference for leaf layers. — Spiderlings occurred only in the first three central layers of the rosettes of B. balansae. Their distribu- tion among the three layers was not random (G = 30.60, 2 df, P < 0.0001), and most spi- derlings (70%) occupied the first layer in the center of the plant (Fig. 7). Although young spiders occurred on plants with five or more layers, 50% of this age interval was observed in the second layer (G = 114.90, 4 df, P < 0.0001, Fig. 8). Juvenile males and females were not found in the first layer and used the other layers randomly (G = 5.03, 3 df, P = 0.170, Fig. 9). The random use of all layers except for the first one was also observed for adult males (G = 1.80, 3 df, P = 0.615, Fig. 10). In the case of subadult and adult females, more than 40% occurred in the third layer (G - 43.20, 4 df, P < 0.0001, Fig. 11). The dis- tribution patterns of spiders among the leaf layers was different between adult females with eggsacs and subadult and adult females without eggsacs. More than 90% of the fe- males with eggsacs occupied the second and the third layers (G = 18.70, 2 df, P < 0.0001), while the subadult and adult females without eggsacs occurred in the third, fourth and fifth layers with higher frequencies (G = 22.65, 4 df, P = 0.0001, Fig. 12). Only one adult or subadult female occupied the first layer. Selectivity of P, chapoda for the host plant. — No individuals of P. chapoda or their vestiges (silk shelters and abandoned eggsacs) were found on 590 rion-bromeliad plants close to B. balansae individuals. Although many spiders ("-400 individuals) belonging to sev- eral families, including 6-1 Salticidae species, were collected by beating eon-bromeliad plants and in pitfall traps on the ground be- tween the stalks of B. balanasae, no P. cha- poda were found. In three years of observa- tions, only three adult P. chapoda males were observed on the ground and one young was ROMERO & VASCONCELLOS-NETO— MICROHABITAT OF PSECAS CHAPODA 129 "d *iiiN % O u s U4 cy s s Z 3 n 2 - 1 - 0 1 □ Grassland ■ Forest Ji 1 I L cold^dry beginning of the rainfall hot/rainy end of the rainfall Periods Figure 5. — Seasonal variation in the mean density of Psecas chapoda individuals on Bromeiia balansae in grassland (open bars) and in forest (black bars). The sampled periods were: cold/dry = July 98, beginning of the rainfall = October 98, hot/rainy = February 99, end of the rainfall = April 99. Error bars are ± 1 SE. seen on a gramineous leaf close to B. balansae in grassland. DISCUSSION Although several studies have shown that spiders of the family Salticidae may select certain microhabitats (Crane 1949; Richman & Whitcomb 1980; Jackson 1986; Cutler 1992; Cutler & Jennings 1992; Johnson 1995; Jackson & Li 1997; Taylor 1998), the distri- bution of P. chapoda on B, balansae and the absence of this species on eon-bromeliad plants and in pitfall traps around bromeliads suggested a strong relationship between P. chapoda and B. balansae. The courtship, mat™ ing, deposition of eggsacs and populational re- cruitment of P. chapoda occur on B. balansae. Psecas chapoda also used B. balansae throughout the year at Sao Jose do Rio Preto (SP), about 200 km from the present study site (Rossa-Feres et aL 2000). Moreover, this spi- der species was collected and photographed (female) on B. balansae in Beni, Bolivia (Hof- er & Brescovit 1994: picture 2a; H. Hofer, pers. comm.). In addition, P. chapoda was ob- served on B. balansae in 26 cities of three Brazilian states and in one locality of Para- guay (G.Q. Romero, unpubk data). Thus, P, chapoda seems to be strictly associated with B. balansae in a large geographic range. Our results show that P. chapoda preferred bromeliads in grassland to those in forest, and that bigger bromeliads were preferred more in grassland, whereas such a relationship be- tween plant size and the average number of spiders was not observed in forest bromeliads. When the bromeliads are approached by an observer, P. chapoda on the leaf layers quick- ly jump towards the bottom of the rosette in a stereotyped jumping behaviour (G. Q. Rom- ero, personal observation). The internal base of the rosette of bromeliads serves as a refuge and shelter from desiccation, as well as a rest- ing place (G.Q. Romero, pers. obs.). In the forest, the bromeliads receive a large number of dry leaves from trees growing nearby and 130 THE JOURNAL OF ARACHNOLOGY □ Without inflorescence ■ With inflorescence Figure 6. — Frequency of bromeliads with and without inflorescence occupied by Psecas chapoda, in December 1998 and 1999. The values above the bars indicate number of bromeliads examined. G-test with Yates’ correction (G^g^ = 13.6, 1 df, R < 0.001; Giggg = 15.6, 1 df, P < 0.001). these leaves form a compact humic mass that fills completely the internal base of the bro- meliad rosettes, regardless of the difference in size. Since a large quantity of dry leaves at the bottom of the rosette hampers the use of this microhabitat, P. chapoda appears to pre- fer grassland bromeliads which gather few or no dry leaves compared to forest bromeliads. Larger bromeliads had more individuals of P. chapoda. Larger plants have a larger sur- face area available for foraging and many leaf layers in their rosettes for shelter, which can support more spiders. Generally, spiders that inhabit larger bromeliads consist of one adult male, one or two adult females frequently with eggsacs and several young and spider- lings, probably offspring of these resident fe- males. In contrast, little, peripheral bromeliads are frequently occupied by young, juveniles and subadult spiders (G.Q. Romero, pers. obs.). Adult females probably choose larger bromeliads to obtain more food and shelter for their offspring, decreasing the probability of intraspeciflc competition and/or cannibalism. Since salticids have good eyesight (Foelix 1982; Foster 1982), they can obtain more food on larger leaves. Figueira & Vasconcellos- Neto (1993) showed a strong relationship be- tween the size of the Paepalanthus brome- Uoides (Eriocaulaceae) rosette and prey availability, and between the size of the P. bromelioides rosette and the weight and/or re- productive success of Latrodectus geometri- cus Koch 1841 (Theridiidae). According to these authors, larger plants offered a larger number of prey for Latrodectus females so that females grew rapidly and produced more eggs. In addition to the size of B. balansae, the presence of inflorescence also affected the abundance of P. chapoda since almost all spi- ders occurred on bromeliads without inflores- cence. During the reproductive period of B. balansae, the green color of the central parts (leaves) of the rosette changes to red prior to inflorescence blooming. At the same time, the leaves fold back and extend parallel to the ground (Fig. 4) probably to expose the flowers ROMERO & VASCONCELLOS-NETO— MICROHABITAT OF PSECAS CHAPODA 131 Leaf layers Figures 7-12, — Distribution of Psecas chapoda individuals with different age class (7-11) and of adult females with eggsacs vs. adult + subadult females without eggsacs (12) in the leaf layers of the Bromelia balansae rosette (see text for the definitions of layers). to pollinators. These changes alter the plant architecture from a conical tridimensional configuration to a flattened, almost bidimee- sional one. Since the leaves do not touch each other even at this time because of the geo- metric conformation of the plant, the surface area of the leaves of bromeliads remains con- slant, even after the blooming season. How- 132 THE JOURNAL OF ARACHNOLOGY ever, the change in plant architecture affects the availability of shelter and breeding sites, and the spiders are exposed to external factors such as predation and climatic conditions. Some jumping spiders are able to find and catch prey in tridimensional and topographi- cally complex environments (Hill 1979; Tar- sitano & Andrew 1999). If P. chapoda also prefers bromeliads with a tridimensional ar- rangement, the preference for bromeliads without inflorescence could be explained by differences in the shelter and breeding sites and by architectural changes in the host plants. Although most arthropods in the tropics show peak numbers in the hot, rainy season (see Wolda 1988), P. chapoda was more abundant in the cold, dry season and at the end of the rainy season. Many grass species around bromeliads grow rapidly in the rainy season and may cover part of the bromeliads. Although additional studies on the causes of the high density of P. chapoda in the cold, dry season are necessary, the abundance of grasses may affect the availability of food for the spiders, and may influence the amount of contact between male and female spiders, as well as the colonization of bromeliads. In some spider species there are differences in the choice of microhabitat among adults and immatures in order to facilitate prey cap- ture and to avoid predation (Edgar 1971). It is possible that P. chapoda may show age-spe- cific use of bromeliads. Approximately 70% of the P. chapoda spi- derlings occurred in the first central layer of the B. balansae rosette. Since the leaves ex- tend vertically in the first layer, they overlap each other to form a cylinder of small diam- eter. Small spiderlings can use this microhab- itat to shelter from desiccation and/or canni- balism by larger spiders. Young spiders, one or two instars older than the spiderlings, and which still need a place to shelter, occurred more frequently in the second layer of the ro- sette because of the difficulty in reaching the first layer, that has very narrow and clumped leaves. Juvenile males and females of a sim- ilar size to the adults were generally restricted to outer layers. The value of the central rosette as a nursery for spiderlings was also suggested by the dif- ferent distribution of females with and without eggsacs. Almost all of the females with egg- sacs (90%) occurred between the second and third layers, whereas females without eggsacs were more common in the outer layers (Fig. 12). When females with eggsacs remained at the center of the rosette, the hatched spider- lings easily reached the first layers and the probability of cannibalism was reduced. Sev- eral studies have shown that during oviposi- tion, the females of insects choose plants that enhance the performance of their offspring (see Schoonhoven et al. 1998). Females of F. chapoda remained over their eggsacs (Rossa- Feres et al. 2000), indicating that there was more than one type of maternal investment in offspring in this species. According to Rich- man & Jackson (1992), such maternal behav- ior is very common, if not universal, in the Salticidae, and presumably deters predators and parasitoids of the eggs. These results sug- gest that the distance from the ovisac to the center of the bromeliad may influence the type of maternal behavior seen. Desiccation and cannibalism can represent selective pressures that influence the choice of breeding sites by females and this may affect the survival of the offspring after leaving the nest. In conclusion, P. chapoda was associated with B. balansae from grassland. This spider occurred in very low frequency on bromeliads from forest and those from grassland with presence of inflorescence. The specific behav- iors of F. chapoda on the plant and the ab- sence of detection of this species on noe-bro- meliad plants suggest a strict association between F. chapoda and B. balansae. ACKNOWLEDGMENTS The authors thank S. Nakano, G. Machado, K. DeLClaro, M. O. Gonzaga and two anon- ymous reviewers for advice and for reviewing the manuscript, A. E. B. Romero for help col- lecting the data and for logistic support in the field, M. Menin, T. J. Izzo and A. Cruz also contributed to the data collection. The staff of Guedes farm kindly provided permission to work on their property. G.Q.R. was supported by a research grant from Fundagao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP, grant no. 01/04610-0) and J.V.N was support- ed by a grant from Conselho Nacional de De- senvolvimento Cientifico e Tecnoldgico (CNPq, grant no. 300539/94-0). This paper is part of BIOTA/FAPESP — The Biodiversity ROMERO & VASCONCELLOS-NETO— MICROHABITAT OF PSECAS CHAPODA 133 Virtual Institute Program (www.biotasp.org. br; proc, 99/05446-8). LITERATURE CITED Abraham, BJ. 1983. Spatial and temporal patterns in a sagebrush steppe spider community (Arach- nida, Araeeae). Journal of Arachnology 11:31- 50. Crane, J. 1949. Comparative biology of salticid spi- ders at Rancho Grande, Venezuela. Part IV. An analysis of display. Zoologica 34:159-215. Cutler, B. 1992. Experimental microhabitat choice in Pseudicius piraticus (Araneae: Salticidae). En- tomological News 103:145-147. Cutler, B. & D.T. Jennings. 1992. Habitat segrega- tion by species of Metaphidippus (Araneae, Sal- ticidae) in Minnesota. Journal of Arachnology 20:88-93. Edgar, W.D. 1971. The life cycle, abundance and seasonal movement of the wolf spider, Lycosa (Pardosa) iugubris, in central Scotland. Journal of Animal Ecology 40:303-322. Figueira, J.E.C. & J. Vasconcellos-Neto. 1991. Pae- palanthus, cupins e aranhas. Ciencia Hoje 13: 20-26. Figueira, J.E.C. & J. Vasconcellos-Neto. 1993. Re- productive success of Latrodectus geometricus (Theridiidae) on Paepalanthus bromelioides (Er- iocaulaceae): rosette size, microclimate, and prey capture. Ecotropicos 5:1-10. Foelix, R.F. 1982. Biology of spiders. Harvard Uni- versity Press, Cambridge, Massachusetts. Foster, L.M. 1982. Vision and prey-catching strat- egies in jumping spiders. American Scientist 70: 165-175. Greenquist, E.A, & J.S. Rovner. 1976. Lycosid spi- ders on artificial foliage: stratum choice, orien- tation preferences, and prey-wrapping. Psyche 83:196-209. Greenstone, M.H. 1984. Determinants of web spi- der species diversity: vegetation structural diver- sity vs. prey availability. Oecologia 62:299-304. Gunnarsson, B, 1990. Vegetation structure and the abundance and size distribution of spruce-living spiders. Journal of Animal Ecology 59:743-752. Gunnarsson, B. 1996. Bird predation and vegetation structure affecting spruce-living arthropods in a temperate forest. Journal of Animal Ecology 65: 389-397. Herberstein, M.E. 1997. The effect of habitat struc- ture on web height preference in three sympatric web-building spiders (Araneae, Linyphiidae). Journal of Arachnology 25:93-96. Hill, D.E. 1979. Orientation by jumping spiders of the genus Phidippus (Araneae: Salticidae) during the pursuit of prey. Behavioral Ecology and So- ciobiology 6:301-322. Hofer, H. & A.D. Brescovit. 1994. Ergebnisse der Bolivien-Expedition des Staatlichen Museums fiir Naturkunde Karlsruhe: spinnen (Araneae). Andrias 13:99-112. Hurlbert, S.H. 1984. Pseudoreplication and the de- sign of ecological field experiments. Ecological Monographs 54:187-21 1. Jackson, R.R. 1986. The display behaviour of Bavia aericeps (Araneae: Salticidae), a jumping spider from Queensland. Australian Journal of Zoology 34:381-409. Jackson, R.R. & D. Li. 1997. Cues by which sus- pended-leaf nests of Euryattus (Araneae: Salti- cidae) females are recognized by conspecific males and by an aggressive-mimic salticid, Por- tia fimbriata. Journal of Zoology 243:29-46, Johnson, S.R. 1995. Observations of the habitat use by Sarinda hentzi (Araneae, Salticidae) in north- eastern Kansas. Journal of Arachnology 23:71- 74. Louda, S.M. 1982. Inflorescence spiders: a cost/ benefit analysis for the host plant, Haplopappus venetus Blake (Asteraceae). Oecologia 55:185- 191. Lubin, Y.D. 1978. Seasonal abundance and diver- sity of web-building spiders in relation to habitat structure on Barro Colorado Island, Panama. Journal of Arachnology 6:31-51. Miller, G.L. & E.M. Drawer. 1984. The influence of microhabitat and prey availability on burrow establishment of young Geolycosa turricola (Treat) and G. micanopy Wallace (Araneae: Ly- cosidae): a laboratory study. Psyche 91:123-132. Richman, D.B. & R.R. Jackson. 1992. A review of the ethology of jumping spiders (Araneae, Sal- ticidae). Bulletin of the British Arachnological Society 9:33-37. Richman, D.B. & W.H. Whitcomb. 1980. The on- togeny of Lyssomanes viridis (Walckeeaer) (Ar- aneae: Salticidae) on Magnolia grandiflora L. Psyche 88:127-133. Riechert, S.E. & C.R. Tracy. 1975. Thermal balance and prey availability: bases for a model relating web-site characteristics to spider reproductive success. Ecology 56:265-284. Robinson, J.V. 1981. The effect of architectural var- iation in habitat on a spider community: an ex- perimental field study. Ecology 62:73-80. Romero, G.Q. 2001. Experimental study of Runci- nioides argenteus (Araneae, Thomisidae) asso- ciation in Trichogoniopsis adenantha (DC.) (As- teraceae). (in Portuguese). MSc Thesis, State University of Campinas, Campinas, SP, Brazil. Romero, G.Q. & J. Vasconcellos-Neto. (2003). Natural history of Misumenops argenteus (Thomisidae): seasonality and diet on Tricho- goniopsis adenantha (Asteraceae). Journal of Arachnology 31:297-304. Romero, G.Q. & J. Vasconcellos-Neto. (2004). Beneficial effects of flower-dwelling predators on their host plant. Ecology 85:446-452. 134 THE JOURNAL OF ARACHNOLOGY Rossa-Feres, D. de C., G.Q. Romero, E, Gongalves- de=Freitas & R J.E Feres. 2000. Reproductive be- havior and seasonal occurrence of Psecas viri~ dipurpureus (Salticidae, Araneae). Brazilian Journal of Biology 60:221-228. Ruhren, S. & S.N. Handel. 1999. Jumping spiders (Salticidae) enhance the seed production of a plant with extrafloral nectaries. Oecologia 119: 227-230. Rypstra, A.L. 1983. The importance of food and space in limiting web-spider densities; a test us- ing field enclosures, Oecologia 59:312-316. Scheidler, M. 1990. Influence of habitat structure and vegetation architecture on spiders. Zoolo- gischer Anzeiger 225:333-340. Schmalhofer, V.R. 2001. Tritrophic interactions in a pollination system: impacts of species composi- tion and size of flower patches on the hunting success of a flower-dwelling spider. Oecologia 129:292-303. Schoonhoven, L.M., T. Jermy & J.J.A van Loon. 1998. Insect-plant Biology. Chapman & Hall, London. Smith, H. 2000. The status and conservation of the fen raft spider (Dolomedes plantarius) a Red- grave and Lopham Fen National Nature Reserve, England. Biological Conservation 95:153-164. Southwood, T.R.E. 1978. Ecological methods. Sec- ond edition, Chapman & Hall, London. Tarsitano, M.S. & R. Andrew. 1999. Scanning and route selection in the jumping spider Portia la- Mata. Animal Behaviour 58:255-265. Taylor, RW. 1998. Dragline-mediated mate-search- ing in Trite planiceps (Araneae, Salticidae). Jour- nal of Arachnology 26:330-334. Uetz, G.W. 1991. Habitat structure and spider for- aging. Pp. 325-348. In Habitat Structure: the Physical Arrangement of Objects in Space. (S.S. Bell, E.D. McCoy & H.R. Mushinsky, eds.). Chapman and Hall, London. Waldorf, E.S. 1976. Spider size, microhabitat selec- tion, and use of food. American Midland Natu- ralist 96:76-87. Wolda, K. 1988. Insect seasonality: why? Annual Review of Ecology and Systematics 19:1-18. Manuscript received 19 February 2003, revised 18 November 2003. 2005. The Journal of Arachnology 33:135-152 A REVIEW OF THE TASMANIAN SPECIES OF PARARCHAEIDAE AND HOLARCHAEIDAE (ARACHNIDA, ARANEAE) M.G. Rix: Queensland Museum, PO Box 3300, South Brisbane, Queensland 4101, Australia ABSTRACT. The Tasmanian species of Pararchaeidae and Holarchaeidae are revised and higher species- group relationships within the Pararchaeidae are examined. Three new species of Pararchaea Forster are described and the genitalia of P. corticola Hickman, P. ornata Hickman, P. saxicola Hickman and P. bryophila Hickman are redescribed, the receptacula of P. ornata, P. saxicola and P. bryophila for the first time. The male of P. ornata is newly described. With the addition of P. hickmani new species, P. lulu new species and P. robusta new species, the Tasmanian pararchaeid fauna is enlarged to include seven species. Holarchaea globosa (Hickman) is rediagnosed and the female genitalia and male are described and illustrated for the first time. Biological information is included where known. Keywords: Tasmania, Pararchaea, Holarchaea, taxonomy, new species, Australia The Pararchaeidae and Holarchaeidae are monogeneric families of small (0.8-3. 2 mm), entelegyne, araneomorph spiders, known only from Australia and New Zealand (Forster & Platnick 1984). Both groups belong to the widely “known, tetrafamilial ‘archaeid assem- blage', sharing with the Afrotropical, Mala- gasy and Australian Archaeidae and the New Zealand and Chilean Mecysmaucheniidae an anterior cephalothoracic foramen completely surrounding the cheliceral bases (Forster & Platnick 1984). While probably more diverse, and clearly more widespread in the past (with two genera of fossil Archaeidae known from European Baltic amber), the four families to- gether form a relatively speciose clade of ex- tant palpimaeoid spiders. Certainly, only a small proportion of the Australian species of Pararchaea Forster, and the New Zealand species of Holarchaea Forster, are currently named, despite extensive collections present in museums. This work is a contribution to the task of elucidating this rich alpha-diver- sity, reviewing in full the known pararchaeid and holarchaeid spider species of Tasmania, Higher species-group relationships within the Pararchaeidae are also examined, and biolog- ical information is summarized for all taxa where known. The Pararchaeidae and Holarchaeidae share similar, largely linked, taxonomic histories. The first species in both families were de- scribed by Forster (1949), with Pararchaea rubra (Forster 1949) initially placed in the ge- nus Zearchaea Wilton 1946 and Holarchaea novaeseelandiae (Forster 1949) in the genus Archaea Koch & Berendt 1854; both taxa were included in the family Archaeidae. The genera Pararchaea and Holarchaea. were sub- sequently erected by Forster (1955), the for- mer expanded to include the generic type P. alba Forster 1955 from New Zealand and P. binnaburra Forster 1955 from the Lamingtoe Plateau, south-eastern Queensland. Forster (1955: 398) noted that “the close relationship shown between the Australian species P. bin- naburra and P. alba is of great interest in that it provides yet another indication of the close affinity of a section of the Australian crypto- zoic fauna with that of New Zealand." Four more species of Australian Pararchaea were described by Hickman (1969) from Tasmania, followed by the holarchaeid Holarchaea glo- bosa (Hickman 1981), from south-western Tasmania. Forster & Platnick (1984) erected the monogeeeric, entelegyne families Parar- chaeidae and Holarchaeidae, along with the Mecysmaucheniidae and the newly delimited Archaeidae, recognizing the heterogeneous nature of the four taxa. Thus the Archaeidae (formerly a generic 'dumping ground' for taxa for over 100 years) was finally restricted to include, among extant taxa, only three genera from South Africa, Madagascar and mainland 135 136 THE JOURNAL OF ARACHNOLOGY Figures 1-2. — Pararchaea species: 1. P. ornata, holotype female, dorsal view, showing abdominal coloration; 2. P. saxicola, allotype female, dorsal view. Note the clearly procurved posterior margin of the pars cephalica on both specimens. Australia, all united by haplogyne genitalia and an extreme elevation of the pars cephalica (Forster & Platnick 1984). METHODS All specimens were described and illustrat- ed in 75% ethyl alcohol, or from scanning electron micrographs. Female genitalia were cleared in lactic acid. Digital photographs were taken through binocular and compound microscopes and cleared epigynes were tem- porarily mounted on glass cavity slides with 100% glycerine. All measurements are in mil- limetres and taken from camera lucida projec- tion, All illustrations are by the author. Abbreviations. — AME = anterior median eyes; ALE = anterior lateral eyes; AES = an- terior lateral spinnerets; DSl = dorsal sigil- lum 1 (anterior left); DS2 = dorsal sigillum 2 (anterior right); DS3 = dorsal sigillum 3 (pos- terior right); DS4 = dorsal sigillum 4 (poste- rior left); DSPl = dorsal sigilla pair 1 (ante- rior); DSP2 = dorsal sigilla pair 2 (posterior); DSQ — dorsal sigilla quadrangle; PME = posterior median eyes; PEE — posterior lateral eyes; PMS = posterior median spinnerets; PLS = posterior lateral spinnerets; PTA = peg tooth group A; PTB = peg tooth group B; PTC = peg tooth group C; SEM = scanning electron micrograph; TAS = Tasmania; VSl = ventral sigillum 1 (anterior left); VS2 = ventral sigillum 2 (anterior right); VS3 = ven- tral sigillum 3 (posterior right); VS4 = ventral sigillum 4 (posterior left); VSPl = ventral sigilla pair 1 (anterior); VSP2 = ventral sigilla pair 2 (posterior); VSQ = ventral sigilla quad- rangle. Specimens examined are located in the fol- lowing repositories: Australian Museum, Syd- ney (AMS); Queensland Museum, Brisbane (QM); Queen Victoria Museum, Launceston (QVM); Museum of Victoria, Melbourne (VICM). SYSTEMATICS Family Pararchaeidae Forster & Platnick Pararchaeidae Forster & Platnick 1984: 65. Type genus. — Pararchaea Forster, by orig- inal designation. Diagnosis. — The Pararchaeidae can be dis- tinguished from all other spider families by chelicerae arising from a distinct, ventrally sclerotized foramen (as in Archaeidae and Mecysmaucheniidae), in combination with en- telegyne female genitalia (Forster & Platnick 1984). Pararchaeid spiders can also be rec- ognized by having the combination of the fol- lowing characters: anterior tarsi longer than metatarsi, stout peg teeth on the distal prola- teral chelicerae, non-reduced female pedi- palps, squamate cephalothoracic cuticle with hairs only on the pars-cephalica and a distinc- tively procurved posterior margin to the pars- cephalica in dorsal view (Figs. 1, 2). Distribution. — The Pararchaeidae are known only from Australia and New Zealand. Within Australia, numerous specimens have been collected from north-eastern, middle- eastern and south-eastern Queensland, eastern RIX— TASMANIAN PARARCHAEA AND HOLARCHAEA 137 New South Wales, Victoria, Tasmania and southwestern Western Australia, Remarks. — -Spiders of the family Parar- chaeidae are most similar in body form and size to certain Mecysmaucheeiidae, namely Aotearoa magna (Forster 1949) from New Zealand, If the number of spinnerets on the latter is noted, however {Aotearoa with two spinnerets, Pararchaea with six), then the Pararchaeidae is unlikely to be confused with any other Araneae, especially in Australia where mecysmaucheniid spiders are apparent^ ly absent. Pararchaea Forster 1955 Pararchaea Forster 1955: 397; Hickman 1969: 3; Forster & Platnick 1984: 71. Type species.— alba Forster 1955, by original designation. Diagnosis.— As for family. Generic description.— In part from Forster & Platnick 1984. Cephalothorax: Carapace, when viewed lat- erally, rhomboidal. Pars cephalica rising steeply from pars thoracica above level of coxae III or IV; highest centrally or posteri- orly, sloping towards eyes. Viewed dorsally, carapace rounded or oval with rounded lateral indentations; posterior, procurved margin of pars cephalica appearing clearly demarcated from rest of carapace (Figs. 1 & 2), Carapace cuticle squamate, without tubercles or mounds. Eight eyes in two rows; laterals pearly-white, contiguous, widely separated from medians; AME closely spaced, dark-col- ored; PME pearly-white, m^ell separated from each other and AME. Carapace mainly devoid of hairs, except on dorsal and dorso-lateral as- pect of pars cephalica and around eyes and clypeus. Anterior margin of carapace encir- cling bases of chelicerae, with sclerotized cu- ticle extending ventrally to form antero-vee- trally-facieg oval foramen. Ventral suture below foramen completely or incompletely fused with sclerotized cuticle; if latter with thin longitudinal division, Clypeus extending aetero- ventrally in front of eyes; longest me- dially (forming dorsal margin of foramen). Lateral margins of pars-thoracica smoothly in- dented, with or without small (separate) tri- angular inter-coxal sclerites projecting ven- trally between coxae; the latter meeting and sometimes fusing with sternal projections. If without intercoxal sclerites, carapace either fused to or separate from sternum. Sternum not much longer than wide, posteriorly obtuse; cuticle squamate, usually fused with posterior carapace around petiole. Maxillae directed across labium; serrula a single row of teeth. Labium triangular, wider than long; not re- bordered. Chelicerae: Paturon relatively long, some- times elongate, proximally constricted; cuticle finely reticulated or squamate. Pronounced keel extending down ventral surface of patu- ron; originating about a third of length from proximal end, continuing to behind distal tip of non-extended fang. Fang relatively short, strongly curved. Pored cheliceral gland mound situated between distal end of keel and tip of eon-extended fang; in some species as- sociated with ridged spur. Promargie adjacent to fang with three groups (PTA, PTB, PTC) of stout peg teeth, each tooth with raised sock- et basally; PTA with 5-6 contiguous teeth di- rectly adjacent to non-extended fang; PTC with 3 larger teeth on promargin of outer sur- face; PTB with 1-3 teeth between PTA and PTC. Outer surface of paturon of males with or without transverse stridulatory ridges. Re- trolateral surface of paturon with strong, smooth, moveable hairs (erected upon full opening of chelicerae). Legs and female pedipalp: Legs (longest to shortest: 4, 1, 2, 3) relatively short, cuticle squamate, clothed with slender serrate or smooth hairs; no spines or scopulae. Single trichobothrium on metatarsi, 2-4 on tibiae; bothria well developed with smooth posterior hood. Tarsi longer than metatarsi (excluding Leg IV of some species), with three claws; upper claws with single row of teeth, inferior claw with single medial tooth. Tip of tarsi with modified serrate hairs; base sometimes distinctly swollen. Tarsal organ capsulate. Fe- mur I usually with proximal, dorsally curved row of retrolateral denticles; in some species forming an apparent stridulatory mechanism with prolateral file on femur II. Female pedi- palp entire, without claw; usually with several long, stiff hairs prolaterally. Abdomen: Abdomen, when viewed dorsal- ly, broadly oval without tubercles. Cuticle co- riaceous; clothed with short to long smooth or serrate hairs. Petiole encircled by sclerotized cuticle; often extending posteriorly on males to cover epigastric region and anterior face of abdomen (forming anterior sclerite). Small to 138 THE JOURNAL OF ARACHNOLOGY large, variably-shaped dorsal scute present on males. Dorsal abdomen with anterior (DSPl) and posterior (DSP2) pair of oval or circular, small (DSl & DS2) to large (DS3 & DS4) sigilla, forming quadrangle (DSQ) antero-cen- trally. Ventral abdomen also with anterior (VSPl) and posterior (VSP2) pair of subequal, circular sigilla (VS 1-4), forming quadrangle (VSQ) centrally. Internal darkened sclerotic invaginations usually visible around tracheal opening and along posteriorly-converging lines either side of VSQ. Book lung covers and external epigyne of females separately sclerotized; intromittent pores surrounded by an epigynal sclerite. Post-epigastric sclerites present on males and females; small and square or triangular on females, significantly enlarged and usually fused to anterior sclerite on males. Six spinnerets, fully developed; sur- rounded ventrally and/or dorsally by separate sclerites, or encircled by sclerotized cuticle. Posterior tracheal opening situated closely an- terior to colulus, surrounded by extended spin- neret sclerite, or by separate tracheal sclerite on females of most species. Colulus small, conical, with two posteriorly projecting hairs. Male genitalia: Epiandrous glands com- posed of spigots arising in clusters either side of genital opening; spigots with shared, raised sockets. Male palpal patella and tibia without processes. Cymbium spoon-shaped with prominent retrolateral apophysis (paracym- bium) proximally, of variable (usually distinc- tive) shape. Bulb large, extending over full length of cymbium; embolus spinous, arising from base and curving around prolateral mar- gin of bulb. Sclerotized distal plate situated over bulb, distal to base of embolus; usually complex with one or more apophyses and or- nate cuticular microstructure. Female genitalia: Epigyne with pair of sep- arate (although sometimes broadly touching), thick-walled, variously lobed receptacula, composed of internal systems of ducts and chambers; a single distinct fertilization duct leads from each receptaculum into bursal cav- ity, bending outwardly or prolaterally (often only visible when cleared epigynes are viewed laterally). Included species. — Pararchaea alba For- ster 1955, P. binnaburra Forster 1955, P. bry- ophila Hickman 1969, P. corticola Hickman 1969, P. hickmani new species, P. lulu new species, P. ornata Hickman 1969, P. robusta new species, P. rubra (Forster 1949), P. sax- icola Hickman 1969. Key to the Tasmanian species of Pararchaea 1. Males ................................................................... 2 Females ................................................................. 8 2. Dorsal abdomen with distinctive anterior cardiac stripe and posterior chevrons ........ .................................................... Pararchaea ornata Hickman Dorsal abdomen not patterned as above ........................................ 3 3. Retrolateral femur I with dorsally curved row of proximal denticles; proximal tarsus I not distinctly swollen; postero-dorsal aspect of pars cephalica without medial indentation ... 4 Retrolateral femur I without dorsally curved row of proximal denticles; proximal tarsus I distinctly swollen; postero-dorsal aspect of pars cephalica with medial indentation (Fig. 10) .............................................. Pararchaea bryophila Hickman 4. Dorsal scute small, not extending posterior to level of DSP2 ....................... 5 Dorsal scute large, extending posterior to level of DSP2 .......................... 6 5. Dorsal scute roughly circular (Fig. 16) .............. Pararchaea hickmani new species Dorsal scute very small, transversely elongate (Fig. 11) ..... Pararchaea saxicola Hickman 6. Dorsal scute longitudinally elongate, pale in color (Fig. 22); paracymbium distally ‘star- shaped' (Fig. 21)..................................... Pararchaea lulu new species Dorsal scute roughly as long as wide, dark brown in color; paracymbium not distally ‘star- shaped' ................................................................. 7 7. Cymbium with retrolateral lobe-like extension at base of paracymbium (Fig. 12); paracym- bium with two divergent apophyses; post-epigastric sclerites not extending posterior to level of VSPl ..................................... Pararchaea corticola Hickman Cymbium without retrolateral lobe-like extension at base of paracymbium; paracymbium RIX— TASMANIAN PARARCHAEA AND HOLARCHAEA 139 a single, distally rounded, curved projection (Fig. 26); post-epigastric sclerites extensive, extending posterior to level of VSPl (Fig. 28) .......... Pararchaea robusta new species 8. Retrolateral femur I with dorsally curved row of proximal denticles ................. 9 Retrolateral femur I without dorsally curved row of proximal denticles ................................................. Pararchaea bryophila Hickman 9. External epigyne distinctive, as illustrated in Fig. 8 ....... Pararchaea corticola Hickman External epigyne not as illustrated in Fig. 8 ................................... 10 10. Dorsal abdomen with distinctive anterior cardiac stripe and posterior chevrons (Fig. 1) . . Pararchaea ornata Hickman Dorsal abdomen not patterned as above 11 11. Receptacula large, ‘comma-shaped’, broadly touching along inward margins (Fig. 6) . . . . Pararchaea saxicola Hickman Receptacula otherwise 12 12. Receptacula oval-shaped, posteriorly convergent (Fig. 5) . . Pararchaea robusta new species Receptacula otherwise 13 13. Receptacula with prominent, ‘nose-like’ inward lobes (Fig. 4); abdomen without ‘marbled’ coloration in life Pararchaea lulu new species Receptacula without prominent, ‘nose-like’ inward lobes (Fig. 3); abdomen with ‘marbled’ coloration in life Pararchaea hickmani new species Pararchaea bryophila Hickman 1969 (Figs. 7, 9-10) Pararchaea bryophila Hickman 1969; 9, figs. 25- 30; Schiitt 2000: 137, figs. 2, 6, 7, 10. Type material. — Holotype male. Punch Bowl Reserve, Launceston, Tasmania, Austra- lia, 4r25'S, 147°7'E, 24 August 1929, moss, V.V. Hickman (AMS KS 6633). Allotype fe- male, same data as holotype (AMS KS 6634). Other material examined. — AUSTRA- LIA: Tasmania: 1 d, 1 9, Launceston (AMS KS 54300); 1 9, Point Sorell (QVM 13: 17998); 1 9, no locality data (QVM 13: 23869); 1 d, 1 9, northeast TAS (AMS KS 25985); 1 d, King River (AMS KS 65966); 1 6, West Downs via Ridgely (AMS KS 66072); 2 9, same data (AMS KS 66078); 1 9, Dip River Falls (AMS KS 66038); 1 9, ~3 km S of Waratah Junction on Murchison Hwy (AMS KS 66088); 2 , Punch Bowl Re- serve, Launceston (AMS KS 28721); 1 d, 2 9, same data (AMS KS 54295). Diagnosis. — Male and female P. bryophila can be distinguished from all other known Tasmanian congeners by the absence of retro- lateral denticles on the femur of leg I and their small size. Description.— Ma/e (AMS KS 66072): Ped- ipalp (Fig. 9): paracymbium large, ‘sickle- shaped’, with two divergent projections. Dis- tal plate with two prominent, pro-distally directed apophyses. Female (QVM 13: 17998): Epigyne (Fig. 7): receptacula posteriorly convergent, togeth- er forming ‘V-shape’; each receptaculum with ‘nose-like’ inward lobe. Distribution and habitat. — Pararchaea bryophila appears to be widespread in Tas- mania. Hickman (1969) recorded that the types were collected from moss. Pararchaea corticola Hickman 1969 (Figs. 8, 12) Pararchaea corticola Hickman 1969: 3, figs. 10- 15. Type material. — Holotype male, The Queen’s Domain, Hobart, Tasmania, Australia, 42°52'S, 147°19'E, 24 May 1937, under the loose bark of eucalypts, V.V. Hickman (AMS KS 6635). Allotype female, same data as ho- lotype except March 1955 (AMS KS 6636). Diagnosis. — Female P. corticola can be distinguished from all other known Tasmanian congeners by the large size and the character- istic shape of the external epigyne (Fig. 8). Males can be distinguished from all other known Tasmanian congeners by the retrola- teral lobe-like extension on the cymbium (at base of paracymbium; Fig. 12), and the pres- ence of an oval sclerite surrounding VSP2. Description. — Male (holotype AMS KS 6635): Pedipalp (Fig. 12): paracymbium large, with two divergent apophyses. Cymbium with retrolateral, lobe-like extension at base of par- acymbium. Distal plate extended distally to 140 THE JOURNAL OF ARACHNOLOGY Figures 3-8. — Epigynes of Pararchaea species: 3-7. Cleared receptacula, dorsal view. 3. P. hickmani; 4. P. lulu; 5. P. rohusta; 6. P. saxicola; 7. P. hryophila; 8. P. corticola, allotype female external epigyne, ventral view. form prominent ‘conductor’ around tip of em- bolus. Female (allotype AMS KS 6636): Epigyne (Fig. 8): as the allotype was the only female specimen of this species examined, the epi- gyne was not dissected. The external appear- ance is, however, characteristic, and sufficient for identification. Distribution and habitat. — Pararchaea corticola is known only from the Queen’s Do- main, Hobart, Tasmania. Hickman (1969) re- corded that the types were collected from un- der the loose bark of eucalypts. Remarks. — I conducted field work at the Queen’s Domain in January and February 2002, but found no evidence of this or any other Pararchaea species (despite targeted collecting). The forest was mainly dominated Figures 9-10. — Pararchaea hryophila, male: 9. Left pedipalp, retro- ventral view, showing ornate distal plate and distinctive paracymbium; 10. Carapace, dorso-lateral view, showing medial indentation. Scale bar = 0.5 mm. RIX— TASMANIAN PARARCHAEA AND HOLARCHAEA 141 12 Figures 11—12. — Pararchaea species: 11. P. saxicola, holotype male abdomen, antero-dorsal view, showing small dorsal scute; 12. P. corticola, holotype male carapace and pedipalp, dorso-lateral view, showing retrolateral lobe-like extension at base of paracymbium. Scale bars = 0.5 mm. by Eucalyptus trees and extensive grassland, and signs of a recent and widespread fire were apparent. Pararchaea hickmani new species (Figs. 3, 13-17) Type material. — Holotype male, Strath- gordon, Tasmania, Australia, 42°46'S, 146°03'E, 17 January 2002, sifted from moss in forested valley overlooking inbound high- way, M. Rix (AMS KS 82657). Allotype fe- male, end of Basils Rd, West Downs via Ridgely, Tasmania, Australia, 42°20'S, 145°39'E, 1 December 1978, S737, map/grid reference 8015-853229, litter, D. DeLittle (AMS KS 82658). Other material examined. — AUSTRA- LIA: Tasmania: 1 $ , Waterhouse Point (QVM 13: 46); 1 $, same data (QVM 13: 3244); 1 $, same data (QVM 13: 3212); 1 d, same data (QVM 13: 46); 1 $, same data (QM S 16727); 1 d, Gordon River Road near May- dena (QM S60759); 1 d, 1 ?, Mount Barrow (AMS KS 54299); 2 d, Punchbowl Reserve, Launceston (AMS KS 28719); 2 d, McPartlan Pass (QM S60758); 1 d, same data (QM S60760); 1 d, same data (QM S60761). Diagnosis. — Female P. hickmani can be distinguished from all other known Tasmanian congeners by the ‘marbled’ abdominal color- ation (in life), and the shape of the receptacula (the latter without distinct, ‘nose-like’ inward lobes; Fig. 3). Males can be distinguished from all other known Tasmanian congeners by the ‘marbled’ abdominal coloration (in life), and the small, circular dorsal scute (Fig. 16). Description. — Male (holotype AMS KS 82657): Carapace 0.68 long, 0.45 wide. Ab- domen 0.85 long, 0.63 wide. Total length 1.53. Color: carapace mustard-yellow. Abdo- men pale cream, with light brown marbled patterning dorsally. Legs uniform pale cream. Carapace: in lateral view rhomboidal; dorsal surface of pars cephalica sloping almost lin- early down to AME from posterior margin. Chelicerae: stridulatory ridges present on out- er surface. Dentition: PTA 5, PTB 2, PTC 3 (10). Abdomen (Figs. 16-17): circular petiolar sclerite extending dorsally and ventrally (forming anterior sclerite); extending ventrally to cover entire epigastric region; extending dorsally to cover anterior face of abdomen. Post-epigastric region separately sclerotized, with two rounded sclerites (extending to half distance of epigastric furrow to VSPl from latter). Small, roughly circular dorsal scute an- terior and posterior to DSPl. Spinnerets en- circled by sclerotized cuticle, extending ven- trally up to length of VSQ from latter. Ventral internal sclerotic invaginations visible later- ally and posteriorly. Abdomen clothed with black hairs; absent on antero- lateral faces. Pedipalp (Figs. 13-15): paracymbium curved, distally widened, with three small distal ex- 142 THE JOURNAL OF ARACHNOLOGY Figures 13-17. — Pararchaea hickmani, male: 13. Left pedipalp, ventral view, showing distally bifurcate embolus; 14, Left cymbium, retrolateral view, showing brush of hairs in groove; 15. Paracymbium of left pedipalp, retrolateral view, showing distinctive distal shape; 16. Abdomen, dorsal view, showing circular dorsal scute and 'marbled' coloration; 17. Abdomen, ventral view, showing separate post-epigastric scler- ites. Scale bars = 0.5 mm. tensions. Distal plate complex, with median apophyses. Embolus distally bifurcate. Cym- bium with brash of hairs in groove along re- troiateral edge. Legs: femur I with dorsally curved row of 5 retrolateral denticles. Female (allotype AMS KS 82658): Cara- pace 0.73 long, 0.48 wide. Abdomen 1.11 long, 0.82 wide. Total length 1.84. Color: car- apace brownish-yellow. Abdomen mustard-yel- low, with very light brown marbled patterning dorsally. Legs uniform mustard-yellow. Cara- pace: in lateral view rhomboidal; dorsal surface or pars cephalica weakly convex, sloping gent- ly down to AME from posterior margin. Che- licerae: stridulatory ridges absent on outer sur- face. Dentition: PTA 5, PTB 3, PTC 3 (11). Abdomen: circular petiolar sclerite encircling petiole; not extending dorsally or ventrally. Epigyne surrounded by rectangular sclerite. Book lung covers plus triangular region pos- terior to each cover sclerotized. Two, small, square post-epigastric sclerites. Spinnerets en- circled by sclerotized cuticle; cuticle medially constricted ventrally. Tracheal sclerite present. Ventral internal sclerotic invaginations visible laterally and posteriorly. Abdomen clothed with black hairs; absent on antero- lateral fac- es. Epigyne (QVM 13: 3244; Fig. 3): recep- tacula anteriorly widened, rounded; inward faces roughly straight, parallel. Legs: femur I with dorsally-curved row of 5 retrolateral den- ticles. Distribution and habitat. — Pararchaea hickmani is widespread in Tasmania, where it RIX— TASMANIAN PARARCHAEA AND HOLARCHAEA 143 Figures 18-23. — Pararchaea lulu, male: 18. Left pedipalp, ventral view; 19. Left pedipalp, retro-ventral view, showing prominent median apophyses of distal plate; 20. Left cymbium, retrolateral view, showing brush of hairs in groove; 21. Paracymbium of left pedipalp, retrolateral view, showing distinctive distal ‘star’ shape; 22. Abdomen, dorsal view, showing longitudinally-elongate scute; 23. Abdomen, ventral view. Scale bars = 0.5 mm. has been collected from moss (growing on the ground and on logs) and pitfall traps. The spe- cies is known from coastal and subalpine heathland habitats, and is the dominant Par- archaea species in some regions (pers. obser.). Etymology. — The specific epithet is a pa- tronym in honor of the late Vernon V. Hick- man, for his substantial contribution to the study of Tasmanian Pararchaeidae. Pararchaea lulu new species (Figs. 4, 18-23) Type material. — Holotype male, Warra Forest near Geeveston, Tasmania, Australia, 43°04'S, 146°43'E, 14 April 2000, ex. log de- cay, D. Bashford (QVM 13: 39992). Allotype female, same data as holotype (QVM 13: 39993). Other material examined. — AUSTRA- LIA: Tasmania: 1 d, Warra Forest near Geev- eston (QVM 13: 39994); 1 d, same data (QVM 13: 39995); 1 $, Pump House Point, Lake St Clair (QVM 13:23690); 1 ?, 1 d, Lake Dobson Road, Mount Field National Park (QM S60757); 2 $, Arve Forest (AMS KS 28716); 1 2, Tarraleah (AMS KS 28724); 1 2, same data (AMS KS 28725); 1 2, Frod- shams Pass (AMS KS 62695); 1 2, Mount Wellington (AMS KS 28722); 1 d, 1 2, same data (AMS KS 54298); 1 2, Fingal (AMS KS 28717); 1 2, Trevallyn (AMS KS 54296); 1 2, Fish River track to Walls of Jerusalem (AMS KS 54301); 1 d, southwest TAS (AMS KS 26475); 1 2, Strathgordon (AMS KS 28726). Diagnosis. — Female P. lulu can be distin- guished from all other known Tasmanian con- geners by the pale abdominal coloration, and the shape of the receptacula (the latter with distinct, ‘nose-like’ inward lobes; Fig. 4). Males can be distinguished from all other known Tasmanian congeners by the pale ab- dominal coloration, the large, longitudinally- elongate dorsal scute (Fig. 22), and the dis- tally ‘star-shaped’ paracymbium (Fig. 21). Description. — Male (holotype QVM 13: 144 THE JOURNAL OF ARACHNOLOGY 39992): Carapace 0.71 long, 0.53 wide. Ab- domen 1.08 long, 0.82 wide. Total length 1.79. Color: carapace mustard-yellow. Abdo- men pale yellow with mustard-yellow dorsal scute. Legs uniform light mustard-yellow. Carapace: in lateral view rhomboidal; dorsal surface of pars cephalica almost flat, except for slightly convex central region. Chelicerae: stridulatory ridges present on outer surface. Dentition: PTA 5, PTB 2, PTC 3 (10). Ab- domen (Figs. 22-23): circular petiolar sclerite extending dorsally and ventrally (forming an- terior sclerite); extending ventrally to cover entire epigastric and post-epigastric regions (extending to a little under half distance of epigastric furrow to VSPl from latter); ex- tending dorsally to cover anterior face of ab- domen. Dorsal scute extending from behind posterior margin of anterior sclerite to half width of DSP2 from latter; widest posterior to DSPl, tapering anteriorly. Spinnerets encir- cled by sclerotized cuticle, extending ventrally up to length of VSQ from latter. Ventral in- ternal sclerotic invaginations visible laterally and posteriorly. Abdomen clothed with black hairs; absent on antero-lateral faces. Pedipalp (Figs. 18-21): paracymbium curved, distally widened, with three distal extensions forming ‘star-shape’. Distal plate complex, with prom- inent median apophyses. Embolus distally bi- furcate. Cymbium with brush of hairs in groove along retrolateral edge. Legs: femur I with dorsally curved row of 4 retrolateral den- ticles. Female (allotype QVM 13: 39993): Cara- pace 0.80 long, 0.55 wide. Abdomen 1.16 long, 0.94 wide. Total length 1.96. Color: car- apace mustard-yellow. Abdomen pale cream. Legs uniform pale mustard-yellow. Carapace: in lateral view rhomboidal; dorsal surface of pars cephalica weakly convex, sloping gently down to AME from posterior margin. Chelic- erae: stridulatory ridges absent on outer sur- face. Dentition: PTA 5, PTB 3, PTC 3 (11). Abdomen: circular petiolar sclerite encircling petiole; not extending dorsally or ventrally. Epigyne surrounded by rectangular sclerite. Book lung covers plus triangular extension posterior to each cover sclerotized. Two, small, square post-epigastric sclerites. Spin- nerets encircled by sclerotized cuticle dorsally and ventrally; cuticle medially constricted ventrally. Tracheal sclerite present. Ventral in- ternal sclerotic invaginations visible laterally and posteriorly. Abdomen clothed with black hairs; absent on antero-lateral faces. Epigyne (AMS KS 28716; Fig. 4): receptacula round- ed, with prominent ‘nose-like’ inward lobes. Legs: femur I with dorsally curved row of 4 retrolateral denticles. Distribution and h.WLhlt^t.—Pararchaea lulu is widespread in Tasmania, where speci- mens have been collected from moss and rot- ting logs. Etymology. — -The specific epithet is a pa- tronym in honor of Lisa Boutin (nicknamed ‘Lulu’), personal friend of the author, and col- lector of many recent pararchaeid and holar- chaeid specimens. The name is to be treated as a noun in apposition. Pararchaea ornata Hickman 1969 (Fig. 1) Pararchaea ornata Hickman 1969: 7, figs. 21-24. Type material* — Holotype female, The Queen’s Domain, Hobart, Tasmania, Australia, 42°52'S, 147°19'E, 13 April 1968, shaking gorse (Ulex europaeus), V.V. Hickman (AMS KS 6638). Other material examined* — AUSTRA- LIA: Tasmania: 1 d, 1 $, A3 roadside be- tween Weldborough and Derby (QVM 13: 39996); 1 d, same data (QVM 13: 39997). Diagnosis. — Female P. ornata can be dis- tinguished from all other known Tasmanian congeners by the body coloration: the dorsal abdomen is pale yellowish, with dark brown posterior chevrons, a dark brown anterior car- diac stripe, and dark brown antero-lateral re- gions (Fig. 1). Males can also be distinguished from all other known Tasmanian congeners by the body coloration, which is similar to that of the female. Description.- — Male (QVM 13: 39997): Carapace 0.65 long, 0.48 wide. Abdomen 0.87 long, 0.71 wide. Total length 1.52. Color: pars cephalica and medial posterior region of pars thoracica mustard yellow; lateral pars thora- cica dark brown. Abdomen pale yellow with dark brown cardiac stripe and five dark brown chevrons dorsally; antero-lateral regions also dark brown. Legs mustard yellow; metatarsi and tarsi banded brown proximally. Carapace: in lateral view rhomboidal; dorsal surface of pars cephalica weakly convex, sloping down to AME from posterior margin, Chelicerae: stridulatory ridges absent on outer surface. RIX— TASMANIAN PARARCHAEA AND HOLARCHAEA 145 Figures 24-28. — Male Pararchaea robusta: 24. Left pedipalp, ventral view; 25. Left pedipalp, retro- ventral view, showing prominent distal ‘conductor’; 26. Paracymbium of left pedipalp, ventral view, showing simple, distally-rounded shape; 27. Abdomen, dorsal view; 28. Abdomen, ventral view, showing extensive post-epigastric sclerites. Scale bars = 0.5 mm. Dentition; PTA 5, PTB 2, PTC 3 (10). Ab- domen: circular petiolar sclerite extending dorsally and ventrally (forming anterior scler- ite); extending ventrally to cover entire epi- gastric and post-epigastric regions (extending to two-thirds distance of epigastric furrow to VSPl from latter); extending dorsally to cover anterior face of abdomen. Small, oval dorsal scute anterior and posterior to DSPl, fusing with anterior sclerite anteriorly. Spinnerets en- circled by sclerotized cuticle, extending ven- trally up to length of VSQ from latter. Ventral internal sclerotic invaginations visible later- ally and posteriorly. Abdomen clothed with black hairs; absent on antero-lateral faces. Pedipalp: paracymbium pointed, sinuous, with inward hook. Legs: femur I with dorsally curved row of 4 retrolateral denticles. Female (QVM 13: 39996): Epigyne: recep- tacula laterally rectangular, with distinctive ‘nose-like’ inward lobes. Distribution and habitat. — Pararchaea ornata is known only from southern and north-eastern Tasmania. Hickman (1969) re- corded that the holotype female was collected by shaking gorse {Ulex europaeus, Fabaceae). The species appears to be very rare. Pararchaea robusta new species (Figs. 5, 24-28) Type material. — Holotype male, Frod- shams Pass, Scotts Peak Road, 1.5 km west of Gordon River Road, Tasmania, Australia, 42°49'S, 146°13'E, 15 February 1990, Noth- ofagus cunninghami Sample 8, R. Coy, P. Lil- lywhite & A.L.Yen (VICM K-8796). Allotype 146 THE JOURNAL OF ARACHNOLOGY female, same data as holotype (VICM K- 8797). Other material examined. — AUSTRA= LIA: Tasmania: 1 $, Mount Wedge Track (QVM 13: 24033); 1 $, Liffey Falls (AMS KS 28713). Diagnosis. — Female P. robusta can be dis^ tinguished from all other known Tasmanian congeners by the distinct, oval-shaped, pos- teriorly-convergent receptacula (Fig. 5). Males can be distinguished from all other known Tasmanian congeners by the extensive post- epigastric sclerites (Fig. 28). Description. — Male (holotype VICM K- 8796): Carapace 0.75 long, 0.50 wide. Ab- domen 1.12 long, 0.93 wide. Total length 1.87. Color: carapace brown; pars thoracica darkest. Abdomen mustard-yellow, with dark brown dorsal scute. Legs mustard-yellow; femora, tibiae, metatarsi and tarsi banded brown proximally. Carapace: in lateral view rhomboidal; dorsal surface of pars cephalica weakly convex, sloping down to AME from posterior margin. Chelicerae: stridulatory ridges absent on outer surface. Dentition: PTA 6, PTB 3, PTC 3 (12). Abdomen (Figs. 27- 28): circular petiolar sclerite extending dor- sally and ventrally to cover entire epigastric and post-epigastric regions (extending to level between VSPl and VSP2 behind epigastric furrow). Broadly oval dorsal scute extending from behind posterior margin of anterior sclerite to half length of DSQ behind latter; with lateral extension directly anterior to DS3. Spinnerets surrounded by sclerotized cuticle dorsally and ventrally, extending ventrally up to length of VSQ from latter. Ventral internal sclerotic invaginations visible laterally and posteriorly. Abdomen clothed with black hairs; absent on antero-lateral faces. Pedipalp (Figs. 24-26): paracymbium simple, curved, distally rounded. Distal plate ornately sclero- tized, extending distally into prominent ‘con- ductor’. Legs: femur I with dorsally curved row of 6 retrolateral denticles. Female (allotype VICM K-8797): Carapace 0.94 long, 0.65 wide. Abdomen 1.33 long, 1.13 wide. Total length 2.27. Color: carapace brown; pars thoracica darkest. Abdomen mus- tard-yellow, with dark brown DSP2. Legs mustard-yellow; femora, tibiae, metatarsi and tarsi banded brown proximally. Carapace: in lateral view rhomboidal; dorsal surface of pars cephalica weakly convex, sloping down to AME from posterior margin. Chelicerae: stridulatory ridges absent on outer surface. Dentition: PTA 6, PTB 3, PTC 3 (12). Ab- domen: circular petiolar sclerite encircling petiole; not extending dorsally or ventrally. Epigyne surrounded by rounded rectangular sclerite. Book lung covers plus triangular ex- tension posterior to each cover sclerotized. Two, small, truncated-triangular post-epigas- tric sclerites. Spinnerets surrounded by scler- otized cuticle dorsally and ventrally; cuticle medially constricted ventrally. Tracheal scler- ite present. Ventral internal sclerotic invagi- nations visible laterally and posteriorly. Ab- domen clothed with black hairs; absent on antero-lateral faces. Epigyne (AMS KS 28713; Fig. 5): receptacula oval-shaped, pos- teriorly convergent. Legs: femur I with dor- sally curved row of 6 retrolateral denticles. Distribution and habitat. — Pararchaea robusta is known only from southern and cen- tral Tasmania. Etymology. — The specihc epithet refers to the robust appearance of this species. Pararchaea saxicola Hickman 1969 (Figs. 2, 6, 11) Pararchaea saxicola Hickman 1969; 5, figs. 16-20. Type material. — Holotype male. The Queen’s Domain, Hobart, Tasmania, Australia, 42°52'S, 147°19'E, 4 May 1938, in copulo on underside of loose stone on ground, VV. Hickman (AMS KS 6639). Allotype female, same data as holotype (AMS KS 6640). Other material examined. — AUSTRA- LIA: Tasmania: 1 9, The Queen’s Domain, Hobart (AMS KS 54297). Diagnosis. — Female P. saxicola can be dis- tinguished from all other known Tasmanian congeners by the distinctive, large, ‘comma- shaped’ receptacula, broadly touching along their inward margins (Fig. 6). Males can be distinguished from all other known Tasmanian congeners by the very small, transversely- elongate dorsal scute (Fig. 11). Description. — Male (holotype AMS KS 6640).- Pedipalp: bulb expanded. Paracym- bium curved, with inner hook. Distal plate projecting over embolus; both interacting with paracymbium on retrolateral side. Female (AMS KS 54297).- Epigyne (Fig. 6): receptacula large, ‘comma-shaped’, broad- ly touching along inward margins. RIX— TASMANIAN PARARCHAEA AND HOLARCHAEA 147 Distribution and habitat, — Pararchaea saxicola is known only from the Queen’s Do- main, Hobart, Tasmania, and was collected from under stones in May 1936. Remarks. — I conducted field work at the Queen’s Domain in January and February 2002, but found no evidence of this or any other Pararchaea species (despite targeted collecting). The forest was mainly dominated by Eucalyptus trees and extensive grassland, and signs of a recent and widespread fire were apparent. Family Holarchaeidae Forster & Platnick Holarchaeidae Forster & Platnick 1984: 71. Type ^cmis.—Holarchaea Forster, by orig- inal designation. Diagnosis. — The Holarchaeidae can be dis- tinguished from all other spider families by elongate chelicerae arising from a distinct but ventrally uesclerotized foramen, in combina- tion with entelegyne female genitalia, an ab- sence of peg teeth on the chelicerae and a swollen (anteriorly projecting) clypeus (see Forster & Platnick 1984). Holarchaeid spiders can also be recognized by having tarsi longer than metatarsi, widened female pedipalps dis- tally, and spherical abdomens. Distribution. — The Holarchaeidae are known only from Tasmania and New Zealand. Despite extensive surveying of Victorian Nothofagus (beech) forests (Graham Milledge, pers. comm.), holarchaeid spiders have not been found on the Australian mainland. Remarks.— The Holarchaeidae are a mor- phologically and biogeographically distinct spider family, unlikely to be confused (upon close examination) with any other Araneae. New Zealand Zearchaea (Mecysmaucheni- idae) appear superficially similar to Holar- chaea, but with only two spinnerets, peg teeth, and a foramen completely surrounded by sclerotized cuticle, the former genus is easily distinguished. Holarchaea Forster 1955 Holarchaea Forster 1955: 392; Forster & Platnick 1984: 76. Type species.-— A rc/taefl novaeseelandiae Forster 1949, by original designation. Diagnosis. — As for family. Generic description.— In part from Forster & Platnick 1984. Cephalothorax: Carapace, when viewed lat- erally, anteriorly raised or triangular. Pars ce- phalica rising steeply from pars thoracica above level of coxa III. Lateral pars thoracica with furrow ventro-lateral to pars cephalica, dorsal pars thoracica slightly concave central- ly. Viewed dorsally, carapace rounded; pos- terior margin of pars cephalica appearing de- marcated from rest of carapace, extending to PLE. Carapace cuticle without tubercles, sometimes punctate. Eight eyes in two rows; laterals contiguous, pearly-white, widely sep- arated from medians; AME smallest, circular, closely-spaced, dark-colored; PME oval, pearly-white, well separated. Carapace mainly devoid of hairs, except on postero-dorsal as- pect of pars cephalica, clypeus and around eyes. Anterior margin of carapace encircling bases of chelicerae, with unsclerotized cuticle extending ventrally to form antero-ventrally- facing oval foramen. Clypeus large, swollen, projecting anteriorly and laterally around ba- ses of chelicerae, connecting with sclerotized cuticle of anterior carapace ventro-laterally; longest medially (forming dorsal margin of foramen). Margin of pars thoracica smoothly curved, with separate, elongate sclerite above coxae III and IV on each side. Sternum longer than wide, posteriorly obtuse; cuticle lightly punctate. Maxillae directed across labium, not meeting in middle; serrula a single row of teeth. Labium triangular, wider than long; strongly rebordered. Chelicerae: Paturon (Figs. 34 & 35) rela- tively long, elongate, constricted proximally; cuticle finely reticulated. Fang (Figs. 34-36) long, distally curved, usually hooked at tip, with raised, finely serrated prolateral edge (Fig. 36); divided at one third of length from base by transverse groove; without poison gland opening. Two or three true slender teeth on prolateral margin of paturon (Fig. 35); peg teeth absent. Pored cheliceral gland mound situated near tip of non-extended fang; retro- laterally-adjacent to proximal tooth. Hairs sparse; several filiform. Legs and female pedipalp: Legs (longest to shortest: 1, 4, 2, 3) relatively long, slender, cuticle finely reticulated, clothed with slender smooth or weakly serrate hairs; no spines or scopulae. Single trichobothrium on metatarsi, 2 or 3 on tibiae; bothria well developed with smooth posterior hood. Tarsi longer than metatarsi, with three smooth claws; tarsi I and 148 THE JOURNAL OF ARACHNOLOGY Figures 29-30. — Holarchaea globosa: 29. Male cephalothorax and abdomen, antero-dorsal view; 30. Cleared female receptacula, dorsal view, showing bilobed morphology of each receptaculum. II with reduced claws. Distal quarter of tarsi I and II more slender than proximal three- quarters; often with group of modified, strong- ly serrate hairs raised on low mounds, sur- rounding discoid organs of unknown function. Tarsal organ capsulate. Tibia and tarsus of fe- male pedipalp shortened, widened, partially fused; with brush of long hairs ventrally; with- out claw. Abdomen: Abdomen spherical or globose. Cuticle thin, without scutes or surface swell- ings; clothed with short hairs. Female epigyne a single slit-like opening, shortly anterior to epigastric furrow; lightly sclerotized, obscured by posterior of sternum in live animals and many specimens. Anterior respiratory open- ings lightly sclerotized. Six spinnerets; ALS largest, PMS smallest. Posterior tracheal spi- racle absent. Colulus linguiform, with two posteriorly projecting hairs. Male genitalia: Pedipalp (Figs. 31-33) with coiled embolus encircling bulb two or three times. Ventral surface of bulb relatively smooth (Fig. 32), without prominent apophy- ses. Cymbium spoon-shaped, with or without spine-like proximal retrolateral apophysis (Fig. 33). Patella and tibia variably-shaped, with spur-like processes distally (Fig. 33). Female genitalia: Epigyne with single slit- like opening leading to pair of unilobed or bi- lobed receptacula (Fig. 30); each receptacu- lum with short, proximal, spur-like fertilization duct leading into bursal cavity. Included species. — Holarchaea globosa (Hickman 1981), H. novaeseelandiae (Forster 1949). Holarchaea globosa (Hickman 1981) (Figs, 29-36) Zearchaea globosa Hickman 1981: 47, figs. 1-5. Holarchaea globosa (Hickman): Forster & Platnick 1984: 76. Type material. — Holotype female, Strath- gordon, Tasmania, Australia, 42°46'S, 146°03'E, 25 April 1978, from moss, V.V. Hickman (AMS KS 6987). Other material examined. — AUSTRA- LIA: Tasmania: 1 (5, 1 $, Hogarth Falls Walk, People's Park, Strahan (QM S60756); 1 $, Main Cave (MU201-13v E-Tw-Tr), Mon- tagu (QVM 13:12671); 1 $, same data (AMS KS 29515); 5 $, 2 S, Andrew River Caves, Western Heritage Area (AMS KS 21290); 1 $ , Cuckoo Ealls Walk, southeast of Scottsdale (QM S60755). Diagnosis. — Male and female H. globosa can be distinguished from all other known congeners by the triangular shape of the car- apace in lateral view (with highest point of pars cephalica separated from PME by dis- tance greater than medial length of clypeus). Other autapomorphies include the single long, serrate, moveable hair near the base of each fang (Eig. 35), fangs with length greater than half length of paturon (Fig. 34), fangs without hooked tips (Fig. 35), a posteriorly-directed, RIX— TASMANIAN PARARCHAEA AND HOLARCHAEA 149 Figures 31-36. — Holarchaea globosa, pedipalp and chelicerae: 31-33, Male left pedipalp; 31. Distal segments, retrolateral view; 32. Bulb and cymbium, retro-ventral view, showing pointed distal process of cymbium; 33, Cymbium, tibia and patella, retrolateral view, showing proximal, posteriorly directed, spine- like process of cymbium and complex tibia and patella. 34-36. Female chelicerae: 34. Chelicerae, frontal view, showing relative lengths of paturoe and fang; 35. Fang, distal tooth and moveable hair of right chelicera, frontal view, showing distally curved fangs and morphology of serrate moveable hair; 36. Fang, showing strongly serrated prolateral edge. spine-like proximal apophysis on the male palpal cymbium (Fig. 33) and bilobed, distally and proximally spherical female receptacula (Fig. 30). Without a cladistic analysis of the entire Australasian holarchaeid fauna, it is unclear whether the above autapomorphies are indic- ative of a highly derived species of Holar- chaea (congeneric with the New Zealand spe- cies H. novae seelandiae), or of a monotypic Australian genus, sister to the former. Description. — Male (QM S60756): Cara- pace 0.45 long, 0.40 wide. Abdomen 0.60 long, 0.55 wide. Total length 1.05. Color: car- apace dark brown. Abdomen dark brown with lighter dotted striations anteriorly and antero- laterally. Legs uniform brown. Body and legs shiny black in life. Carapace (Fig. 29): in lat- eral view triangular; highest point of pars ce- phalica separated from PME by distance greater than medial length of clypeus. Ciypeus swollen; triangular in dorsal view. Chelicerae: elongate, constricted proximally, with single long, serrate, proximally-widened/flattened moveable hair projecting from near base of fang. Fang greater than half length of paturon; tip curved but not hooked; without poison gland opening. Dentition: 2 prolateral (true) teeth, widely spaced. Abdomen (Fig. 29): spherical, without surface sclerotization. Ped- ipalp (Figs. 31-33): patella large, wedge- shaped, with distal spurs. Tibia complex, twisted. Cymbium spoon-shaped, with prom- inent, posteriorly directed, spine-like apophy- sis proximially; retro-distally with broad, pointed apophysis. Ventral surface of bulb rel- atively smooth. Embolus coiled. Female (QM S60756): Epigyne (Fig. 30): receptacula elongate, bilobed. Distribution. — Holarchaea globosa speci- mens are known from south-west, west, north- west, south-central and north-east Tasmania, Remarks. — Adult specimens of Holar- chaea globosa have been collected at various 150 THE JOURNAL OF ARACHNOLOGY months of the year, including January, Feb- ruary, April, May and October. General biology. — Very little is known about the biology of H. globosa. From the rel- atively few collection details available, it would appear that the species is restricted to wet and consistently humid habitats. Most specimens have been found on ferns or within moss and leaf litter in temperate rainforest (al- though several specimens have also been col- lected from caves: Main Cave near Montagu, Andrews River Caves and Cardia Cave near Acheron River, see Eberhard et al. 1991). Of these, the majority have not been observed alive (e.g., they were collected using tullgren extractions or pyrethrum fogging). However, I collected four H. globosa alive in January 2002: two from Hogarth Falls near Strahan (1 male & 1 female) and two from Cuckoo Falls near Scottsdale (1 juvenile & 1 female). All four specimens were collected from among the leaves of the ‘hard water fern’ (Blechnum wattsii, Blechnaceae), an abundant, low-grow- ing species within many Tasmanian rainfo- rests (Garrett 1996). The former two were found close to midnight, during persistent rain, with the male seen hanging from a single line of silk between the fern leaves. The fe- male was swept from vegetation nearby. The Cuckoo Falls female was beaten from ferns in tall beech (Nothofagus) and tree fern forest during overcast and humid conditions, whilst the juvenile was collected in the same manner, close to the waterfall. Interestingly, a male and female were also collected by Lisa Boutin (QVM) at Hogarth Falls four years earlier, again during persistent rain. The diet of H, globosa is unknown, although of the organ- isms beaten from the Blechnum and tree ferns, oribatid mites, collembola and other spiders dominated. Observations of live specimens. — Live H. globosa were maintained alive in captivity from 27 January until 11 February, 2002. The H. globosa specimens I collected (see General Biology, above) were all shiny black in life (this appearance was rapidly lost after ethanol preservation), and superficially not unlike small theridiid spiders. Both sexes were agile when walking along a line of silk, but spent most of their time in captivity hanging or clinging upside-down. When lowered onto a horizontal surface the spiders would walk around until they found an object to assail. then proceed upwards to find a suitable posi- tion for resuming an upside-down pose. While walking the spiders would regularly wave their first two pairs of legs around in the air, and when at rest would occasionally do the same (with leg I). In the upside-down resting position the legs were held close against the carapace and abdomen, and the elongate che- licerae were held vertically and flat against the anterior cephalothorax and endites (at an an- gle to each other, to form a triangle in anterior view). While the chelicerae of many holar- chaeid specimens (in ethanol) point at an an- gle to the cephalothorax (due to relaxation of the cheliceral muscles during preservation), those of the live spiders were not seen to ex- tend to such a degree, and the only cheliceral movement observed was of strictly diaxial form (when the spiders ‘cleaned’ their legs with their mouthparts). INTERRELATIONSHIPS OF THE AUSTRALIAN TAXA Species-group relationships are hypothe- sized and outlined below for the eight de- scribed Australian pararchaeid species. With- out a full revision and cladistic analysis of the family, it is unclear whether the groups as here delimited represent separate monophyletic genera, or merely clusters of similar species united by substantial homoplasy. However, multiple somatic and correlated genitalic sim- ilarities clearly exist between groups of Aus- tralian species of Pararchaea, and the major- ity of species examined by the author, including those currently undescribed from the Australian mainland, can be attributed to one of the four putatively monophyletic clades as here diagnosed. Pararchaea saxicola species group Diagnosis. — United by: femur of leg I with proximal retrolateral denticles; male abdomen with small to very small dorsal scute (separate or fused to anterior sclerite), not surrounding or extending posterior to level of DSP2; male pedipalp with relatively short, inwardly hooked paracymbium, and without brush of hairs in groove along retrolateral edge of cym- bium. Distribution. — Known from north-eastern Queensland, south-eastern Queensland, north- eastern New South Wales, Tasmania and south-western Western Australia. RIX— TASMANIAN PARARCHAEA AND HOLARCHAEA 151 Included species. — Pararchaea oniata Hickman, P. saxicola Hickman, and several unnamed species. Pararchaea lulu species group Diagnosis. — United by: femur of leg I with proximal retrolateral denticles; male abdomen with small to medium-sized, pale dorsal scute (often longitudinally elongate), usually ex- tending posterior to level of DSP2; male ped- ipalp with brush of hairs in groove along re- trolateral edge of cymbium and distally expanded, bifurcate embolus. Distribution. — Known from north-eastern, middle-eastern and south-eastern Queensland, eastern New South Wales, Victoria and Tas- mania. Included species. — Pararchaea lulu new species, P. hickmani new species and several unnamed species. Pararchaea corticola species group Diagnosis. — United by: femur of leg I with proximal retrolateral denticles; male abdomen with large, broad, dark brown dorsal scute, surrounding and extending posterior to level of DSP2; male pedipalp with prominent distal extension of distal plate into pointed ‘conduc- tor’, without brush of hairs in groove along retrolateral edge of cymbium. Distribution. — Known from south-eastern Queensland, eastern New South Wales, Vic- toria and Tasmania. Included species. — Pararchaea binnabur- ra Forster, P. corticola Hickman, P. robusta new species and several unnamed species. Pararchaea bryophila species group Diagnosis. — United by: femur of leg I without proximal retrolateral denticles; pos- tero-dorsal aspect of male pars-cephalica with medial indentation; male anterior tarsus dis- tinctly swollen proximally; male abdomen with large, broad dorsal scute, extending pos- terior to level of DSP2; male pedipalp without brush of hairs in groove along retrolateral edge of cymbium; female receptacula together forming distinctive, posteriorly convergent ‘V-shape’, with ‘nose-like’ inward lobes. Distribution. — Known from south-eastern Queensland, eastern New South Wales, Vic- toria and Tasmania. Included species. — Pararchaea bryophila Hickman, and several unnamed species. ACKNOWLEDGMENTS This paper would not have been possible without the support and assistance provided by a number of people. To Lisa Boutin of the Queen Victoria Museum (Launceston), I am particularly grateful for the extended help and hospitality given to me during field work in Tasmania, for the prompt delivery of loan ma- terial and for the organization of the collecting permit. To Graham Milledge and Mike Gray (both of the Australian Museum, Sydney) and Robert Raven (of the Queensland Museum, Brisbane), for their extensive help in organiz- ing loans and accessing museum collections and facilities. Also to Mike Gray for his as- sistance in digitally photographing epigynes and type specimens and to Robert Raven for use of the scanning electron microscopy fa- cilities at the Queensland Museum. The Tas- manian Parks and Wildlife Service provided assistance in obtaining a collecting permit (Permit Number FA 01270). Thanks are also due to Robert Raven, who made helpful com- ments on an earlier draft of the manuscript. LITERATURE CITED Eberhard, S.M., A.M.M. Richardson & R. Swain. 1991. The Invertebrate Cave Fauna of Tasmania. University of Tasmania Zoology Department, Hobart. Forster, R.R. 1949. New Zealand spiders of the family Archaeidae. Records of the Canterbury Museum 5:193-203. Forster, R.R. 1955. Spiders of the family Archaei- dae from Australia and New Zealand. Transac- tions of the Royal Society of New Zealand 83: 391-403. Forster, R.R. & N.I. Platnick. 1984. A review of the archaeid spiders and their relatives, with notes on the limits of the superfamily Palpimanoidea (Arachnida, Araneae). Bulletin of the American Museum of Natural History 178:1-106. Garrett, M. 1996. The ferns of Tasmania: their ecol- ogy and distribution. Tasmanian Forest Research Council, Hobart. Hickman, V.V. 1969. New species of Toxopidae and Archaeidae (Araneida). Papers and Proceedings of the Royal Society of Tasmania 103:1-11. Hickman, V.V. 1981. New Tasmanian spiders of the families Archaeidae, Cycloctenidae, Amaurobi- idae and Micropholcommatidae. Papers and Pro- ceedings of the Royal Society of Tasmania 115: 47-68. Koch, C.L. & G.C. Berendt. 1854. Die im Bernstein 152 THE JOURNAL OF ARACHNOLOGY befindlichen Crustaceen, Myriapoden, Arachni- den und Apteren der Vorwelt. Edwin Groening, Berlin. Schtitt, K. 2000. The limits of the Araneoidea (Arachnida: Araneae). Australian Journal of Zo- ology 48:135-153. Wilton, C.L. 1946. A new spider of the family Ar- chaeidae from New Zealand. Dominion Museum Records in Entomology 1:19-26. Manuscript received 9 September 2003, revised 9 December 2003. 2005. The Journal of Arachnology 33:153-158 RELATIONSHIP BETWEEN ESCAPE SPEED AND FLIGHT DISTANCE IN A WOLF SPIDER, HOGNA CAROLINENSIS (WALCKENAER 1805) Matthew K. Nelson and Daniel R. Formanowicz Jr.: Department of Biology, University of Texas at Arlington, Arlington, Texas 76019. E-mail: kmnelson@uta.edu ABSTRACT. The relationship between running speed and flight distance is an important one in terms of escape from predators, especially in species that may have multiple defensive strategies. In the wolf spider Hogna carolinensis, one important antipredator mechanism is flight. We examined the relationship between sprint speed and flight distance in wolf spiders by measuring sprint speed on a running track and, in a separate set of experiments with the same individual spiders, measured the distance at which they fled from an advancing model predator. Sprint speed was not significantly correlated with mass, size, or sex of the spiders. Sprint speed was positively correlated with flight distance. This correlation may be the result of a trade-off between two competing modes of antipredator mechanisms: escape and crypsis. In individuals with higher sprint speeds, escape may be the more advantageous option. Slower individuals may have a greater chance of surviving an encounter with a predator simply by remaining still and relying on crypsis. Keywords: Antipredator strategy, risk, flee, sprint speed Behavior patterns associated with predator escape and avoidance are important to indi- vidual survival. These result in strong selec- tive pressure favoring individuals that suc- cessfully avoid or escape from predators. When an animal is approached by a potential predator, it must evaluate the level of preda- tion risk, and utilize the appropriate antipred- ator mechanism to neutralize the risk. The dis- tance from an approaching predator at which an animal chooses to flee has been referred to as “flight distance” (e.g. Fernandez-Juricic et al. 2002), “flight initiation distance” (e.g. Bonenfant & Kramer 1996), “approach dis- tance” (e.g. Martin & Lopez 1999), and “flush distance” (e.g. Fernandez-Juricic et al. 2001). The latter two of these imply the per- spective of the predator. Since we will be dis- cussing the issue from the perspective of the prey, “flight distance” seems the most appro- priate and concise terminology. Ydenberg & Dill (1986) discussed in detail the economics of escape from predators. They suggested a cost-benefit model of flight dis- tance, incorporating the costs and benefits of continuing a particular behavior (such as for- aging) relative to the costs and benefits of fleeing. A concept critical to the predictions made by Ydenberg & Dili’s (1986) model is that “response” does not necessarily equal “detection,” in that it can often be difficult to assess whether or not the potential prey has detected a predator. In some cases, an individ- ual may ignore an approaching predator until it becomes necessary to initiate flight. In other cases, certain “alert behaviors” may occur that precede a flight decision. The Ydenberg- Dill model generally predicts that individuals should delay flight until the costs associated with staying (e.g., increased predation risk) exceed the benefits associated with staying (e.g., time spent searching for food or mates). Several studies have examined the relation- ship between flight distance and running abil- ity. Rand (1964) found that body temperature affected the distance at which Anolis lizards fled from approaching predators, attributing differences in escape distances among individ- uals to lower body temperatures which re- duced sprint speeds. Cooler individuals tended to flee at greater distances because lower body temperatures result in greater risk of capture. Heatwole (1968) suggested that crypsis might also play a role in flight distances. Cryptic species of Anolis may decrease their risk of capture by remaining motionless and fleeing 153 154 THE JOURNAL OF ARACHNOLOGY at shorter distances than less cryptic species. Species that rely on crypsis may not flee from an approaching predator until detection by the predator is certain. Schwarzkopf & Shine (1992) suggested that “vulnerability” (risk of capture) of prey should be evaluated in terms of the probability of being detected by a predator. They found that gravid female water skinks, Eulamprus tympanum, exhibited decreased running abil- ity and shorter flight distances relative to non- gravid females. They suggested that gravid fe- males switched antipredator tactics from escape to crypsis because of the decrease in running speed. They interpreted these results as evidence that escape speed may not always be the most important element involved in de- termining when to flee. Formanowicz et al. (1990) investigated similar effects in the liz- ard Scincella lateralis with differences in sprint speed related to tail autotomy. Skinks with autotomized tails were found to exhibit slower running speeds and relatively shorter flight distances. They suggested that individ- uals that had lost their tails switched to a cryp- tic antipredator strategy to compensate for re- duction in sprint speed. In this study, we examined the relationship between running speed and flight distance in the wolf spider Hogna carolinensis (Walcken- aer 1805). Hogna carolinensis is a large, bur- rowing wolf spider that is active on the sur- face of the ground from dusk until dawn and is distributed from southernmost Maine and Ontario throughout the southeastern U.S. and west to Baja California (Dondale & Redner 1990). Very little has been published concern- ing the life history of this species. Individuals of Hogna carolinensis construct a burrow with a turret of sticks and grass surrounding the mouth of the burrow. Or, in some cases, these spiders may inhabit a deserted rodent burrow (Shook 1978). The depth of the bur- row likely varies between geographical re- gions and possibly with the substrate. In west Texas, where this study was conducted, I have found burrows as deep as 25 cm (pers. obs.). Likely predators include lizards, centipedes (pers. obs.), scorpions, coyotes, owls and var- ious predacious insects (Shook 1978). If a burrow is near, individuals will retreat to a burrow when disturbed (Kuenzler 1958); how- ever, if a burrow is not near, the animal will usually flee a meter or so, and then remain motionless (pers. obs.). We examined the relationship between body size and running speed in male and fe- male H. carolinensis, testing the hypothesis that larger individuals were faster. Since there is a sexual dimorphism in body size in this species, we also predicted that females and males should differ in running speed. Using the same spiders, we examined the distance at which they fled from an approaching model predator. We used the data collected on run- ning speed and flight distance to test the fol- lowing hypothesis based on Ydenberg & Dill’s (1986) model: faster individuals would be expected to flee at shorter distances from the predator. METHODS Hogna carolinensis (n = 77; 44 males, 33 females) used in this study were collected on 26 March and 1 1 April, 1997 at the Texas Na- ture Conservancy’s Independence Creek Pre- serve, approximately 37 km south of Shef- field, Terrell County, Texas, on the northeastern edge of the Chihuahuan desert. Voucher specimens have been deposited at the Denver Museum of Nature & Science. Most spiders were collected at night by using head- lamps to produce eyeshine; a few were col- lected by turning rocks during the day. Spiders were not found to be active during the day. Females were often found near the mouth of a burrow, and sometimes removed from a bur- row. In almost every case, females were found within a meter of the burrow. Males, however, were only occasionally found near a burrow but never in a burrow. Spiders were housed individually, in clear plastic containers (18.5 X 7.5 X 9 cm) with a sand substrate (approx. 1 cm deep). Each spider was fed one adult cricket/week, and water was available ad li- bitum. Temperatures in the housing and test- ing area ranged from 25-26 °C. Escape Speed. — Spider escape speeds were measured on a wooden track 9 cm wide and 2 m long, with sheet-metal side walls approx- imately 21 cm high. All trials were conducted during daylight hours. A start box was sepa- rated from the track by a removable metal di- vider (21X9 cm). A spider was placed in the start box, allowed to acclimate for 15 minutes, the divider was raised, and the spider was prodded on the posterior end of the abdomen NELSON & FORMANOWICZ— ESCAPE DISTANCE OF WOLF SPIDER 155 with a fiberglass rod until it ran. Using a stop- watch, we recorded the time that the spider crossed each 50 cm segment of track. Each spider was run twice with 24 hours between trials, after which time its mass was recorded. Spider cephalothorax lengths were measured at the end of the study with a caliper. The fastest 50 cm speed (cm/s) for each spi- der was used for statistical analyses. T- tests were used to determine whether mass, ceph- alothorax length and speed differed between the sexes. Normality was evaluated using Sha- piro-Wilk's W, and none of the groups violat- ed this assumption at 0.05 level. Pearson cor- relation coefficients were used to examine relationships between speed and mass, speed and cephalothorax length, and mass and ceph- alothorax length. Flight distances. — The distances at which spiders fled from an approaching model pred- ator were recorded using a wooden runway apparatus 2.7 m long, and 28 cm wide with black plastic walls approximately 48 cm high. The spider chamber (32 X 28 X 51 cm) was located at one end of the runway, and sepa- rated from the runway by a glass divider. The walls of the spider chamber were sheet metal with two observation holes (0.5 cm diameter) that allowed the spider to be viewed with min- imal disturbance. The floor of the spider chamber had a sand substrate 1 1 cm deep. To minimize vibratory cues, the runway and the spider chamber were separated from the coun- ter top by 5.5 cm of foam rubber, and sepa- rated from each other by a space of 2 cm. A 15 cm tall green plastic lizard was used as a model predator (meant to represent a novel predator rather than a particular known pred- ator) to elicit escape behavior. Each spider was placed in the spider chamber for 10 min. to acclimate. The model predator was con- cealed by a black plastic curtain at the end of the runway, opposite the spider chamber. Af- ter 10 min., the model predator was pulled toward the spider using a length of fishing line connected to a spool that was turned by a small motor at a speed of approximately 33.9 cm/s (mean = 1.4747 ± 0.0922 [seconds per 50 cm segment]). We ran a set of 10 test trials where we measured four 50 cm segments of track to test for consistency of speed of the model predator. Repeated-measures ANOVA (using trial as the repeated measure) showed no significant effect {¥^^21 0.4963; P = 0.8640) indicating that the speed of the model predator from trial to trial was not signifi- cantly different. Another set of trials was run using only the motor without the model pred- ator to rule out the possibility of cues from the sound and vibration of the motor. In these trials, none of the spiders responded to the activation of the motor {n = 10). The response of the spider to the approaching model pred- ator was viewed through the observation holes in the wall of the spider chamber. Escape was operationally defined as a spider turning and running in the opposite direction from the model predator. When the spider exhibited an escape response, the motor was stopped and the distance was measured from the front end of the model to the original position of the spider. Spiders were run only once, unless no response occurred, in which case they were given a second trial. Flight distances were de- termined for thirty-eight of the individuals (19 males, 19 females) whose escape speeds had been measured. Flight distances were transformed using the natural log to alleviate normality issues. Pear- son correlation coefficients were calculated to examine the relationships between flight dis- tance and spider size (mass & cephalothorax length) and sprint speed (as measured above). Discrepancies in sample size between tests re- sulted from specimen mortality and unrespon- siveness of some individuals. All statistical tests were carried out using SPSS 11.0.2. RESULTS Escape Speed. — This species shows some degree of sexual size dimorphism (cephalo- thorax length: females, n ^ A3, mean ± SE = 12.92 ± 1.09 mm; males, n = 33, mean ± SE “ 11.94 ± 0.74mm). Female H. caroli- nensis are significantly larger than males (mass, t52 = 3.946, P < 0.001 two-tailed; cephalothorax length, i22mi ~ 4.641, P < 0.001 two-tailed [unequal variances]). Mass and cephalothorax length were significantly correlated (Pearson’s r ~ 0.470, P < 0.001). However, when correlations were examined separately for the two sexes, this relationship only held true for the males (r = 0.439, P = 0.017, males; r — 0.209, P = 0.326 females). Although males and females differed in both measures of size, their sprint speeds were not significantly different (tgs = 1.439, P ~ 0.156, two-tailed). Neither mass nor cephalothorax 156 THE JOURNAL OF ARACHNOLOGY Figure 1. — Scatterplot of the natural log of flight distances and sprint speeds (r- = 0.241, P = 0.013). length was significantly correlated with fastest sprint speed (Pearson’s r = —0.145, P = 0.296, ti = 54; r = 0.077, P = 0.571, n = 56, respectively). Flight distance. — There was no signiflcant correlation between spider size and log flight distance (mass, Pearson’s r = 0.024, P = 0.916, n = 22; cephalothorax, r = —0.314, P = 0.055, n = 38). However, males tended to flee from the model predator at greater dis- tances than females (137 = 2.663, P = 0.011, two-tailed). Furthermore, there was a positive correlation between fastest sprint speed and log flight distance (Pearson’s r = 0.491, P = 0.013, n = 25, see Figure 1). DISCUSSION The results of our study indicate that sprint speeds and flight distances of H. carolinensis are not affected by spider size. There were no significant differences in speed between males and females and no significant correlation be- tween sprint speed and either measure of size (mass or cephalothorax length). Although size does not affect sprint speed or flight distance, sex appears to affect the decision to flee. Males fled from the model predator at greater distances than females. Differences in flight distances for males and females may be the result of different cost- benefit relationships for males and females. Males and females may have very different lifestyles that require different considerations. Shook (1978) suggested that females might tend to stray farther from the burrow than males. If this is true, they may have a different escape strategy. For spiders associated with burrows, escape consists of only a short sprint to a burrow. However, for an individual that is not near its burrow, escape may involve a longer sprint, as well as an assessment of available shelter. To date, we have not been successful in getting this species to occupy burrows in the lab. Although females will oc- casionally inhabit a man-made burrow, none of our spiders have excavated their own bur- rows in the lab. In the field, males were rarely found near a burrow. It is possible that male H. carolinensis are not usually associated with a burrow and, therefore, are more reliant upon running to escape a predator. It would be in- teresting to determine whether flight distance is related to distance from the burrow in this species as has been shown in other organisms (squirrels. Dill & Houtman 1989; Cichlid fish. NELSON & FORMANOWICZ— ESCAPE DISTANCE OF WOLF SPIDER 157 Dill 1990; woodchucks, Bonenfant & Kramer 1996; and skinks, Cooper 1997). Sexual size dimorphism is common in spi- ders, Although not as exaggerated in wander- ing spiders as it is in web-builders, size di- morphism is still present. In wolf spiders, females may have longer cephalothoraxes, larger chelicerae, and larger abdomens than males (Walker & Rypstra 2001). The different body shape of males and females may result in different values for costs and benefits used in decision-making. The lack of a correlation between mass and cephalothorax length among females reflects the overall difference in body shape between males and females. The stouter build of the female in this species results in the size of the abdomen contributing more to overall mass than in males. Males have a smaller abdomen relative to cephalo- thorax length. As a result, males may possess lower energy stores, therefore placing a higher value on foraging. Females are generally con- sidered to be more effective foragers than males, since they often consume more prey items (e.g. Walker & Rypstra 2001). It is, however, possible that males consume less due to their smaller size, but are more reliant on regularity of foraging success than females. In this case, a male that has not fed recently may be willing to risk predation in order to continue foraging. However, a male that has recently fed may flee when an approaching predator is farther away. It would be interest- ing tO' determine if feeding regime or the time since last feeding has an effect on flight dis- tance and if that effect is different for males and females. There was a positive correlation between sprint speed and flight distance. Spiders that were faster fled at greater distances from the approaching model predator while slower spi- ders waited until the model predator was clos- er before fleeing. This relationship between sprint speed and flight distance may seem counter-intuitive. The cost-benefit model of Ydeeberg & Dill (1986) predicted that faster individuals should wait until the predator was closer before attempting to escape. When the predator is still relatively far away, the cost of flight (lost foraging time) would be higher than the risk of predation (risk of capture), resulting in an inverse relationship between maximum sprint speed and flight distance. Ac- cording to the model, faster individuals are more likely to continue foraging, since the risk of capture for any given distance is less for a faster individual than for a slower indi- vidual. In the present study, the individuals were not performing any specific task. We therefore need to consider what costs may be associated with flight and what benefits may be associ- ated with staying. For spiders, the energy ex- pended during escape can be costly (Prestwich 1988). Therefore, in cases where the risk of capture is low, it may not be worth the effort for the individual to attempt to escape. This cost might be higher for females, since they are larger than males and may have to expend more energy when running. Another, perhaps more important cost of flight in some species involves cryptic anti- predator mechanisms. In cryptic species, flight may actually increase the risk of capture (Heatwole 1968; Regalado 1998; Cuadrado et ah 2001). As a predator approaches a cryptic individual, the individual must decide whether it has been detected, making it necessary to flee. If, however, the individual flees before the predator has detected it, the individual may draw attention to itself and increase its risk of capture. The individual may also at- tract other potential predators. In this type of situation, the cost of flight is related to the probability of detection by the potential pred- ator. This is a function of the perceptual fields of both the predator and prey species. If the predator has a larger perceptual field than the prey, the prey v/ould benefit by fleeing while the potential predator is still relatively far away. When the predator has a smaller per- ceptual field than the prey, the prey would benefit by waiting to flee until the predator is closer, and the probability of detection is high- er (Heatwole 1968; Martin & Lopez 1999; Cuadrado et al. 2001). The wolf spiders used in this study are a light mottled brown color and blend in readily with the desert substrate where they are likely to be encountered. We believe, therefore, that the results of this study can be explained upon the basis of crypsis. In faster individuals, it may be advantageous to flee at farther dis- tances, since there is a higher probability that the individual will survive entirely on the ba- sis of escape speed. In slower individuals with less chance of escaping solely on the basis of speed, individuals may rely on crypsis to es- 158 THE JOURNAL OF ARACHNOLOGY cape detection. It may be advantageous for slower individuals to remain still, relying on crypsis for survival rather than fleeing and be- coming more conspicuous to the predator. Our results are similar to those obtained by Formanowicz et al. (1990) in ground skinks, Scincella lateralis. In individuals that had ex- perienced tail loss 48 hours prior to testing, sprint speeds were significantly reduced, and individuals exhibited shorter flight distances. They interpreted the shorter flight distances in slower individuals to be the result of a behav- ioral compensation for tail loss. They sug- gested that autotomized individuals compen- sated for decreased speed by adopting a cryptic anti-predator strategy. This interpre- tation was based on information involving the relationship between flight distances and cryp- sis in lizards (Heatwole 1968; Bauwens & Theon 1981). Heatwole (1968) examined the relationship between flight distance and levels of crypsis in Anolis lizards. They found that cryptic species exhibited shorter flight dis- tances than those that were less cryptic. Bau- wens and Theon (1981) found similar results in gravid lizards, Lacerta vivipara. Gravid liz- ards compensated for decreased speed by adopting a cryptic anti-predator strategy. In summary, maximum sprint speed was not significantly different for males and fe- males, and maximum sprint speed was not significantly affected by the size of the indi- vidual. Furthermore, flight distance was not significantly related to size, but males tended to flee at a greater distance from a model pred- ator. Sprint speed and flight distance were pos- itively correlated. This positive correlation was considered to be the result of a trade-off between two alternative modes of predator avoidance: escape and crypsis. ACKNOWLEDGMENTS We would like to thank the Jobeth Holub and the Nature Conservancy for use of the Independence Creek Nature Preserve as a col- lection site. We also thank Jonathan Campbell and John Bacon for reviewing portions of this manuscript in its early development. I would also like to extend a special thanks to Gail Stratton for her thoughtful and detailed review of this manuscript. We appreciate the help of ail those who aided in the collection of spec- imens, including Chris Brown, Chris Amaya, Dan O’Connell, Marina Gerson, and Julia Long. LITERATURE CITED Bonenfant, M. & D.L. Kramer. 1996. The influence of distance to burrow on flight initiation distance in the woodchuck, Marmota monax. Behavioral Ecology 7:299-303. Cooper, W.E.,Jr. 1997. Escape by a refuging prey, the broad-headed skink {Eumeces laticeps). Ca- nadian Journal of Zoology 75:943-947. Dill, L.M. 1990. Distance-to-cover and the escape decisions of an African cichlid fish, Melanoch- romis chipokae. Environmental Biology of Fish- es 27:147-152. Dill, L.M. & R. Houtman. 1989. The influence of distance to refuge on flight initiation distance in the gray squirrel (Sciurus carolinensis). Canadi- an Journal of Zoology 67:233-235. Fernandez-Juricic, E., M.D. Jimenez & E. Lucas. 2001. Bird tolerance to human disturbance in ur- ban parks of Madrid (Spain): Management im- plications. Avian ecology and conservation in an urbanizing world., Kluwer Academic. 261-275. Fernandez-Juricic, E., M.D. Jimenez & E. Lucas. 2002. Factors affecting intra- and inter-specific variations in the difference between alert dis- tances and flight distances for birds in forested habitats. Canadian Journal of Zoology 80:1212- 1220. Kuenzler, E.J. 1958. Niche relations of three species of Lycosid spiders. Ecology 39:494-500. Martin, J. & P. Lopez. 1999. Nuptial coloration and mate guarding affect escape decisions of male lizards Psammodromus algirus. Ethology 105: 439-447. Shook, R.S. 1978. Ecology of the wolf spider, Ly- cosa carolinensis Walckenaer (Araneae). Journal of Arachnology 6:53-64. Walker, S.E. & A.L. Rypstra. 2001. Sexual dimor- phism in functional response and trophic mor- phology in Rabidosa rabida (Araneae: Lycosi- dae). American Midland Naturalist 146:161-170. Manuscript received 2 June 2003, revised 15 March 2004. 2005. The Journal of Arachnology 33:159-166 SEISMIC COMMUNICATION DURING COURTSHIP IN TWO BURROWING TARANTULA SPIDERS: AN EXPERIMENTAL STUDY ON EUPALAESTRUS WEIJENBERGHI AND ACANTHOSCURRIA SUINA Veronica Quirici and Fernando G* Costa: Laboratorio de Etologia, Ecologia y Evolucion, IIBCE, Av. Italia 3318, Montevideo, Uruguay. E-mail: vquirici@ iibce.edu. uy ABSTRACT. During courtship, males of Eupalaestrus weijenberghi and Acanthoscurria suina per- formed body vibrations and palpal drumming after contacting conspecific female silk at the burrow en- trance. Receptive females responded by leg tapping. To elucidate the communicatory channels involved in both species, courting males were placed in terraria with females that had burrowed. In the first ex- periment, the courting male was covered with a glass cup, minimizing airborne acoustic communication but allowing seismic communication. In the second, the male courted without the cup cover. In the third experiment, the male and the female were placed into two separated parts of the terrarium, greatly limiting seismic communication. In the fourth, these last parts were joined. Females of both species responded to the courtship with receptive behavior in all of the experiments except experiment 3. We conclude that male signals produced during courtship in these two species are mainly seismic. Male body vibrations (that would generate seismic signals) as well as female display, are a widespread phenomena in theraphosid spiders. Keywords: Theraphosidae, seismic signals, male vibration, female sexual display Spiders use different channels to commu- nicate during courtship: chemical, tactile, vi- sual and acoustic/vibratory (Krafft 1980; Uetz & Stratton 1983). Each channel has advantag- es and disadvantages in relation to the lifestyle of the animal and its environmental con- straints. As a consequence of the potential nuptial cannibalism of spiders and the poor vision in most taxa, pressures of selection may have favored acoustic or seismic species-spe- cific signals during courtship. An advantage of these signals is that they are relatively in- dependent of environmental conditions (light, temperature, humidity) for efficiency of signal propagation (Foelix 1982; Krafft 1982; Re- dondo 1994). Another advantage is the tem- poral characteristic of the signal, which can be modified quickly according to the motiva- tional state of the animal. Disadvantages in- clude the short temporal persistence of the sig- nal, and the high cost of production. The advantages could explain why acoustic/vibra- tory signals are so widespread in Araneae. Acoustic/vibratory signals in spiders can be produced in three ways, according to Uetz & Stratton (1982): a) stridulation (22 families), b) percussion (six families) and c) vibration of structures (two families). Spiders may use air, water or substrate (ground, leaves, silk threads, etc.) for propagating vibrations. Strid- ulation and percussion have been studied in some species, but sometimes they are difficult to isolate from one another because a single motion can produce both signals, as happens in male palpal drumming. Some lycosids have a stridulatory organ located at the tibio-tarsal joint of each palp. Rovner (1967, 1975) found that, in some wolf species, palpal movement not only produced acoustic signals but also vibrations, which were transmitted into the substrate by means of specialized spines at the tip of the tarsal palp, a mechanism termed “substratum-coupled stridulation.’' Using playback techniques, Rovner discovered that females are capable of perceiving acoustic signals, but their responses are more intense when the speaker is laying on the ground. He concluded that female spiders orient better to substratum vibrations than to airborne sounds. The third method of sound production, vi- 159 160 THE JOURNAL OF ARACHNOLOGY bration of structures, has been described in two species: by Rovner (1980) in Heteropoda venatoria (Linnaeus 1767) (Heteropodidae) and by Barth (1982) and Barth et al. (1988) in Cupiennius salei (Keyserling 1877) (Cten- idae). It consists of movements of the legs or abdomen, in such a way that the entire body vibrates. These movements produce vibrations which are transmitted via substrate (seismic communication). A growing number of studies on sexual be- havior of mygalomorphs (Coyle 1985, 1986; Coyle & OShields 1990; Jackson & Pollard 1990; Costa & Perez-Miles 1998), and in par- ticular from the theraphosid family (Baerg 1958; Minch 1979; Prentice 1992, 1997; Cos- ta & Perez-Miles 1992, 2002; Perez-Miles & Costa 1992; Shillington & Verrell 1997; Yanez et al. 1999) has revealed previously hidden intricacies in the mechanisms of com- munication employed by this group. As an ex- ample, 30 years ago it was believed that ta- rantula males initiated their courtship only after touching the females (Platnick 1971). Today we know that these males start court- ship after detecting tactochemical cues asso- ciated with the female silk (Minch 1979; Cos- ta & Perez-Miles 1992, 2002; Prentice 1997; Shillington & Ven'ell 1997; Yanez et al. 1999). Eupalaestrus weijenberghi (Thorell 1894) and Acanthoscurria suina Pocock 1903 are burrowing theraphosids that have a wide- spread distribution in Uruguay. They are fre- quently sympatric, syntopic and synchronous, presenting a similar reproductive strategy (Costa & Perez-Miles 2002). Their sexual pe- riods occur during March and April, at the end of summer and beginning of autumn in the southern hemisphere (Costa & Perez-Miles 2002). Mignone et al. (2001) and Costa & Perez-Miles (2002) observed males of both species courting outside female burrow en- trances after contacting conspecific female silk. Mignone et al. (2001) reported that fe- males of E. weijenberghi responded to male courtship by displaying foreleg waving at the burrow entrance. Male courtship, either for E. weijenberghi or A. suina, was mainly char- acterized by Mignone et al. (2001) and Costa & Perez-Miles (2002) as bouts of body vibra- tions while the male grasps the substrate with its legs. These vibrations apparently originate in the third pair of legs (unpublished data from restraining each pair of legs). According to these authors, courting males also perform palpal drumming, that can produce acoustic signals (airborne) as well as seismic signals (substrate borne). Theraphosid spiders possess stridulatory organs (Legendre 1963). More- over, A. suina has stridulatory setae located retrolaterally at the trochanter of the palps (Perez-Miles et al. 1996). Acoustic and or vi- bratory signals were suggested by Costa & Perez-Miles (1992, 2002) as species-specific isolating mechanisms in theraphosids, as pre- viously tested among Mesothelae species by Haupt & Traue (1986). Our main objective was to find whether acoustic, seismic or both channels are in- volved in the courtship of A. suina and E. we- jenberghi. Moreover, we described and ana- lyzed elements of courtship by males and females for the two species. METHODS Materials* — Males were collected in the provinces of Canelones (Solymar Norte, 34° 45' S, 56° 00' W and Salinas Norte, 34° 45' S, 55° 50' W) and Montevideo (Melilla, 34° 45' S, 56° 20' W), Uruguay, during March 2002. For all experiments we used females of known reproductive history, which were col- lected from the same localities, between 1996 and 1999. As is well-known for Theraphosi- dae, adult females continue molting through- out their lives, so in each molt they become “virgin’' (without sperm) again. All the fe- males molted in the laboratory between De- cember 2001 and January 2002. We used a total of 20 females and 20 males from each species. They were housed in glass jars of 9.5 cm diameter and 15 cm height, with soil as substrate and water provision. They were fed cockroaches (Blaptica dubia, Blattaria, Bla- beridae) ad libitum. Voucher spiders speci- mens of both species were deposited in the entomological collection at the School of Sci- ences, Universidad de la Republica, Monte- video, Uruguay. Experiments were carried out in glass ter- raria of 30cm X 16cm base x 20cm height, containing 6 cm of soil as substrate or, in the case of the third experiment, the aquaria were 15cm X 16 cm X 20cm. Females inhabited burrows in these terraria, which were con- structed by us against the glass wall, allowing our observations. Each female walked along QUIRICI & COSTA— SEISMIC COMMUNICATION IN TARANTULAS 161 the soil at night, so the silk with pheromone was widely released on the soil surface. We carried out experiments during March-May 2002, in coincidence with the reproductive pe- riod of these species in natural populations. All terraria were placed over polyurethane blocks in order to isolate animals from ground vibrations. Distances between males and fe- males varied between 10-25 cm. For experi- ment three, ten glass terraria were built as two separated parts; one part contained the female burrow and the other only substrate. These “separated blocks” were later put together us- ing an iron clamp, thee being similar to an unitary block, contacting both soil and glass walls. In other experiments we used a thick glass cup, of 10 cm diameter and 10.5 cm height, which covered the courting male. For video recording, a Super VHS video camera was used. Sexual encounters were analyzed with a frame-by-frame video recorder in the Ethology Laboratory of the School of Scienc- es (Uoiversidad de la Republica), Montevideo, Uruguay. The experiments were carried out at an average environmental temperature of 25.13 °C ± 1.05 SD. Experimental design.- — To test for the oc- currence of acoustic (airborne) communica- tion, a series of two consecutive experiments (A & B : see below) were carried out using the same ten pairs of female/male individuals of both species. For testing the occurrence of seismic (substrate borne) communication, an- other series of two consecutive experiments (C & D: see below) were carried out using a different set of ten pairs of female/male spi- ders of both species. Each pair of spiders was reused 1-7 days after the first experiment. In- dividuals were randomly assigned to pairs and experimental series. This design allows us to avoid the influence of individuality and/or subtle differences in the terraria (cut blocks, humidity). The observational time began when the male was placed in the terraria until female sexual display, or until 30 min, if there were no female response. In the experiment A, or “cup block”, a male was placed into a confined sector which occupied one third of the total surface of the terrarium, whereas a female inhabited her bur- row in the other sector. A metallic grid with vertical bars separated 6mm from one another, impeded the access of the male to the female burrow. The male was covered with the glass cup, minimizing any possible acoustic com- munication. The experiment B, or “unitary block”, was similar to A but no glass cup was used. In the experiment C, or “separated blocks”, each terrarium was built as two sep- arate parts: one containing the female in her burrow, the other, the confined male. The two parts, separated from each other by three mil- limeters, were set on polyurethane blocks, with each part located on separated tables, eliminating any possible seismic communica- tion between male and female. During the night prior to the test, another female was lo- cated in the smaller container for depositing silk and pheromone. This female was removed before the trial. In this way when the male contacted the silk and pheromone during the trial, he responded with courtship. The exper- iment D, or “joined blocks”, was similar to C, but in this case the two parts were pushed together, eliminating the gap, and joined with an iron clamp (Fig. 1). Description and analysis. — The observed behavior of both females and males during the experiments was described and analyzed. The courtship behavioral units of males and fe- males were described from the experiment B for both species, because this group best re- flected what occurs in nature. Normality and homogeneity of variance of continuous vari- ables (durations of the behaviors) were tested using the Kolgomorov- Smirnov and Cochran C-test, respectively. Non parametric Mann- Whitney U-test, the one sample and two sam- ples Chi-square tests were used for frequen- cies and non- parametric durations. The McNemar test for the significance of changes was used for dependent samples (A vs. B and C vs. D), but when the expected frequency was less than 5, the Binomial test was used. All statistical analyses were performed using free software programs (http:/www.r-pro- ject.org). RESULTS Courtship. — Male courtship of both spe- cies was characterized by the alternation of periods of activity and inactivity. Activity consisted mainly of body vibrations and pal- pal drumming. Male body vibrations were caused by spasmodic contractions of legs, ap- parently by the third pair. During vibrations, tarsal claws were fixed to the ground. Vibra- tion was complex, its intensity was very var- 162 THE JOURNAL OF ARACHNOLOGY Figure 1. — Schematic drawings showing the experimental design used for the two Theraphosidae spe- cies. Broken vertical lines represent the metallic grid separating the male from the female. Each male was placed on the soil, while each female remained inside her burrow. Experiment A = cup block, experiment B = unitary block, experiment C = separated blocks, experiment D = joined blocks. iable, and could not be quantitatively de- scribed using the video register because it was not possible to observe male movements in detail. However, vibrations seem to be of low frequency. Palpal drumming consisted of al- ternative, soft 'cycling movements' of the palps on the substrate. Both body vibrations and palpal drumming, in general, were alter- nated but sometimes they took place synchro- nously, mainly when the body vibrations were of low intensity. Bouts of vibration and drum- ming were considered together when analyz- ing the durations of active courtship periods of males. Tables 1 & 2 show the mean dura- tions of these bouts until female response for the two species. Mean duration of bouts of vibration and drumming was approximately seven seconds for both species. Females of both species showed their char- acteristic sexual display inside the burrows, tapping vigorously with the first and second pair of legs against the substrate, immediately after a male bout. In frame-to-frame video analyses, females of both species showed the following displays: leg flexing, lifting and lowering, contacting the ground. In some cas- es, the percussion was audible to the observer. Two latencies were considered: Latency 1 was from the end of the last male signal bout until female leg tapping, and Latency 2 from the end of the first male bout until female leg tap- ping. Some females responded immediately after the first bout; thus, these two latencies are equal (Tables 1 & 2), Mean number of leg movements during the first bout of female leg tapping, as well as the number of female bouts of leg tapping during the whole experimental period, are shown in Tables 1 & 2, After fe- male responses, males frequently changed their behavior. In E. weijenberghi, 6 of 10 males oriented to the female burrow, 2 of 10 increased their locomotive rate without ori- entation and 2 of 10 showed no response to the female call. In A. suina, 8 of 10 females responded to male courtship. Two of 8 males oriented to the female burrow, 2 of 8 increased their locomotive rate and 4 of 8 showed no responses. QUIRICI & COSTA— SEISMIC COMMUNICATION IN TARANTULAS 163 Table 1. — Courtship characteristics of Eupalaestrus weijenberghi (experiment B). Male courtship du- ration includes both vibrations and palpal drumming until female response. Latency 1 = latency from the end of the last male signal to the first leg tapping of the female. Latency 2 = latency from the end of the first male signal to the first leg tapping of the female. Leg movements = number of movements of one leg during female leg tapping. Leg tapping = number of female bouts performed during the whole ex- periment. Pair Courtship (sec) Latency 1 (sec) Latency 2 (sec) Leg movements Leg tapping 1 9 1 1 15 4 2 15 1 4 21 2 3 li 0 6 13 4 4 2 1 1 14 2 5 5 3 53 5 7 6 9.5 1 83 14 4 7 4 1 1 22 3 8 5.75 3 53 11 2 9 4 1 22 15 1 10 2 1 53 16 3 Mean ± SD 6.7 ± 4.3 1.3 ± 0.9 27.7 ± 30.2 14.6 ± 4.8 3.2 ± 1.7 When comparing mean durations of male signaling bouts (vibration + drumming) be^ tween species, both before first female re- sponse, no significant differences were found using the Mane- Whitney test {U = 30.5, P = 0.397). No statistical differences were found either when comparing the latency of female response to the last bout of a male {U = 20.5, P = 0.083), or when comparing latency to the first male bout (U = 34, P = 0.60). The num- ber of movements during female leg tapping was greater in E. weijenberghi than in A. suP na (U = 17. 5, P = 0.04); the number of bouts of female leg tapping was also higher in E. weijenberghi {U = 15, P = 0.03). Communicatory channels. — The number of female responses from the four experiments are given in Table 3. All the females of E. weijenberghi belonging to experiments A, B and D responded to male courtship. On the other hand, in A. suina 7 of 10 responded to male courtship in experiment A, 8 of 10 in B, and 4 of 10 in D. In separated blocks (exper- iment C), none of the E. weijenberghi nor A. suina females showed responses to male courtship. Observed versus expected Chi- Table 2. — Courtship characteristics of Acanthoscurria suina (experiment B) corresponding to the eight cases where females responded. Male courtship duration includes both vibrations and palpal drumming until female response. Latency 1 = latency from the end of the last male signal to the first leg tapping of the female. Latency 2 = latency from the end of the first male signal to the first leg tapping of the female. Leg movements = number of movements of one leg during female leg tapping. Leg tapping = number of female bouts performed during the whole experiment. Leg Couple Courtship (sec) Latency 1 (sec) Latency 2 (sec) Movements Leg tapping 1 7 0 0 6 1 2 11.3 0 0 8 1 3 7 0 21 6 2 4 7.3 3 26 14 4 5 6.1 1 436 19 2 6 5 0 38 10 1 7 7.3 1 67 5 1 8 8 0 110 6 1 Mean ± SD 7.4 ± 1.8 0.6 ± 1.1 87.3 ± 145.6 9.3 ± 4.9 1.6 ± 1.1 164 THE JOURNAL OF ARACHNOLOGY Table 3. — Number of females that performed leg tapping in response to the male courtship in the four experimental groups. E. weijenberghi A. suina Leg tapping No leg tapping Leg tapping No leg tapping Cup block (A) 10 0 7 3 Unitary block (B) 10 0 8 2 Separated blocks (C) 0 10 0 10 Joined blocks (D) 10 0 4 6 square test among the four experiments (as- suming 50% as expected value) showed sig- nificant differences for E. weijenberghi (x^ = 10, P < 0.019, df = 3) and also for A. suina (X^ = 8.16, P < 0.043, df = 3). The female response in experiment C is significantly dif- ferent from response in B for both species (for E. weijenberghi, x^ — 16.20, P = 0.0001, df = 1; for A. suina x^ = 10.21, P = 0.0014, df = 1). In E. weijenberghi, experiments A and B were identical (P = 1, Binomial test), but significant differences were found between C and D (x“ = 10; P < 0.001) with the Mc- Nemar test. Experiments B and D were iden- tical (x^ = 0, P = 1, df == 1) using the Chi- square test in this species. In A. suina, there were no significant differences between A and B (P > 0.31) with the Binomial test, nor be- tween C and D (P = 0.16). There were no differences between B and D (x" = 1.880, P = 0.17, df = 1) using the Chi-square test. DISCUSSION Our main objective was to determine ex- perimentally what communicatory channel is mainly used during courtship for the focal species. Rado et al. (1989) demonstrated, us- ing a similar experimental design, that the Mole Rat, Spalax ehrenberghi, communicates by seismic signals. In E. weijenberghi the re- sults clearly showed that separated blocks (ex- periment C) prevented the transfer of seismic signals between the sexes, whereas commu- nication was unimpeded in the other treat- ments. The females which showed no response in separated blocks, all responded to male court- ship once these blocks were joined (experi- ment D). Thus, we conclude that communi- cation through the substrate (seismic communication) is present during courtship. Moreover, the absence of female response in separated blocks also indicate that airborne acoustic communication, is not important; at least at the experimental distances used in this study. Absence of acoustic communication is also supported by the lack of differences be- tween unitary and cup blocks. Hence, seismic signals are sufficient to elicit a complete fe- male response during the courtship of E. wei- jenberghi. The results of A. suina were similar to those of P. weijenberghi, indicating that they also use the seismic channel for communicating during courtship. The main difference in the A. suina was in the non-significant differences between separated and joined blocks (experi- ments C & D). This could be explained by a lower intensity of the male vibration in A. sui- na (Quirici, unpub. data) and/or less respon- siveness from conspecific females than those of E. weijenberghi. Acoustic communication in A. suina seems not to have an important role in sexual communication, as in E. wei- jenberghi, results from unitary and cup blocks were similar. Due to the presence of a putative stridulatory organ on the palpal trochanter of A. suina, the occurrence of acoustic commu- nication would appear reasonable. However, occasional observations in the field showed that males spend a long time performing pal- pal drumming at the bun'ow entrance. Acous- tic communication could be possible when males reach the burrow entrance, thus avoid- ing possible obstacles that could deform or in- terrupt a delicate acoustic signal. Therefore, an acoustic channel of communication could be functional at short distances. Male vibrations in courtship appear to be a widespread behavior observed in many Ther- aphosidae spiders, first reported by Gerhardt (1929). Minch (1979) described this behavior as body oscillations; Shillington & Ven*ell (1997) called it “quiver”; Yanez et al. (1999) called it “shaking”; Costa & Perez-Miles QUIRICI & COSTA— SEISMIC COMMUNICATION IN TARANTULAS 165 (1992, 2002) and Perez-Miles & Costa (1992) named it “body vibrations”. Prentice (1992, 1997) termed the behavior “stridulating vibra- tion” and found that the signals could be per- ceived by the female up to 1.2 m distance on a heterogeneous substrate. Moreover, he re- ported that stridulation was audible by the ob- server under laboratory conditions in Aphon- opelma Joshua Prentice 1997. However, these vibrations remind us of the third method of sound production postulated by Rovner (1980), “vibration of structures”, but not the stridulatory method. Some tests (unpub. data) in which we tied the third pair of legs and in others tied the second pair of legs (control), showed that the third pair would be respon- sible of the vibrations (a geophone did not register vibrations when the third pair was tied). According to our findings, the Thera- phosidae would communicate by “vibration of structures”. All authors postulate a com- municative role for this behavior, alerting the female of male presence. The possible func- tion of the vibration as a way of transmitting a species-specific signal through the ground was postulated by Haupt & Traue (1986) for Mesothele, and by Costa & Perez-Miles (1992, 2002) for Mygalomorphae. Prelimi- nary observations, however, have shown some degree of confusion in sexual communication between E. weijenberghi and A. suina in the laboratory. This opens an exciting field of re- search because, as was previously mentioned, these species are sympatric and synchronous and share similar reproductive strategies. Leg tapping of burrow-occupying females was observed only as a response to male courtship, indicating a receptive state. It was first observed by Prentice (1992) in three spe- cies of Aphonopelma, who called it “drum- ming”. We found that both E, weijenberghi and A. suina respond to male courtship from inside their burrows. Female leg tapping would not only inform the male about her willingness to copulate, but also help the male to orient towards the burrow entrance. Eupa- laestrus weijenberghi males seem to orient more easily than A. suina males for the calling female, probably due to the vigorous E. wei- jenberghi female responses. This behavior is possibly more widespread than previously supposed, since female behavior is often un- observable inside the burrow. For example, Prentice (1997) reported females of another Aphonopelma species performing leg tapping, and Yanez et al. (1999) observed females of Brachypelma klaasi (Schmidt & Krause 1994) shaking. Burrowing tarantulas share similarities with other subterranean species in some of their ways of communication, independent from phylogenetic constraints. Compared to acous- tic signals, seismic signals have the advantage of propagating through long distances and at speed two-five times faster than the acoustic signals, depending on the type of soil and de- gree of soil moisture (Rado et al. 1989). Tak- ing into account the advantages of seismic sig- nals, the widespread occurrence of male body vibration, the probable female seismic re- sponse, and the absence of costly specialized emission organs, we suggest that seismic sig- nals are the main communicatory channel used by burrowing Theraphosidae during courtship. ACKNOWLEDGMENTS Thanks to Gabriel Francescoli, who sug- gested the isolated blocks technique. We also thank the Ethology Laboratory (School of Sci- ences) for the use of the video-recorder, Anita Aisenberg for improving the English, Gabriel Francescoli and Fernando Perez-Miles for critically reading the manuscript, and all the partners at our laboratory for helping us in collecting and rearing the specimens. Gail Stratton and two anonymous reviewers im- proved the last version of the manuscript. LITERATURE CITED Baerg, W.J. 1958. The Tarantula. University of Kansas Press. Lawrence. Barth, EG. 1982. Spiders and vibratory signals: sensory reception and behavioral significance. Pp. 67-122. In Spider Communication: Mecha- nisms and Ecological Significance, (P.N. Witt & J.S. Rovner, eds.). Princeton University Press, Princeton, New Jersey. Barth, EG., H. Bleckmann, J. Bohnenberger, & E.A. Seyfarth. 1988. Spiders of the genus Cu- piennius Simon 1891 (Araneae, Ctenidae). II. On the vibratory environment of a wandering spider. Oecologia 77:194-201. Costa, EG. & F. Perez-Miles. 1992. Notes on mat- ing and reproductive success of Ceropelma lon- gisternalis (Araneae, Theraphosidae) in captivity. Journal of Arachnology 20:129-133. Costa, EG. & E Perez-Miles. 1998. Behavior, life cycle and webs of Mecicobothrium thorelU (Ar- 166 THE JOURNAL OF ARACHNOLOGY aneae, Mygalomorphae, Mecicobothriidae). Jour- nal of Arachnology 26:317-329. Costa, EG. & E Perez-Miles. 2002. Reproductive biology of Uruguayan theraphosids (Araneae, Mygalomorphae). Journal of Arachnology 30: 571-587. Coyle, EA, 1985. Observation on the mating be- haviour of the tiny mygalomorph spider. Micro- hexura montivaga Crosby & Bishop (Araneae, Dipluridae). Bulletin of the British Arachnolog- ical Society 6:328-330. Coyle, EA. 1986. Courtship, mating and the func- tion of male-specific leg structures in the myga- lomorph spider Genus Euagrus (Araneae, Di- pluridae). Pp. 33-38. Proceedings of the Ninth International Congress of Arachnology, Panama. Coyle, EA. & T.C. OShields. 1990. Courtship and mating behavior of Thelechoris karschi (Ara- neae, Dipluridae), an African funnel web spider. Journal of Arachnology 18:281-296. Foelix, R.F. 1982. Biology of Spiders. Harvard Uni- versity Press, Cambridge, Massachusetts. Gerhardt, U. 1929. Zur vergleichenden Sexualbiol- ogie primitiver Spinnen, insbesondere der Te- trapneumonen. Zeitschrift fiir Morphologie und Okologie der Tiere 14:699-764. Haupt, J. & D. Traue. 1986. Comparative study of vibration signals produced by males of three Me- sothelae spider species (Araneae: Liphistiidae, Heptathelidae). Verhandlungem der Deutschen Zoologen Gesellschaft 79:212-213. Jackson, R.R. & S.D. Pollard. 1990. Intraspecific interactions and the function of courtship in my- galomorph spiders: a study of Porrhothele anti- podiana (Araneae: Hexathelidae) and a literature review. New Zealand Journal of Zoology 17: 499-526. Krafft, B. 1980. Les systemes de communication chez les araignees. Pp. 197-213. Proceedings of the 8*'^ International Congress of Arachnology, Wien. Krafft, B. 1982. The significance and complexity of communication in spiders. Pp. 13-66. In Spider Communication: Mechanisms and Ecological Significance. (P.N. Witt & J.S. Rovner, eds.). Princeton University Press, Princeton, New Jer- sey. Legendre, R. 1963. L’audition et I’emission de sons chez les Araneides. Annales de Biologic 2:371- 390. Mignone, A., EG. Costa, C. Toscano-Gadea, & E Perez-Miles. 2001. El comportamiento sexual de Eupalaestrus weijenberghi (Araneae, Theraphos- idae): un analisis preliminar. Actas VI Jornadas de Zoologia, Uruguay: 54. Minch, E.W 1979. Reproductive behaviour of the tarantula Aphonopelma chalcodes (Araneae: Theraphosidae). Bulletin of the British Arach- nological Society 4:416-420. Perez-Miles, E & EG. Costa. 1992. Interacciones intra e intersexuales en Grammostola mollicoma (Araneae, Theraphosidae) en condiciones exper- imentales. Boletm de la Sociedad Zoologica. Uruguay 7:71-72. Perez-Miles, E, S.M. Lucas, P.I. da Silva & R. Ber- tani. 1996. Systematic revision and cladistic analysis of Theraphosinae (Araneae: Theraphos- idae). Mygalomorph 1:33-68. Platnick, N.I. 1971. The evolution of courtship be- haviour in spiders. Bulletin of the British Arach- nological Society 2:40-47. Prentice, T.R. 1992. A new species of North Amer- ican tarantula, Aphonopelma paloma (Araneae, Mygalomorphae, Theraphosidae). Journal of Ar- achnology 20:189-199. Prentice, T.R. 1997. Theraphosidae of the Mojave Desert west and north of the Colorado River (Ar- aneae, Mygalomorphae, Theraphosidae). Journal of Arachnology 25:137-176. Rado, R., Z. Wollberg, & J. Terkel. 1989. The seis- mic communication of mole rats. Israel Land and Nature 14:167-171. Redondo, T. 1994. Comunicacion: teorfa y evolu- cion de las senales. Pp. 255-297. In Etologia: Introduccion a la Ciencia del Comportamiento. (J. Carranza, ed.). Universidad de Extremadura, Caceres, Espana. Rovner, J.S. 1967. Acoustic communication in a ly- cosid spider (Lycosa rabida Walckenaer). Ani- mal Behaviour 15:273-281. Rovner, J.S. 1975. Sound production by Nearctic wolf spiders: a substratum-coupled stridulatory mechanism. Science 190:1309-1310. Rovner, J.S. 1980. Vibration in Heteropoda vena- toria (Sparassidae): a third method of sound pro- duction in spiders. Journal of Arachnology 8: 193-200. Shillington, C. & P. Verrell. 1997. Sexual strategies of a North American ‘Tarantula’ (Araneae: Ther- aphosidae). Ethology 103:588-598. Uetz, G.W & G.E. Stratton. 1982. Acoustic com- munication and reproductive isolation in spiders, Pp. 123-159. In Spider Communication: Mech- anisms and Ecological Significance. (P.N. Witt & J.S. Rovner, eds.), Princeton University Press, Princeton, New Jersey. Uetz, G.W. & G.E. Stratton. 1983. Communication in spiders. Endeavour 7:13-18. Yanez, M., A. Locht, & R. Macias-Ordonez. 1999. Courtship and mating behavior of Brachypelma klaasi (Araneae, Theraphosidae). Journal of Ar- achnology 27:165-170. Manuscript received I April 2003, revised I Eeb- ruary 2004. 2005. The Journal of Arachnology 33:167-174 MATING AND SELF-BURYING BEHAVIOR OF HOMALONYCHUS THEOLOGUS CHAMBERLIN (ARANEAE, HOMALONYCHIDAE) IN BAJA CALIFORNIA SUR Karina Dominguez: Laboratorio de Aracnologia y Entomologia, Centro de Investigaciones Biologicas del Noroeste, S. C. (CIBNOR) Apdo. Postal 128, La Paz, B.C.S., 23000, Mexico Maria-Luisa Jimenezb Laboratorio de Aracnologia y Entomologia, Centro de Investigaciones Biologicas del Noroeste, S. C. Apdo. Postal 128, La Paz, B.C.S., 23000, Mexico, E-mail: ljimenez04@cibnor.mx ABSTRACT. The spider Homalonychus theologus is endemic to desert zones from southwestern Cali- fornia to southern Baja California Peninsula. Until now little has been published about its biology. In this paper we describe the reproductive and self-burying behavior and some aspects of the ecology of the species. Courtship behavior is between levels I and II, and the copulation position is a modification of type III. The male wraps the female’s legs in silk before mating. This behavior could help justify inclusion of the Homalonychidae in the superfamily Lycosoidea. Possible camouflage behavior was attributed to the observation that these spiders can camouflage themselves by adhered sand grains to their bodies and buried themselves in the substratum. Females constructed eggsacs two days on average after mating one eggsac contained 29 eggs and other zero. Females incorporated sand “collars” to the egg sac with silk, probably as protection for the eggs against the dry environment as well as camouflage. This activity was carried out within 34 hours before oviposition. In the field, solitary spiders were found mainly under dead fallen cacti Pachycereus pringlei. RESUMEN. La arana Homalonychus theologus es endemica de las zonas deserticas del sur de California hasta el sur de la peninsula de Baja California. Hasta ahora se conoce poco acerca de su biologia. En este articulo describimos los habitos reproductores, conducta de enterramiento y aportamos algunos datos ecologicos de esta especie. La conducta de cortejo es intermedia entre los niveles I y II y la posicion de copula corresponde a una modificacion del tipo III. El macho envuelve las patas de la hembra con seda antes de la copula. Esta conducta puede contribuir a que las Homalonychidae puedan ser incluidas en la Superfamilia Lycosoidea. La posible conducta de enterramiento fue registrada cuando las aranas incor- poraron granos de arena a sus cuerpos y se enterraron en el sustrato. Las hembras fabricae sus ovisacos pocos dias despues del apareamiento con un promedio de dos dias en su elaboracion y el numero de huevos observado fue de 0-29 por ovisaco. Las hembras incorporan “collares” de arena con seda al ovisaco como una probable proteccion de los huevos a la desecacion del medio. Este evento fue llevado a cabo en 34 horas. En el campo, las aranas se encontraron principalmente solas y bajo cardones en descomposicion Pachycereus pringlei. Keywords? Homalonychus, Baja California, mating behavior, self-burying behavior Homalonychus theologus Chamberlin 1924 is one of two homalonychid species endemic to North America. This family is distributed in the warm deserts of southwestern United States and northwestern Mexico (Gertsch 1979; Roth 1984). Homalonychus theologus is found from southern California to southern Baja California Peninsula, on the adjacent is- lands Cedros and Margarita in the Pacific * Corresponding author. Ocean, and on several islands in the Gulf of California (Roth 1984); it is considered en- demic to these regions. Homalonychids are wandering spiders usu- ally found in fine sand or soil, under loose boulders, boards or detritus. Only females and immatures cover their bodies with fine soil, which adheres to the setae of their integument (Roth 1984). Homalonychus theologus may mimic dry cactus spines by joining their legs in pairs as a potential defensive response. 167 168 THE JOURNAL OF ARACHNOLOGY They cover the egg sacs with fine sand, prob- ably to avoid predation (Vetter & Cokendolp- her 2000). Although H. theologus appears to be one of the most numerous spiders in the Baja Cali- fornia Peninsula and adjacent islands (Roth 1984), only one short paper (Vetter & Coken- dolpher 2000) focused on the biology of this species, and another on the taxonomy of the family Homalonychidae (Roth 1984) has been published. In this paper, we examine mating and self-burying behavior of H. theologus. METHODS Spiders were collected at two sites in the Cape region of southern Baja California Pen- insula: El Comitan and San Pedro, located at 24°08'7"N, 110°25'52"W and 23°54'44''N, 110°15'8"W, respectively. The local climate is very dry to semidry with rain in summer only and median annual temperatures from 22-28 °C (Garcia 1973). Vegetation is sarcocaules- cent scrub consisting mostly of “cardon” Pachycereus pringlei and “cholla” Opuntia cholla (Leon de la Luz et al. 1996). Collections were taken weekly in El Co- mitan from 1200-1400 h, from August 2000- June 2001. Spiders were collected by hand from under decaying cardons and other cacti. Each spider was transported individually in a 250 ml plastic jar to the laboratory. Voucher specimens of H. theologus were deposited in the arachnid collection of the CIBNOR. In San Pedro, spiders were collected in Au- gust, October and November 2000, and Jan- uary 2001 for behavior observations under laboratory conditions. The microhabitat of spiders at both sites was described, and the number of specimens captured at each site was recorded. A total of 57 immature and adults were maintained in the laboratory and were used for behavior studies. Spiders were kept always in a dark 1.87 X 2.00 m room with temperature 23-27 °C and relative hu- midity 50-60%. Observations of mating be- havior were made from 6 March- 17 April 2000 between 1000-1300. Sixteen male/fe- male pairs were used. Females were intro- duced to a 22.7 X 20.5 cm glass container at 26.2 °C and 46.8% relative humidity with fine soil as a substrate; males were introduced 1 hr later; each pair was permitted to mate, after which females were placed individually in transparent 250 ml plastic jars. Fine soil was placed in the bottom of each jar as substrate, with a piece of dry cactus as retreat and a small container of wet cotton for water. Each jar was covered with fine weave cloth. Mating time was recorded. If a pair didn’t mate within 10 minutes, one of the pair was replaced by another of the same sex. Adults and immatures were fed weekly with Tenebrio molitor L. larvae. The time dur- ing pre-oviposition, oviposition, number of egg sacs per female was recorded. Self-bury- ing behavior was recorded for 27 recently molted spiders. These observations were re- corded once with an RCA CCD video camera, with a 24x200m lOOx eyepiece in natural light, and photographs were taken with a MI- NOLTA Dynax 8000i camera. RESULTS Field observations. — In both localities, 94% {n — 385) of the spiders were found un- der sections of fallen Pachycereus pringlei cacti, from 5X3 cm to 250 X 30 cm of size. Two percent {n = 9) of spiders were found under dead tree trunks, 2% {n — 7) under car- tons, and 2% {n = 8) in crevices between cac- ti. Eighty-four percent of the spiders were found alone, 12% were grouped in pairs; and 3% were in threes. Of all spiders, 97% were found on the sand under cacti, 2% burrowing in soil and only 1% were observed in the paired leg formation. All captured spiders were found camouflaged with sand grains. At El Comitan sub-adults and females of H. theo- logus were present in October and November, whereas immatures were active all year and maintained an almost constant population size. Mating behavior. — Courtship and mating behaviors of eight pairs of adult spiders were observed (8 males, 5 females were matured in the laboratory and then mated, 3 females of unknown mating status were captured in the field.). Sperm induction by males was not ob- served, but small triangular webs were at- tached to the jar walls indicated probable fill- ing of palps with sperm. Sexual behavior was divided in to three stages: pre-copulation, cop- ulation and post-copulation (Figs. 1-3). Pre-copulation: The male approaches the female (Fig. 4), drums his palpi in an alter- nating sequence and attemps to mount her. If the female is not receptive, she attaches him (Fig. 1). Then the male courts by moving his DOMINGUEZ & JIMENEZ— BEHAVIOR OE HOMALONYCHUS THEOLOGUS 169 MALE 1 FEMALE Approaching female t ^ Figures 1-3. — Mating behavior of Homalonychus theologus. 1. Pre-copulation behavior. 2. Copulation behavior. 3, Post- copulation behavior. Asterisk means behavior observed only in some individuals (see text). 170 THE JOURNAL OF ARACHNOLOGY Figures 4-9. — Mating behavior of Homalonychus theologus. 4. M ale approaching to female. 5. Male tapping palpi and front legs on female’s body. 6. Male drawing female’s legs above her carapace. 7, Frontal view of male circling female’s legs with silk. 8. Male and female mating. 9. Lateral view of female with the silk circle after mating. front pairs of legs alternately up and down tapping the substratum, walking a few steps and stopping. The male repeats the sequence several times until he stands again in front of the female. This behavior was observed in only two males. Mean approach time was 11.3 min ± 23.6 (range 0-68.4 min, n = 8). Copulation: When the female was recep- tive, she remained motionless on the substra- tum (Fig. 5) while the male mounted her, tap- ping his palpi on her carapace and tapping his front pairs of legs on her abdomen. During this process, the female adopted a passive pos- ture, drawing her legs in close to her body so that the patellae of her legs almost touched one another above her carapace while the male helped her to maintain this position with his third pair of legs, resting only his fourth pair of legs on the substratum (Fig. 6). He immediately began spinning silk threads in a ring around the patellae and tibiae of the fe- male to keep them together (Fig. 7). When she was well tied, the male leaned to the right or left side of the female for the mating position (Figs. 3, 8). The left palp was inserted in the left side (x 1.5, SD ± 1.2), and the right palp in the right side (x2.6, SD ± 2.3) alternately several times. With each insertion, the male produced fast vibrations with the second and third pairs of legs. He added more silk threads to the ring, mated again and repeated the be- havior. Mating lasted approximately 3.6 min (range 0.5-13.3 min, n = 8). Post-copulation: After mating, the male ran DOMINGUEZ & JIMENEZ— BEHAVIOR OF HOMALONYCHUS THEOLOGUS 171 away rapidly and the female remained mo- tionless for few seconds on the substrate (Fig. 9) suddenly breaking the silk circle, raising and extending her legs. Six of the 8 females cleaned the silk from their legs and rubbed them together. After mating, two females dis- played the self“burying behavior, which is de- scribed later. Only two males tried mating again with mated females and only one of these was successful. Of eight mated females, only two made egg sacs. The process was observed once. One egg sac was constructed under a fragment of cac- tus on the day following mating. The other was attached to the wall of a jar eleven days after mating. Egg sac construction,— One female spun a silk sheet on the lateral wall of the container. After that, she attached silk threads with sand grains like “collars”, made by moving her spinnerets from side to side on the substratum secreting silk to affixed small sand grains add- ed to the spinnerets and then onto the silk sheet. She repeated this behavior to make the upper wall of the egg sac taking the form of a dome. Then she held herself with her two front pairs of legs to the inner wall of the dome, standing in a vertical position. In this position she continued making silk collars with sand grains, then she stopped this behav- ior and with the sand collars attached to her spinnerets, and still in vertical position she pushed herself to the top of dome adhering the sand collars in the outer wall, secreting silk threads to strengthen it. From time to time the female scratched in the sand on the bottom of the container, throwing sand grains with her two front pairs of legs and continued making collars, repeating the behavior described pre- viously. Although it could not be seen how the egg sac was finished, this behavior was repeated until an opening in the lower rim was left, where she entered and covered the inside with silk. After 34 hrs the egg sac was fin- ished, and the female deposited eggs for 30 minutes. She remained inside 13.5 hours more; then came out and closed the opening of the egg sac. The emergence of the imma- tures three months later was not observed. When the egg sacs were opened, one of them was empty and the other had 29 desiccated eggs. Self-burying and possible defensive be- havior.— Under laboratory conditions obser- vations were recorded on 27 recently molted spiders. To cover their bodies with sand, spi- ders scratched in the sand substrate with their palpi and first two pairs of legs, throwing sand grains from underneath the abdomen and making a small cavity (Fig. 10). They jumped and put their abdomen inside the cavity (Fig. 11). With their bodies in a vertical position, the spiders lay down on the sand mound with their ventral side up (Fig. 12). In this position, the spiders rocked their bodies slowly and continuously from side to side (Fig. 13). Then they flexed all their legs back and shook them from the patellae to the tarsi (Fig. 14). Finally they jumped up and in dorsal position placed their bodies on one side and extended the legs of the opposite side, shaking them rapidly back and forth in the sand. They scratched the sand substrate and repeated the behavior. Fi- nally they expanded all their legs on the other side of their bodies and stood up totally cov- ered with sand. Each spider performed this be- havior twice (n — 26) with one spider per- forming it 7 times. This behavior was observed from the fourth instar to adult with the exception of adult males. In captivity, almost all spiders of every in- star burrowed in the soil. This behavior is dif- ferent from described above and was recorded once as follows: The spider scratched in the sand with her two front pairs of legs, making a cavity. Then she jumped down and covered herself, throwing sand with her fourth pair of legs until completely buried. Then she extend- ed her legs, moving them back and forth until they were outstretched and completely cov- ered with sand. Quiescent spiders and those collected in the field placed their legs in a rigid paired for- mation: the first two pairs forward and the last two pair backward, giving the appearance of dead cactus spines, according to Vetter & Co- kendolpher (2000). When a spider was held by the leg with a pair of forceps, it rapidly autotomized the leg. DISCUSSION Field observations. — In San Pedro and El Comitan, spiders were found mainly under dead fallen cacti because rocks and stones are scarce in these habitats. In similar habitats H. theologus has been found under big rocks, loose boulders, boards and detritus (Roth 1984); but Vetter & Cokendolpher (2000) re- 172 THE JOURNAL OF ARACHNOLOGY Figures 10-14. — Self-burying behavior of Homalonychus theologus. 10. Lateral view of H. theologus scratching in the sand, forming a mound. 11. Lateral view of H. theologus putting its abdomen in the cavity. 12. Upper view of H. theologus with her ventral body up on the sand mound. 13. Upper view of H. theologus rocking its body from side to side on the sand mound. 14. Frontal view of H. theologus flexing her legs back and shaking them up and down in the sand. Arrows indicate the movements of H. theologus legs and body on the sand surface. ported that the spiders were very scarce dur- ing daytime and speculated that they spend the daytime in rodent burrows and under rocks. Mating behavior. — Sperm web structure of H. theologus males was similar to that de- scribed by Foelix (1996). When males were ready to reproduce, they rested on the sub- stratum the container, presumablely searching for females; if they were not ready to mate, they remained suspended at the top of the con- tainer. Homalonychus theologus courts at level I according to the classification of Platnick (1971) because it requires direct contact be- tween male and female, but the courtship level could be between I and II because like lyco- sids, pisaurids and sicariids, the male of H. theologus probably detects the female by DOMINGUEZ & JIMENEZ—BEHAVIOR OF HOMALONYCHUS THEOLOGUS 173 some type of chemical stimulus, but this could not be verified in this study. The mating po- sitioe of this species is a modification of type III position used by most hunting spiders, such as pisaurids, lycosids and thomisids (Foelix 1996). The male behavior of tying the female with strands of silk before or during mating has been recorded in other spiders such as the thomisid Xysticus, the philodromid Tibellus (Platnick 1971), the theridiid Latro- dectus (Stern & Kullmann 1981), the dictynid Dictyna (Starr 1988) and the oxyopid Oxyopes (Preston-Mafham 1999). Similar bonds also are used by tetragnathid Nephila macuiata (Fabricius 1793): the male places threads among the legs, the base of the abdomen and the carapace of the female (Robinson & Rob- inson 1980). The mating position assumed by H. theologus is very similar to that of the pi- saurid Ancylometes bogotensis (Keyserling 1877) (Merrett 1988) in that the female’s legs are trussed up tightly over the carapace. The male of A, bogotensis spies two silk rings, an outer ring around the distal ends of the front tibiae and an inner ring around the patellae (Merrett 1988), In the pisaurid Pisaurina mira (Walckenaer 1837), the male spies threads only between legs I and II of the female (Bruce & Carico 1988). Probably the male ties the female with silk to supress predation by the female during mating as has been the most consistent suggestion, although Foelix (1996) states that this behavior has symbolic signifi- cance only. Nevertheless Prestoe-Mafham (1999) suggests that producing the wrapping by the male is an important behavior and it seems highly likely that the silk plays a prin- cipal role in preparing the female physiolog- ically and behaviorally for copulation. Post copulation behavior of the H. theologus fe- male w^as similar to that observed in A. bo- gotensis, in which the female releases herself and cleans the silk from her legs (Merrett 1988). Considering that courtship and mating be- havior is an important phylogenetic character, it is possible that H. theologus is closely re- lated to Pisauridae species, because the males of both tie the female with silk threads prior to copulation. Previously Homaloeychidae was included in Pisauroidea (Lehtieen 1967) because they share some morphological char- acteristics with Oxyopidae and Pisauridae, such as eye pattern, feathery hairs, notched trochanters, and basic appearances of male and female genitalia. Nevertheless Roth (1984) argued to retain the Homaloeychidae as a separate family because those character- istics are insufficient as justification to include this family in the Pisauroidea. Later Codding- toe & Levi (1991) grouped Oxyopidae, Pisau- ridae and Lycosidae, which share synapo- morphias of male palp structure with other families in the super family Lycosoidea. We think that although homalonychid spiders have been isolated and restricted to the arid zones of the southwest USA and northwest of Mexico, its reproductive biology, genitalia and other morphological characteristics indi- cate a relationship with this family and there- fore could be included in the super family Lycosoidea proposed by Coddington & Levi (1991). Egg sac coestruction,“-There are parallels among aspects of the behavior of H. theologus and the sicariid Sicarius peruensis (Keyserling 1880) because both are predominantly desert spiders. The construction of the H. theologus egg sac is similar to that of S. peruensis in that both species incorporate silk threads with sand grains. The size, form and texture of egg sacs are notably different between the species, as well as in the time for its construction and ovipositioe. It is interesting to point out that 5'. peruensis throws sand to bury the egg sac (Levi & Levi 1969), v/hile 77. theologus only attaches the eggsac to the substratum (Vetter & Cockeedolpher 2000). This was verified in the field when an egg sac was found under a fallen dry cactus, and was so similar to the substratum that it was difficult to identify. We agree with Vetter & Cokendolpher (2000) that it could serve to protect the eggsac against predators and parasites, but also to prevent it from desecation in the dry environ- ment. During this study, none of the other fe- males made egg sacs, but Vetter & Cokee- dolpher (2000) recorded two egg sacs per female. If our results and those of other au- thors are considered, females of 77. theologus produce from 20-30 eggs per sac. Self-burying and possible defensive be- havior*— -This behavior has been observed in other spiders such as Sicarius sp. (Sicaridae), but spiders of this species throw sand on the body when burrowing in the substratum (Reis- kind 1965). Other spiders of the genera Cryptothele (Zodariidae), Paratropis (Paratro- 174 THE JOURNAL OF ARACHNOLOGY pididae), Microstigmata (Microstigmatidae), and Bradystichus (Bradystichidae) and the opilionid Trogulus (Trogulidae) have similar habits (Roth 1984). This behavior probably is an adaptation of these arachnids, including H. theologus, to protect themselves from preda- tors although could it also serves as thermo- regulatory function. This type of primary de- fense is of great importance in arid zones and deserts because there is relatively little vege- tation cover to protect against predators (Cloudsley-Thompson 1996). The behaviors of leg autotomy and pairing of legs observed in H. theologus both belong to a secondary type of defense, effective when the spiders are threatened by predators (Cloudsley-Thompson 1995). Nevertheless H. theologus is mainly nocturnal like most other desert-dwelling spi- ders, therefore, a visual defense may be effec- tive only in full moonlight, so sand camou- flage could has obvious advantages however the leg pairing behaviour is more difficult to imagine functionally. ACKNOWLEDGMENTS Thanks to Oscar Armendariz for help with the drawings, to Aldo Vargas for use of and help with video equipment, to Taylor Morey of the CIBNOR editing staff and to the anon- ymous reviewers for their valuable comments to this manuscript. This work was supported with a grant from CIBNOR. LITERATURE CITED Bruce, J. A. & J. E. Carico. 1988. Silk use during mating in Pisaurina mira (Walckenaer) (Araneae, Pisauridae). Journal of Arachnology 16:1-4. Cloudsley-Thompson, J.L. 1995. A review of the anti-predator devices of spiders. Bulletin of the British Arachnological Society 10:81-96. Cloudsley-Thompson, J.L. 1996. Biotic Interactions in Arid Lands. Springer, Germany. Coddington, J.A. & H.W. Levi. 1991. Systematics and evolution of spiders (Araneae). Annal Re- view of Ecology and Systematics 22:565-92. Foelix, R. 1996. Biology of Spiders. 2"^^ ed. Oxford, New York, U.S.A. Garcia, E. 1973. Modificaciones al sistema de cla- sificacion climatica de Koeppen. 2^ ed. Institute de Geologia. Universidad Nacional Autonoma de Mexico. Mexico. Gertsch, W.J. 1979. American Spiders. 2"^^ ed. Van Nostrand Reinhold, New York, U.S.A. Lehtinen, P. T. 1967. Classification of the cribellate spiders and some allied families, with notes on the evolution of the suborder Araneomorpha. Annales Zoologici Fennici 4:199-468. Leon de la Luz, J.L., R. Coria & M. Cruz. 1996. Fenologia floral de una comunidad arido-tropical de Baja California Sur, Mexico. Acta Botanica Mexicana. 35:45-64. Levi, H. W. & L. R. Levi. 1969, Eggease construc- tion and further observations on the sexual be- havior of the spider Sicarius (Araneae: Sicarii- dae). Psyche 76:29-40. Merrett, P. 1988. Notes on the biology of the neo- tropical pisaurid, Ancylometes bogotensis (Key- serling) (Araneae: Pisauridae). Bulletin of the British Arachnological Society 7:197-201. Platnick, N. 1971. The evolution of courtship be- haviour in spiders. Bulletin of the British Arach- nological Society 2:40-47. Preston-Mafham, K.G. 1999. Notes on bridal veil construction in Oxyiopes schenkeli Lessert, 1927 (Araneae: Oxyopidae) in Uganda. Bulletin of the British Arachnological Society 1 1(4): 150-152. Reiskind, J. 1965. Self-burying behavior in the ge- nus Sicarius (Araneae, Sicariidae). Psyche 72(3): 218-224. Robinson, M. H. & B. Robinson. 1980. Compara- tive studies of the courtship and mating behavior of tropical araneid spiders. Pacific Insects Mono- graph 36, Hawaii, U.S.A. Roth, V. 1984. The spider family Homalonychidae (Arachnida, Araneae). American Museum Novi- tates. 2790:1-1 1. Starr, C.K. 1988. Sexual behavior in Dictyna volu- cripes (Araneae, Dictynidae). Journal of Arach- nology 16:321-330. Stern, H. & E. Kullmann. 1981. Leben am seidenen Faden. Kindler, Miinchen. Vetter, R.S. & J.C. Cokendolpher. 2000. Homalony- chus theologus (Araneae, Homalonychidae): De- scription of egg sacs and a possible defensive posture. Journal of Arachnology 28:361-363. Manuscript received 23 January 2003, revised 18 February 2004. 2005= The Journal of Arachnology 33:175-192 NOTES ON THE GENUS BRACHISTOSTERNUS (SCORPIONES, BOTHRIURIDAE) IN CHILE, WITH THE DESCRIPTION OF TWO NEW SPECIES Andres A. Ojanguren Affilastro: Museo Argentieo de Cieecias Naturales “Bernardino Rivadavia”, Division Aracnologia, Av. Angel Gallardo 470, CMOS DJR, Buenos Aires, Argentina. E-mail: ojanguren@ciudadxom.ar ABSTRACT. Two new species of Brachistosternus from Chile are described. Brachistosternus {Lep- tosternus) cekalovici nev/ species can be distinguished from most other species of the genus because the divided dorsal gland of the telsoe. The closest species are B. (L.) artigasi Cekalovic 1974 and B. (L.) negrei Cekalovic 1975, for which redescriptions are provided. Brachistosternus cekalovici has only been collected in “Tres Cruces”, Coquimbo Province, Chile. Brachistosternus (Leptosternus) mattonii new species is also described. This species is most closely related to B. (L.) donosoi Cekalovic 1974, from which it can be distinguished by its more densely granular tegument (especially on the ventral surface of the metasoma), hemispermatophore with more developed internal spines, and the lack of a telsoe gland. A redescription of B, donosoi is also provided. Both species are related to the Argentine plains species, whilst B. (L.) artigasi, B. (L.) cekalovici and B. (L.) negrei seem to be more related to the Andean species of the subgenus Leptosternus. R.ESUMEN. Notas sobre el genero Brachistosternus (Scorpiones, Bothriuridae) en Chile, con la descrip- cion de dos nuevas especies, En el presente artfculo se describen dos nuevas especies del genero Bra- chistosternus de la Repilblica de Chile. Brachistosternus {Leptosternus) cekalovici new species puede diferenciarse de la mayoria de las especies descriptas del genero porque la glandula de la cara dorsal del telson, esta dividida en dos mitades separadas. Las especies mas relacionadas son B. (L.) artigasi Cekalovic 1974 y B. (L.) negrei Cekalovic 1975; en este trabajo se brindan tambien las redescripciones de ambas especies. Brachistosternus cekalovici solo ha sido colectada en la localidad de Ties Cruces, en la provincia de Coquimbo, Chile. Brachistosternus {Leptosternus) mattonii n. sp se encuentra estrechamente relacio- nada con B. (L.) donosoi Cekalovic 1974, puede diferenciarse de ella por poseer un tegument© mas granuloso, especialmente en la faz ventral del metasoma, por el mayor desarrollo de las espinas internas del hemiespermatoforo y por carecer de la glandula del telson. Tambien se brinda la redescripcion de B. donosoi. Ambas especies se encuentran relacionadas con las especies argentinas de llanura, mientras que B. (L.) artigasi, B. (L.) cekalovici y B. {L.) negrei parecen estar mas relacionadas con las especies andinas del subgenero Leptosternus. Keywords: Scorpiones, Brachistosternus, new species, South America, biogeography, taxonomy The genus Brachistosternus has been stud- ied in Chile by Kraepelin (1911), Mello-Lei- tao (1941), Ochoa & Acosta (2002) and es- pecially by Cekalovic (1970, 1973, 1974, 1975). There are records of this genus from Arica to Talca (Cekalovic 1974, 1975), but it is particularly diverse in northern and central Chile, the most arid regions of the country. Several specimens of Brachistosternus from this region were examined by the author, who recognized several unearned species of the subgenus Leptosternus, most of them from coastal areas and high mountain habitats in the Andes. Both regions include environ- ments that are slightly more humid than those found in the extremely xeric surrounding re- gions. The species of Brachistosternus are always distributed in well-defined elevations; there- fore the peculiar orography of Chile favors the presence of several different species within small geographic areas. A similar distribution- al pattern of the genus has been observed in northwestern Argentina (Ojanguren Affilastro 2002a). Brachistosternus (Leptosternus) cekalovici new species and Brachistosternus {Leptoster- nus) mattonii new species are described here. In the first species the dorsal gland of the tel- soe (Roig Alsiea & Maury 1981) is divided 175 176 THE JOURNAL OF ARACHNOLOGY into separate halves. So far, only Timogenes mapuche Maury 1975, T. sumatranus Simon 1880 and some specimens of B. {Leptoster- nus) negrei Cekalovic 1975 share this char- acteristic within the family Bothriuridae (Maury 1975, 1982; De la Serna de Esteban 1977; Prendini 2000). Brachistosternus cekalovici is very similar to B. (L.) artigasi Cekalovic 1974 and B. (L.) negrei. Although the original descriptions of B. artigasi and B. negrei given by Cekalovic (1974, 1975) are very complete, some char- acters currently used in the systematics of the genus remain undescribed; therefore the re- descriptions of these species are provided. Brachistosternus (L.) mattonii is described here and compared to the closely related spe- cies B. (L.) donosoi Cekalovic 1974. So far, this species has only been collected from coastal environments of northwestern Chile. METHODS The terminology of the hemispermatopho- res structures follows Maury (1974). Tricho- bothrial terminology follows Vachon (1974). Terminology of the telson gland follows Roig Alsina & Maury (1981). Terminology of the metasomal carinae follows Stahnke (1970). Abbreviations are as follows: MACN-Ar “ Museo Argentino de Ciencias Naturales '‘Ber- nardino Rivadavia”, National Arachnological Collection (Cristina Scioscia); ARA = Arturo Roig Alsina personal collection; lADIZA “ Instituto Argentino de Investigacion de las Zonas Aridas (Sergio Roig Junent); MZUC = Museo de Zoologia de la Universidad de Con- cepcion (Jorge Artigas); AMNH ™ American Museum of Natural History, New York, USA; A AO A = Andres Alejandro Ojanguren Affi- lastro personal collection; FKPC = Frantisek Kovarik personal collection, Prague, Czech Republic. All measurements are given in mm and were taken using an ocular micrometer. Illustrations were produced using a stereomi- croscope and camera lucida. The hemisper- matophores were dissected from surrounding tissues and observed in 80% ethanol. TAXONOMY Family Bothriuridae Simon Genus Brachistosternus Pocock Brachistosternus {Leptosternus) cekalovici new species Figs. 1-13, 58 Type specimens.— -Holotype male, CHILE: Coquimbo Province: Tres Cruces (29°22'24"S, 70°56'2"W), 10 January 1984, Maury (MACN-Ar 10243). Paratypes: CHILE: Co- quimbo Province: Tres Cruces, 7 d, 4 9 and 2 Juveniles, 10 January 1984, Maury (MACN- Ar 10244); 2 S and 2 9, 10 January 1984, Maury (MZUC). Other material examined.— CHILE: Co- quimbo Province: Tres Cruces, 10 January 1984, 8 d, 6 9 and 3 juveniles, Roig Alsina (ARA). Etymology. — This species is named after the Chilean arachnologist Dr. Tomas Cekalo- vic Kuschevich. Brachistosternus (L.) cekalo- vici can be distinguished from most other spe- cies of the genus because the dorsal gland of the telson is divided into separate halves (Fig. 8). Only some specimens of B. negrei share this characteristic (Fig. 53), but in most spec- imens of this species, this gland is absent. Brachistosternus negrei can be distinguished from B. cekalovici because it lacks the ventro- median carina of the fifth metasomal segment (Fig. 52) that is present in B. cekalovici (Fig. 5), and because it has two ventromedian stripes on metasomal segments II and III that are absent in B. cekalovici. Brachistosternus cekalovici is most closely related to B. artigasi. Besides the shape of their telson glands (Figs. 8, 19) both species can be distinguished by the different shape of their caudal glands or androvestigia (Cekalo- vic 1973). In B. artigasi they occupy approx- imately 50% of the dorsal surface of the fifth metasomal segment (Fig. 17), whereas in B. cekalovici they occupy less than 25% (Fig. 4). Brachistosternus {Leptosternus) galianoae Figures 1-13. — Brachistosternus {Leptosternus) cekalovici: 1. Left hemispermatophore, ventral aspect; 2. Left hemispermatophore, dorsal aspect; 3. Left hemispermatophore, detail of the lobe region; 4. Fifth metasomal segment, male, dorsal aspect; 5. Fifth metasomal segment, ventral aspect; 6. Telson, male, lateral aspect; 7. Telson, female, lateral aspect; 8. Telson, male, dorsal aspect. 9. Right pedipalpal chela. OJANGUREN AFFILASTRO— IN CHILE 177 female, ventral aspect; 12. Left pedipalpal chela, male, prolateral aspect; 13. Left pedipalpal chela, male, ventral aspect. Scale bars = 1 mm. 178 THE JOURNAL OF ARACHNOLOGY Figures 14-23„ — Brachistosternus (Leptosternus) artigasi: 14. Left hemispermatophore, ventral aspect; 15. Left hemispermatophore, dorsal aspect; 16. Left hemispermatophore, detail of the lobe region; 17. Fifth metasomal segment, male, dorsal aspect; 18. Fifth metasomal segment, ventral aspect; 19. Telson, male, dorsal aspect; 20. Telson, male, lateral aspect; 21. Telson, female, lateral aspect; 22. Left pedipaipal chela, male, ventral aspect; 23. Left pedipaipal chela, female, prolateral aspect. Scale bars = 1 mm. OJANGUREN AFFlhASTRO—BRACHISTOSTERNUS IN CHILE 179 Ojaeguren Affilastro 2002, a species from Bo- livia, also has such small caudal glands, but it has a single telsoe gland (Ojaeguren Affilastro 2002b). Description.-— Color: General color dark yellow with a dusky pattern. Carapace with a dark stripe from the lateral ocelli to the pos^ tocular furrow; ocular tubercle black; the rest without pigmentation except for two postero- lateral dark spots. Tergites with three spots, two lateral and a median spot, connected by a dark reticulated pigment. Stereites depig- mented. Metasomal segments dorsally with two posterolateral dark spots and a mediae spot; segments WII ventrally with two late- roventral stripes; IV with two lateroventral stripes and two mediae stripes that converge with the lateroventral stripes in the posterior margin of the segment; V with two lateroven- tral stripes and a mediae stripe that converge in the posterior margin of the segment where there is abundant reticulated pigmentation. Telson faintly spotted on the ventral surface. Legs with some spots on the prolateral sides of the femur and patella. Pedipalps: femur and patella with some spots on the retrolateral sur- face. Morphology: Measurements of male holo- type (MACN-Ar 10243) and a female paraty- pe (MACN-Ar 10244) in Table 1. Prosoma: Chelicerae with two subdistal teeth in the movable finger; anterior edge of the carapace with a slight median bulge and six setae, two on each side and two in the middle; tegument slightly granular; anterior and posterior lon- gitudinal sulcus, lateral sulcus and postocular furrow deeply marked; ocular tubercle medi- ally situated on the carapace with a slight in™ terocular sulcus, median ocelli two diameters apart with a seta behind each. Sternum: Ster- num type 2 (Soleglad & Fet 2003), much wid- er than long; apex width equal to posterior width; posterior emargieation quite well de- veloped, with convex lateral lobes conspicu- ously separated. Mesosoma: Tergites I-VI smooth near the anterior margin and finely granular near the posterior margin; VII smooth medially, the rest densely granular, with two posterolateral carieae. Metasoma: Segment I: ventral surface smooth with three pairs of ventral setae, lateral surface with scat- tered granulation, dorsally smooth, dorsosub- median, dorsolateral and mediae lateral cari- eae extend the entire length of the segment; segments II and III similar to segment I but less granular, with less well developed carinae and with four pairs of ventral setae; segment IV: dorsally smooth, lateral surfaces with sparse granulation, ventrally smooth with a large number of scattered setae; segment V: ventral surface irregularly granular, ventro- median and ventrolateral carieae extend the entire length of the segment (Fig. 5); dorsal and lateral surfaces finely granular or smooth; ventral setae usually comprising 4 rows: 1 basal row of 4 setae, and 3 posterior rows of 1 or 2 setae, in some specimens there is an additional row of 1 or 2 setae; in males the caudal glands occupy approximately 10 or 20% of the dorsal surface (Fig. 4). Telson: Sparsely granular; vesicle with rounded ven- tral surface; aculeus slightly curved, of the same length as the vesicle (Figs. 6 & 7); the dorsal gland of the telson is divided into two separated halves (Fig. 8), but in less than 10% of the examined specimens joined in the an- terior margin. Pedipalps: Trichobothrial pat- tern, neobothriotaxic major type C: femur with 3 trichobotliria: I d, 1 i and 1 e; patella with 3 ventral trichobothria, 2 dorsal tricho- bothria, 1 internal trichobothrium, and 13 ex- ternal trichobothria: 3 et, 1 est, 2 em, 2 esb and 5 eb; chela with 27 trichobothria: 1 Est, 5 Et, 5 V, 1 Esb, 3 Eb, 1 Dt, 1 Db, 1 1 est, 1 esb, 1 eb, 1 dt, 1 dst, 1 dsb, 1 db, 1 ib, 1 it, no ietraspecific variation has been observed in these characters. Femur smooth, ventroie- tereal and dorsoieternal carinae poorly devel- oped, patella scarcely granular and without ca- rieae; chela stout with relatively short fingers, smooth tegument, with a very developed vee- troexternal cariea (Figs. 9™ 13); in males the proiateral apophysis is well developed; mov- able finger with a central row of granules and 7 or 8 internal and external granules. Legs: finely granular; telotarsi I and II with the inner ungue 10-15% shorter than the external. He- mispermatophore: Distal lamina thick, slightly curved, and shorter than the basal portion (Figs. 1 & 2); cylindrical apophysis well de- veloped, longer than the laminar apophysis; basal triangle well developed, formed by three or four crests (Fig. 3); internal spines absent; basal spines well developed; row of spines well developed, these spines can be branched in some specimens, and in some cases they can have up to three points. Variation.— Total length in males, 50-55 180 THE JOURNAL OF ARACHNOLOGY Table 1. — Measurements (mm), number of pectinal teeth and telotarsal setae: Brachistosternus cekalov- ici new species, male holotype (MACN-Ar 10243) and female paratype (MACN=Ar 10244), and Brach- istosternus mattonii new species, male holotype (MACN-Ar 10235) and female paratype (MACN-Ar 10236). Br. (L.) cekalovici Br. (L.) mattonii Male holotype Female paratype Male holotype Female paratype Total length 51.03 51.63 54.46 52.92 Carapace, length 5.66 6.92 5.74 6.14 Carapace, anterior width 4.20 4.44 3.88 4.53 Carapace, posterior width 6.38 6.71 6.3 6.87 Mesosoma, total length 13.86 13.53 14.83 15.75 Metasoma, total length 24.4 24.15 20.09 17.29 Metasomal segment I, length 3.72 4.36 4.61 4.04 Metasomal segment I, width 3.07 3.23 3.72 3.55 Metasomal segment I, height 3.96 4.04 2.83 2.83 Metasomal segment II, length 4.44 4.36 5.09 4.44 Metasomal segment II, width 3.15 3.15 3.31 3.07 Metasomal segment II, height 3.72 3.55 2.99 2.83 Metasomal segment III, length 4.85 4.36 5.09 4.61 Metasomal segment III, width 3.15 2.99 3.23 2.99 Metasomal segment III, height 3.47 3.31 2.67 2.51 Metasomal segment IV, length 5.33 5.01 5.74 5.25 Metasomal segment IV, width 2.91 2.75 2.99 2.83 Metasomal segment IV, height 3.23 3.07 2.54 2.34 Metasomal segment V, length 6.06 6.06 6.46 5.82 Metasomal segment V, width 2.51 2.42 3.23 2.82 Metasomal segment V, height 3.23 3.07 2.51 2.18 Telson, length 7.11 7.03 6.9 6.87 Vesicle, length 3.64 3.39 3.88 3.64 Vesicle, width 2.42 2.18 2.75 2.34 Vesicle, height 1.94 1.90 2.18 2.1 Aculeus, length 3.47 3.64 3.75 3.23 Pedipalp, total length 15.67 14.30 15.84 16.96 Femur, length 4.12 3.55 5.09 4.68 Femur, width 0.81 1.37 1.37 1.37 Patella, length 4.04 3.72 4.44 4.2 Patella, width 1.45 1.62 1.62 1.62 Chela, length 7.51 7.03 9.13 8.08 Chela, width 1.86 1.86 2.59 1.94 Chela, height 2.34 2.51 3.07 2.58 Movable finger, length 4.53 4.36 5.33 5.01 Fixed finger, length 4.01 3.87 4.9 4.72 Number of pectinal teeth, left-right 34-34 28-29 39-39 28-29 Telotarsus I, ventrointernal setae 3 3 4 3 Telotarsus I, ventroexternal setae 5 3 0 0 Telotarsus I, dorsal setae 10 9 8 8 Telotarsus II, ventrointernal setae 5 5 5 5 Telotarsus II, ventroexternal setae 5 3 4 4 Telotarsus II, dorsal setae 12 9 7 7 Telotarsus III, ventrointernal setae 9 9 7 7 Telotarsus III, ventroexternal setae 5 6 5 6 Telotarsus III, dorsal setae 13 12 10 10 Telotarsus IV, ventrointernal setae 6 5 4 5 Telotarsus IV, ventroexternal setae 4 5 4 5 Telotarsus IV, dorsal setae 6 6 5 4 OJANGUREN AFFILASTRO—BRACHISTOSTERNUS IN CHILE 181 mm (n = 15; mean ^ 52,9), 51-59 mm in females (n ^ 10; mean = 54,8), Leegth/width ratio of the fifth metasomal segment 1,81- 2.22 (« = 10; mean — 2,01), Pectiees with 33-36 pectinal teeth in males {n = 15; median = 35) and 28-32 in females {n — 10; median = 30). Leegth/height ratio of the pedipalpal chela 3.04-3.17 in males (n = 15; mean = 3.11) and 2,74-3,12 in females (n = 10; mean = 2.87). Telotarsus I with 3 or 4 ventrointer- eal setae (n = 20; mediae = 3), 3-5 veetroex- temal setae (n — 20; mediae = 3) and 9 or 10 dorsal setae (n = 20; mediae == 10), Te- lotarsus II with 5 or 6 veetrointernal setae (n = 20; median = 5), 3 to 5 veetroexternal setae (n = 20; median = 3) and 9 to 12 dorsal setae (n — 20; mediae = 10), Telotarsus III with 8 or 9 veetrointernal setae (n = 25; median = 8), 5-7 veetroexternal setae (n = 25; median = 6) and 11-14 dorsal setae (n = 25; median = 12). Telotarsus IV with 5 or 6 ventrointernal setae (n = 25; mediae = 6), 4 or 5 veetroex- temal setae (n = 25; median = 5) and 6 or 7 dorsal setae (« = 25; mediae = 6). Fourth metasomal segment with 31-38 ventral setae (n = 20; mediae = 36). Fifth metasomal seg~ meet with 9-12 ventrolateral setae (n = 25; median = 10), and 8-12 lateral setae (« = 25; median = 9). Distribution.— This species has only been collected at the type locality (Fig. 58). BmcMstosternus (Leptosternus) mattonii new species Figs, 24-35, 41, 58 Type specimens.— Holotype male, CHILE: Antofagasta Province: Horeitos (22°55'S, 70°18'W), 2 October 1983, Maury (MACN^ Ar 10235). Paratypes: CHILE: Antofagasta Province: Antofagasta (23°39'S, 70°24'W), 1 $, 22 October 1982, Maury (MACN-^Ar 10236); Hornitos, 16,6 October 1983, Roig Alsiea (MACN-Ar 10245). Iquique Province: Alto Patache (20°45'S, 70°9'W), 1 juvenile 6, 26 August 1998, C. Moreira (FKPC). Other material examined.— CHILE: An- tofagasta Province: Hornitos, 6 October 1983, 2 6 and 2 juveniles, Roig Alsina (ARA). Etymology,— This species is named after the Argentinian arachnologist Camilo Ivan Mattoni. Diagnosis.— (L.) mattonii is most closely related to B. (L,) donosoi, from which it can be distinguished by its more densely granular tegument, especially on the ventral surface of the metasomal segments (Figs, 41, 42); the lack of a telson gland; and the lower number of ventral setae on meta- somal segment V (6-9 in B. mattonii vs, 14- 19 in B. donosoi). There are also minor dif- ferences in the shape of the hemispermatop- hore (Figs. 24-26, 36-38), especially in the development of the internal spines. In B. mat- tonii they are distributed in two areas, one above the basal triangle and the other in front of it (Fig, 26), with a smooth area in the mid- dle; whereas in B. donosoi the internal spines are restricted to a small area in front of the basal triangle (Fig, 38). In the rest of the spe- cies of the genus, these spines usually occupy the whole area above the basal triangle (Ojan- gureri Affilastro & Roig Alsina 2001) or they are absent, as in the Andean species of the subgenus Leptosternus (Roig Alsina 1977; Ochoa & Acosta 2002). Description. — Color: Yellow with some spots on the carapace and the tergites. Cara- pace with a dark stripe from the lateral ocelli to the postocular furrow; ocular tubercle black; the rest lacking pigmentation. Tergites with three spots, two lateral and one mediae that join in some specimens. Sternites, meta- somal segments, telson, pedipalps, and pecti- nes unpigmeeted. Some specimens are almost completely unpigmented. Morphology: Measurements of male holo- type (MACN-Ar 10235) and female paratype (MACN-Ar 10236) in Table 1, Prosoma: Che- licerae with two subdistal teeth in the movable finger; anterior edge of the carapace with a slight mediae bulge and four setae, one on each side and two in the middle; tegument densely granular; anterior and posterior lon- gitudinal sulcus, lateral sulcus and postocular furrow deeply marked; ocular tubercle in the middle of the carapace with a slight intero- cular sulcus, median ocelli two diameters apart with a seta behind each. Sternum: Ster- num. type 2 (Soleglad & Fet 2003), much wid- er than long; apex width equal to posterior width; posterior emargieation quite well de- veloped, with convexed lateral lobes conspic- uously separated. Mesosoma: Tergites I-VI finely granular near the anterior margin and densely granular near the posterior margin; VII finely granular medially, the rest densely granular, with two posterolateral carinae. Me- tasoma: segments I-III: ventral and lateral 182 THE JOURNAL OF ARACHNOLOGY Figures 24-35. — Brachistostemus {Leptostemus) mattonii: 24. Left hemispermatophore, ventral aspect; 25. Left hemispermatophore, dorsal aspect; 26. Left hemispermatophore, detail of the lobe region; 27, Fifth metasomal segment, male, ventral aspect; 28. Fifth metasomal segment, dorsal aspect; 29. Right pedipalpal chela, female, retrolateral aspect; 30, Left pedipalpal chela, female, prolateral aspect; 31, Left pedipalpal chela, female, ventral aspect; 32. Left pedipalpal chela, male, prolateral aspect; 33. Left pedipalpal chela, male, ventral aspect; 34. Telson, female, lateral aspect; 35, Telson, male, lateral aspect. Scale bars = 1 mm. OJANGUREN AFFILASTRO^BRACMSTOSTERNUS IN CHILE 183 surfaces densely granular, dorsally finely gran- ular, dorsosubmediae, dorsolateral and mediae lateral carieae extend the entire length of the segment; segment IV: dorsally finely granular, lateral surfaces densely granular, ventraily densely granular with a large number of scat- tered setae, each one in a depression with smooth tegument (Fig» 41); segment V: ven- tral surface irregularly granular, veetromediae and ventrolateral carieae extend the entire length of the segment; dorsal and lateral sur- faces finely granular or smooth; ventral setae usually comprising 3 rows (Fig. 27): 1 basal row of 2—4 setae, and 2 posterior rows of 1 or 2 setae, in one specimen there is an addi- tional row of 2 setae; in males the caudal glands are long and narrow (Fig. 28). The ju- veniles and the females of the species are less granular than males. Telson: Densely granular in males (Fig. 35) and with scarce granulation in females (Fig. 34); vesicle with rounded ventral surface; aculeus slightly curved, of the sam.e length as the vesicle; in males the telson gland is absent, but there is a small circular depression on the dorsal surface of the vesicle. Pedipalps: Trichobotlirial pattern, neobothrio- taxic major type C: femur with 3 trichobotli- ria: 1 d, 1 i and 1 e; patella with 3 ventral tricliobotliria, 2 dorsal trichobothria, 1 internal triclioboitiriem, and 13 external trichobothria: 3 et, 1 est 2 em, 2 esb and 5 eb; chela with 27 trichobothria: 1 Est, 5 Et, 5 v, 1 Esb, 3 Eb, 1 Dt, I EU, 1 et, 1 est, 1 esb, 1 eb, 1 dt, 1 dst, 1 dsb, 1 db, 1 ib, 1 it; no intraspecific variation has been observed in these charac- ters. Femur scarcely granular, ventrointemal, veetroextemal, and dorsointemal carieae well developed, patella scarcely granular; ventroin- temal and veritroexternal carieae well devel- oped; chela stout with long fingers, tegument finely granular or smooth, with a very well developed ventrointemal cariea (Figs. 29-33); in males the prolateral apophysis is well de- veloped; movable finger with a central row of granules and 7 or 8 internal and external gran- ules. Legs: Finely granular; telotarsi I and II with the inner ungue 5 to 10% shorter than the external one. Hemispermatophore: Distal lamina thick, slightly curved, approximately the same size as the basal portion (Figs, 24 & 25); cylindrical apophysis well developed, longer than the laminar apophysis; basal tri- angle well developed, formed by three or four crests (Fig. 26); internal spines distributed in two areas, one above the basal triangle and the other in front of it; basal spines well de- veloped; row of spines well developed, these spines can be ramified in some specimens. Variation*— Total length in males, 49-58 mm (n = 4; mean = 54.25) and 53 mm in the only studied female. Pectines with 36-41 pec- tieal teeth in males {n = 4, mediae = 39) and 28-29 in the only studied female. Length/ width ratio of the fifth metasomal segment 2 to 2.11 in males (n = 4; mean = 2.06) and 2.05 in the only studied female. Leegth/height ratio of the pedipalpal chela 2.90^3.11 in males (n = 4; mean = 2.98) and 3.13 in the only studied female. Telotarsus I with 3 or 4 ventrointemal setae (h = 8; mediae = 3), and 7 or 8 dorsal setae (n = 8; mediae = 8), no ventroextemal setae have been observed. Te- lotarses II with 3-5 veetroietemai setae (n = 8; mediae = 4), 3-5 ventroextemal setae (n = 8; median = 4) and 7-9 dorsal setae (n = 8; mediae = 7). Telotarsus III with 6 or 7 ventrointemal setae (w = 8; mediae = 7), 4- 6 ventroextemal setae (« = 8; mediae == 6) and 9-11 dorsal setae (« = 8; mediae = 10). Basitarsus III with 7 or 8 dorsal setae (« = 8; mediae = 7). Telotarsus IV with 4 or 5 vee- troietemai setae (w = 8; mediae = 5), 4 or 5 ventroextemal setae (w = 8; mediae — 5) and 4-6 dorsal setae (« — 8; mediae = 6). Fourth metasomal segment with 28-36 ventral setae (n = 1; mediae — 34). Fifth metasomal seg- ment with 8 ventrolateral setae (n = 8), and 8 or 9 lateral setae (n = 7; mediae = 8). Distribution,— This species has only been collected at three coastal localities in northern Chile: Homitos and Antofagasta, both in An- tofagasta Province: and Alto Paiache, in Iqui- qiie Province (Fig 58). Northerly, in coastal areas of southern Peru, this species is replaced by B. (L.) turpuq Ochoa 2002 (Ochoa 2002); southerly, in central Chile B. mattonii is re- placed by B, (L.) roigaisinai OJanguren Affi- lastro 2003 and B. (L.) sciosciae OJanguren Affilastio 2003 (OJanguren Affilastro 2003). Brachistosternus (Leptostemus) donosoi Cekalovic 1974 Figs. 36-40, 42-47, 58 Brachistosternus {Leptostemus) donosoi Cekalovic 1974: 250-252. Type materiaL— "Holotype male, CHILE, Tarapaca Province, Pampa del Tamamgal, 10 184 THE JOURNAL OF ARACHNOLOGY Figures 36-47. — 36-40, 42-47. Brachistosternus (Leptosternus) donosoi: 36. Left hemispermatophore, ventral aspect; 37. Left hemispermatophore, dorsal aspect; 38. Left hemispermatophore, detail of the lobe region; 39. Fifth metasomal segment, male, dorsal aspect; 40. Fifth metasomal segment, ventral aspect; 42. Fourth metasomal segment, male, ventral aspect; 43. Right pedipalpal chela, male, ventral aspect; 44. OJANGUREN AFFILASTRO—BRACHISTOSTERNUS IN CHILE 185 km E Pica (20°30'S, 69°2rW) (MZUC 530, not examined). Description. — Color: Yellow with some spots on the carapace and the tergites. Cara- pace with a dark stripe from the lateral ocelli to the postocular furrow; ocular tubercle black; the rest lacking pigmentation. Tergites with two faint lateral spots. Sternites, meta- somal segments, telson, pedipalps, and pecti- nes unpigmented. Some specimens are almost completely unpigmented. Morphology: Measurements a of a male specimen (AAOA) and female specimen (AMNH) in Table 2. Prosoma: Chelicerae with two subdistal teeth in the movable finger; anterior edge of the carapace with a slight me- dian bulge, tegument densely granular; ante- rior and posterior longitudinal sulcus, lateral sulcus and postocular furrow deeply marked; ocular tubercle in the middle of the carapace with a slight interocular sulcus, median ocelli two diameters apart with a seta behind each. Sternum: Sternum type 2 (Soleglad & Fet 2003), much wider than long; apex width equal to posterior width; posterior emargina- tion quite well developed, with convexed lat- eral lobes conspicuously separated. Mesoso- ma: Tergites: I- VI finely granular near the anterior margin and finely granular near the posterior margin in males, smooth in females; VII densely granular, with two posterolateral carinae. Metasoma: Segments I-III: ventral and lateral surfaces densely granular, dorsally finely granular, dorsosubmedian, dorsolateral and median lateral carinae extend the entire length of the segment; segment IV: dorsally finely granular, lateral surfaces densely gran- ular, ventrally smooth with a large number of scattered setae (Fig. 42); segment V: ventral surface smooth near the anterior margin and irregularly granular in the second half, the ventromedian carina is weakly developed or absent and the ventrolateral carinae extend throughout the entire length of the segment (Fig. 40); the ventral setae usually comprise 5 rows: 2 basal rows of 4-6 setae and 3 or 4 posterior rows of 2-4 setae; dorsal and lateral surfaces finely granular or smooth; in males. the caudal glands occupy more than 60% of the dorsal surface (Fig. 39). Telson: Densely granular in males (Fig. 47) and with scarce granulation in females (Fig. 45); vesicle with rounded ventral surface; aculeus slightly curved, of the same length as the vesicle; in males the telson gland is almost triangular (Fig. 46). Pedipalps: Trichobothrial pattern, neobothriotaxic major type C: femur with 3 trichobothria: I d, I i and 1 e\ patella with 3 ventral trichobothria, 2 dorsal trichobothria, 1 internal trichobothrium, and 13 external tri- chobothria: 3 et, 1 est, 2 em, 2 esb and 5 eb\ chela with 27 trichobothria: 1 Est, 5 Et, 5 v, 1 Esb, 3 Eb, 1 Dt, 1 Db, 1 et, 1 est, 1 esb, 1 eb, 1 dt, 1 dst, 1 dsb, 1 db, 1 ib, 1 it; no intraspecific variation has been observed in these characters. Femur scarcely granular, ventrointernal, ventroexternal, and dorsointer- nal carinae well developed, patella scarcely granular; ventrointernal and ventroexternal ca- rinae well developed; chela stout with long fingers, tegument finely granular or smooth, with a very well developed ventrointernal ca- rina (Figs. 43 & 44); in males the prolateral apophysis is well developed; movable finger with a central row of granules and 7 or 8 in- ternal and external granules. Legs: Finely granular; telotarsi I and II with the inner un- gue 10-15% shorter than the external one. Hemispermatophore: Distal lamina thick and of the same proportions as the basal portion (Figs. 36 & 37); cylindrical apophysis well developed, and longer than the laminar apoph- ysis; basal triangle well developed formed by three or four crests; internal spines poorly de- veloped reduced to a small area in front of the basal triangle (Fig. 38); basal spines well de- veloped; row of spines well developed. Variation.— Total length in males, 56-64 mm {n — 8; mean = 59.5), 53-62 mm in fe- males (« — 9; mean — 59.20). Pectines with 28-33 teeth in males (ji = 6; median = 32), 25-31 in females {n = 9; median = 29). Length/width ratio of the fifth metasomal seg- ment 2.10-2.57 in males {n = 5; mean = 2.34), 1.95-2.35 in females (w = 5; mean — 2.21). Length/height ratio of the pedipalpal Right pedipalpal chela, female, ventral aspect; 45. Telson, female, lateral aspect; 46. Telson, male, dorsal aspect; 47. Telson, male, lateral aspect. 41. Brachistosternus (L.) mattonii, fourth metasomal segment, male, ventral aspect. Scale bars = 1 mm. 186 THE JOURNAL OF ARACHNOLOGY Table 2.-=-Measurements (mm), number of pectinal teeth and telotarsal setae: of a male specimen and a female specimen of BracMstosternus artigasi, B. donosoi and B. negrei. Br. (L.) artigasi Br. (L.) donosoi Br. (L.) negrei Male (ARA) Female (AMNH) Male (AAOA) Female (AMNH) Male (MACN) Female (MACN) Total length 53.81 55.22 56.27 59.07 55.78 65.37 Carapace, length 6.2 6.53 6.65 7.32 6.54 7.76 Carapace, anterior width 3.87 4.13 4.26 4.66 4.68 6.06 Carapace, posterior width 5.8 6.33 6.92 7.45 6.7 8.65 Mesosoma, total length 17.42 18.62 15.96 17.02 14.67 18.75 Metasoma, total length 23.59 24.07 26.34 27.41 34.57 38.86 Metasomal segment I, length 3.6 4 3.99 4.66 4.04 4.44 Metasomal segment I, width 4.13 3.93 4.12 4.66 4.44 5.41 Metasomal segment I, height 3.4 3.2 3.33 3.72 3.39 4.04 Metasomal segment II, length 4.33 4.47 4.66 4.92 4.84 5.66 Metasomal segment II, width 3.87 3.6 3.72 3.99 4.28 4.12 Metasomal segment II, height 3.2 3.13 3.33 3.59 3.55 4.04 Metasomal segment III, length 4.33 4.47 5.32 5.19 5.25 5.66 Metasomal segment III, width 3.67 3.47 3.59 3.72 4.04 4.68 Metasomal segment III, height 3.13 3 3.19 3.46 3.55 4.04 Metasomal segment IV, length 5.33 5.13 5.99 5.99 6.06 6.46 Metasomal segment IV, width 3.53 3.2 3.33 3.46 3.88 4.61 Metasomal segment IV, height 2.8 2.67 2.93 3.19 3.31 3.96 Metasomal segment V, length 6 6 6.38 6.65 4.68 8.08 Metasomal segment V, width 3.47 3.13 3.33 3.33 2.02 4.44 Metasomal segment V, height 2.6 2.33 2.79 2.79 1.69 3.64 Telson, length 6.6 6 7.32 7.32 7.27 8.56 Vesicle, length 3 2.67 3.99 3.99 3.23 4.2 Vesicle, width 2.07 2.07 2.79 3.1 2.83 3.23 Vesicle, height 1.87 1.87 2.39 2.45 2.18 2.83 Aculeus, length 3.6 3.33 3.33 3.33 4.04 4.36 Pedipalp, total length 15.38 14.52 20.57 18.75 17.12 18.75 Femur, length 4 3.67 5.94 4.92 4.44 4.85 Femur, width 1.33 1.47 1.73 1.73 1.86 1.69 Patella, length 3.93 3.67 5.05 5.05 4.44 4.85 Patella, width 1.8 1.73 1.86 2.13 1.94 2.26 Chela, length 7.45 7.18 9.58 8.78 8.24 9.05 Chela, width 1.73 1.86 2.66 2.53 2.42 2.34 Chela, height 2,39 2.66 3.33 3.06 3.23 3.07 Movable finger, length 4.52 4.39 5.32 4.79 4.85 5.41 Fixed finger, length 3.99 3.99 4.92 4.52 4.2 4.98 Number of pectinal teeth, left-right 30-29 24-24 3L31 27-27 34-34 31-31 Telotarsus I, ventrointemal setae 3 3 3 3 2 2 Telotarsus I, ventroextemal setae 7 6 0 0 0 0 Telotarsus I, dorsal setae 9 9 7 8 7 8 Telotarsus II, ventrointemal setae 4 5 5 5 4 4 Telotarsus II, ventroextemal setae 4 4 4 3 2 1 Telotarsus II, dorsal setae 11 11 8 9 8 9 Telotarsus III, ventrointemal setae 11 12 8 8 6 6 Telotarsus III, ventroextemal setae 5 4 5 5 4 2 Telotarsus III, dorsal setae 11 11 12 11 6 5 Telotarsus IV, ventrointemal setae 4 5 5 5 4 5 Telotarsus IV, ventroextemal setae 5 5 5 5 4 4 Telotarsus IV, dorsal setae 6 5 5 6 5 5 OJANGUREN AFFILASTRO—BRACHISTOSTERNUS IN CHILE 187 chela 2.87“2.97 in males {n = 5; mean = 2.91), 2.85-3.15 in females (n = 5; mean = 3.03). Telotarsus I with 3 or 4 ventrointernal setae (n = 10; median = 3), 0 or 1 ventroex- ternal setae (n = 10; median = 0) and 7 or 8 dorsal setae (n ~ 10; median = 7). Telotarsus II with 4 or 5 ventrointernal setae (n = 10; median = 5), 3 or 4 ventroexternal setae (n = 10; median = 4) and 7-10 dorsal setae (n = 10; median = 9). Telotarsus III with 6-8 ven- trointernal setae (n — 10; median = 8), 5 or 6 ventroexternal setae (n = 10; median = 5) and 11-13 dorsal setae (n = 10; median — 12). Telotarsus IV with 4 or 5 ventrointernal setae (n = 10; median = 5), 4 or 5 ventroex- ternal setae (n = 10; median == 5) and 5 or 6 dorsal setae (n — 10; median — 6). Fourth metasomal segment with 26-32 ventral setae (n = 10). Fifth metasomal segment with 9 or 10 ventrolateral setae (n = 10; median = 10), and 6 or 7 lateral setae (n — 10; median — 6). Distribution. — This species has been col- lected from 800-1400 m a.s.L at Tarapaca province, in northern Chile (Fig. 58). Most of the localities where this species has been col- lected are placed at the “Pampa del Tamaru- gal”; and are related with forests of Prosopis tamarugo Philippi. This species was not found by the author in coastal areas of this province. Material examined. — CHILE: Tarapaca Province: Fuerte Baquedano (20°11'S, 69°47'W), 26 December 1977, 2 c3, 4 9 and 2 juveniles, Pena (AMNH); December 1978, 2 (3, 6 $ and 7 juveniles, Pena (AMNH); Quebrada de Tarapaca (19°40'S, 69°10'W), 25 January 1992, 1 9 and 3 juveniles, Pena (AMNH); Dolores (19°40'S 69°57'W), 8 Feb- ruary 1992, 1 juvenile, Pena (AMNH); 25 Km. West Pica (20°31'S, 69°22'W), 6 Decem- ber 2001, 1 S and 1 juvenile, Ojanguren Af- filastro & Korob (A AO A). Brachistosternus {Leptosternus) artigasi Cekalovic 1974 Figs. 14-23, 58 Brachistosternus {Leptosternus) artigasi Cekalovic 1974: 248-250. Type material. — Holotype male, CHILE, Coquimbo Province, La Serena, Lomas de Pe- nuelas (29°54'S, 7ri5'W) (MZUC 528, ex- amined). Description. — Color: General color dark yellow with a dusky pattern. Carapace with a dark stripe from the lateral ocelli to the pos- tocular furrow; ocular tubercle black; the rest without pigmentation except for two postero- lateral dark spots. Tergites with three spots, two lateral and a median spot, connected by a dark reticulated pigment. Sternites depig- mented. Metasomal segments dorsally with two posterolateral dark spots and a median spot, connected by a dark reticulated pigment; segments I to III ventrally with two lateroven- tral stripes; IV with two latero ventral stripes and a thin median stripe, that converge with the lateroventral stripes in the posterior mar- gin of the segment; V with two lateroventral stripes and a median stripe that converge in the posterior margin of the segment where there is abundant reticulated pigmentation. Telson faintly spotted on the ventral surface. Legs with some spots on the proiateral sides of the femur and patella. Pedipalps: femur, pa- tella and chella with some spots on the retro- lateral surface. Morphology: Measurements a of a male specimen (ARA) and female specimen (AMNH) in Table 2. Prosoma: Chelicerae with two subdistal teeth in the movable finger; anterior edge of the carapace with a slight me- dian bulge; tegument densely granular; ante- rior longitudinal sulcus slightly marked; posterior longitudinal sulcus, lateral sulcus and postocular furrow deeply marked; ocular tubercle medially situated on the carapace with a slight interocular sulcus, median ocelli two diameters apart with a seta behind each. Sternum: Sternum type 2 (Soleglad & Fet 2003), much wider than long; apex width equal to posterior width; posterior emargina- tion quite well developed, with convexed lat- eral lobes conspicuously separated. Mesoso- ma: Tergites I to VI smooth near the anterior margin and finely granular near the posterior margin; VII densely granular, with two pos- terolateral carinae. Metasoma: Segment I: ventral surface smooth, lateral surface finely granular, dorsally smooth, dorsosubmedian, dorsolateral and median lateral carinae slight- ly marked, extend the entire length of the seg- ment; segments II and III similar to segment I but less granular, with less well developed carinae; segment IV: dorsally smooth, lateral surfaces with sparse granulation, ventrally smooth with a large number of scattered setae; segment V: ventral surface irregularly granu- lar, the ventromedian and ventrolateral carinae extend throughout the entire length of the seg- 188 THE JOURNAL OF ARACHNOLOGY ment (Fig, 18); the ventral setae usually com- prise 3 rows: 1 basal row of 2-5 setae, 1 me- dian row of 1 or 2 setae, and 1 posterior row of 1 or 2 setae; dorsal and lateral surfaces fine- ly granular or smooth; in males, the caudal glands occupy approximately 50% of the dor- sal surface (Fig, 17), Telson: Sparsely granu- lar; vesicle with rounded ventral surface; acu- leus slightly curved, slightly longer than the vesicle (Figs. 20 & 21); the dorsal gland of the telson is almost triangular, and in most specimens the posterior corner of this triangle is doubled (Fig. 19). Pedipalps: Trichobothrial pattern, neobothriotaxic major type C: femur with 3 trichobothria: I d, I i and 1 e; patella with 3 ventral trichobothria, 2 dorsal tricho- bothria, 1 internal trichobothrium, and 13 ex- ternal trichobothria: 3 et, 1 est, 2 em, 2 esb and 5 eb; chela with 27 trichobothria: 1 Est, 5 Et, 5 V, 1 Esb, 3 Eb, 1 Dt, 1 Db, 1 et, 1 est, 1 esb, 1 eb, 1 dt, 1 dst, 1 dsb, 1 db, 1 ib, 1 lY; no intraspecific variation has been observed in these characters. Femur smooth, ventroin- ternal and dorsointernal carinae poorly devel- oped, patella scarcely granular and without ca- rinae; chela stout with relatively short fingers, smooth tegument, with a very developed ven- troexternal carina (Figs. 22 & 23); in males the prolateral apophysis is well developed; movable finger with a central row of granules and 7 or 8 internal and external granules. Legs: Smooth in females and finely granular in males; The inner ungue of telotarsi I and II are 5-10% shorter than the external one. He- mispermatophore: Distal lamina thick and shorter than the basal portion (Figs. 14 & 15); cylindrical apophysis well developed, and lon- ger than the laminar apophysis; basal triangle well developed formed by three or four crests (Fig. 16); internal spines absent; basal spines well developed; row of spines well developed. Variation. — Total length in males, 49-60 mm {n = 10; mean = 53.9); 47-57 in females {n = 6; mean = 50.8). Pectines with 25-31 pectinal teeth in males (« = 11; median = 27); 22-29 in females (« = 6; median = 25). Length/height ratio of the pedipalpal chela 3.00-3.23 in males {n = 11; mean = 3.11); 2.75-2.91 in females {n = 6; mean = 2.87). Telotarsiis I with 3 or 4 ventrointernal setae {n = 10; median = 3), 6-8 ventroexternal se- tae {n = 10; median = 6) and 9 or 10 dorsal setae {n = 10; median = 9). Telotarsus II with 3-5 ventrointernal setae {n — 10; median = 5), 4-6 ventroexternal setae {n ^ 10; median = 4) and 10 or 11 dorsal setae {n = 10; me- dian = 11). Telotarsus III with 10-13 ven- trointernal setae (« = 10; median = 12), 5-7 ventroexternal setae {n = 10; median =^7) and 12-15 dorsal setae {n = 10; median ^ 15). Telotarsus IV with 4 or 5 ventrointernal setae {n — 10; median = 5), 4 or 5 ventroexternal setae {n = 10; median = 5) and 5-7 dorsal setae {n = 10; median = 5). Fourth metasomal segment with 30-35 ventral setae {n = 5). Fifth metasomal segment with 9-13 ventro- lateral setae {n = 11; median = 12), and 9- 13 lateral setae {n = 5; median = 11). Length/ width ratio of the fifth metasomal segment 2- 2.26 {n = 11; mean — 2.15). Distribution. — Besides the type locality at Lomas de Penuelas, La Serena, this species has only been collected in other neighboring localities: Guanaqueras, 2, 10 and 20 km south of Coquimbo. All of these localities be- long to the Coquimbo Province, and are very close to the coast (Fig. 58). At this latitude, only a few kilometers inland this species is replaced by B. cekalovici. The author failed to collect this species at Pan de Azucar National Park and Caldera, both in Copiapo Province; where inhabits B, (L.) sciosciae (Ojanguren Affilastro 2003). Material examined.— CHILE: Coquimbo Province: Holotype male, La Serena, Lomas de Penuelas (29°54'S, 7ri5'W), 5 September 1968, Cekalovic (MZUC 528); Guanaqueras (30°11'60"S, 71°25'60"W), 9 January 1984, 1 6, Roig Alsina (ARA); 25 November 1992, 1 6, Roig Junent (lADIZA); 9 January 1984, 1 (3, Maury (MACN-Ar); 10 km S Coquimbo (30°4'S, 7r22%0"W), 2 November 1983, 1 juvenile, Maury (MACN-Ar); 20 km. S. Co- quimbo, 1 January, 1985, 13 juveniles, 8 S and 10 9, Plateick & Francke (AMNH); 2 km S Coquimbo, 1 January 1985, 2 S and 3 ju- veniles, Platnick & Francke (AMNH). Brachistosternus (Leptosternus) negrei Cekalovic 1975 Figs. 48-58 Brachistosternus {Leptosternus) negrei Cekalovic 1975: 69-72. Type materiaL- — Holotype male, CHILE, Talca Province, 22 miles N of Talca (35°17'S, 7r38'W) (MZUC 546, not examined). The holotype of this species is lost, but the author OJANGUREN AFFILASTRO—BRACHISTOSTERNUS IN CHILE 189 Figures 4H-51 .—Brachistosternus (Leptosternus) negrei: 48. Left hemispermatophore, ventral aspect; 49. Left hemispermatophore, dorsal aspect; 50. Left hemispermatophore, detail of the lobe region; 51. Fifth metasomal segment, male, dorsal aspect; 52. Fifth metasomal segment, ventral aspect; 53. Telson, m.ale, dorsal aspect; 54, Telson, female, lateral aspect; 55. Telson, male, lateral aspect; 56. Left pedipalpal chela, male, ventral aspect; 57. Left pedipalpal chela, female, ventral aspect. Scale bars = 1 mm. 190 THE JOURNAL OF ARACHNOLOGY was able to study one male specimen identi- fied by Cekalovic as B. negrei. Description. — Color: General color dark yellow with a dusky pattern. Carapace with a dark stripe from the lateral ocelli to the pos- tocular furrow; ocular tubercle black; anterior edge of the carapace with dark spots; the rest without pigmentation except for two postero- lateral dark spots. Tergites with two lateral spots, and a median clear stripe without pig- mentation. Sternites depigmented. Metasomal segments dorsally with two posterolateral dark spots and a median spot; segments I-IV ven- trally with two lateroventral stripes and two median stripes, in some specimens the median stripes can be absent; V with two lateroventral stripes and a median stripe, in some speci- mens the median stripe can be absent, but in very pigmented specimens there are three me- dian stripes. Telson faintly spotted on the ven- tral surface. Legs with some spots on femur and patella. Pedipalps: femur and patella with some spots on the retrolateral surface. Morphology: Measurements a of a male specimen (MACN-Ar) and female specimen (MACN-Ar) in Table 2. Prosoma: Chelicerae with two subdistal teeth in the movable finger; anterior edge of the carapace with a median bulge and six setae, two on each side and two in the middle; tegument densely granular in males, finely granular in females; anterior and posterior longitudinal sulcus, lateral sulcus and postocular furrow deeply marked; ocular tubercle medially situated on the carapace with a slight interocular sulcus, median ocelli one diameter apart. Sternum: Sternum type 2 (Soleglad & Fet 2003), much wider than long; apex width equal to posterior width; posterior emargination quite well developed, with con- vexed lateral lobes conspicuously separated. Mesosoma: Tergites I-VI smooth near the an- terior margin and finely granular near the pos- terior margin; VII smooth medially, the rest densely granular, with two posterolateral ca- rinae. Metasoma: segment I: ventral surface smooth, lateral surface with scattered granu- lation, dorsally smooth, dorsosubmedian, dor- solateral and median lateral carinae extend the entire length of the segment; segments II and III similar to segment I but less granular, with less well developed carinae and with four pairs of ventral setae; segment IV: dorsally smooth, lateral surfaces slightly granular, ven- trally smooth with a large number of scattered setae; segment V: ventral surface smooth near the front margin and irregularly granular in the second half; the ventrolateral carinae ex- tend throughout the entire length of the seg- ment, but there is not a ventromedian carina (Fig. 52); the ventral setae usually comprise 5 rows: 1 basal row of 3-5 setae, 1 subbasal row of 2-4 setae, and 3 posterior rows of 1 or 2 setae; dorsal and lateral surfaces finely gran- ular or smooth; in males the caudal glands oc- cupy 15-20% of the dorsal surface (Fig. 51). Telson: Sparsely granular; vesicle with round- ed ventral surface; aculeus slightly curved, of the same length as the vesicle (Figs. 54 & 55); the holotype of this species has a very con- spicuous depression on the ventral surface of the telson (Cekalovic 1975, fig. 9), but it was not present in any of the specimens studied. The telson gland is divided into two separated halves (Fig. 53), but it is absent in almost 80% of the specimens. Pedipalps: Trichobothrial pattern, neobothriotaxic major type C: femur with 3 trichobothria: \ d, \ i and 1 e\ patella with 3 ventral trichobothria, 2 dorsal tricho- bothria, 1 internal trichobothrium, and 13 ex- ternal trichobothria: 3 et, 1 est, 2 em, 2 esb and 5 eb\ chela with 27 trichobothria: 1 Est, 5 Et, 5 V, 1 Esb, 3 Eb, 1 Dt, 1 Db, 1 et, 1 est, I esb, 1 eb, 1 dt, 1 dst, 1 dsb, 1 db, 1 ib, 1 it, no intraspecific variation has been observed in these characters. Femur smooth, ventroin- ternal and dorsointernal carinae poorly devel- oped, patella scarcely granular and without ca- rinae; chela stout, with smooth tegument and a very developed ventroexternal carina (Figs. 56 & 57); in males the prolateral apophysis is well developed; movable finger with a central row of granules and 8-10 internal and external granules. Legs: Finely granular; telotarsi I and II with the inner ungue 5-10% shorter than the external. Hemispermatophore: Distal lam- ina thick and shorter than the basal portion (Figs. 48 & 49); cylindrical apophysis well developed, and longer than the laminar apoph- ysis; basal triangle very well developed formed by three or four crests (Fig. 50); in- ternal spines absent; basal spines well devel- oped; row of spines well developed; distal crest undulated. Variation, — Total length in males, 50-66 mm (n = 7; mean = 56.7), 55-68 mm in fe- males (n = 7; mean 61.9). Pectines with 32- 38 pectinal teeth in males (n = 9; median = 33), 30-33 in females (n = 10; median = 31). OJANGUREN AFFILASTRO^BRACHISTOSTERNUS IN CHILE 191 Length/width ratio of the fifth metasomal seg- ment L74-™2.00 in males and females (n = 14; mean = L87)e Leegth/height ratio of the pe- dipalpal chela 2.64-2„96 in males (w = 8; mean = 2.84), 2.96-3. 13 in females (« = 8; mean = 3.03). Telotarsus I with 1-4 veetroie- temal setae (n = 12; mediae = 2), 0 or 1 veetroextemal setae (« = 12; mediae = 0) and 6-9 dorsal setae {n = 12; median = 8). Te- iotarsus II with 4 or 5 veetroietemal setae (n = 12; mediae = 4), 1-3 veetroextemal setae (w = 12; mediae = 2) and 7 to 10 dorsal setae (n = 12; mediae = 8). Telotarsus III with 5 to 7 veetroietemal setae (n = 20; mediae = 6), 3-5 veetroextemal setae (n = 12; mediae = 4) aed 9-11 dorsal setae (ii = 20; mediae = 10). Telotarsus IV with 4-6 veetroietemal setae {n = 12; median = 5), 2-5 veetroexter- eal setae (n = 12; mediae = 4) and 5 or 6 dorsal setae (n = 12; mediae = 5). Fourth metasomal segment with 27-33 ventral setae (h = 8; mediae = 28). Fifth metasomal seg- ment with 8-10 ventrolateral setae (n = 20; mediae = 9); aed 8-10 lateral setae (n = 20; mediae = 8). Distribution*— Brflc/iiTtostemMJ (L.) ne~ grei is the southernmost species of the genus in Chile. It has been collected in southern Chile, in Maule aed Bio Bio provinces (Fig. 58). Material examined.— CHILE: Maule province: Curico, Los Quefies (35°10^S, 70°47'60"W), 4 9 aed 9 juveniles, 1 January 1984, Roig Alsina (ARA); 2 9,3 juveniles and 1 d, Maury (MACN-Ar); Vilches (35°36'S, 7ri2'W), 1 9, 7 January 1989, Maury (MACN-Ar): Curico, Las Tablas (34°58^60LS, 71°13'60"Wl, 2 9,3 d aed 2 juveniles, 10-15 Fetnuary 1985, Pena (AMNH); Maule, CuyaiTariqiiil (west Cauque- nes) (35°58'S, 72°2Cf60AV), 2 d, 1 9 aed 2 juveniles, 24-31 January 1981, Pena (AMNH); Toelemo, Talca (35°7^S, 72°20^60"W), 1 juvenile, 14-21 December 1984, Pena (AMNH); Linares, Bullileo (35°5rS, 7r35^60"W), 2 juveniles, 13 Janu- ary 1979, Pena (AMNH). Bio Bio Province: Nuble, Chilian (36°36'S, 72°7'W), 3 d aed 2 9 , January 1970, Pena (AMNH); Nuble, 8 km west San Fabian de Alico (36°32'60"S, 7r32'60"W), 1 d, 1 9 and 2 juveniles, 19 January 1985, Platnick & Fraecke (AMNH), Figure 58.— -Map with the distribution of the Chi- 50 Km. west San Carlos (35°58'S, lean species of the genus Brachistosternus. 192 THE JOURNAL OF ARACHNOLOGY 7U37'60"W), 1 (7, 26 December 1950, Ross & Michelbacher (MZUC). ACKNOWLEDGMENTS I am grateful to Arturo Roig Alsina, Camilo Mattoni, Lorenzo Prendini, Frantisek Kovafik and Sergio Roig Junent for loaning part of the specimens used in this paper. I am grateful to Jose A. Ochoa who provided me with some data about the Peruvian Brachistosternus . I am also grateful to Cristina Scioscia and Cris- tina Marinone for their help during the com- pletion of the manuscript. LITERATURE CITED Cekalovic, K.T 1970. Antecedentes nomenclatura- les de Brachistosternus castroi Mello-Leitao, 1940 (Scorpionida — Bothriuridae). Boletm de la Sociedad Biologica de Concepcion 41:163-171. Cekalovic, K.T. 1973. Nuevo caracter sexual secun- dario en los machos de Brachistosternus (Scor- piones, Bothriuridae). Boletm de la Sociedad Biologica de Concepcion 46:99-102. Cekalovic, K.T. 1974. Dos nuevas especies del ge- nero Brachistosternus (Scorpiones, Bothriuri- dae). Boletm de la Sociedad Biologica de Con- cepcion 47:247-257. Cekalovic, K.T. 1975. Brachistosternus (Leptoster- nus) negrei n. sp. de escorpion de Chile (Scor- piones, Bothriuridae). Brenesia 6:69-75. De la Serna de Esteban, C.J. 1977. Las glandulas tegumentarias del metasoma y vesicula de Ti- mogenes (Latigenes) mapuche Maury 1975 (Bothriuridae, Scorpionida). Neotropica 23(69): 1-6. Kraepelin, K. 1911. Neue Beitrage zur Systematik der Gliederspinnen. Mitteilungen aus dem Na- turhistorischen Museum (2, Beiheft zum Jahr- buch der Hamburgischen Wissenschaftlichen Anstalten, 1910) 28(2):59-107. Maury, E.A. 1974. Escorpiofauna chaquena. 1. La verdadera identidad de Brachistosternus {Mi- crosternus) ferrugineus (Thorell 1876) (Bothriu- ridae). Physis (Buenos Aires) C 33(86):73-84. Maury, E.A. 1975. Escorpiofauna Patagonica. 1. So- bre una nueva especie del genero Timogenes Si- mon 1880 (Bothriuridae). Physis (Buenos Aires) C 34(88):65-74. Maury, E.A. 1982. El genero Timogenes Simon 1880 (Scorpiones, Bothriuridae). Revista de la Sociedad Entomologica Argentina 41(l-4):23- 48. Mello-Leitao, C. de. 1941. Aracnidos de Maullm. Revista Chilena de Historia Natural 4:136-143. Ochoa, J.A. & L.E. Acosta. 2002. Two new Andean species of Brachistosternus Pocock (Scorpiones: Bothriuridae). Euscorpius 2:1-13. Ochoa, J.A. 2002. Nueva especie de Brachistoster- nus Pocock (Scorpiones: Bothriuridae) del sur del Peru. Revista Peruana de Biologia 9(2):55- 63. Ojanguren Affilastro, A. A. 2002a. Brachistosternus (Leptosternus) zambrunoi, una nueva especie del noroeste argentino (Scorpiones, Bothriuridae). Re vista Iberica de Aracnologia 5:33-38. Ojanguren Affilastro, A. A. 2002b. Brachistosternus galianoae (Scorpiones, Bothriuridae), una nueva especie de Bolivia. Revista del Museo Argentino de Ciencias Naturales 4(1):104-109. Ojanguren Affilastro, A. A. 2003. Nuevos aportes al conocimiento del genero Brachistosternus en Chile con la descripcion de dos nuevas especies (Scorpiones, Bothriuridae). Boletm de la Socie- dad de Biologia de Concepcion 73:37-46 Ojanguren Affilastro, A. A. & A.H. Roig Alsina. 200 1 . Brachistosternus angustimanus, una nueva especie del norte de la Patagonia, Argentina (Scorpiones, Bothriuridae). Physis (Buenos Ai- res) C, 58(134-135):15-22. Prendini, L. 2000. Phylogeny and classification of the superfamily Scorpionoidea Latrielle 1802 (Chelicerata, Scorpiones): An exemplar ap- proach. Cladistics 16:1-78. Roig Alsina, A.H. 1977. Una nueva especie de es- corpion andino en Mendoza, Republica Argen- tina. Physis (Buenos Aires) C, 37(93):255-259. Roig Alsina, A.H. & E.A. Maury. 1981. Conside- raciones sistematicas y ecologicas sobre Brachis- tosternus {Leptosternus) borellii Kraepelin 1911 (Scorpiones, Bothriuridae). Physis (Buenos Ai- res) C, 39(97): 1-9. Soleglad, M.E. & V. Fet. 2003. The scorpion ster- num: structure and phylogeny (Scorpiones: Ort- hosterni). Euscorpius 5:1-34. Stahnke, H.L. 1970. Scorpion nomenclature and mensuration. Entomological News 83:121-133. Vachon, M. (1974). Etude des caracteres utilises pour classer les families et les genres de scorpi- ons (Arachnides). 1. La trichobothriotaxie en Arachnologie. Sigles trichobothriaux et types de trichobothriotaxie chez les scorpions. Bulletin du Museum National dHistorie Naturelle, 3® ser. 140:857-958. Manuscript received 31 March 2003, revised 5 Jan- uary 2004. 2005. The Journal of Arachnology 33:193-195 SHORT COMMUNICATION PREDATION BY ARGYRODES TRIGONUM ON LINYPHIA TRIANGULARIS, AN INVASIVE SHEET^WEB WEAVER IN COASTAL MAINE Jeremy D. Houser: Neuroscience & Behavior Program, Tobin Hall, University of Massachusetts, Amherst, Massachusetts 01003 USA Daniel T. Jennings: USDA, Forest Service. Northeastern Research Station, 686 Government Road, Bradley, Maine 04411 USA Elizabeth M, Jakob: Psychology Department, Tobin Hall, University of Massachusetts, Amherst, Massachusetts 01003 USA ABSTRACT. A female Argyrodes trigonum (Theridiidae) was observed feeding on a female Lin- yphia triangularis (Linyphiidae), a recently established European immigrant in Maine. Multiple ob- servations of Argyrodes spiders inhabiting L. triangularis webs suggest that this invasive sheet-web weaver is not immune to web invasions, kleptoparasitism or predation by A. trigonum. The potential impacts of A. trigonum on the invasion dynamics of L. triangularis are unknown, but likely to be minimal. Keywords: Kleptoparasitism, araneophagy, exotic Members of the genus Argyrodes Simon 1864 (Theridiidae) are known for diverse and flexible foraging strategies. Although capable of spinning small tangle webs of their own, many species for- age more often as kleptoparasites, web-stealers or predators of other spider species (Cangialosi 1991, 1997). Argyrodes trigonum (Hentz 1850) is common in the eastern U.S. (Exline & Levi 1962), and is also found in Ontario (Levi & Ran- dolph 1975) and Quebec (Paquin et al. 2001). Cangialosi (1997) provides a thorough descrip- tion of the diverse and flexible foraging strategies of this species. The European Hammock spider, Linyphia trian- gularis Clerck 1757 (Linyphiidae), has recently be- come established in parts of coastal Maine (Jen- nings et al. 2002) and apparently is spreading inland. In some coastal habitats, such as those of Schoodic Peninsula in Acadia National Park, the invasion has become severe, with population den- sities of L. triangularis reaching 12 individuals/m^. In these high-density areas, native linyphiids, such as Neriene radiata (Walckenaer 1841) and Pityoh- yphantes costatus (Hentz 1850), are now scarce (Houser, Jakob, & Jennings, pers. obs.). During the summer of 2002, while studying the invasion at Acadia N.P., we noticed A. trigonum in some webs of L. triangularis. On 24 August 2002, we observed an adult female A. trigonum feeding on an adult female L. triangularis in the prey’s web. The predator-prey habitat was a roadside/coniferous forest-edge on the Schoodic Peninsula (Winter Har- bor, Maine). The L. triangularis was not extensively digested, suggesting that the capture by A. trigonum was recent. Several more A. trigonum were found nearby in the superstructure of L. triangularis webs. To the best of our knowledge, the earliest obser- vation of Argyrodes in the web of L. triangularis was on 28 August 1999, when D.TJ. collected a juvenile Argyrodes sp. from a female-occupied web of L. triangularis in Pittston, Kennebec County, Maine. During August and September of 2003, surveys of L. triangularis webs were conducted at four lo- cations in Maine to determine whether the occu- pation of L. triangularis webs by A. trigonum is a common occurrence or better described as a nov- elty. Surveys were conducted in habitat favorable to L. triangularis, primarily seedlings, saplings, shrubs and forbs. At two of the locations, the pro- portion of webs containing at least one A. trigonum was rather high: 1 1 out of 36, or 30.6% (Dixmont, Penobscot Co.), and 19 out of 35, or 54.3% (Gar- land, Penobscot Co.). At the other sites, however, the frequency of A. trigonum was low; none were found among 33 webs surveyed at Guilford, Pis- 193 194 THE JOURNAL OF ARACHNOLOGY cataquis Co., and only 1 was found among 1 1 webs at Milbridge, Washington County. Multiple A. tri- gonum (always 2 or 3) were found in 11 of the 115 (9.6%) webs surveyed, or 11 of the 31 (35.5%) webs containing at least one A. trigonum. Although not found in these surveys, higher levels of occu- pancy are possible. D.T.J. observed 5 or 6 Argyro- des juveniles co-inhabitieg a female L. triangularis web in Garland, Penobscot County. At two of our survey sites, the proportion of L. triangularis webs containing A. trigonum is com- parable to, if not higher than previously observed rates of A. trigonum in other linyphiid webs. Over- all, 21.0% of L. triangularis webs surveyed in 2003 contained A. trigonum. In a large study of the for- aging strategies of A. trigonum, Cangialosi (1997) recorded A. trigonum co-inhabiting 6.1% of N. ra- diata webs, 1.9% of P. costatus webs and 2.6% of Frontinella pyramitela (Walckenaer 1841) webs. Our observed proportions may be high relative to those reported in Cangialosi (1997) due to a variety of factors, including differences in sampling meth- od, date or location, and therefore should be inter- preted cautiously. Our observations support the already consider- able evidence that foraging behavior of A. trigonum is very flexible. Species of Argyrodes have been classified as either host specialists, which use a va- riety of behavioral techniques to exploit their hosts, or host generalists, which have a more limited be- havioral repertoire, but can take advantage of a large variety of hosts (Vollrath 1984; Whitehouse 1988). Cangialosi (1997) has argued that a host generalist would also benefit by having a variety of techniques at its disposal and presents A. trigonum as an example. The behavioral repertoire of A. tri- gonum is quite broad; in addition, hosts of A. tri- gonum include (in various geographic locations) linyphiids, agelenids, theridiids, and araneids (Larcher & Wise 1985; Cangialosi 1997). The abil- ity of A. trigonum to exploit an introduced exotic species is further evidence that it is a host gener- alist, and that its foraging success is not, at least at present, likely to be driven by co-evolution with any particular host. The possible effects of A. trigonum on the inva- sion of L. triangularis are unclear. Because A. tri- gonum makes use of both L. triangularis and native host webs, it could mitigate or exacerbate the ef- fects of the invader on native populations. It would be useful to know the relative preference, if any, that A. trigonum has for native linyphiids vs. the invader. Host- web structure, particularly the amount of barrier silk, affects selection and occupancy po- tentials of A. trigonum (Cangialosi 1997). Superfi- cially, the semi-dome shaped webs of L. triangu- laris are more similar to those of N. radiata and P. costatus than the bowl and doily webs of F. pyr- amitela. At the Schoodic study site, N. radiata and P. costatus appear to have declined more dramati- cally than F. pyramitela. However, in New Hamp- shire, Cangialosi (1997) found that A. trigonum uses N. radiata as hosts more often than either F. pyramitela or P. costatus. Comparable host-prefer- ence data including L. triangularis in addition to native hosts are needed to better evaluate the im- pacts, if any, of A, trigonum on this invasion. Be- cause of its host-generalist behavior, we suspect that A. trigonum has (and will have) minimal regulatory impacts on populations of L. triangularis in Maine. Instead, assemblages of natural enemies (e.g., par- asites, parasitoids, predators, and pathogens) may be needed for control or containment of this inva- sive spider. The impetus for this note comes from the sharp eye of Adam Porter, who made the initial discovery and observation of the predation encounter on 24 August 2002. The 2003 surveys were conducted with the much appreciated assistance of Nancy Jen- nings and Frank Graham, Jr. We are grateful to Da- vid Manski, Chief Biologist, Acadia National Park, for issuance of collecting permits, and to Park Bi- ologist Bruce Connery for logistical support. Voucher specimens are deposited in the park col- lection of the Acadia National Park Research Cen- ter, Bar Harbor, Maine. LITERATURE CITED Cangialosi, K.R. 1991. Attack strategies of a spi- der kleptoparasites: effects of prey availability and host colony size. Animal Behaviour 41: 639-647. Cangialosi, K.R. 1997. Foraging versatility and the influence of host availability in Argyrodes tri- gonum (Araneae, Theridiidae). Journal of Arach- nology 25:182-193. Exline, H. & H.W. Levi. 1962. American spiders of the Argyrodes (Araneae, Theridiidae). Bul- letin of the Museum of Comparative Zoology 127:75-204. Jennings, D.T., K.M. Catley & F. Graham, Jr. 2002. Linyphia triangularis, a Palearctic spider (Ara- neae: Linyphiidae) new to North America. Jour- nal of Arachnology 30:455-460. Larcher, S.F. & D.H. Wise. 1985. Experimental studies of the interactions between a web-invad- ing spider and two host species. Journal of Ar- achnology 13:43-59. Levi, H.W. & D.E. Randolph. 1975. A key and checklist of American spiders of the family Ther- idiidae north of Mexico (Araneae). Journal of Arachnology 3:31-51. Paquin, R, N. Duperre ,& R. Hutchinson. 2001. Liste revisee des Araignees (Araneae) du Que- bec. Pp. 5-87. In Contributions a la connaissance des Araignees (Araneae) d’ Amerique du Nord. (P. Paquin & D.J. Buckle, eds.). Fabreries, Sup- plement 10. HOUSER ET AL.— PREDATION BY ARGYRODES 195 Vollrath, F. 1984. Kleptobiotic interactions in in- vertebrates. Pp 61-94. In Producers and scroung- ers: Strategies of exploitation and parasitism. (C.J. Barnard, ed.). Grom Helm, London & Syd- ney. Whitehouse, M.E.A. 1988. Factors influencing specificity and choice of host in Argyrodes an- tipodiana (Araneae, Theridiidae). Journal of Ar- achnology 16:349-355. Manuscript received 28 February 2003, revised 8 December 2003. INSTRUCTIONS TO AUTHORS (revised October 2003) General: Manuscripts are accepted in English only. Authors whose primary language is not English may consult the editors for assistance in obtaining help with manuscript preparation. All manuscripts should be prepared in general accordance with the current edition of the Council of Biological Editors Style Manual unless instructed otherwise below. Authors are advised to consult a recent issue of the Journal of Arachnology for additional points of style. Manuscripts longer than three printed journal pages should be prepared as Feature Articles, shorter papers as Short Communications. One invited Review Article per year will be solicited by the editors and published in the third issue at the discretion of the editors. Suggestions for review articles may be sent to the Managing Editor. Submission: Send one electronic version of the entire manu- script (in PDF or Microsoft Word format) or send four identi- cal copies of the typed material together with copies of illus- trations to the Managing Editor of the Journal of Arachnology. Paula E. Cushing, Managing Editor, Denver Museum of Nature and Science, Zoology Department, 2001 Colorado Blvd., Denver, CO 80205-5798 USA [Telephone: (303) 370- 6442; FAX: (303) 331-6492; E-mail: PCushing@dmns.org or PECushing@juno.com]. The Managing Editor will forward your manuscript to one of the Subject Editors for the review process. You will receive correspondence acknowledging the receipt of your manuscript from the Managing Editor, with the manuscript number of your manuscript. Please use this number in all correspondence regarding your manuscript. Correspondence relating to manu- scripts should be directed to the appropriate Subject Editor. After the manuscript has been accepted, the author will be asked to submit the manuscript on a PC computer disc in a widely-used word processing program. The file also should be saved as a text file. Indicate clearly on the computer disc the word processing program used. Voucher Specimens: Voucher specimens of species used in scientific research should be deposited in a recognized scien- tific institution. All type material must be deposited in a rec- ognized collection/institution. FEATURE ARTICLES Title page. — The title page will include the complete name, address, and telephone number of the author with whom proofs and correspondence should be exchanged, a FAX num- ber and electronic mail address if available, the title in capital letters, and each author’s name and address, and the running head (see below). Abstract. — The heading in bold and capital letters should be placed at the the beginning of the first paragraph set off by a period. A second abstract, in a language pertinent to the nationality of the author(s) or geographic region(s) empha- sized, may be included. Keywords. — Give 3-5 appropriate keywords following the abstract. Text. — Double-space text, tables, legends, etc. throughout. Three levels of heads are used. • The first level (METHODS, RESULTS, etc.) is typed in capitals and on a separate line. • The second level is bold, begins a paragraph with an indent and is separated from the text by a period and a dash. • The third level may or may not begin a paragraph but is italicized and separated from the text by a colon. Use only the metric system unless quoting text or referencing collection data. All decimal fractions are indicated by the peri- od (e.g., -0.123). Citation of references in the text: Cite only papers already published or in press. Include within parentheses the surname of the author followed by the date of publication. A comma separates multiple citations by the same author(s) and a semi- colon separates citations by different authors, e.g., (Smith 1970), (Jones 1988; Smith 1993), (Smith 1986, 1987; Smith & Jones 1989; Jones et al. 1990). Include a letter of permission from any person who is cited as providing unpublished data in the form of a personal communication. Citation of taxa in text: Please include the complete taxonom- ic citation for each arachnid taxon when it appears first in the paper. For Araneae, this taxonomic information can be found on-line at http://research.amnh.org/entomology/spiders/cata- log81-87/INTR02.html. For example, Araneus diadematus Clerck 1757. Literature cited section. — Use the following style and include the full unabbreviated journal title. Opell, B.D. 2002. How spider anatomy and thread configura- tion shape the stickiness of cribellar prey capture threads. Journal of Arachnology 30:10-19. Krafft, B. 1982. The significance and complexity of communi- cation in spiders. Pp. 15-66. In Spider Communications: Mechanisms and Ecological Significance. (P.N. Witt & J.S. Rovner, eds.). Princeton University Press, Princeton, New Jersey. 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Assemble manuscript for mailing. — Assemble the separate sections or pages in the following sequence; title page, abstract, text, footnotes, tables with legends, figure legends, figures. Page charges, proofs and reprints. — Page charges are vol- untary, but non-members of AAS are strongly encouraged to pay in full or in part for their article ($75/journal page). The author will be charged for changes made in the proof pages. Reprints are available only from the Allen Press and should be ordered when the author receives the proof pages. Allen Press will not accept reprint orders after the paper is published. The Journal of Arachnology also is publishea by BioOne. Therefore, you can download the PDF version of your article from the BioOne site or the AAS site if you are a member of AAS or if your institute is a member of BioOne. PDF’s of arti- cles older than one year will be freely available from the AAS website. SHORT COMMUNICATIONS Short Communications are usually limited in length to three journal pages, including tables and figures. They will be print- ed in a smaller (10 point) typeface. The format for these is less constrained than for feature articles: the text must still have a logical flow, but formal headings are omitted and other deviations from standard article format can be permitted when warranted by the material being covered. Short Communication Predation by Argyrodes trigonum on Linyphia triangularis, an invasive sheet-web weaver in coastal Maine by Jeremy D. Houser, Daniel T. Jennings & Elizabeth M. Jakob 193 USERNAME: ala-on05 PASSWORD: spiderOS CONTENTS Volume 33 The Journal of Arachnology Featured Articles Number 1 Behavior of web-invading spiders Argyrodes argentatus (Theridiidae) in Argiope appensa (Araneidae) host webs in Guam by Alexander M. Kerr 1 Scytodes vs. Schizocosa: predatory techniques and their morphological correlates by Robert B. Suter & Gail E. Stratton 7 Mating frequency in Schizocosa ocreata (Hentz) wolf spiders: evidence for a mating system with female monandry and male polygyny by Stephanie Norton & George W. Uetz 16 Day vs. night sampling for spiders in grape vineyards by Michael J. Costello & Kent M. Daane 25 Determining a combined sampling procedure for a reliable estimation of Araneidae and Thomisidae assemblages (Arachnida, Araneae) by Alberto Jimenez- Valverde & Jorge M. Lobo 33 Surface ultrastructure of labial and maxillary cuspules in eight species of Theraphosidae (Araneae) by Fernando Perez-Miles & Laura Montes de Oca 43 Natural history and karyotype of some ant-eating zodariid spiders (Araneae, Zodariidae) from Israel by Stano Pekar, Jif i Krai & Yael Lubin 50 A new species of Apostenus from California, with notes on the genus (Araneae, Liocranidae) by Darrell Ubick & Richard S. Vetter 63 The effect of perceived predation risk on male courtship and copulatory behavior in the wolf spider Pardosa milvina (Araneae, Lycosidae) by Abraham R. Taylor, Matthew H. Persons & Ann L. Rypstra 76 Web orientation, stabilimentum structure and predatory behavior of Argiope florida Chamberlin & Ivie 1944 (Araneae, Araneidae, Argiopinae) by Michael J. Justice, Teresa C. Justice & Regina L. Vesci 82 First fossil Filistatidae: a new species of Misionella in Miocene amber from the Dominican Republic by David Penney 93 Diversity among ground-dwelling spider assemblages: habitat generalists and specialists by Rachael E. Mallis & Lawrence E. Hurd 101 Seasonal habitat shift in an intertidal wolf spider: proximal cues associated with migration and substrate preference by Johanna M. Kraus & Douglass H. Morse 110 Spatial distribution and microhabitat preference of Psecas chapoda (Peckham & Peckham) (Araneae, Salticidae) by Gustavo Quevedo Romero & Joao Vasconellos-Neto 124 A review of the Tasmanian species of Pararchaeidae and Holarchaeidae (Arachnida, Araneae) by M.G. Rix 135 Relationship between escape speed and flight distance in a wolf spider, Hogna carolinensis (Walckenaer 1805) by Matthew K. Nelson & Daniel R. Formanowicz Jr. 153 Seismic communication during courtship in two burrowing tarantula spiders: an experimental study on Eupalaestrus weijenberghi and Acanthoscurria suina by Veronica Quirici & Fernando G. Costa .. 159 Mating and self-burying behavior of Homalonychus theologus Chamberlin (Araneae, Homalonychidae) in Baja California Sur by Karina Dominguez & Maria-Luisa Jimenez 167 Notes on the genus Brachistosternus (Scorpiones, Bothriuridae) in Chile, with the description of two new species by Andres A. Ojanguren Affilastro 175 Contents continued on inside back cover