TAXONOMY, ETHOLOGY, AND ECOLOGY OF Phidippus (ARANEAE: SALTICIDAE) IN EASTERN NORTH AMERICA BY GLAVIS BERNARD EDWARDS, JR. A DISSERTATION PRESENTED TO THE GRADUATE COUNCIL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 1980 ACKNOWLEDGMENTS In a work of this scope, it is impossible to individually thank every person who has contributed to its completion, but I do sincerely thank every one of you. I would like to single out my committee members: Dr. W. H. Whitcomb, who tolerated the development of lines of research astray from his own; Dr. Jonathan Reiskind, for his positive reinforcement and assistance; and Dr. T. J. Walker, for demanding excellence. Various types of technical assistance were provided by Mrs. Thelma C. Carlysle, Mr. P. M. Choate, Dr. Jonathan Reiskind, and Dr. Robert Paul. Special thanks are due Mrs. Katrina Vaughanfor typing the manuscript and going to special effort to help make deadlines. For identifications of prey and enemy records I thank Mrs. E. C. Beck, and Drs. W. F. Buren, R. J. Gagne, E. E. Grissell, D. H. Habeck, F. W. Harmston, L. A. Hetrick, K. W. Knopf, P. M. Marsh, F. W. Mead, E. L. Mock- ford, J. C. E. Nickerson, C. W. Sabrosky, R. I. Sailer, L. A. Stange, T. J. Walker, H. V. Weems, Jr., and R. E. Woodruff. Thanks are due the technical staff of the Bureau of Entomology, Division of Plant Industry, for their assistance and encouragement. This list would not be complete without mentioning the dear friends who have put up with me and helped in so many ways: Ron and Peggy Williams, Earl Williams, Allen Mosler, Fred and Peggy Hansen, Anzle Mead, Wanda Weintraub, Ruth Schaeffer, Mary Warren; my parents, Glavis and Margaret Edwards, for their patient and continued support; and most of all, my wife, Sue, who has managed to keep both of us going. TABLE OF CONTENTS ACKNOWLEDGMENTS ABSTRACT CHAPTER GENERAL INTRODUCTION TAXONOMY OF EASTERN Phidippus Introduction Key to Adult Male Phidippus of the Eastern U. S. Key to Adult Female Phidippus of the Eastern U. S. Subgenus Anipalpus, new subgenus Subgenus Phidippus IMMATURE STAGES OF Phidippus SPECIES HYBRIDIZATION IN Phidippus SPECIES Introduction Methods Laboratory Results Ecological Factors Affecting Hybridization Species Relationships, Geologic History, and Speciation Hybridizations Between Other Species THE COURTSHIPS OF EASTERN Phidippus Introduction Methods, Materials, and Terminology Results Discussion SOUND PRODUCTION BY COURTING MALES OF Phidippus mystaceus (Araneae: Salticidae) Introduction Experimental Procedure Results Discussion Conclusion Additional Observations PAGE ii v 1 4 4 18 20 22 27 98 102 102 103 103 108 111 115 117 117 117 121 133 135 135 135 136 139 144 145 CHAPTER 7 10 DIFFERENTIAL ATTACK RESPONSES BY Phidippus SPP. (ARANEAE: SALTICIDAE) TO CONTRASTING PREY TYPES Introduction Materials and Methods Results Discussion INSTINCT AND CONDITIONED LEARNING AS FACTORS IN THE PREY-CAPTURE BEHAVIOR OF NAIVE SPIDERLINGS (ARANEAE: SALTICIDAE) Introduction Methods and Materials Results and Discussion MIMICRY IN Phidippus Introduction Methods Results and Discussion ECOLOGY OF Phidippus SPECIES Introduction Methods Background Results and Discussion Resource Analysis Species Summaries 11 SYNTHESIS APPENDICES A GLOSSARY B PLACE NAMES C LAKE EDGE HABITATS D OTHER STUDY HABITATS E PREY OF MUD DAUBERS F NEW RECORDS OF PREY CAPTI SALT IC IDS OTHER THAN Phidippus Attus otiosus HENTZ, 1846, (ARANEAE: SALTICIDAE): PROPOSED PRESERVATION UNDER THE PLENARY POWERS PAGE 151 151 151 153 157 161 161 161 164 177 177 177 178 186 186 190 195 209 233 243 304 308 311 312 318 326 327 331 REFERENCES CITED BIOGRAPHICAL SKETCH 334 354 iv Abstract of Dissertation Presented to the Graduate Council of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy TAXONOMY, ETHOLOGY, AND ECOLOGY OF Phidippus (ARANEAE: SALTICIDAE) IN EASTERN NORTH AMERICA By Glavis Bernard Edwards, Jr. December, 1980 Chairman: Dr. Willard H. Whitcomb Major Department: Entomology and Nematology The 16 species of Phidippus occurring in the eastern United States are redescribed and illustrated together for the first time. Thirteen of these species occur in Florida. First instars are briefly described for most of these species for the first time. Both field and laboratory hybrids of P. regius x P. otiosus and F backcrosses of hybrid females to males of both parent species are des- cribed. Hybrid males were sterile; hybrid females backcrossed to males of either parent species were significantly less fecund than either parent species. The two species are considered to be advanced sibling species which lack only the late stages of pre- and/or post zygotic isolating mechanisms (behavior and/or complete hybrid sterility) to completely separate each species. The courtship behavior of 13 of the 16 eastern species, as well as the P. otiosus x P. regius hybrid, are described, 8 for the first time. A new method of communication for salticids, sound (made by a stridula- tory mechanism on each palpus) , is reported for P_. mystaceus. A combined visual-vibratory display is reported for P_. whitmani. Differences in prey-capture behavior are noted for adult Phidippus prof erred house flies and cabbage looper larvae. Cabbage looper larvae were captured by all species tested from an average distance of 5 - 6 mm, whereas average capture distances of house flies averaged 2-3.5 times this distance, depending upon the species of Phidippus. Prey-capture behavior was noticeably different depending upon the type of prey ap- proached, with a much more stealthy approach used against house flies. Naive spiderlings, in similar prey-capture tests involving other types of prey, were shown to rely at least in part on experience after initial encounters with various prey types. In tests with small ants as the inten- ded prey, the spiderlings initially attacked the ants, but were driven away by the ants. Spiderlings thereafter avoided ants for up to 4 days (the longest test), demonstrating learning of the basic trial-and-error type. That adult Phidippus generally avoid ants both in the field and laboratory is evidence that this type of learning is long-lasting. Preliminary investigations with 2 lizard species indicated that P_. apacheanus was a generalized Batesian mimic of red and black species of the velvet ant genus Dasymutilla (Hymenoptera: Mutillidae) . Nearly all instars of P_. apacheanus exhibited the red and black coloration; mimicry in adult males was most complete, as it included behavioral elements as well as color pattern similarity. Adult males of P_. cardinalis are similar in color to males of P. apacheanus, and can probably also be considered Batesian mimics of Dasymutilla, although other possibilities are examined. Most species were found to occur in several habitats, but dominant in only one, or never dominant. In habitats with more than one domi- nant, the phenology of the dominants was different. Some microhabitat separation was exhibited, both between species and between immatures and adults of the same species. Prey included members of the orders Dip- tera, Hymenoptera, Lepidoptera, Coleoptera, Odonata, Orthoptera, Hemiptera, Homoptera and Araneae. Prey size was significantly correla- ted with spider size. Enemies included pompilid and sphecid wasps, acrocerid and mermithid parasitoids, mantispid and dipteran egg predators, hymenopteran egg parasites, predaceous fungi, frogs, lizards, birds, and other spiders. Mean reproductive rates correlated well with mean length of each species; _P. clarus was an exception. Niche breadth varied widely among species, and overall niche overlap was low among species. Temperature in peninsular Florida probably is less critical than in most temperate areas; however, at least one activity, hunting, ceased at temperatures below 15° C. vii CHAPTER 1 GENERAL INTRODUCTION The present research can be best described as a multi-discipline study of the biosystematics of members of the salticid genus Phidippus in eastern North America, with emphasis on the species occurring in Florida. It is a natural extension and expansion of previous research (on the biology of P_. regius; Edwards, 1975) and an offshoot of other research (e.g., Whitcomb et al., 1963) implicating species of Phidippus and other salticids, as well as many other spiders, as important preda- tors in agro-ecosystems. The final organization is in reverse order from how the research was initially conceived, from a study of the ecology of each species to a comparison of certain behaviors to the redescriptions and phylogenetic relationships of the species. The taxonomic section is presented first to introduce and describe the species. It is followed by ethological research, some of which (courtship behavior) is directly related to the phylogeny. The ecology section describes the phenology and both faunal and floral associations of the species. Finally, all three sections are interwoven to form an overview of the genus. Adult Phidippus are medium to large spiders (Figure 1-1) and often brightly colored. Generally they are docile spiders, which will attempt to hide or flee if threatened by the proximity of a human. Some can be easily handled; the specific epithet of one species (audax, meaning bold or audacious) was used to describe the manner of one of these spiders which would hop onto a person's hand if the hand was placed down carefully near the spider. That they can and will bite if carelessly handled is demonstrated by numerous reports in California of people bitten by P_. formosus (=P. johnsoni). Elsewhere in the U. S., other species occasionally have been reported to bite humans, to which I can personally attest in the case of P. regius. The pain of the bite is light to moderate and of short duration, usually not lasting more than a few minutes. At least three species occur commonly about human dwellings: P. johnsoni along the west coast, P. audax throughout the eastern and central states, and P. regius in Florida. Further introduction is best placed with the subject to which it appertains. Figure 1-1. Phldippus habitus (dorsal view) CHAPTER 2 TAXONOMY OF ADULT Phidippus Introduction The genus Phidippus has not been revised since the Peckhams ' pioneering work (1901, 1909). Their 1909 paper, "Revision of the Atti- dae of North America," still stands as the definitive work on nearctic salticids, although numerous species and a few genera have been added subsequently to the faunal list. Little further work has been done on Phidippus other than new species descriptions, except for Bryant (1942), who attempted to redescribe several species; unfortunately, her paper contained several errors, and the single new species she described is placed into synonymy herein. The type species of Phidippus is Salticus variegatus Lucas = Phidippus audax (Hentz) . Genus Phidippus C. L. Koch, 1846 Attus Walckenaer (in part), 1805 Phidippus C. L. Koch, 1846 Phiale C. L. Koch (in part), 1846 Cyrtonota Simon (in part) , 1864 Phidippia Simon, 1864 Megatimus Thorell, 1891 Dendryphantes (C. L. Koch, 1837) (in part), Peckham & Peckham, 1896 Synonymical listings indicate only the first use of a name prior to 1940. For complete listings before 1940 see Bonnet (1958). I have attemp- ted to list all subsequent significant citations for species including those of Roewer (1954) , which are more recent than those of Bonnet even 4 though published earlier. For explanation of morphological structures and abbreviations, see Appendix A (Glossary). For explanation of name and place abbreviations, see Appendix B. Medium to mostly large jumping spiders, 3.3 mm (small males) to 22 mm (large, gravid females). Integument of prosoma and prosomal appen- dages sclerotized, reddish brown; ocular quadrangle darker; venter often yellowish brown. Integumental surface highly reflective. Carapace width .75 to .90 length, height .50 (females) to .67 (males) width. Ocular quadrangle .40 to .50 carapace length, more coarsely reticulated than surrounding integument. PME .30 to .40 distance from ALE to PLE (nearer ALE). PLE row .75 to .90 carapace width. ALE row .56 to .85 carapace width. Clypeus radius or less of AME. Central short, longitudinal furrow within transverse depression just behind PLE row. Thoracic slope .33 carapace length, approximately 45°; cephalic area anterior to PLE slanted slightly downward. Distinct setal tufts present in ocular area, usually 2 or 4 (0-6) situated one laterally below and lightly anterior to each PME, one half- way between each PME and PLE dorsally (always present in females) , and/or a pair in the middle of the ocular quadrangle. Setal tufts are present in all free-living individuals of the genus except 1st instars, and, in several species, adult males. Scale-like setae ("scales") usually present on palpi, legs, clypeus (in females), and on various dorsal markings; sometimes covering most of dorsal surface and part of abdominal venter. Black vestitural setae more or less covering all of body surface, reduced on chelicerae and sometimes in ocular quadrangle. Elongate black setae also covering body to lesser extent, concentrated on lateral cephalic area and on anterior and lateral edges of ocular quadrangle. Chelicerae rugose, robust, slightly porrect especially in males, and iridescent, usually gold-green-blue. Cheliceral promargin with 2 contiguous teeth (partially fused in male), retromargin with 1 tooth. Endites convergent in females, divergent and with anterolateral cusp in males. Labium longer than wide, 1/2 length of endites. Sternum slight- ly narrower to as wide as labium anteriorly, narrowed sharply posteriorly, 4th coxae nearly touching. Abdomen ovoid, with dorsal pattern which varies from species to species, several variations on the presumed ancestral central dark stripe overlain by 4 pairs of light spots. In many species the 2nd spot pair is fused to form a central triangle. Usually with 2 pair of lateral bands and a basal (anterior) band, which may be fused together. The whole dorsum may be overlaid with red or gray scales which obscure the pattern, especially in males. Venter with 4 rows of dots between epi- gastric furrow and spinnerets; usually with light stripes bounding a dark central stripe. The legs have a structure also occurring in Dendryphantes sensu latu that I have seen only in these 2 genera and in another dendryphan- tine genus, Rhetenor. On the dorsal surface of the femur, patella, and tibia are 2 longitudinal, subparallel depressions in the integument, most pronounced on the patella. These depressions are very slight in depth, but readily recognizable by the dense micro-reticulation of the integument within the depression, much denser and finer than on the surrounding integument. These depressions are also devoid of setae or scales. The depressions run nearly the entire length of each segment, except for the prolateral femoral one which is reduced to half the length of the femur. It is tempting to speculate a sensory function for this structure, but there appears to be no difference in sclerotization from the surrounding integument, nor do there appear to be any glandular structures associated with these depressions. They are even more reflec- tive than the surrounding integument, and may function during inter- individual recognition (occurs in both sexes) somewhat like the chelicerae, which are much more coarsely reticulate over a larger surface. Another possible, passive, use is that these small reflective spots may contribute to an overall camouflage effect; they are more prominent on females which do not have as extensive leg fringes which tend to hide these structures. Leg formula I, IV, II, III for males; IV, I, II, III (or IV, I, III, II) for females. First pair of legs half again as stout and 2nd legs slightly stouter than 3rd and 4th pairs. All legs fringed at least ventrally, especially the first pair, much more developed in males. Larger males may have proportionately larger and longer forelegs than smaller conspecific males; this appears to be an allometric growth phenomenon. Leg I of males usually fringed as follows: femur with black fringes dorsally, and on pro- and retrolateral edges of venter (area between ventral fringes glabrous and reflective distally) ; patella with white brush and tibia with black brush covering pro-, retrolateral, and ventral surfaces; metatarsus and tarsus with similar but reduced brushes, white on proximal half and black on distal half of each segment. White scales on prolateral surface on segments with white brushes (patella and proximal halves of metatarsus and tarsus). Palpal femora have 1-3 dorsal macrosetae each. Leg macrosetation is restricted to the femur, patella, tibia, and metatarsus of each leg. Based on the spacing of macrosetae and the arrangement of macrosetae in other genera, the ancestral leg macrosetation is presumed to have been arranged in 4 sets on the femur and tibia and 3 sets on the patella and metatarsus. Otherwise the system of macroseta identification is similar to that used by Platnick & Shadab (1975) . Ventral macrosetae are usually paired; dorsal and lateral macrosetae are single, with the dorsal macro- setae along the midline of the segment. Lateral macrosetae are sometimes marginal but are usually not identified as such unless confusion with another seta could occur. Marginal macrosetae, when necessary, are identified by the identification letters of both adjacent surfaces (e.g., DP = dorsoprolateral) . If only one of a ventral pair is present, it is indicated as either pro- or retrolateral when distinguishable. Typical macrosetation is as follows: femur I*D 0-1-1-1, DP 0-0-0-2, tibia I*V 0-2-2-2, metatarsus I*V 0-2-2; femur II D*0- 1-1-1, DP* 0-0-0-2, DR 0-0-0-1, tibia II V 0-1R-2-2, P*0-0-l-0, metatarsus II* V 0-2-2; femur III*D 0-1-1-1, DP 0-0-0-2, DR 0-0-0-1, patella III R 0-1-0, tibia III V 0-1P-0-2*, P 0-0-1-0, R 0-l-l*-0, metatarsus III V 0-2-2*, P 0-1-2*, R 0-1-2*, femur IV* D 0-1-1-1, DP 0-0-0-1, DR 0-0-0-1, patella IV R 0-1-0, tibia IV V 0-1P-0-2*, P 0-0-1-0, R 0-l-l*-0, metatarsus IV V 0-2-2*, P 0-1-2*, R 0-1-2*. Segments or individual sets of macrosetae marked with an asterisk (*) are invariable or nearly so. Those not so marked are more variable. Consistent differences from the above formula are noted with species descriptions. Larger specimens tend to have a fuller complement of macrosetae. Scale-like setae, if present on legs, much denser on females and encompassing all but ventral surface of legs. Scales on legs of males predominantly on but not limited to legs I. Scales on palpi similar in females to leg scales, in males situated differently, apparently situated for display as it has evolved for each species. Females have a well-sclerotized epigynum usually with well- developed anterolateral rims forming guides or shields over spermathecal duct openings, the latter usually bending away from each other. Males have palpi each with a simple embolus; the tegulum has an anterior rugose area (which I term the protegulum) associated with the embolus, and an external loop of the sperm duct; and usually a simple lateral (ectal) tibial apophysis. The genus is most readily recognized by the possession of a dorsal pair of setal tufts, iridescent chelicerae, conspicuous leg fringes, and generally by their large size and dense vestitural setal covering. Phidippus is a typical genus of the Salticidae: Dendryphantinae and is most closely related to Dendryphantes sensu latu (i.e., including Metaphidippus and Eris) . Figures 2-1 and 2-2 illustrate the body parts used in the descrip- tions. Body measurements and ratios for the species under consideration in this study are given in Table 2-1. Characters on which hypothetical phylogeny are based are given in Table 2-2, and the resulting phylogeny is illustrated in Figure 2-3. The following species included in Phidippus by Chamberlin and Ivie (1944), based on the descriptions by Walckenaer (1837) of Abbot's (1792) unpublished illustrations, are considered to be nomena dubia; their descriptions give little or no clue as to their specific identity, and the types are illustrations which contribute little to their identifi- cation. Also included here are species left in the genus Attus by Chamberlin & Ivie (ibid), but which are probably juvenile Phidippus; these latter are marked with an asterisk. 10 Table 2-1. Measurements and ratios of body parts of species of Phidippus occurring in the eastern U. S. See Glossary (Appendix A) for explanation of abbreviations. Ranges represent smallest (on left) and largest specimens examined. Phidippus ALE-PME species, sex ALE-PLE ALE CW PLE CW CW apacheanus cf .33-. 31 .67- .65 .84- .81 2.8-3.9 9 .32-. 31 .63- .61 .84- .83 4.4-4.5 audax o* .35-. 32 .71- .59 .85- .75 2.9-5.5 9 .35-. 30 .71- .56 .89- .78 3.4-5.4 borealis cf .40-. 35 .66- .64 .77- .76 3.1-3.5 9 .36-. 38 .63- .62 .78- .77 3.7-3.9 cardinalis d* .36-. 31 .72- .64 .87- .82 3.0-3.9 9 .36-. 32 .68- .62 .86- .85 3.6-4.2 clarus cf .42-. 39 .79- .69 .87- .84 2.5-3.9 9 .40-. 35 .73- .69 .83- .80 3.1-5.0 insignarius d 9 .42-.39 .43-. 40 .74- .83- .69 .69 .82- .97- .83 .88 2.3-3.1 2.3-3.3 mystaceus cf .43-. 41 .79- .71 .86- .84 2.7-3.4 9 .39-. 36 .76- .71 .90- .89 3.4-4.2 otiosus cf 9 .39". 32 .41-. 30 .69- .73- .58 .54 83- 88- .74 .71 3.9-5.6 3.5-7.0 pius cf .42-. 37 .73- .70 87- .84 2.6-3.2 9 .39". 38 .67- .68 84- .86 2.8-3.1 princeps cf .39". 39 .75- .79 87- .89 2.5-2.9 9 .41-. 37 .68- .70 83- .86 2.9-3.6 pulcherrimus cf .39 -.40 .82- .72 89- .86 2.6-3.5 9 .43-.36 .84- .70 89- .87 3.1-3.9 purpuratus cf .36-.33 .70- .63 89- .80 3.3-4.1 9 • 34-.35 .72- .62 90- .81 3.5-4.3 putnami cf .42-.42 .86- .76 94- .89 2.5-3.4 9 .43-.42 .82- .76 95- .91 2.9-3.8 regius cf 9 .37-.31 .32-.36 .64- .63- 49 55 76- 80- 63 72 4.2-7.5 4.9-6.7 whitmani cf .42 -.39 .77- 71 85- 85 2.7-3.4 9 .42-. 40 .78- 74 89- 85 2.5-3.5 xerus cf 9 .37-.34 .38_.36 .75- .76-. 72 70 89- 90-. 87 90 2.6-3.2 2.8-3.6 Table 2-1 - extended. 11 cw CL CL 74- .78 3.8-5.0 76- .77 5.7-5.9 81- .87 3.6-6.3 77- .78 4.5-7.0 80- .76 3.9-4.6 77- .80 4.9-4.9 78- .83 3.8-4.7 79- .r83 4.5-5.1 79- .82 3.2-4.8 81- .85 3.8-5.9 83- .79 2.8-3.9 72- .81 3.1-4.0 81- .84 3.3-4.0 79- .81 4.3-5.2 82- .88 4.8-6.4 81- .93 4.3-7.8 76- .78 3.5-4.1 81- .74 3.5-4.2 79- 70 3.2-4.1 84- .78 3.4-4.7 77- .77 3.3-4.5 76- .84 4.1-4.6 76- 87 4.4-4.7 81- .80 4.3-5.3 78- 77 3.2-4.4 73- 81 4.0-4.4 85- 90 4.8-8.3 79- 80 6.2-8.3 78- 79 3.5-4.3 74- 73 3.4-4.8 81- 76 3.2-4.2 75- 78 3.7-4.6 LOQ CL .47-. 46 .46-. 45 .51-. 45 .49-. 41 .47-. 43 .46-. 43 .51-. 49 .48-. 49 .54-. 50 .51-. 47 .51-. 47 .51-. 50 .52-. 49 .52-. 46 .45-. 43 .50-. 46 .48-. 51 .49-. 42 .47-. 45 .50-. 46 .49-. 47 .47-. 49 .48-. 50 .51-. 46 .54-. 49 .49-. 50 .49-. 42 .47-. 38 .49-. 49 .50-. 45 .50-. 46 ,50-. 49 BL X BL 5.18-10.63 7.25 7.08-13.35 10.69 4.36-15.24 8.39 4.48-18.10 10.93 4.90- 9.05 7.58 8.45-13.81 10.96 4.36- 9.52 6.90 6.00-14.29 10.06 3.27-10.10 6.37 4.29-14.17 8.48 4.91- 7.81 6.32 5.45- 9.90 7.65 4.91- 8.57 6.96 6.81-13.33 9.84 6.27-13.65 10.04 7.63-17.10 13.10 4.91- 8.72 6.21 6.00-10.48 7.79 4.36- 8.54 6.75 6.00-11.46 8.34 6.25- 8.54 7.32 8.48-11.98 9.87 5.18-10.48 8.31 8.18-14.76 10.07 5.18- 9.06 6.94 6.00-11.88 8.98 6.00-17.78 11.78 6.63-21.88 14.80 4.09- 9.58 6.38 5.18-11.56 8.05 5.90-10.20 7.70 8.60-11.70 10.20 12 Figure 2-1. Diagrammatic illustration showing characters measured and macrosetae of legs of Phidippus (dorsal view) . 13 palpus epigynum epigastric furrow coxa trochanter femur patella tibia metatarsus tarsus spinnerets Figure 2-2. Diagrammatic illustration of Phidippus showing ventral characters and leg macrosetae. 14 Table 2-2. Characters used to construct hypothetical phylogeny of species of Phidippus in the eastern U. S. See Glossary (Appendix A) for definitions of terms. Characters are considered primitive or derived based on frequency of occurrence within Phidippus (more common are considered more primitive) or by comparison with sister group (Dendryphantes ) ; characters shared between the two genera are consi- dered more primitive. Character Primitive Derived 1. Epigynum guides absent present 2. Epigynum septum absent present 3. Epigynum surface smoothly sloping depressed centrally 4. Embolus shape cylindrical sickle-shaped 5. Lateral tufts absent present 6. Abdomen spotted yes no 7. Chelicera tubercle absent present 8. Carapace transverse bands absent 9. Leg I fringe black & white 10. 2nd Abdominal spots separate 11. Epigynum surface smoothly sloping 12. Leg I fringe black & white 13. Ventral lateral stripes white 14. Ventral stripes 2 white 15. Ventral stripes 2 white 16. Embolus tip cylindrical 17. Central tufts absent 18. Tibial apophysis simple present white only fused elevated centrally black & orange black or gray 3 light gray 2 or 3 black flared present bifid at tip 15 16 Attus cinereus Walckenaer, 1837 A. multlvagus Walckenaer, 1837* A. dissimulator Walckenaer, 1837 A. pileatus Walckenaer, 1837 A. excubitor Walckenaer, 1837 A. pilosus Walckenaer, 1837 A. explorater Walckenaer, 1837* A. purpurarius Walckenaer, 1837 A. fraudulentus Walckenaer, 1837 A. rlmator Walckenaer, 1837 A. infestus Walckenaer, 1837* A. sagax Walckenaer, 1837 A. insidiosus Walckenaer, 1837 A. scrutator Walckenaer, 1837* A. Investigator Walckenaer, 1837 A. signatus Walckenaer, 1837 A. latus Walckenaer, 1837 A. trldentlger Walckenaer, 1837 The descriptions of the following species are also equivocal: Phidippus carolinus C. L. Koch, 1846 Attus rupicola Hentz, 1846 JP. testaceus C. L. Koch, 1846 Attus sinister Hentz, 1850 Other species considered riomina dubia are listed with their sus- pected synonyms. Species misplaced in Phidippus P_. fasciatus Koch & Berendt = Gorgopis fasciata (Koch & Berendt) P_. formosus Koch & Berendt = Gorgopis fasciata (Koch & Berendt) P.. frenata Koch & Berendt = Gorgopis frenata (Koch & Berendt) P_. impressus Koch & Berendt = Gorgopis melanocephala (Koch & Berendt) P_. marginatus Koch & Berendt = Gorgopis marginata (Koch & Berendt) P_. melanocephalus Koch & Berendt = Gorgopis melanocephala (Koch & Berendt) P. paululus Koch & Berendt = Gorgopis frenata (Koch & Berendt) _P. pusillus Koch & Berendt = Gorgopis frenata (Koch & Berendt) _P. bucculentus Gerst'acker = Thyene bucculenta (Gerst'acker) P. inf latus Gerstacker = Thyene inflata (Gerst'acker) 17 P. orbicularis Gerstacker = Thyene orbicularis (Gerstacker) P. chrysis, Banks = Dendryphantes aurantius (Lucas) P. disjunctus Banks = Dendryphantes disjunctus (Banks) _P. fartilis, Banks = Dendryphantes fartilis (Peckham & Peckham) P_. fraternus Banks = Dendryphantes aurantius (Lucas) F_. funebris Banks = Dendryphantes funebris (Banks) F_. luteus, Banks = Dendryphantes luteus (Peckham & Peckham) P_. marmoratus, Banks = Dendryphantes fartilis (Peckham & Peckham) _P. militaris, Peckham & Peckham = Dendryphantes marginatus (Walckenaer) _P. molinor Chamberlin = Dendryphantes marginatus (Walckenaer) _P. multicolor Banks = Dendryphantes aurantius (Lucas) P. nigropilosus Banks = Dendryphantes nigropilosus (Banks) P. orichalceus Peckham & Peckham = Dendryphantes aurantius (Lucas) P_. capitatus, Banks = Dendryphantes galathea (Walckenaer) P_. parvus F. 0. P. -Cambridge = Dendryphantes galathea (Walckenaer) _P. cyanidens C. L. Koch = Parnaenus cyanidens (C. L. Koch) P. keratodes Hasselt = Hyllus keratodes (Hasselt) The several species described from India by Tikader (e.g., 1974) as Phidippus species do not belong in this genus; I am unable to place them at present. I have included in the keys to species alternate characters for each species in cases where the destruction or absence of one character might cause confusion. The reader should be aware of populations variable in color pattern, especially of P_. audax. I have attempted to use characters which would avoid problems in the keys caused by color pattern, although the latter character is used to some extent. Geographic 18 area is included where it might be helpful. The term "semi-encircled" means that the periphery of the dorsum of the abdomen is covered with colored scales except for the posterior end, which is covered by part of the central black stripe. The dorsum of the carapace does not include the clypeus, sides or thoracic slope. Key to Adult Male Phidippus of the Eastern U. S. 1. Ocular setal tufts or crests present 2 1'. Ocular setal tufts or crests absent 8 2. Ocular quadrangle with pair of setal crests and single white triangular spot, without setal tufts putnami 2'. Without crests or single spot, with 2 or 4 setal tufts 3 3. With 4 setal tufts, both dorsal and lateral 4 3'. With 2 dorsal setal tufts only 6 4. Ocular quadrangle with 3 red (rarely white or absent) spots arrang- ed transversely, abdomen gray with white spots and very hirsute, palpal tibial apophysis bifid at tip mystaceus 4'. Ocular quadrangle without spots, abdomen not gray or exceptionally hirsute, palpal tibial apophysis simple 5 5. Leg I fringe white, abdomen orange to red; not in Florida insignarius 5'. Leg I fringe black and orange, abdomen black with yellow to orange spots; SE U. S., Atlantic coast to MD otiosus 6. Dorsum of carapace and abdomen red apacheanus 6' . Dorsum of carapace black, abdomen semi-encircled with tan or yellow to red 7 7. Embolus projecting distally post protegulum; Canada and adjacent states borealis 19 7'. Embolus not projecting distally post protegulum purpuratus 8. Embolus sickle-shaped 9 8'. Embolus not sickle-shaped 10 9. Carapace unmarked, dorsum of abdomen completely red (rarely brown with white spots) ; not in Florida princeps 9'. Carapace with a short white band behind each PLE, abdomen semi- encircled with red; SE U. S. pulcherrimus 10. Dorsum of carapace and abdomen orange to red 11 10' . Dorsum of carapace black, of abdomen variable 13 11. Posterior half abdominal dorsum with 2 pair of white spots, venter with 3 black stripes, leg I fringe white whitmani 11'. Posterior half abdominal dorsun with 2 black stripes enclosing 2 pair white spots, venter otherwise, leg I fringe black and white 12 12. Venter of abdomen with 3 gray stripes on pale background, embolus flared distally cardinalis 12'. Venter of abdomen black, embolus slender and hooked distally pius 13. Addomen with pair of red stripes, 2nd spot pair separate or no spots clarus 13'. Abdomen without stripes, 2nd spot pair fused 14 14. White transverse bands behind PLE; small species, Florida endemic xerus 14.' White submarginal bands below PLE or usually carapace unmarked 15 15. White posterior abdominal spots linear (all light spots may be fused and yellow to orange) , abdomen dorsum with metallic black scales surrounding 8 quadrangular black spots audax 20 15' . White posterior abdominal spots oval, black areas monotonous, without metallic scales; large species, SE U. S., Atlantic coast to VA regius Key to Adult Female Phidippus of the Eastern U. S. 1. Epigynum without anterolateral guides 2 1' . Epigynum with anterolateral guides 3 2. Ocular area with 6 setal tufts, quadrangle with a white or tan triangular spot, abdomen brown with white spots putnami 2'. Ocular area with 4 or 6 setal tufts, quadrangle with 3 white spots arranged transversely, abdomen gray with white spots, hirsute mystaceus 3. Epigynum with deep transverse depression in middle third 4 3'. Epigynum without depression 6 4. Dorsum of carapace and abdomen yellow to red apacheanus 4'. Dorsum of carapace gray or black, of abdomen otherwise 5 5. Abdomen semi-encircled with tan to orange, 2nd spot pair fused; Canada and adjacent states. borealis 5'. Abdomen gray, sometimes semi-encircled with white, 2nd spot pair not fused purpuratus 6. Epigynum elevated immediately posterior to septum in center of epigynal plate 7 6'. Epigynum essentially flat or gradually sloping upward posteriorly, with or without distinct septum 8 7. Carapace with distinct submarginal bands, posterior abdominal spots enlarged and quadrangular; SE U. S., Atlantic coast to MD otiosus 21 7'. Carapace rarely with distinct bands, usually either without markings or covered with colored scales, posterior abdominal spots oval, not enlarged; large species, SE U. S., Atlantic coast to VA regius 8. Abdominal venter white with black or gray lateral stripes, usually with narrow median dark stipe; 2nd spot pair separate 9 8'. Abdominal venter black with or without lateral white stripes; 2nd spot pair fused or no dorsal pattern 12 9. Posterior abdomen with 2 pair white spots, dorsum of carapace and abdomen red to brown, 3 black ventral stripes whitmani 9'. Posterior abdomen with 2 black stripes enclosing 2-3 pair white spots, dorsum and venter variable 10 10. Two black ventral stripes (median stripe absent), abdomen dorsum gold to reddish-brown, usually darker in central stripe between spots clarus 10'. Three light gray ventral stripes, abdomen dorsum variable in color 11 11. Dorsum of carapace and abdomen red to brown, width of posterior epigynal notch 3 times its length, equal in width to distance between duct openings cardinalis 11'. Dorsum of carapace and abdomen yellow to orange, width of posterior epigynal notch 2 times its length, less in width than distance between duct openings pius 12. Dorsum of carapace and abdomen brown, without paired spots (rarely with fused 2nd pair and separate 3rd and 4th pairs, all white); not in Florida princeps 12'. Dorsum otherwise 13 22 13. Ocular area with 4 distinct setal tufts, abdomen semi-encircled with yellow to red 14 13'. Ocular area with 2 dorsal tufts only, the lateral setae not concentrated into a tuft, but spread out into a weak fringe, abdomen variable 15 14. Uniquely-shaped white spot in middle of ocular quadrangle, short yellow-orange transverse bands behind PLE or entire carapace encircled with gray and/or yellow-orange scales; Florida endemic xerus 14'. No spot in ocular quadrangle, carapace with white submarginal bands below PLE or carapace encircled with white scales; not in Florida insignarius 15. Short white to tan transverse bands behind PLE or entire carapace encircled with white or tan scales, abdomen semi-encircled with yellow to red, black quadrangular spots present but mostly covered by semi-encircling band of scales; SE U. S. pulcherrimus 15'. Carapace without markings or with white submarginal bands below PLE, never encircled by scales, abdomen rarely semi-encircled by white or orange, 2nd-4th pair spots rarely fused together and/or orange, black metallic scales encircling 8 black quadrangular spots. audax Subgenus Anipalpus, new subgenus The name of the subgenus is a contraction of "animated pedipalpus," referring to the unusual use of the palpi during courtship by males of the included species. I designate Phidippus putnami as the type species of this subgenus. 23 Two species in this subgenus occur in the eastern U.S., P. putnami and P. mystaceus. Females of both species have 6 ocular setal tufts (the central pair is occasionally missing) . The epigyna of both species lack guides; the spermathecal duct openings are in a narrow slit. The emboli of the males have been modified (flattened) to fit into the slit. Males of P_. putnami have a double setal crest in the ocular quadrangle, while males of P_. mystaceus have a stridulatory organ on each palpus. Males of both species have yellow fringes on the legs I. The subgenus is characterized by the 6 tufts, the slit openings in the epigynum and the flattened embolus. Phidippus putnami (Peckham & Peckham) , 1883 Figures 2-4, 2-21 Attus putnamii Peckham & Peckham, 1883; type in MCZ, examined Phidippus gracilis Keyserling, 1884 (synonymized by Peckham & Peckham, 1909) Plexippus putnamii, Peckham & Peckham, 1888 Philaeus princeps (not Peckham & Peckham), Banks, 1892 Phidippus putnamii, Peckham & Peckham, 1901, 1909; Bryant 1942; Muma 1944, 1945; Bonnet, 1958; Richman & Cutler, 1978; Oehler, 1980 P_. otiosus, Peckham & Peckham, 1909 (in part,? ; Plate 34, fig. 6a, f) Dendryphantes putnami, Petrunkevitch, 1911; Roewer, 1954 The female was illustrated as early as 1909 by the Peckhams, but thought to be a variety of P_. otiosus. Males have yellow leg fringes and light metallic blue femur in more northern specimens, mostly white leg fringes (with a few yellow setae) and dark metallic blue femur in more southern specimens. 24 MALE: integument dark; carapace with white bar just below and behind each PME, large white triangle between PLE, third white bar (often rubbed off) anteriorly at apex of triangle, short white stripe directly behind center of triangle; yellow fringe of setae over anterior eyes, dense cover of bluish gray setae across anterior dorsal ocular area; no ocular tufts, instead dorsal black setal crests originating from between PME and PLE extending forward ental to PME almost to level of ALE; chelicerae proximal half each side with scales in 3 vertical white and 2 vertical red stripes, with a red transverse bar below stripes, distal half iridescent blue covered with bluish-gray setae; clypeus covered with red scales, fringed with white setae; palpal femur covered dorsally with white scales, tibia with long ectal fringe of white-tipped black setae, cymbium fringed with black setae and covered dorsally with bluish-gray setae; leg I fringes all yellow or all white except black setae mixed in on prolateral tibia, covered dorsally with white scales; femur I dorsal fringe rudimentary, ventral setal fan pale yellow, distal prolateral and ventral surfaces covered densely with white scales and white or yellow prolateral setal fan, retrolatero- ventral edge with elongate tuft of pale yellow setae, swollen ventrally, light to dark metallic blue on pro-, retrolateral, and ventral surfaces; dorsal abdominal markings white; venter of abdomen blue-black or black bordered laterally by wide white stripes. FEMALE: integument normal color; carapace with dorsal markings as in male or covered with white scales, chelicerae covered with white setae on proximal half, metallic green distal half; 6 ocular tufts, the midocular pair somewhat smaller than the other 2 pair, rarely lacking; clypeus, palpi, and legs with white setal fringes; abdominal integument brown, bronze, or black, dorsal abdominal spots white or tan. 25 LEG MACROSETATION: no consistent differences; sometimes metatarsi III & IV V 0-0-1 or 0-0-2. Phidippus mystaceus (Hentz) , 1846 Figures 2-5, 2-22 Attus mystaceus Hentz, 1846; type destroyed Phidippus asinarius C. L. Koch, 1846; (synonymized by Marx, 1890) Phidippus electus C. L. Koch, 1846; (synonymized by Marx, 1890) Cyrtonota multivaga, Simon, 1864; not Attus multivagus Walckenaer, 1837, a NOMEN DUBIUM Phidippus mystaceus, Emerton, 1877; Peckham & Peckham, 1909; Muma, 1944: Muma & Jeffers, 1945; Bonnet, 1958; Specht & Dondale, 1960; Whitcomb et al. , 1963; Berry, 1970; Edwards, in Richman & Cutler, 1978; Oehler, 1980 Phidippus incertus Peckham & Peckham, 1901; type in MCZ, examined (synonymized by Peckham & Peckham, 1909) Dendryphantes mystaceus, Petrunkevitch, 1911; Roewer, 1954 Phidippus hirsutus Barrows, 1919; type in OSU, examined (synonymized by Edwards, in Richman & Cutler, 1978) P_. incertus, Bryant, 1942; Warren et al., 1967 P. hirsutus, Bryant, 1942; Kaston, 1948; Whitcomb et al., 1963 Dendryphantes hirsutus, Roewer, 1954 Hentz' s written description could fit either P_. mystaceus or P_. purpuratus, but his illustration of the extra long setal tufts on the carapace indicates that the species he was describing was P_. mystaceus. Stability of nomenclature also favors retaining P_. mystaceus for this species. 26 MALE: carapace integument with dark blue tinge, ocular area with 3 red-orange transverse spots; chelicerae iridescent green; 4 long ocular tufts; clypeus with mixed yellow and white fringe over-hanging proximal two-thirds of chelicerae; palpi with white lateral fringes on patella and tibia, dorsal cymbium with white and yellow setae and central spot of white and yellow scales; aplpi with short, blunt macrosetae encir- cling tip; leg I femur lacks dorsal fringe, with dorsal subproximal black setal tuft projecting anteriorly, venter with band of yellow scales, prolateroventral fringe lacking, prolateral surface metallic dark blue, dorsal distal edge of femur and all other segments covered with yellow scales, all fringes yellow; legs II-IV with yellow scales on distal segments and white scales on proximal segments; dorsum of abdomen with pattern like female overlain with long gray setae; venter of abdomen gray with 4 rows of pale dots. A single dimorphic male of P_. mystaceus is known. It is similar to the typical males with the following differences: carapace covered dorsally, laterally, and posteriorly with red scales, edged with yellow scales posteriorly; rounded transverse integumental ridge in ocular quadrangle (similar to P. toro Edwards); 4 typical setal tufts absent, instead 2 central tufts in ocular quadrangle. FEMALE: similar to male with following differences: integument normal color, carapace covered with gray scales, ocular spots white outlined in black; third pair weak ocular tufts often present between ocular spots; clypeus covered with white scales, clypeus and palpi fringed with white setae, overhanging chelicerae as in male; legs covered with scales and having simple fringes, both white on females from eastern states, both yellow on females from midwestern states. 27 LEG MACROSETAE: metatarsus III & IV V 0-1-2. Subgenus Phldippus The remainder of the species of the eastern U. S. belong to the nominal subgenus. They are characterized by the usually cylindrical shape of the embolus and well developed anterolateral epigynal rims forming guides for the emboli. Most species have a longitudinal median septum dividing the anterior 1/3 to 1/2 of the spigynum. The purpuratus group has the protegulum extended ectanteriorly and the epigyna have a deep transverse depression across the central third. cardinalis group Four species in this group (P. cardinalis , P_. pius, P_. whitmani, P_. clarus) occur in the eastern U. S. All are covered dorsally with yellow to red or brown scales and have a bilineate dark stripe pattern on the abdominal dorsum, and a trilineate dark stripe pattern on the abdominal venter (central stripe usually absent in P_. clarus) . The epigynum lacks a septum; the tegulum of the palpus is relatively narrow compared to other species groups. Phidippus cardinalis (Hentz) , 1845 Figures 2-6, 2-23 Attus rufus Hentz, 1835; NOMEN NUDUM Attus cardinalis Hentz, 1845 ( d ) ; type destroyed Attus rufus Hentz, 1846 (?); type destroyed; NEW SYNONYMY Plexippus rufus C. L. Koch, 1846 (synonymized by Marx, 1890) Plexippus bivittatus C. L. Koch, 1846 (synonymized by Marx, 1890) Phiale modesta C. L. Koch, 1846 (synonymized by Banks, 1913) Attus mccookii Peckham & Peckham, 1883; type in MCZ, examined; NEW SYNONYMY 28 Phidlppus ruber Keyserling, 1884; type in BMNH, examined (synonymized with _P. mccookii by Peckham & Peckham, 1909) P. cardinalis, Peckham & Peckham, 1888; Wallace, 1950; Bonnet, 1958; Richman & Cutler, 1978; Gertsch, 1979 Dendryphantes cardinalis, Simon, 1901; Roewer, 1954 Phidippus Oakland ens is Tullgren, 1901 (synonymized by Petrunkevitch, 1911) P. mccooki, Muma, 1944; Kaston, 1948; Whitcomb et al. , 1963 Much confusion about the identities of P_;_ cardinalis and P. mccooki has existed since the Peckhams (1909) illustrated both species in consecutive figures. I have never seen a male palp as illustrated for P. mccooki. The drawing of the epigynum of this species appears to be a good rendition of P_. whitmani, whereas the description of the female color pattern is that of P. pius. The type of P. mccooki is a female with a typical P_. cardinalis epigynum. I can only speculate that the illustration of the P_. mccooki male habitus is misplaced, and was meant to be the initial entry under P_. cardinalis. Cheliceral color in the male of P_. cardinalis agrees with Hentz's description and distinguishes this species from _P. apacheanus . Although the Peckhams (1909) were unable to recognize P. rufus, which they had previously attributed to what they renamed as P_. whitmani, Hentz's description must be of the female of P_. cardinalis. Only 3 eastern species _(P. cardinalis, P_. pius, P_. whitmani) have 3 ventral, dark longitudinal stripes, and only 2 of these _(P_. cardinalis, P. pius) have 2 short dorsal, dark longitudinal stripes broken by 2 pairs of white spots. Since the type locality of P_. rufus is Alabama, and the red form of P_. pius occurs east of the Appalachians, P_. rufus must be P_. cardinalis. 29 MALE: integument reddish; carapace covered with red scales dor- sally; chelicerae dark red proximal half, weakly iridescent blue distal half; no ocular setal tufts clypeus and palpi fringed with black setae; palpal femur with white or red scales on distal edge; leg I femur also with white or red scales on distal edge (white on legs II-IV) , petellar brush black except white on proximal half of prolateral surface, white scales on proximal half patella; scales on proximal halves metatarsus and tarsus white to orange; dorsum of abdomen covered with red scales, with 2 black stripes in posterior half overlaid with 2 pair white spots, all of which may also be covered with red scales; venter of abdomen dark gray. FEMALE: similar to male with following differences: 2 dorsal setal tufts; white scales below lateral eyes, across proximal edge of chelicerae, and on clypeus; clypeus also with dense fringe of white setae; palpi fringed with white-tipped black setae; dorsum red to brown, posterior stripes and spots not overlaid with red scales; venter of abdomen pale with 3 narrow gray stripes. LEG MACROSETAE: femur II DR 0-0-0-0, tibia II V 0-1R-1R or 0-0-2; tibia III V 0-0-0-2, R 0-0-1-0; metatarsus III V 0-0-1 or 0-1-2, R 0-0-2; metatarsus IV V 0-0-1 or 0-0-2. Phidippus pius Scheffer, 1906 Figures 2-7, 2-24 Phidippus pius Scheffer, 1906; type supposed to be in USNM, lost .P. pius, Peckham & Peckham, 1909; Bonnet, 1958; Edwards, 1977; Cutler, 1977; Richman & Cutler, 1978 Dendryphantes pius, Petrunkevitch, 1911; Roewer, 1954 30 Phidippus abboti Chamberlin & Ivie, 1944; type in AMNH, examined (synonymized by Edwards, 1977) Dendryphantes abboti, Roewer, 1954 Phidippus abboti, Barnes & Barnes, 1955; Bonnet, 1958; Berry, 1970 Considerable variation in color pattern occurs in this species. In the typical form, females are yellow and males are orange; this color form holds throughout the northern range of the species and to the southwest (from the eastern plains to New Jersey and south to Texas) . Southeast of the Appalachian Mountains, from Virginia to Florida, fe- males are orange and males are red (P. abboti color form) and the amount of black on the legs and palpi is increased. Toward the southwestern portion of the range, in Texas, the black markings on the legs and palpi are only faintly indicated. Although the type of P_. pius is lost, Scheffer's description leaves no doubt as to which species he was describing. MALE: integument yellow to red; carapace covered dorsally with yellow to red scales, lacking in ocular area in red males; no ocular setal tufts; clypeus with white setal fringe; palpi yellow to red, cymbium black, femur black in red males, white lateral fringes on patella, tibia, and cymbium; legs with black on ventral half of pro- lateral surface of all femora, distal third patella, distal half tibia, distal two-thirds metatarsus, distal half tarsus except for extreme distal edge which is pale (red males have femur, tibia and metatarsus all black), white scales sparsely on all legs and palpi; dorsum of abdomen covered with yellow to red scales; 2 posterior stripes similar to P_. cardinalis and covered sparsely with metallic scales; venter pale (orange males) to black (red males) . 31 FEMALE: similar to male with following differences: integument yellow to orange; 2 weak dorsal setal tufts; clypeus and palpi fringed with white setae; venter of abdomen with 3 narrow gray lines like P_. cardinalis. LEG MACROSETAE: femur II DR 0-0-0-0, tibia II V 0-1R-1R-2; patella III R 0-0-0, tibia III V 0-0-0-2, R 0-0-1-0, metatarsus III V 0-0-2; tibia IV R 0-0-1-0, metatarsus IV V 0-0-2. Phidippus whitmani Peckham & Peckham, 1909 Figures 2-8, 2-25 Phidippus paludatus C. L. Koch, 1846; NOMEN OBLITUM P_. rufus (not Hentz) , Peckham & Peckham, 1889 (in part,cO Dendryphantes rufus, Simon, 1901 Phidippus whitmanii Peckham & Peckham, 1909 Dendryphantes whitmanii, Petrunkevitch, 1911; Roewer, 1954 P. whitmani, Comstock, 1912; Kaston, 1948; Bonnet, 1958; Berry, 1970; Cutler, 1977; Richman & Cutler, 1978; Gertsch, 1979 P_. insolens (not Hentz), Kaston, 1938a, b Banks' description (1913) of the pinned type of P_. paludatus indicates it to be a specimen of P_. whitmani. The latter name has been used for the species ever since the Peckhams' description (1909), over 50 years ago. Females are brown in the northern states, red in the southern states. Southern males are more completely covered with red scales on anterior dorsum of carapace, only anterior half of distance from PME to AME exposed. MALE: carapace covered with red scales dor sally except anterior to PME, where dark integument is exposed, laterally and on thoracic slope 32 covered with white scales; chelicerae proximal half covered with white setae, especially medially, distal half faintly metallic blue; no ocular setal tufts; clypeus covered with white scales and setal fringe; palpi with white fringe entire length laterally and on cymbium dorsally, covered with white scales entire length dorsally; leg I-IV covered with white scales, all fringes white; integument of all femora black; dorsal abdomen covered with red scales, dorsal abdominal markings white; venter of abdomen gray laterally, with 3 narrow black stripes enclosing 2 sub- mesal white stripes. FEMALE: similar to male with following differences: carapace completely covered with red or brown scales dorsally; 2 weak dorsal setal tufts; palpi fringed with white setae but lacking scales; dorsal abdomen covered with red to brown scales except for white markings, rarely with 2 black lines posteriorly like P_. cardinalis and P. pius. LEG MACROSETAE: femur II DR 0-0-0-0, tibia II V 0-1R-1P or 0-0-2; patella III IV R 0-0-0, tibia III V 0-0-0-2, metatarsus III V 0-0-2, P 0-0-2, R 0-0-2; metatarsus IV V 0-0-2. Phidippus clarus Keyserling, 1884 Figures 2-9, 2-26 Attus podagrosus Hentz, 1846; type destroyed; NOMEN DUBIUM, NOMEN OBLITUM Phidippus auctus C. L. Koch, 1846; specimens from Keyserling coll., BMNH, examined; NOMEN OBLITUM Phidippus castrensis C. L. Koch, 1846; NOMEN DUBIUM, NOMEN OBLITUM Phidippus clarus Keyserling, 1884 P. clarus, Peckham & Peckham, 1909; Kaston, 1948; Wallace, 1950; Barnes & Barnes, 1955; Bonnet, 1958; Whit comb & Tadic, 1963; Whitcomb, 1963; Berry, 1970; Richman & Cutler, 1978, Oehler, 1980 33 P_. insolens (not Hentz) , Peckham & Peckham, 1888 P. multiformis Emerton, 1891; type in TiCZ, examined (synonymized by Peckham & Peckham, 1909) P_. minutus Banks, 1892; type in MGZ, examined (synonymized by Peckham & Peckham, 1909) Philaeus princeps (not Peckham & Peckham), Banks, 1892 Phidippus bilineatus Tullgren, 1901 (synonymized by Roewer, 1954) Phidippus clarconensis Tullgren, 1901 (synonymized by Wallace, 1950) Dendryphantes insolens, Simon, 1901 I), multiformis, Simon, 1901 I), castrensis, Simon, 1901 Phidippus podagrosus, Banks, 1910 Dendryphantes clarus, Petrunkevitch, 1911; Roewer, 1954 _P. rimator, Chamberlin & Ivie, 1944 (not Attus rimator Walckenaer, 1837 a NOMEN DUBIUM) ; Kaston, 1953, 1972, 1978; Snetsinger, 1954; Cutler, 1977 Numerous other references cited in behavior or ecology sections. The usage of P_. rimator (Walckenaer) for this species, a name which has become increasingly used for P_. clarus, is completely unwarranted. The single illustration by Abbot (1792) given the name Attus rimator by Walckenaer (1837) was recognized as an immature by Chamberlin & Ivie (1944) when they resurrected the name. It is well know that immatures have been usually difficult, if not impossible given past techniques, to identify to species. Furthermore, I have examined a color reproduction of the copy of Abbot's drawing kept at the Museum of Comparative Zoology, and cannot positively identify the drawing to genus, much less to species; the dorsal pattern cannot be matched with any known species. 34 In saying this I might add that I have personally reared most of the species of Phidippus occurring in the eastern U. S., including P_. clarus, and therefore have first hand acquaintance with their appearance as immatures. MALE: integument dark; no dorsal ocular tufts; clypeus and lateral edges of palpi fringed with black setae; dorsum of palpal femur, patel- la, tibia, and cymbium covered with white scales and setae; leg I femur with dorsal fringe white, prolateroventral fringe absent, patella brush black, proximal fourth of tibial brush white; dorsum of abdomen with short white basal band, side stripe of red scales each side, dark metallic central stripe; venter of abdomen dark gray with 3 black stripes, the stripes sometimes enclosing a slight amount of white. FEMALE: similar to male with following differences: integument normal color; 2 weak dorsal tufts; white scales below eyes laterally and densely covering clypeus, long white setal fringe on clypeus, palpi; abdomen with variable coloration, lateral wide stripes tan, yellow, or orange and median stripe tan, brown or black; venter of abdomen white enclosed by lateral black stripes which meet posteriorly, sometimes with faint median gray stripe. LEG MACROSETAE: femur II DR 0-0-0-0; metatarsus IV V 0-0-1 or 0-0-2. audax group The 5 eastern species in this group (P. audax, P_. otiosus, _P. regius, P_. xerus, P_. insignarius) all have 4 setal tufts on the females as opposed to 6 or 2 tufts on females of other groups. Lumping these species together on the basis of number of setal tufts seems tenuous; _P. insignarius and probably _P. xerus will likely be shown to belong to 35 other species groups when the fauna of the western U. S. becomes better known. Males of the 3 other species all have a cheliceral tubercle, which seems to be a shared, derived character. Behavioral data also seems to relate these 3 species (see chapter on courtship). Phidippus audax (Hentz) , 1845 Figures 2-10, 2-27 Attus morsitans Walckenaer, 1805; NOMEN NUDUM, NOMEN DUBIUM Salticus variegatus Lucas, 1833; type lost; petition to suppress (Levi & Pinter, 1970) under consideration by the I. C.Z.N. Attus audax Hentz, 1835; NOMEN NUDUM A. tripunctatus Hentz, 1835; NOMEN NUDUM A. morsitans Walckenaer 1837; NOMEN DUBIUM A. audax Hentz, 1845; type destroyed; petition submitted to designate as type species of genus (Levi & Pinter, 1970) A. tripunctatus Hentz, 1846 (synonymized by Banks, 1893) A. fasciolatus, Hentz, 1846 (synonymized by Banks, 1910) Phidippus togatus C. L. Koch, 1846; NEW SYNONYMY Phidippus purpurifer C. L. Koch, 1846 P. smaragdifer C. L. Koch, 1846 P. alchymista C. L. Koch, 1846 P_. ruf imanus C. L. Koch, 1846 P. dubiosus C. L. Koch, 1846 P. mundulus C. L. Koch, 1846 P. personatus C. L. Koch, 1846 P. concinnatus C. L. Koch, 1846 (Koch names synonymized by Banks, 1910) P_. morsitans, Peckham & Peckham, 1888 (synonymized by Peckham & Peckham, 1909) 36 P. rauterbergii Peckham & Peckham, 1888 (synonymized by Banks, 1916) P_. tripunctatus, Emerton, 1891 P. audax, Banks, 1893; Peckham & Peckham, 1909; Bonnet, 1958; Kaston, 1948, 1953, 1972, 1978; Levi & Levi, 1968; Cutler, 1977; Richman & Cutler, 1978; Gertsch, 1979; Oehler, 1980 P. howardii Peckham & Peckham, 1896, NEW SYNONYMY P. rauterbergii, Peckham & Peckham, 1901, 1909; Bonnet, 1958 P. howardi, Peckham & Peckham, 1901, 1909; Bonnet, 1958 P_. variegatus, Peckham & Peckham, 1909 (the Peckhams considered audax and variegatus to be 2 separate species); Kaston, 1938; Bryant, 1942 Dendryphantes audax, Petrunkevitch, 1911; Roewer, 1954 D. howardi, Petrunkevitch, 1911; Roewer, 1954 J), rauterbergii, Petrunkevitch, 1911; Roewer, 1954 Phidippus bryantae Kaston, 1945 (synonymized by Kaston, 1948) Also mentioned in numerous behavioral and ecological papers which are mentioned with their respective chapters. Phidippus morsitans might also apply to P_. regius C. L. Koch but would be unavailable for that species also. This is an extremely common species over most of eastern and mid- western North America. It varies widely in both size and color pattern, although at least some individuals of a particular population retain the typical color pattern. Some individuals in Texas and Mexico reach nearly 20 mm in length, perhaps in part due to the lack of competition from a common, large species (like P. regius in Florida). MALE: integument dark; carapace with or without lateral white sub- marginal band of variable size extending behind and below PLE; anterior face of each chelicera with subdistal tubercle; no ocular setal tufts; 37 clypeus fringed with black setae; palpal femur and patella with white scales and setae dorsally, black setae laterally and on dorsal cymbium; leg I with typical fringing; abdomen with spots white, yellow, or red, either distinct or coalesced with each other or with lateral bands, most of resulting patterns illustrated by Hill (1978) ; venter of abdomen with outer rows of dots often overlain with white scales which encroach to variable extent over median black stripe which is never completely covered. FEMALE: similar to male with following differences: no cusp on chelicerae; 4 setal tufts; clypeus sparsely covered with white scales and white setae; palpi fringed with black setae, some of which have white tips. LEG MACROSETAE: metatarsus III R 0-0-2; metatarsus IV V 0-0-2. Only species with an individual with femur I DR 0-0-0-1. Phidippus otiosus (Hentz) , 1846 Figures 2-11, 2-28 Attus pulcher Walckenaer, 1837, p. 439 A. pulcher pallida Walckenaer, 1837, p. 439 A. peregrinus Walckenaer, 1837, p. 445 A. otiosus Hentz, 1846; type destroyed; petition for retention submitted to I. C. Z. N. (see Appendix C) Phidippus lunulatus C. L. Koch, 1846 (synonymized by Banks, 1910) P. otiosus, Peckham & Peckham, 1888, 1901, 1909; Bryant, 1942; Murrill, 1942; Wallace, 1950, Bonnet, 1958; Anderson, 1966; Levi & Levi, 1968; Kaston, 1972, 1978; Edwards et al. , 1974; Muma, 1975; Edwards, 1977; Richman, 1977; Hill, 1979; Gertsch, 1979 38 Dendryphantes otiosus, Petrunkevitch, 1911; Roewer, 1954 Phidippus dorsalis Bryant, 1942 ( o"holotype) ; holotype in MCZ, examined; NEW SYNONYMY P. pulcher, Chamber lin & Ivie, 1944; Richman, 1978; Richman & Cutler, 1978 Dendryphantes pulcher, Roewer, 1954 Although P_. pulcher (Walckenaer) has priority, the specific epithet pulcher in various generic combinations has only been used 6 times in the literature (3 in checklists) , whereas P_. otiosus (Hentz) has been used over 20 times (7 in checklists). Usage favors retention of P_. otiosus. MALE: carapace with very wide yellow to orange submarginal bands from PME to near posterior edge, not meeting behind but partially cover- ing thoracic slope; chelicerae with tubercle like P_. audax; 4 setal tufts; clypeus sparsely fringed with black setae; palpi covered with yellow to orange scales and setae on dorsal and lateral femur, ectal edge of patella; dorsal cymbium covered with black setae; leg I with typical fringes except yellow to orange where normally white, prolatero- ventral femur fringe lacks distal third, yellow setae and scales on distal femur; legs II-IV with yellow scales on dorsal distal femur and proximal patella; dorsal abdominal markings yellow, gold, or orange, center stripe metallic black, green, or blue; venter of abdomen black. FEMALE: similar to male with following differences: carapace submarginal bands white to yellow; chelicerae without tubercle; ventral edge of clypeus to entire face covered with white scales, weakly fringed with yellow setae to strongly fringed with white overhanging proximal third of chelicerae; palpi densely fringed laterally with white or yellow setae; legs covered with white or yellow scales; abdomen integument 39 gray, tan, or black, dorsal abdominal markings white to yellow-orange; venter of abdomen with broad black stripe with or without white border which may encroach on middle of black band. LEG MACROSETAE: metatarsus IV V 0-1-2. Phidippus regius C. L. Koch, 1846 Figures 2-12, 2-13, 2-29 Phidippus regius C. L. Koch, 1846, p. 146 Attus regius, Walckenaer, 1847 Salticus sagraeus Lucas, 1857 Attus miniatus Peckham & Peckham, 1883 (synonymized by Edwards, 1975, unpubl.; Richman & Cutler, 1978) Phidippus miniatus, Peckham & Peckham, 1888, 1901, 1909 P. variegatus (not Lucas), Franganillo, 1930; Chamberlin & Ivie, 1944; Wallace, 1950 P. regius, Bryant, 1943; Bonnet, 1958; Levi & Levi, 1968; Levi & Pinter, 1970; Muma, 1975; Cutler, 1977; Hill, 1977; Kaston, 1978; Richman & Cutler, 1978; Edwards, 1975, 1979; Cutler, 1979; Gertsch, 1979 Dendryphantes regius, Simon, 1901; Roewer, 1954 D. miniatus, Petrunkevitch, 1911; Roewer, 1954 Phidippus tullgreni Wallace, 1950; NEW SYNONYMY (may be P_. otiosus - P. regius hybrid) Richman & Cutler (1978) synonymized P_. miniatus with P_. regius on the authority of the unpublished thesis of Edwards (1975) . This species has been involved in considerable confusion with P_. audax over use of the name P_. variegatus and because of their similar appearance. MALE: integument dark; carapace rarely with wide white submarginal bands (possibly hybrid) ; chelicerae with tubercle like _P. audax; no 40 ocular tufts; clypeus and palpi fringed with black setae; leg I femur with distal prolateral white setae and scales; dorsal abdomen black with white markings; venter of abdomen black. FEMALE: carapace lacking scales or covered to variable extent with gray, tan and/or orange scales, ocular quadrangle never completely covered; chelicerae without tubercle, sometimes red-violet, may be covered proximally with white scales; 4 ocular setal tufts; clypeus and palpi with white fringes, clypeus covered with white scales; legs with or without gray, tan or orange scales; dorsal abdomen black or dark brown with or without covering of gray, tan, brown and/or orange scales; dorsal markings white or pale orange, sometimes overlaid with tan or orange scales, markings outlined with remnant of central dark band; venter of abdomen black, bordered with stripes of white scales when abdomen black dorsally. LEG MACROSETAE: metatarsus IV V 0-1-2. P. regius, the largest species represented, was most likely to have more macrosetae than normal; especially the ventral subproximals on tibiae II-IV might be paired. Phidippus xerus Edwards, 1978, emendation Figures 2-14, 2-30 Phidippus xeros Edwards, 1978; holotype deposited in MCZ _P. xeros, Richman, 1979 A few specimens in collections were labeled P_. workmani. The specific epithet was not latinized in the original description, and is here emended. All known specimens of this species have been collected in Florida. MALE: integument dark; carapace with short white transverse bands behind PLE; no ocular tufts; clypeus and palpi fringed with black setae; 41 palpi with dorsal white scales on femur and patella; leg I like P. regius, except dorsal femur fringe of white-tipped black setae; dorsal abdomen black with white markings; venter of abdomen black with 4 rows pale dots. FEMALE: integument normal color; carapace with markings like male (except they are yellow) or usually (including clypeus and over anterior eyes) covered with gray, yellow, and/or orange-yellow scales, except for lower thoracic slope and ocular quadrangle (which has white spot in center); 4 weak ocular setal tufts; clypeus and palpi fringed with white; tibia I reddish on proximal half with white fringe; dorsal abdominal markings orange-yellow to red-orange, or rarely lateral stripes lacking and yellow spots and basal band present; venter of abdomen like male. LEG MACROSETAE: no consistent differences; ventral and lateral medians on metatarsi III & IV variable. Phidippus insignarius C. L. Koch, 1846 Figures 2-15, 2-30 Phidippus insignarius C. L. Koch, 1846, 1851 Philaeus monticola Banks, 1896 (synonymized by Peckham & Peckham, 1909) Phidippus comatus Peckham & Peckham, 1901 (in part, C) (recognized by Peckham & Peckham, 1909) P. insignarius, Peckham & Peckham, 1909; Kaston, 1948; Muma, 1949; Whitcomb & Tadic, 1963; Cutler, 1977; Richman & Cutler, 1978 Dendrvphante.s insignarius, Petrunkevitch, 1911; Roewer, 1954 P. fraudulentus, Chamberlin & Ivie, 1944; not Attus fraudulentus Walckenaer, 1837, a NOMEN DUBIUM P. insigniarius, Bonnet, 1958 42 Bonnet (1958) noted that the correct Latin spelling of the specific epithet is insigniarius. If Koch had misspelled the name unintentional- ly, this correction would be valid. However, Koch used the same spelling again in 1851, indicating he deliberately spelled the name without the extra "i", therefore the original spelling must stand. There are no authenticated records of P_. insignarius occurring anywhere in Georgia. If it does occur there, I would expect it to be in the mountains of the northwest part of the state, certainly not in the coastal plain of the southeast part from where Abbot made his drawings. Attus f raudulentus Walckenaer could be an immature of any of several southeastern species of Phidippus. MALE: chelicerae weakly iridescent green; 4 ocular tufts, the dorsal pair longer and denser than usual; carapace with submarginal white band of scales extending well back on thoracic slope; clypeus densely covered with white scales and with long white fringe overhanging chelicerae; palpal femur, patella, tibia, and cymbium covered dorsally with white setae; leg I dense white scale cover on prolateroventral surface of femur, patella and tibia; leg I femur with weak dorsal fringe of mixed black and white setae, prolateroventral fringe white and short, retrolateroventral fringe white, very long and dense; all other leg I fringes white, dorsal stripe of white scales from distal tip patella to distal tip tarsus; legs II-IV similar but with progressively reduced fringes and scales, leg IV lacking most scales; dorsum of abdomen with pattern like female but overlain with orange scales; venter of abdomen with median black stripe that narrows toward spinnerets, white stripes on each side. FEMALE: similar to male with following differences: 4 normal setal tufts; submarginal band less distinct than in male; white scales 43 covering clypeus; clypeus and palpi fringed with white setae; legs with simple white fringes; abdomen with white basal band and lateral bands, tan to orange wide stripes laterally, white central triangular spot and white to orange posterior spots. LEG MACROSETAE: femur II DR 0-0-0-0, tibia II 0-0-1R-1P or 0-0-1R-0; patella III R 0-0-0, tibia III 0-0-0-lP, metatarsus III P 0-0-2; metatarsus IV V 0-0-2. princeps group The 2 species in this group, P_. princeps and P_. pulcherrimus, are closely related allopatric species. Both have large, sickle-shaped emboli and a very long epigynal septum. Phidippus pulcherrimus is known from Florida and the southern parts of Alabama and Georgia. Phidippus princeps occurs from northeastern Texas and North Carolina north to Minnesota and New England. This group is probably related to the audax group, as evidenced by some similarities in color pattern. Phidippus princeps (Peckham & Peckham) , 1883 Figures 2-16, 2-31 Attus insolens Hentz, 1835; NOMEN NUDUM A. insolens Hentz, 1845; type destroyed; NOMEN DUBIUM Attus princeps Peckham & Peckham, 1883; type in MCZ, examined Philaeus princeps, Peckham & Peckham, 1888 Phidippus brunneus Emerton, 1891; type in MCZ, examined (synonymized by Bryant, 1942) P. princeps, Peckham & Peckham, 1901, 1909; Kaston, 1948; Barnes & Barnes, 1955; Bonnet, 1958; Berry, 1970; Cutler, 1977; Hill, 1977a, b; Richman & Cutler, 1978; Oehler, 1980 44 P. insolens, Peckham & Peckham, 1909 (in part, cf); Muma & Jeffers, 1945; ?Muma & Muma, 1949 Dendryphantes princeps, Petrunkevitch, 1911; Roewer, 1954 P. dorsalis Bryant, 1942 (in part, 9); paratypes in MCZ, examined The only eastern species that comes close to resembling Hentz's description is the species now known as P_. princeps. The name P_. insolens has been misused for P_. apacheanus, although a badly rubbed specimen of the latter species could fit the description. MALE: integument nearly black; no ocular setal tufts; clypeus sparsely fringed with black setae; palpi fringed laterally with black setae, covered dorsally with white scales on femur and patella; leg I distal prolaterodorsal femur with white scales and setae, distal half patella with black fringe, all fringes unusually short; dorsum of abdomen completely covered with red scales, rarely brown with white or red central triangle and 2 pair posterior spots; venter of abdomen black bordered with row of pale dots. FEMALE: sparse cover of white scales on carapace and legs; 4 ocular setal tufts; clypeus densely covered with white scales and setae especially along ventral edge; palpi fringed with white setae; dorsum of abdomen usually unmarked brown, occasionally with white median stripe running length of abdomen but not reaching either anterior or posterior ends of abdomen, rarely with white triangle followed by 2 pair posterior spots, or intermediate condition between central stripe and spots; venter of abdomen with broad black stripe bordered laterally and posteri- orly by white. LEG MACROSETAE: tibia II V 0-1R-1R-2; tibia III & IV V 0-0-0-2, metatarsus III & IV V 0-0-2. 45 Phidippus pulcherrimus Keyserling, 1384 Figures 2-17, 2-31 Phidippus pulcherrimus Keyserling, 1884; type in MCZ, examined P. pulcherrimus, Marx, 1890; Banks, 1901, 1904, 1910; Peckham & Peckham 1909; Bonnet, 1958; Edwards, 1977; Richman & Cutler, 1978; Edwards & Hill, 1978 Dendryphantes pulcherrimus, Petrunkevitch, 1911; Roewer, 1954 The anecdote by Hill (Edwards & Hill, 1978), proclaiming to be the first description of the male of P_. pulcherrimus, is incomplete. MALE: carapace with short white transverse bands behind PLE; no ocular setal tufts; clypeus with sparse black fringe; palpi fringed with black setae, femur covered dorsally with white scales; dorsal leg I like P_. princeps; dorsal abdominal semi-encircling band yellow (1 specimen) or red, spots white to red, metallic scales on black median stripe; venter of abdomen black. FEMALE: similar to male with following differences: 2 dorsal setal tufts; carapace with bands like male or entire carapace sparsely covered with white to tan scales; clypeus with white scales and setae, especially along ventral edge; palpi with white setal fringe, white scales on tarsus and distal tibia; legs covered with white setae; dorsal abdominal spots usually white, rarely yellow to orange; venter of abdomen with wide black stripe with or without white borders laterally. LEG MACROSETAE: femur II DR 0-0-0-0, tibia II V 0-1R-1R-2; tibia III V 0-0-0-2, R 0-0-1-0; tibia IV V 0-0-0-2; metatarsus III & IV V 0-0-2. purpuratus group Three species occurring in the eastern U. S. belong to the purpuratus 46 group. One species, P_. borealis, ranges across northern North America west from New Hampshire to Washington and Alaska. A primarily south- western species, P_. apacheanus, ranges east from California and Utah to North Carolina and Florida. The third species, P. purpuratus, is restricted to the eastern half of North America. All the species in this group can be readily recognized by the forms of the genitalia. In males, the protegulum is extended anteriorly on the ectal side. The embolus is a short, notched structure which arises anteriorly, but appears to be entally attached to the extension of the protegulum. The epigynum is like other members of the subgenus in the placement of anterior guides but differs in having a deep, rectangular, transverse depression across the central third. The johnsoni group of western North America is intermediate between this group and the audax group. In the johnsoni group, the protegulum is less extended, the embolus longer, and the epigynum lacks the central depression. Phidippus apacheanus Chamberlin & Gertsch, 1929 Figures 2-18, 2-32 Phidippus bardus Peckham & Peckham, 1901; type in MCZ, examined; NOMEN OBLITUM; NEW SYNONYMY P_. insolens (not Hentz) , Peckham & Peckham, 1901, 1909 (in part?) Dendryphantes insolens, Simon, 1901; Roewer, 1954 Phidippus ferrugineous Scheffer, 1904; type in MCZ, examined; NOMEN OBLITUM; NEW SYNONYMY Phidippus apacheanus Chamberlin & Gertsch, 1929; type in AMNH, examined Phidippus nikites Chamberlin & Ivie, 1935; type in AMNH, examined; NEW SYNONYMY 47 P. nikites, Muma, 1949; Bonnet, 1958 Dendryphantes apacheanus, Roewer, 1954 _D. nikites, Roewer, 1954 P. apacheanus , Bonnet, 1958; Gardner, 1965; Levi & Levi, 1968; Cutler, 1977; Richman & Cutler, 1978; Edwards & Hill, 1978; Kaston, 1978; Gertsch, 1979 P. paludatus (not C. L. Koch), Kaston, 1972 The Peckhams (1909) incorrectly synonymized P_. bardus and P_. ferrugineous with .P. insolens (Hentz) . This confusion resulted in a redescription of the species by Chamberlin & Gertsch (1929) as P. apacheanus, by which name it has been known since; the lone exception was Kaston (1972) who used P. paludatus C. L. Koch, but later recognized and corrected his error (Kaston, 1978) . The males of _P. apacheanus (described from Utah) and _P. nikites (described from California) are identical. The P_. nikites type of epigynum differs from the typical P_. apacheanus epigynum in that the central depression is shallow and not set off by a distinct rim. I consider this only a variation; a single female from Florida had a P_. nikites type epigynum, but all other Florida specimens were typical. Other specimens from the type locality of P. nikites were typical of P_. apacheanus (S. Johnson, personal communication, and specimens sent for confirmation). A similar type of variation occurs in females of P_. borealis, and may represent a remnant recessive genetic representation of a less derived condition. The epigynum of the female allotype of P_. nikites is somewhat shrivelled, which has changed the direction of the openings to the spermathecal ducts, accounting for this difference as noted in Chamberlin & Ivie's description. 43 MALE: integument dark; carapace covered with yellow to red scales dorsally in ocular quadrangle and above thoracic slope; 2 dorsal setal tufts; clypeus and palpi fringed with black setae; leg I patellar brush black except white on proximal half of prolateral surface, white scales on proximal half patella; scales on proximal halves metatarsus and tarsus white to orange; abdomen covered dorsally with yellow to red scales except for mid-dorsal black stripe, which may also be overlaid with scales; venter of abdomen black, outer rows of pale dots more conspicuous than inner rows. FEMALE: similar to male with following differences: palpi with lateral yellow fringes; tibia I proximal half reddish, legs with scat- tered white scales; yellow to red dorsal scale cover may be reduced so that spider appears to be black with yellow or red abdominal stripes and a pale basal band; black central stripe may be indented by 0-3 pair of yellow or red spots. LEG MACROSETAE: femur II DR 0-0-0-0; metatarsus III P 0-0-2, R 0- 0-2; tibia IV P 0-0-0-0, metatarsus IV V 0-0-0 or 0rl-2. Phidippus borealis Banks, 1895 Figures 2-19, 2-33 Phidippus borealis Banks, 1895; 2 syntypes supposed to be at MCZ, lost; Neotype designated, the larger of 2 specimens in a vial from the type locality Phidippus altanus Gertsch, 1934 (synonymized by Edwards, 1977) P. altanus, Gertsch & Jellison, 1939; Chickering, 1944; Levi & Levi, 1951 P. borealis, Edwards, 1977; Cutler, 1977; Richman & Cutler, 1978 Phidippus borealis was incorrectly synonymized with P_. purpuratus Keyserling. The types are lost; since Banks' original description was 49 somewhat equivocal, I have designated a neotype male from Crawford Notch, New Hampshire, the type locality; it is deposited in the Museum of Comparative Zoology. MALE: 2 weak dorsal tufts; clypeus and palpi fringed with black setae; leg I patella and proximal half tibia reddish, both fringed with black setae; dorsal abdominal markings tan to orange; venter of abdomen black, inner rows of dots inconspicuous. FEMALE: similar to male with following differences: 2 dorsal tufts; clypeus and palpi fringed with white setae; leg I unicolorous, not banded like male; dorsal abdominal markings white to orange. LEG MACROSETAE: femur II DR 0-0-0-0; tibia III V 0-0-0-2, R 0-0-1- 0; metatarsus III V 0-0-0 or 0-1-2, P 0-0-2, R 0-0-2; tibia IV R 0-0-1- 0; metatarsus IV V 0-1-2, P 0-0-2, R 0-0-2. Phidippus purpuratus Keyserling, 1884 Figures 2-20, 2-33 Phidippus purpuratus Keyserling, 1884 (p. 489) Phidippus albomaculatus Keyserling, 1884 (p. 491); syntypes in MCZ, BMNH, examined; NEW SYNONYMY, Lectotype designated _P. galathea (not Walckenaer) , Peckham & Peckham, 1888 P. mystaceus (not Hentz) , Emerton, 1875, 1891 _P. purpuratus, Peckham & Peckham, 1909; Kaston, 1948, 1978; Bonnet, 1958; Whitcomb et al. , 1963; Cutler, 1977; Richman & Cutler, 1978 _P. electus (not C. L. Koch), Banks, 1910, 1913; NOMEN DUBIUM Dendryphantes purpuratus, Petrunkevitch, 1911; Roewer, 1954 Banks (1910) considered P_. electus to be a synonym of P. albo- maculatus (purpuratus) . Later (1913) he examined the pinned type, found 50 it to be a juvenile, and made no comment on its identity. Other authors have considered it a synonym of P. mystaceus. It probably cannot be recognized. I examined specimens labelled "Type" of _P. albomaculatus from both the Museum of Comparative Zoology and from the British Museum (Natural History). A specimen at the MCZ has been labelled lectotype by L. Pinter, and I so designate it. MALE: integument dark; 2 weak dorsal setal tufts; clypeus and palpi fringed with black setae; leg I all fringes black, with few white setae below normally placed white scales on proximal halves patella, metatarsus, and tarsus, femur prolateroventral fringe very short, prolateral surface of femur with metallic green or blue reflections; dorsal abdominal markings tan to red, spots usually less distinct than in female; venter dark edged with white laterally. FEMALE: similar to male with following differences: 2 dorsal setal tufts; clypeus and palpi fringed with white setae; integument of abdomen dark gray, dorsal abdominal markings white or tan; venter of abdomen black with or without lateral white stripes, inner rows of dots conspicuous. LEG MACROSETAE: femur II DR 0-0-0-0; patella III R 0-0-0, tibia III V 0-0-0-2, metatarsus III V 0-0-1 or 0-0-2, P 0-0-2, R 0-0-2; metatarsus IV V 0-0-1 or 0-0-2. Figure 2-4. Phidippus putnami: A. Ventral view of male palp, B. Ventral view of female epigynum, C. Dorsal view of female. 52 B |ft# 1. Figure 2-5. Phldippus mystaceus: A. Ventral view of male palp, B. Ventral view of female epigynum, C. Dorsal view of female. 54 ^OP^^tf B Figure 2-6. Phidippus cardinalis: A. Ventral view of male palp, B. Ventral view of female epigynum, C. Dorsal view of female. 56 B Figure 2-7. Phidippus pius: A. Ventral view of male palp, B. Ventral view of female epigynum, C. Dorsal view of female. 58 ' gp •• i*M«4 B Figure 2-8. Phidippus whitmani: A. Ventral view of male palp, B. Ventral view of female epigynum, C. Dorsal view of female. 60 jUkJmk B Figure 2-9. Phidippus clarus: A. Ventral view of male palp, B. Ventral view of female epigynum, C. Dorsal view of female, D. Dorsal view of abdomen of male. 62 m a^ /■.*•'/= B^ ■"-/ If if. B »'% #8- '•4i^i:*^ D Figure 2-10. Phidippus audax: A. Ventral view of male palp, B. Ventral view of female epigynum, C. Dorsal view of female. 64 &:r*m B \ Figure 2-11. Phldippus otlosus: A. Ventral view of male palp, B. Ventral view of female epigynum, C. Dorsal view of female. 66 J&z&ii "-■4rar / Figure 2-12. Phidippus regius: A. Dorsal view of female, B. Dorsal view of abdomen of male. 68 B Figure 2-13. Phidippus regius: A. Ventral view of male palp, B. Ventral view of female epigynum. 70 B Figure 2-14. Phidippus xerus : A. Ventral view of male palp, B. Ventral view of female epigynum, C. Dorsal view of female, D. Dorsal view of abdomen of male. 72 B /-..- Figure 2-15. Phidippus insignarius: A. Ventral view of male palp, B. Ventral view of female epigynum, C. Dorsal view of female. 74 B #^^ Figure 2-16. Phidippus princeps: A. Ventral view of male palp, B. Ventral view of female epigynum. 76 *■ ■ B Figure 2-17. Phidippus pulcherrimus: A. Ventral view of male palp, B. Ventral view of female epigynum, C. Dorsal view of female. 78 ^^ri^g^^VT^wTS^A-frf-r**^1^ • m. i c .i!&i*ss5!$ Figure 2-18. Phidippus apacheanus : A. Ventral view of male palp, B. Ventral view of female epigynum, C. Dorsal view of female. 80 &r£& v ^yET i^# . B Figure 2-19. Phidippus borealis: A. Ventral view of male palp, B. Ventral view of female epigynum, C. Dorsal view of female. 82 i te A *£■ Figure 2-20. Phidippus purpuratus: A. Ventral view of male palp, B. Ventral view of female epigynum, C. Dorsal view of female. 84 *\ f^iSP \ vjfc \>* ;^ •-- ,- B 85 Figure 2-21. Distribution map of Phidippus putnami . 86 Figure 2-22. Distribution map of Phidippus mystaceus. 87 Figure 2-23. Distribution map of Phidippus cardinalis, Figure 2-24. Distribution map of Phidippus pius, 89 Figure 2-25. Distribution map of Phidippus whitmani. 90 Figure 2-26. Distribution map of Phidippus clarus. 91 Figure 2-27. Distribution map of Phidippus audax. 92 Figure 2-28. Distribution map of Phidippus otiosus. 93 . N^ Figure 2-29. Distribution map of Phidippus regius. 94 Figure 2-30. Distribution maps of Phidippus insignarius (closed circles) and Phidippus xerus (open circles). 95 Figure 2-31. Distribution maps of Phidippus princeps (closed circles) and Phidippus pulcherrimus (open circles). 96 Figure 2-32. Distribution maps of Phidippus apacheanus (closed circles) and Phidippus borealis (open circles). 97 Figure 2-33. Distribution map of Phidippus purpuratus, CHAPTER 3 IMMATURE STAGES OF Phidippus SPECIES Peckham and Peckham (1909) and Kaston (1948) illustrated some of the immature stages of P_. clarus, and Kaston (ibid) described some penultimate specimens of P_. cardinalis (as P_. mccookii) and P_. whit- man i. Bailey (1968) and Taylor and Peck (1975) measured carapace width for instars of P. audax, and the latter authors also illustrated some of the instars. Edwards (1975) measured carapace width for instars of P. regius. The lack of ability to identify immature stages of spiders has been a hindrance to workers attempting ecological studies (Turn- bull, 1973) and for those working on the effects of spiders on pest populations in agro-ecosystems (e.g., Whitcomb et al. , 1963). For the most part, immatures have color patterns similar to adult females, and the pattern becomes more similar with each succeeding in- star. The most difficult stage to determine to species is the first free-living instar, which in most species has a dark body with no scale pattern. The leg segments distal to the femur are usually much paler in color than the rest of the spiderling. This report is preliminary in many ways, since characters of all instars of all species studied have not yet been quantified. Below I list known color patterns of first instars: P_. apacheanus - body black, distal leg segments black _P. audax, P_. pulcherrimus, P. regius - body black, distal leg segments red 98 99 _P. clarus, _P. otiosus - body brown, distal leg segments light brown _P. putnami - body brown, distal leg segments light brown, small white scale patches at back of ocular quadrangle and on each side of abdomen _P. whitmani - body black, distal leg segments pale yellow P_. xerus - body brown, distal leg segments distinctly orange Those species with the same color pattern are usually separated either by season of occurrence, habitat, or microhabitat . In a preliminary study of the leg macrosetae of successional instars of P. regius, definite differences between instars were noted for the first seven instars (Table 3-1) . Macrosetae were added with each suc- cessive molt. Postembryos lacked macrosetae, and first instars had only a few macrosetae, establishing completely only the dorsal femoral sets and the ventral set of metatarsus I. The second instar added macrosetae to tibia II and metatarsus III, and increased the number on metatarsi II and IV. The third instar added a dorsoprolateral macroseta to all fe- mora, and increased the number on tibia I and metatarsi II, III and IV, completing the set on metatarsus II. The fourth instar completed the full complement of macrosetae on the femora, added setae to all tibiae, and increased by one the number on metatarsus III. The fifth instar added the full complement of setae on patellae III and IV and tibia I, and increased the number on tibiae II, III, and IV and on metatarsi III and IV. The sixth instar completed sets of macrosetae on tibiae II and IV and metatarsi III and IV, while the seventh instar completed the macrosetal complement on tibia III, producing the adult macrosetation pattern. 100 Since most species of Phidippus mature in 6-8 instars, and penul- timate males can be distinguished by their swollen pedipalpi, this method of instar determination is likely to be a more accurate method than measurement of carapace width, since variable growth patterns of individuals result in a size range overlap in the later instars. Randall (1978) found that the macrosetal patterns of the femora of the green lynx spider, Peucetia viridans (Hentz), were virtually 100% reliable for determining individuals of this species to instar. 101 Table 3-1. Leg raacrosetae of instars 1-7 of Phidippus regius. Macro- setal codes are the same as those used for adult Phidippus (see Chapter 2). Values in parentheses indicate variation. Sample size was four individuals for each instar. Macrosetal additions to the previous instar are underlined. First instar femur I, II, III, IV D 0-1-1-1; tibia I V 0-0-2-0; metatarsus I V 0-2-2, II, IV V 0-1-1 Second instar femora unchanged; tibia I V 0-0-2-0, II V 0-0-1R-0; metatarsus I V 0-2-2, II V 0-1-2^, III V 0-0-1, IV V 0-0-1, R 0-0-1 Third instar femur I, II, III, IV D 0-1-1-1, DP 0-0-0-1; tibia I V 0-lR(2)-2-lP, II V 0-0-1R-0; metatarsus I V 0-2-2, II V 0-2-2, III V 0-0-2^, P 0-0-2, R 0-0-1, IV V 0-0-2, P 0-0-2, R 0-0-1 Fourth instar femur I D 0-1-1-1, DR 0-0-0-2^, II, III D 0-1-1-1, DP 0-0-0-2, DR 0-0-0-1, IV D 0-1-1-1, DP 0-0-0-1, DR 0-0-0-1; tibia I V 0-2UR)-2-2, II V 0-0-1R-0, P O-Q-l-0, III P 0-0-1-0, R 0-0-l(0)-0, IV V 0-0-0-2 (1R), r o-Q-i-0; metatarsus I, II V 0-2-2, III V 0-0-2, P 0-0-2, R-0-0-2^ IV V 0-0-2, P 0-0-2, R 0-0-1 Fifth instar femora unchanged; patella III, IV R 0-1-0; tibia I V 0-2-2-2, II V 0-0-(_lR)-lR-2(lP), P 0-0-1-0, III V 0-0-0-2 (IP), P 0-0-1-0, R 0-0(l)-l-0, IV V 0-0-0-2, P 0-0-1-0, R 0-1-1-0; metatarsus I, II V 0-2-2, III V 0-1-2, P 0-0-2, R 0-0-2, IV V 0-1-2, P 0-0-2, R 0-0(1) -2 Sixth instar femora unchanged; patella unchanged; tibia I V 0-2-2-2, II V 0 lR(0)-2(lR)-2, P 0-0- ;-0, III V 0-0-0-2, P 0-0-1-0. R 0-l(0)-l-0, IV V 0-1P-0-2, P 0-0-1-0, R 0-1-1-0; metatarsus I, II V 0-2-2, III V 0-2(l)-2, P 0-l(0)-2, R 0-0-2, IV V 0-1-2, P 0-l(0)-2, R 0-1-2 Seventh instar femora unchanged; patellae unchanged; tibia I, II unchanged, tibia III V 0-0-0-2, P 0-0(l)-l-0, R 0-1-1-0, IV V O-lp-0-2, P 0-0-1-0, R 0-1-1-0; metatarsus I, II un- changed, metatarsus III V 0-2-2, P 0-l(0)-2, R 0-l(0)-2, IV V 0-1-2, P 0-1-2, R 0-l(0)-2 (essentially adult macrosetae pattern established) CHAPTER 4 HYBRIDIZATION IN Phidippus SPECIES Introduction Hybridization in arthropods has been known for several decades. Much of the early work on Drosophila by Dobzhansky and Patterson and their respective coworkers was reviewed by Patterson and Stone (1952). Clarke and Sheppard (1953) crossed four species of swallowtails (Papilionidae) in the laboratory. The contention of early taxonomists was that interspecies hybridization was unimportant to the evolution of species. This view was challenged by Sailer (1954), who, using his own data on crossing of 2 species of Euschistus (Pentatoraidae) and reanalyzing data of earlier workers, demonstrated that hybridization could be a highly influential factor in affecting evolution of species, and even in creating new species. Spider hybrids have been infrequently reported (Gerhardt, 1928; Bonnet, 1933; Locket, 1939). Dondale (1964, 1967) used hybridization experiments as an aid in species determinations in Philodromus (Philo- dromidae) . Below I report on laboratory hybridization of Phidippus otiosus X P. regius and the subsequent discovery of hybridization under natural conditions between these two species. Speciation events are hypothesized based on geographic distribution of the two species. Laboratory crosses of other species of Phidippus are also noted and their significance discussed. 102 103 All laboratory crosses were obtained by the methods described under the courtship behaviors of other species (Chapter 5), and the descrip- tions of hybrid courtship are reported there. Rearing of hybrid offspring followed the procedure described by Edwards (1975). Maturation rates and sizes of F crosses were compared with parent species. Matings were attempted between F males and females, and F individuals were back- crossed to both parent species. Fecundity of hybrids and backcrosses was compared to parent species. Laboratory Results Crosses Three out of three attempted crosses of P_. otiosus males X P. regius females from Alachua County were successful and produced viable offspring. Offspring from two of the crosses were reared; male hybrids were signifi- cantly smaller than males of P_. regius and P_. otiosus reared under similar conditions and the hybrid males matured in fewer instars than either of the parent species. Of 80 original offspring, 4 died as juveniles, 24 became males, and 52 became females. This sex ratio is approximately 1:2 in favor of females, whereas the sex ratio of P_. regius is typically about 1:1. Although Pinter and Walters (1971) reported the 2n chromosome comple- ment of males of 3 species of Phidippus (P. regius, P_. audax, and P_. j ohn- soni) to be 20 autosomes + X X„0, Wayne Maddison (personal communication) has found the chromosomes of P_. audax and P_. purpuratus to be 26 + X X 0, as has been noted for most of the 35 species of salticids reported in the 104 literature (e.g., Painter, 1914; Mittal, 1964). If the sex chromosomes were involved in the determination of the unusual sex ratio, one might have expected the females rather than the males to be the affected sex, due to the sex determining mechanism (males are X X 0, females are X.. X- X„X„ / • Although theoretically, hybrid males should be partially fertile when backcrossed to parent species, evidence presented below indicates that they were sterile or at least incapable of reproducing. This could be due to a number of factors: premature maturation could affect the number or viability of sperm, small size and/or hybrid courtship could cause rejection by females, and hybrid structure of embolus or palpal tibial apophysis could prevent successful copulation. The latter case was observed in the single successful courtship of a female P_. regius by a hybrid male. The male was unable to engage the epigynum of the female, even after repeated attempts. A single attempted cross of a P_. otiosus male with a P_. regius female from Palm Beach County was unsuccessful. This female accepted a P_. regius male immediately prior to rejecting the P_. otiosus male, and subsequently accepted an F hybrid male (which was unable to copulate; see above) immediately after rejecting the P_. otiosus male. Phidippus otiosus has not been reported from south of Lake Okeechobee; the southern- most record is a male from Archbold Biological Station near Lake Placid, Highlands County. Muma (1975) reported P_. otiosus from Polk County. The geographic significance is discussed below. Three attempted reciprocal crosses with P_. regius males X P_. otiosus females resulted in two successful matings but no offspring, and in the third encounter, the male killed the female. 105 Eight F male X F female crosses were attempted. On three occasions the females refused to mate, on four occasions females killed the male, and one male successfully copulated but no offspring were produced. The small size of the males apparently contributed both to their inability to defend themselves and to their rejection by females. Female predation on males prior to copulation is probably a strong selective pressure on males too small to defend themselves. In most cases, the large chelicerae and enlarged legs I of the male are used to repel a frontal attack by a female (Hill, 1977a); but small males do not have sufficient strength to fend off a female's attack. Supportive evidence is provided in later discussion of other attempted crosses. Two hybrid F females were backcrossed to parent species males, one each to a P_. regius male and to a j?. otiosus male. Total viable offspring (measured by number of eggs hatched) for the backcross to the P_. regius male was 8 in the first eggsac, and 42 in the second eggsac, a total of 50. The number of viable offspring for the back- cross to the P_. otiosus male was 36, 16, and 8 in the first, second, and third eggsacs, respectively, a total of 60. Total infertile eggs were not counted, but few were noted. Hybrids were described by Edwards (1975). To briefly summarize, 7 females looked like _P. otiosus with dorsal abdominal spots like _P. regius, whereas F males looked like P. regius with carapace bands and dorsal abdominal spots like _P. otiosus; the markings of males were very pale orange, not white like J?, regius or deep orange like _P. otiosus. Results of F backcrosses are incomplete as laboratory populations, reared in an outside insectary, were killed by exposure to the sun's rays as the angle of the sun changed in the fall. However, a few males did 106 mature before the colonies were destroyed. Fourteen males and 4 males, as a result of F1 backcrosses to P_. otiosus and P_. regius males, res- pectively, matured before destruction of the colony. Off- spring of backcrosses to P. otiosus were evenly divided between males that looked like F1 males and males that looked very much like _P. otiosus males (the main difference in the latter males from _P. otiosus males was the exaggerated color pattern which was more brightly orange and gold than a normal P_. otiosus male) . Offspring of backcrosses to P_. regius resulted in 2 males that looked like an F male, and 2 males that looked like P_. regius males (except that the carapace bands were still present; all of the markings were pure white as in a normal P. regius male) . This last mentioned form was of great interest, as it was essentially identical in pattern to the species described as Phidippus tullgreni by Wallace (1950) , and was also the same as occasional males previously determined to be a rare color form of P_. regius. Field Records As part of a rearing program designed to compare life histories of various species of Phidippus (not reported here) , I began rearing off- spring from 5 different females of P_. regius, each collected from a different locality. After only a few instars, it became apparent that the offspring of the female from a very xeric habitat in Levy County (a turkey oak- rosemary area, just across the Alachua County line) were different in appearance than offspring of the other females, and were very similar to the F hybrids I had reared earlier. When some of these offspring matured, they were determined probably to be the result of either a direct mating with a P_. otiosus male, or of a male from a second or third generation removed backcross from an earlier hybridiza- 107 tion. The latter situation was considered a possibility since most of the males resembled the F.-backcross males more than they did F. males from the laboratory crosses, i.e., most of the males had white markings and only a few showed the pale orange tint present in the laboratory- reared F males. Since I began collecting P. regius 8 years ago, I have collected several dozen males and examined approximately 200 others in various collections. Of these specimens, 7 had white carapace bands. As mentioned above, F -backcross males were very similar to the field- collected males with white carapace bands. I therefore had to consider the possibility that these 7 males were exhibiting introgressive charac- ters as a result of a previous hybridization in their ancestry. I was able to collect one of these males in the xeric hammock which constituted one of the three primary study sites (see Chapter 10 and Appendix D) . This male was crossed with a gray female also from Alachua County. The female made 2 eggsacs, neither of which was fertile (in fact, no distinct eggs were formed). This result seems to be addi- tional evidence supporting the hypothesis that hybrid males are sterile. The only field-collected female that I would consider a hybrid was a specimen collected in Ocala National Forest, Marion County. It essentially had the appearance of P. otiosus, but the posterior abdominal spots were intermediate in shape with P_. regius. Females of P. regius almost always have either an unmarked carapace, or the carapace is almost completely covered with scales. Occasionally (in about the same propor- tion as males) females have pale yellowish or white carapace bands which are similar to those of P. otiosus. Possibly these females also repre- sent earlier introgressive matings. 108 Much of the above was more or less speculative, since what occurs in nature does not necessarily follow what might be manipulated in the laboratory. It is possible that the variation apparently exhibited by P. regius could be the result of true genetic polymorphism. A simi- lar polymorphism in presence or absence of white carapace bands is well documented for the related P_. audax (Kaston, 1948). Strong evidence supporting the validity of the preceding discussion of hybridization in natural situations was provided by Dr. John F. Anderson, who collected a male ¥_. otiosus in copula with a female J?, regius, 19 September 1980, on a small tree at the interface of a field and swamp forest at the south end of Newnan's Lake. Ecological Factors Affecting Hybridization My first hypothesis for hybridization between P_. otiosus and P_. regius was based on the fact that I had collected apparent hybrids in xeric woods habitats. Since the populations of the two species were likely to be and seemed to be at very low densities in xeric habitats, the chances of a female going unmated once maturity was reached were increased. A female should, eventually, rather mate with a related species and produce some viable offspring, than to not mate and be totally without offspring. Another factor is that a female is more likely to mate if it is in a nest when found by a male (Jackson, 1976); in Jackson's laboratory experiments, even already mated females occasionally remated under these circumstances. (I have on one occasion found a male J?, regius cohabiting with an obviously gravid conspe- cific female, lending support to the possibility that multiple matings of a single female occasionally occur under natural conditions.) Of course, the implication is that a male has an increased chance of mating with a 109 non-specific female if he finds her in a nest. Other crosses between species under similar circumstances are reported below. Using the clue provided by Anderson, who found a hybridizing pair in copula in an obviously non-xeric environment, I rechecked the habitat data for the seven white-banded males of P_. regius . They were found in one of three situations: lake edge, xeric hammock, and open pine flat- woods. Because P. otiosus is a canopy species, while P_. regius is an old field species that moves onto shrubs and palmettoes as an adult and then to various trees to reproduce, two types of opportunities are pre- sented for interaction: 1) When P_. regius females are searching for shelter under tree bark in which to lay their eggs, they may be encount- ered by P. otiosus males searching for conspecific females that are also searching for nesting sites in the smae situations at the same time; opportunity for this type of interaction would be most frequent at inter- faces of fields and woods along lake shores, where P_. otiosus is most abundant. 2) In open woodlands, young P_. regius develop in the herb zone, but if there is no shrub or mature palmetto understory, the adult P_. regius move directly to the trees instead. Here they are directly competing with P_. otiosus for food and nesting sites for a longer period of time than in the first situation. In one such situation, a slash pine plantation in Duval County, P_. regius has apparently completely displaced P. otiosus in the trees (R. A. Belmont, personal communication and specimens brought in for identification from the canopy of the pine plantation, obtained with the use of a cherry-picker at 50' height in the top of the canopy) . Phidippus regius has been taken from the top of coconut palms by similar means in South Florida (J. A. Reinert, collector), where P_. otiosus does not occur. Muma (1975) reports both species from citrus groves, another instance of a single-layered canopy. 110 It is perhaps in this second situation that my original hypothesis is partially valid, since conditions favorable to P_. regius may permit it to exclude P_. otiosus. In certain arid habitats, for example xeric hammock (which has little shrub understory) , environmental factors may be stringent enough to keep populations of both species at low levels, allow them to coexist, and thus improve the chances for crossbreeding. Sailer's (1954) contention that introgression may be important to the evolution of species seems to apply for one character of P_. otiosus. This species increases in mean length from the northern part of its range to the southern part, which, considering its potential competitors, is just the reverse of what might be expected. In Maryland, _P. otiosus is the same size as the synchronic P. mystaceus, the other primary canopy species in the region. Since both of these species are apparent- ly uncommon in the region, perhaps the populations are small enough so that the resources are not limiting and therefore no competition is occurring. In the other situation, P_. otiosus approaches the size of P_. regius where the two species occur together. Since these two species are also synchronic, and P_. regius can potentially displace P_. otiosus in certain circumstances, one might expect that _P. otiosus would evolve toward smaller size in order to reduce competition for food and nesting sites. Although other factors may be involved that are not readily apparent (such as competition with other medium-sized canopy salticids like Dendryphantes pineus, Metacyrba undata, or Thiodina sylvana) , one feasible explanation of large size in P_. otiosus is the introgression of genes for large size from P. regius. This would imply a massive period of interbreeding over one time period or frequent hybridization presently, discussed in the following section. Ill Species Relationships, Geologic History, and Speciatlon Although I have emphasized in the above discussion the ability of P_. otiosus and P_. regius to hybridize, I have said nothing about their actual relationship. They in fact appear to be sister species, and a comparative examination of their genitalia (see Chapter 2) reveals a great deal of similarity between the two species. However, although the basic structures of the body markings are similar, the color patterns are quite different. In contrast, the color patterns of the sister species (?) _P. cardinalis and P_. pius are nearly identical, yet the male genitalia are quite different. These two opposite extremes seem to represent a principle that has not been commented on in the litera- ture (P. Perkins, personal communication), but is apparently a widespread phenomenon. That is, closely related species differ greatly in the form of the genitalia or in their appearance. An example of the former is the species of Mycotrupes (Scarabeidae) , which are similar metallic green or blue in appearance, but have amazingly complex genitalia which look completely different from species to species; an example of the latter is a species pair of Cicindela which have nearly identical genitalia, but one species is extremely hirsute, while the other species is nearly glabrous and highly iridescent (personal observation and P. M. Choate, personal communication). While the principle may be generally applicable, this particular interpretation seems to apply most readily to visually-oriented animals. It should be applicable to any two- dimensional system including genitalia as one dimension, e.g., cricket song similarities versus genitalic similarities, and therefore is a testable hypothesis. The ranges of P_. otiosus and P. regius overlap to great extent (see maps Chapter 2). Phidippus otiosus ranges a little farther north 112 than P_. regius, whereas the range of P_. regius includes the southern tip of Florida, the Florida Keys, and the Greater Antilles. The geo- logic history of Florida has been one of alternate island formation and reconnection throughout the Cenozoic with little agreement as to whether or not the peninsula was totally submerged. At least there seems to be agreement that a peninsula existed in late Pliocene, and that four periods of island formation occurred during the Pleistocene, at least two of which caused major island formation (MacNeil, 1950). Certain groups of lizards (Carr, 1940), snakes (Highton, 1956), scarabs (Myco- trupes; also see above) (Hubbell, 1954), cicindelids (P. M. Choate, personal communicaton; one of the two species of Cicindela mentioned above has a distribution which corresponds with Red Hill Island of the Pleistocene Aftonian Interglacial stage), grasshoppers (Hubbell, 1956), and wolf spiders (Wallace, 1942; McCrone, 1963; Brady, 1972) have endemic Florida species with distributions roughly corresponding to the divi- sion of the Florida peninsula into islands during the Pleistocene. McCrone hypothesized that the Aftonian Interglacial isolated three populations of Geolycosa (Lycosidae) , on the Trail Ridge, Lake Wales, and Red Hill island groups. Since these spiders are fossorial they probably dispersed little from their centers of origin during the subsequent Kan- san Glacial stage. During the next Interglacial, the Yarmouth, the Trail Ridge islands were connected to the mainland, although extensive swamp prevented gene flow, and Lake Wales Ridge and Red Hill Island were connec- ted, allowing gene flow between these populations. The net result was the formation of two new species from the parent Geolycosa pikei (Marx) of the mainland: C;. patellonigra Wallace in north-central Florida, and CI. xera McCrone; the latter species was further divided into subspecies corresponding morphologically with the initial geographic isolation of the Lake Wales island group from Red Hill Island. 113 Island formation can be used to hypothesize the speciation process separating P_. regius from P. otiosus. A different interpretation of the significance of island formation from Geolycosa must be presented, since Phidippus species have much greater dispersal ability than species of Geolycosa, and only one new species evolved (actually three new species evolved, but P_. xerus and P_. pulcherrimus are not closely related to P_. regius and are the result of isolation of parts of populations of different parent species) . Assuming P. otiosus to be the parent species, since it has the more northern distribution, it would have been isolated on the mainland during the Aftonian Interglacial, with isolated populations in the same three island groups mentioned above. But the distance of Red Hill Island from the Lake Wales island group, and the distance between the Lake Wales and western Tampa Bay island groups, was probably insufficient to maintain isolation of the populations in this region, since the ballooning early instars could easily travel this distance if the wind was favorable. Therefore, probably two populations were isolated, a northern and a southern. Edwards (1975) noted a marked delineation in color pattern of P_. regius females which corresponds well with this hypothetical isolation pattern. Females from Alachua County north were either black or gray, whereas females from Marion County south were either orange or brown. The gray and brown forms may represent various intergrades of the black and orange populations which are nearly pure at the northern and southern extremes, respectively, of their ranges. This may be a relative function of actual gene distribution or selection for various colors. Evidence for the latter is found in various other animals. Animals in wet forested habitats tend to be darker than rela- 114 tives in open arid habitats. Scarabs of the genus Phanaeus in Florida are dark in river swamp and metallic green and copper in xeric open woodlands (P. M. Choate, personal communication); Phidippus otiosus is darker in river swamp and cypress dome habitats than in xeric open woodlands (personal observation). Color selection in _P. regius may be for darker females in the extensively forested north Florida area, and oranger females in the sandy open xeric scrub areas of central and south Florida. I have collected gray females from tropical forest in south Florida, which adds further support to the general observed pattern of color distribution with habitat association. During the Kansan Glacial stage, when the populations were recon- nected, gene flow on the sibling north-central population would come from both north and south. Some genetic isolation must have occurred prior to this time due to the gene complexes of the isolated popula- tions adapting to the peripheral habitats in the absence of gene flow from the mainland population (genetic isolation of this type is dis- cussed by Mayr, 1954). The more northern isolated population would be subject to greater hybridization pressure due to its proximity to the parent population. Also, the swamp barrier of the Yarmouth Interglacial would be ineffective in preventing gene flow between mainland and Trail Ridge populations. The southern population would again be isolated at this time. Presumably, the southern population was at one time connected to or was able to disperse to the Greater Antilles; females of P. regius in the Caribbean are generally orange. Since the two populations of _P. regius apparently interbred freely upon reuniting, it can be assumed that the conditions of their separate isolations and respective gene pools were so similar that reproductive isolation between the two populations was not achieved. Their rapid 115 and extensive dispersal ability was probably also a factor in reuniting populations once the peninsula had reformed. This pattern of isolation and speciation could explain why northern females of _P. regius, which historically have more often been associated with _P. otiosus, were more likely to mate with _P. otiosus males than were the southern _P. regius females which rejected a JP. otiosus male, despite the fact that the reverse (behavior isolation in sympatric popu- lations) would be expected. The amount of introgression of JP. otiosus into_P. regius is certainly like to be greater in the northern population of _P. regius, perhaps enough so that pre-copulatory reproductive isolating mechanisms are broken down, at least under certain circumstances, e.g., low population densities. Southern females of P. regius would be far less likely to be affected by introgression, and might be expected to be more discriminating in choosing mates. Hybridizations Between Other Species P. regius X P. audax A male of _P. audax from Arkansas was placed in a petri dish with a nesting, virgin _P. regius female from Alachua County (P. regius does not occur in Arkansas, but_P. audax occurs in Florida). The P_. audax male was able to enter the nest and attempt mating; however, he was apparently unable to copulate, i.e., he could not engage the epigynum with the palpal tibial apophysis. The female did not produce offspring. P. princeps X P. pulcherrimus Seven Type 1 (visual) courtships were observed between members of these sister species; three were P_. pulcherrimus males X P. princeps fe- males and four were P_. princeps males X P. pulcherrimus females. Only one courtship was successful, between a_P. pulcherrimus male and _P. prin- 116 ceps female, and it culminated in a successful mating. This particular female was feeding during courtship, and did not successfully fend off the male as did the non-feeding females in the other pairings. The female that mated died 20 days after mating without making an eggsac, which is less than the average 30 days reported for P. regius to make an eggsac after mating (Edwards, 1975). Therefore the results of the mating were inconclusive. Laboratory-reared males of _P. princeps are usually small when compared with females and they are subject to intense predation by females during laboratory mating experiments. I have observed a single case of post-copulatory predation by a female of a male immediately following copulation after Type I (visual) courtship. Hill (1977a) noted several instances of post-copulatory predation after Type II (tactile) courtships; he also noted, however, that Type II courtship was a much more successful mating strategy thau Type I courtship in terms of mating duration. P. apacheanus X P. cardinalis These two species are synchronic and syntopic, and both appear to mimic mutillids. The males also have similar courtships (see Chapter 5). On two occasions, I placed males of P_. cardinalis with females of P_. apacheanus. All were field collected, an adult and an immature of each species; the latter were reared to maturity in the laboratory. Both males of _P. cardinalis were smaller than average. Both males began courting the females. The females watched for a few seconds, then approached, attacked, and killed the males. In both instances it was clear that the males were too small to defend themselves. CHAPTER 5 THE COURTSHIPS OF EASTERN Phidippus Introduction The known courtships of salticids have recently been reviewed by Jackson (1976) and Richman (1977). The courtships of only 9 species of Phidippus have been described (with a tenth in preparation; Jackson, in manuscript) (Peckham & Peckham, 1889; Kaston, 1936; Snetsinger, 1955; Gardner, 1965; Dewey, 1965; Bailey, 1963; Taylor and Peck, 1975; Ed- wards, 1975; Richman, 1977; Jackson, 1978b). Jackson (1977a, 1978a, b) described 2 types of courtship employed by male P_. Johns on i under the following 3 conditions: Type I courtship with adult females outside nests, Type II courtship with adult females inside nests, and Type II courtship plus cohabitation with subadult females inside nests. These courtship strategies appear to be utilized throughout the genus, as several of the species in this study were found to cohabit in the field. The present work reviews and redescribes the courtships of 5 species, and describes for the first time the courtships of 8 additional species. Courtship of a hybrid (P. otiosus XV. regius) is also described. All eastern U. S. species of Phidippus are represented except P. borealis, J?, insignarius, and _P. pius, which were unavailable for study. The courtship of P. mystaceus, which includes a new method of communication for salticids, is dealt with in greater detail in the following chapter. Methods, Materials and Terminology Observations of courtship were made in one of two ways: Either a male and female were released onto a formica-covered table top about 10 117 118 cm apart, or a male was introduced into a petri dish containing a female and her nest. If in the former case the event was to be filmed, the table top was covered with a sheet of construction board marked with a grid containing 1 cm graticules. Timing of movements was made with the sweep hand of wrist watch for sequences of observed movements, or by counting frames in filmed courtships and converting to seconds. The analyses of courtships for each species are composites of both observed and filmed courtships. Due to the fact that sample sizes for most species were small, only ranges are given for particular measures of positioning or movement, unless this figure is mis- leading, in which cases the means are also given. The mean was closely associated with the median (e.g., range 1-3, mean = 2 indicates that most of the time the measurement was 2; range 1-3, mean =1.5 indicates measurements were usually 1 or 2) . This is important to remember, since all measures of movement were integers except for the actual timing of events. Femora I were either perpendicular to the substrate (90°) or angled forward (<90°); they were also held close to the body (0°) or held away from the body (45°+). The distal segments of leg I (patella, tibia, metatarsus, tarsus) were always at a different angle than the femur since the leg was bent at the femur-patella joint; usually the distal segments were in a straight line, but in a few species a second bend occurred at the tibia-metatarsus joint. In the latter cases, the figure for the metatarsus-tarsus angle is given in Table 1, and the patella- tibia (mid-leg) angle is discussed in the text. In most species, the distal leg was turned outward at the femur-patella joint; the amount of this positioning is measured in degrees from each leg I to the midline (sagittal plane) of the spider. A flick is defined as a sudden upward 119 Table 5-1. Courtships of eastern Phidlppus species, describing major types of movements and positioning of appendages used by males to sig- nal females. Details are described in the text. Asterisk indicates forward movement lacks a lateral component. Letter R indicates leg I is rotated. # filmed // observed femur I to substrate (°) femur I to spider (°) distal leg I to substrate (° ) distal leg I to spider midline (° ) 10-20 peak of flick (°) # leg movements/sequence // paired alternate palp movements /sequence // lateral moves/sequence // sequences time of sequences (sec.) time of pause (sec.) 2 4 5 5 1 1 3 12 20 90 90 70-90 60 45 45 45 0-40 45 30-35 45 .0-20 0-5 30-40 45-85 none none 80 90 2-5 6-8R 1 1 0 l/4sec 2-4 2-6 x=3 x=4.2 1-4 1* 1 1 1-8 4-5 6+ 4-11 4-7 1-3.5 2.5-6 x=4.9 x-2.5 x=3.9 5-23 2-7 2-4 x=10.8 x=4 x=3 Table 5-1 - extended. 120 4 2 90 45 0 7 0 90 0 20 45-85 30-40 90 35 1 4 45-60 45 0 0 20 2-4 3-4 x=2.5 x-3.2 4-7 x=5 1 6+ 2.0 4.5-7 3-5 4-14 x=7 3-4 1 9-10 1-1.5 2.2 3-9 x=3.6 1 5 90 0 45 0-40 70 1-3 x=2 1 6+ 1-2.5 1.5-6 1 4 45 0 10 15 25 2 2-3 1 16 1-1.5 1.0 2 0 40 45 -10 45 70 1 0 2 5 90 0 75 0 90 1-2 2? 1 1 1 8 0 0 90 90 90 0 45 0 45-50 30-70 30 0-10 0-25 0-5 90 50-90 45 1-3 ? 1-2 5-1.5 0 0? 11 1* 1 6+ 13-15 3-20 4+ 1-2.5 1-1.8 .5-1.5 1.6-2 3-4.5 x=1.5 3-6 4-15 9-60 4.5-6.5 5-11 x=6.2 x-21 x=5.3 x-8.8 121 movement of an appendage, which in most species is brought immediately back down to the original position of the appendage. The amplitude of a flick varies among species. A sequence of movement is defined as any actions occurring consecutively or simultaneously. Each sequence is separated by a pause in which no leg movement occurs. Results General Similarities Males, even though they have several species-specific components to courtship, have certain components in common. The palpi are always held to the sides of the chelicerae, which exposes the iridescent sur- face of the chelicerae. Only in P. putnami , which has cheliceral scale and setal patterns, do the palpi cross in front of the chelicerae (also in the closely related J?, femoratus ; R. R. Jackson, personal communica- tion) . Stage II courtship (Crane, 1949) is also essentially the same among all species; T?. mystaceus assumes a similar position early in Stage I. In Stage II courtship, the legs I are extended forward paral- lel to touch the female and the whole body is lowered close to the substrate, whereas in Stage I the prosoma is elevated and the legs I are positioned or moved otherwise in a species-specific manner. Although the abdomen may appear to be shifted from side-to-side during the zig- zag approach of males of most species, this position appears to result from reattaching the dragline to the substrate at the end of each sequence of lateral stepping movements. When the spider changes direction, the release of silk for the dragline may not occur as fast as the spider is moving, resulting in the abdomen, which turns easily on the pedicel, being held back by the pull of the attached dragline. While this could be done deliberately, there do not appear to be any abdominal modifications 122 intended for use in courtship. Likewise, abdomen bobbing by males did not appear to have any particular significance to courtship and usually occurred in an erratic fashion. It often occurred in conjunction with the specific sudden movement of an anterior appendage and may be an artifact of a sudden increase in hemolytic pressure intended to move the appendages, since spiders have an open circulatory system. Abdomen bobbing also occurs during mating, with each expansion and contraction of the hematodocha. Males began courting from 3-6 cm from females, although Kaston (1936) reported three of the species reexamined here (P. audax , P_. clarus, P_. purpuratus) began courting as far away as 10 cm. Several species, during a lateral movement sequence which angled toward the female, partially retreated at the end of a sequence. The lateral movement was in the form of an asymmetrical arc. The behavior of females during courtship consists of a set of actions, which, as they are not as directly involved in species specific recognition as are the movements performed by males, are essentially the same from species to species. Jackson (1978b) has described the set of behaviors used by female P_. johnsoni during attempted courtship by males, and although all of the behaviors described by Jackson have not been observed for each species considered here, it seems likely that these behaviors will be found to apply generally throughout the genus. To briefly summarize these movements, adult females outside nests, upon the approach of a courting male, may strike at the male with fangs or forelegs, may raise the forelegs to block an attempted mount by the male, may remain motionless and allow mounting and mating, or may decamp (run away). Adult and subadult females inside nests have a similar 123 repertoire of behaviors; additionally they have a variety of percus- sionary activities utilizing the legs and/or body, as well as the option of holding the entrance to the silken chamber closed with their fore- legs. Phidippus mystaceus Anterior decorations of male. Chelicerae covered with white fringe proximally, iridescent green dis tally; clypeus fringe white and yellow; palpi with white fringes and dorsal cymbial spot of mixed yellow and white scales; legs I fringed with yellow ventrally, covered with yellow scales (especially venter of femur) except lateral sides of femur, and with black tuft on dorsum of femur; 4 dorsal setal tufts. Type I courtship. Stage I courtship is divided into two stages; la, whish is similar to Stage I in other species, and lb, which is a stage in which sound is produced. Stage lb is elaborated on in the following chapter. Stage la is sometimes omitted altogether in the courtship sequence. In one instance (first courtship) the stages were alternated several times. When it occurs, Stage la is unusual in that the legs I are bobbed or rotated slightly (films are inconclusive) and continuously while lateral movement occurs. Lateral movements usually consists of one change of direction (0-3) with virtually no pause when changing direction during a sequence. Pauses between sequences were fairly long; the legs I continued to be bobbed and the palpi stridulated during pauses. Lateral movements were much wider than other species (2-2.5 cm vs 0.5-1 cm for other species). 124 Phidippus putnami Anterior decorations of male. Chelicerae striped with red and white scales proximally, covered with blue-gray scales distally; clypeus with red scales and white fringe; palpi with blue-gray and white scales; legs I fringed ventrally with yellow or variegated with black, white and yellow, and venter of femur metallic blue, with ventral yellow tuft; dorsal setal crests. Type 1 courtship. The courtship of this species is quite slow, equalled or surpassed in length only by that of P_. whitman! and Stage lb of _P. mystaceus, both of which are otherwise quite different. At the beginning, both legs are bobbed alternately, then one begins rotating and the other stops. After a long pause, the other leg begins rotating. During each rotation of a leg I, the male advances directly toward the female, initially as much as 1.5 cm per move, later only a few mm as he nears the female. The palpi keep up a steady, alternate rotation, crossing in front of the chelicerae beginning with an upward, inward motion. One rotation occurs every 2 sec. and continues whether the male is moving or stationary; palpal movement continues until Stage II begins. The courtship of _P. putnami differs from other species in its long pauses, alternate rotation of legs, and rotation of palpi. Phidippus otiosus Anterior decorations of male. Chelicerae iridescent green-blue; clypeus fringe black; palpi black and orange, legs I fringed with black and orange; 4 ocular tufts. Female chelicerae are iridescent orange- gold-green, a unique color combination that may be important for recog- nition of the female by the male. 125 Type I courtship. The legs I are held away from the body and fairly high. The single flick per sequence occurs at the beginning of lateral movement; it is not quite vertical nor are the legs I quite parallel. The flick is relatively soft, i.e., is not a quick up-and-down jerky movement, but rather a smooth upward movement after which the legs I are gradually dropped back to their original position. The palpi are moved back-and-forth alternately just as the movement sequence ends. Some individual variation exists in timing of movement and pauses, but in all cases the pause is about twice the length of the movement se- quence. The courtship is similar to that of P_. regius, except the flick is softer, the legs I are not spread as wide or brought as high, and the movement sequence faster. The anterior decorations also have different coloration than P_. regius. Phidippus regius Anterior decorations of male. Chelicerae iridescent green-blue- violet; clypeus fringe black; palpi black and white; leg I fringed with black and white; no ocular tufts. Type I courtship. The legs I are held wide and moderately high. The flick is a quick, strong up-and-down movement, bringing the legs I straight up and parallel, then quickly back to their original position. The flick occurs at the beginning of the lateral movement sequence, and palpal movement as in P_. otiosus occurs at the end of the sequence. Some individual variation occurs in timing, but sequences averaged only slightly longer than pauses. Although similar to _P. otiosus, the courtship of P_. regius was more extreme in its position and movements, and the timing of the lateral movement sequences was longer and similar in duration to the pauses 126 between sequences. Large males, with their allometrically larger legs I, held the legs I closer together and lower than normal, and did not raise them as high during the flick. Phidippus otiosus X Phidippus regius hybrid Anterior decorations of male. Chelicerae iridescent green-blue; clypeus fringe black; palpi black and white; legs I fringed with black and white; no ocular tufts. Type I courtship. Although parts of the courtships of both parent species were sometimes mixed in various ways, most often the courtship of the hybrids was as follows: The femora were held straight up and the distal part of the leg was spread very wide and parallel to the sub- strate. The flick was at the beginning of the lateral movement, and was very high and parallel, usually hard like P_. regius, sometimes soft like P. otiosus. The palpi were moved at the end of the sequence as in both parent species. The pause was at least twice as long as the lateral movement sequence. Overall, the position and movement of the legs I and the coloration was like P_. regius, but the timing of movements and pauses was like P_. otiosus. Phidippus audax Anterior decorations of male. Chelicerae iridescent gold-green- blue; clypeus fringe black; palpi black and white; legs I fringed with black and white, no ocular tufts. Type I courtship. At the beginning of courtship the legs I are waved alternately; occasionally this type of movement is maintained throughout Stage I. Usually, however, the legs 1 become synchronized on the second or third lateral movement sequence. The legs I are held close to the body, moderately spread at the femur-patella joint, and 127 distally held about 20° above parallel to the substrate. The flick is a short upward inward movement, bringing the tarsi halfway between par- allel and touching one another. Usually two but up to four flicks may occur beginning as the lateral movement starts. The palpi move at the end of the movement sequence as in .P. otiosus. The lateral movements and pauses are both quick, the pauses slightly longer. The combination of femora held close to the body, moderate upward angle to the distal legs I (intermediate between J?, princeps and P_. pulcherrimus) , and double flick are distinctive for P_. audax. Phidippus xerus Anterior decorations of male. Chelicerae iridescent gold-green; clypeus fringe black; palpi black and white; leg I fringed with black and white, no ocular tufts. Type I courtship. The legs I are held partially forward, away from the body; distally the legs I are parallel both to the substrate and to each other. Usually three quick upward inward flicks are done consecu- tively at the beginning of each lateral movement sequence; these are done so smoothly that they appear to be 3 consecutive rotations, and they may be, but the film is inconclusive on this point. The palpi are moved as in P_. otiosus, but at the same time as the leg movements. The pause is nearly twice as long as the lateral movement sequence. The relatively low position of the femur, the double parallel position of the distal leg segments, the triple smooth flick, and the timing of the palpal movements are diagnostic of the courtship of P. 128 Phidippus princeps Anterior decorations of male. Chelicerae iridescent green; clypeus fringe black; palpi black and white; leg I fringed with black and white; no ocular tufts. Type I courtship. The femora I are held straight up and close to the body. The legs I are held apart a variable distance, varying with individuals. The legs I are held moderately high; the usually double flick is upward and inward, so that the tarsi are halfway between parallel and touching, and occurs at the beginning of the lateral movement sequence. The palpi are moved twice each alternately at the end of the movement sequence. Pauses are 1.5-2 times longer than movement sequences; neither are particularly quick, although there is some individual variation. The higher leg position and higher flick distinguish the courtship of P_. princeps from those of the similar P_. pulcherrimus and _P. audax. Phidippus pulcherrimus Anterior decorations of male. Chelicerae iridescent green; clypeus fringe black; palpi black and white; leg I fringes black and white; no ocular tufts. Type I courtship. The femora I are held partially forward, the distal segments of legs I only slightly apart and slightly angled away from the substrate. The double flick occurs at the beginning of each lateral movement sequence, and is short and straight up. Palpi are moved at the end of sequence as in P_. princeps. Alternation of movement and pause is quick. The courtship of P_. pulcherrimus is very similar to the closely related P_. princeps; the legs I are held much lower and the flick is of less amplitude and is straight upward, lacking the inward component of the flick of both P_. princeps and P. audax. 129 Phidippus clarus Anterior decorations of male. Chelicerae iridescent green; clypeus fringe black; palpi black and white; leg I fringe black and white; no ocular tufts. Type I courtship. The femora I are held forward and away from the body. The distal segments of legs I are held wide at the femur-patella joint and slanted slightly toward the substrate (below parallel). A single flick occurs at the beginning of lateral movements sequence and covers 80° of arc (each leg) . The legs I are straight up and parallel at the peak of the flick, then rapidly dropped back down. The palpi are held wide and downward without any movement. The timing varies with individuals, but generally the pause is about 3 times as long as the movement sequence. The low, wide leg position and the quick, high amplitude flick easily distinguish the courtship of P_. clarus. Phidippus cardinalis Anterior decorations of male. Chelicerae dull red proximally, slightly iridescent blue distally; clypeus fringe black; palpi black; legs fringed with black and white; no ocular tufts. Type I courtship. The legs I are held high (the highest of any species studied), close to the body, and parallel to each other. The mid-leg is bent forward at a 60° angle from the substrate and 45° outward; the distal 2 segments are bent straight upward at a 70° angle. The single, sometimes double, flick at the beginning of a lateral movement sequence brings the legs I straight upward and inward so that the tarsi touch or cross. Palpal movement could not be confirmed by the films, but in one instance 2 alternate pair of palpal movements seemed to occur at the end of a movement sequence. Each lateral movement was 130 quick, but the intervening pauses were much longer, usually 5-6 sec. The courtship of _P. cardinalis is similar to the related P_. whitmani, but differs in holding the legs higher and lacking the vibratory com- ponent. Also similar is the courtship of _P. apacheanus, but _P. cardinalis holds the legs I close to the body, not away from the body as does P_. apacheanus. Type II courtship. On one occasion a male performed a vibratory courtship while entering a nest occupied by a female. I was unable to observe details of this courtship, and note here only that _P. cardinalis does have a Type II courtship. Phidippus whitmani Anterior decorations of male. Chelicerae black, with proximal median white fringes, slightly iridescent blue distally; clypeus with white scales and fringes; palpi white; leg I fringes white; no ocular tufts. Type I courtship. The legs I are held close to the body, the femora straight up. The distal segments of leg I are moderately high, angled outward slightly at the femur-patella joint. Usually 1 or 2 inward upward flicks bring the legs I parallel or rarely touching tarsi; the peak of the flick is held for 3-5 seconds, then the legs I are gradually returned to their original position. Simultaneous with each flick, the whole body is vibrated. The stance of the supporting 3 pairs of legs is exceptionally wide. The prosoma is held high and the abdomen angled downward. The palpi are angled outward about 30°, except the cymbia which were about 45° (in one instance the cymbia were bent upward 90°, parallel with the substrate). Movement time was very quick and consisted of the quick flicks and vibrations, and a shuffle forward straight at the female. Pause time varied considerably among individuals 131 but was always quite long. Although there is no lateral movement in this courtship, one individual rocked back and forth in place several times at the beginning of the courtship, then commenced the usual flick and vibrate advance. The courtship of P_. whitmani, although showing some similarities to the related _P. cardinalis in leg position and flicking, is very dis- tinctive. The positioning of the palpi, the slow return of a high flick, and especially the vibrations are all unique. The positioning of the support legs and the vibrations seem remarkably similar to those re- ported for the courtship of a sparassid, Heteropoda venatoria (L.), by Rovner (1980) . Phidippus whitmani is the only species which lives exclusively on forest leaf litter, a substrate that is used by lycosids to transmit and amplify vibrations during courtship (Rovner, 1967). There is considerable circumstantial evidence that the vibratory part of the courtship is a signal sent through the substrate to the female; it may be the single most important component of the courtship (since most of the male's courtship time is spent motionless) and merits further investigation. Type II courtship. Five males were observed performing a vibratory courtship while attempting to enter nests of females (some were oc- cupied, some were empty). The entire body was vibrated while the male was engaged with the silk. One male performed 9 consecutive vibrations, averaging about 1.2 vibrations per sec. A second male vibrated 3 times consecutively. The other males performed multiple sequences of vibra- tions (pauses between sequences averaged about 3 sec), which I terminated after 6, 5, and 5 sequences, respectively. The ranges and mean number of vibrations per sequence were as follows: 9-12, x=10; 2-4, x=3; 6-12, 132 x=7.6. See the end of the following chapter for further discussion of vibratory courtship. Phidippus apacheanus Anterior decorations of male. Chelicerae iridescent green; clypeus fringe black; palpi black; leg I fringe black and white; 2 dorsal tufts. Type I courtship. During the single partial courtship I filmed, the legs I were held fairly low, the femora held away from the body. The single flick was upward and inward, the tarsi nearly touching. The palpi were moved twice each alternately at the end of a movement sequence. The pause was about 3 times as long as the movement sequence. The courtship is similar to that of P. cardinalis, but the legs are held away from the body and usually not parallel to each other. The highly iridescent chelicerae are strikingly different from the dull chelicerae of P_. cardinalis. Possibly the part of the courtship I observed was a transitional stage between Stage I and Stage II, as the legs I were held much lower than described by Gardner (1965). Individual or geographic variations may also be the reason for the observed differences. Phidippus purpuratus Anterior decorations of male. Chelicerae iridescent gold-green- blue; clypeus fringe black; palpi black; leg I fringe black and white; 2 dorsal tufts. Type I courtship. The legs I are held in an unusual fashion, the femora close to the body and straight up, the mid-legs parallel to the substrate and bent out 45°, and the distal segments straight forward and angled upward 30°. The flick is single or double, upward and inward and at the beginning of the lateral movement sequence. If double, the second flick is held up briefly before returning to original position. 133 The palpi did not appear to move, although the film did not show them well. Timing was a little slower than most of the quicker courtships; the pause was about twice as long as the movement sequence. The peculiar angles of the leg segments are the most distinguishing feature of the courtship of P_. purpuratus. Discussion The Type I courtships of P. mystaceus and P_. putnami were clearly different in method (the types of movements of the legs I and palpi) from all of the other species observed, supporting their phylogenetic separation from the other species based on morphology (see Chapter 2) . However, the courtships of J?, mystaceus and P_. putnami were as different from each other as they were from the other species, indicating that these two species may not belong to the same phylogenetic line. Further examination of related species will be necessary in order to determine the relationship of these two species. Jackson (in prep.) has found that the apparent sister species of .P. putnami (JP. femoratus Peckham & Peckham of western North America) has a courtship very similar to that of P_. putnami. In the subgenus Phidippus, similarities among courtships generally agreed with morphological groupings. The courtships of P.. audax, P_. otiosus, _P. regius, P_. princeps, P_. pulcherrimus, J?, purpuratus, and P_. xerus differ only in details. The courtships of the related P_. cardinalis and P_. whitmani are very similar; _P. whitmani appears to have evolved a vibratory component in connection with its leaf litter habitat. The courtship of P. apacheanus is more like the unrelated P. cardinalis than like the related P_. purpuratus, and the courtship of ?_. clarus has 134 more in common with those like _P. audax than to its apparent morphologi- cal relatives, the P. cardinalis group (this latter group holds the legs I high, while the other species drop the legs I to a lower position after a high flick) . Overall, courtship behavior was a good indicator of phylogenetic relationship based on morphology. This finding agrees with that of Richman (1977), who examined one or a few representatives of several genera. The pitfalls of leaning too much on behavioral data are also pointed out; within a single genus, three phylogenetic lines of court- ship development are apparent, two of which include components unknown for other salticids (stridulation and vibration) , and the third line demonstrates a behavior (palpal rotation by P. putnami) which is known only from one species group of Pellenes, an unrelated genus also con- taining several lines of courtship development (Richman, 1977). CHAPTER 6 SOUND PRODUCTION BY COURTING MALES OF Phidippus mystaceus (ARANEAE: SALTICIDAE) The courtship rituals of male salticids generally are considered to be visually-oriented, despite the fact that a primarily tactile type of courtship has been demonstrated for 2 species of Phidippus (Edwards, 1975; Jackson, 1977a). In addition, chemotactic cues probably assist a male in locating a female in most species of jumping spiders (Richman, 1977) . Males of Phidippus mystaceus (Hentz) produce sound as an inte- gral part of their courtship. The sound, produced by means of a palpal stridulatory mechanism, is the first known case of this type for a salticid, although a similar stridulatory organ has been reported for lycosid spiders (Rovner, 1975). The only other reports of a salticid producing sound were by Bristowe (1958) , who reported that Euophrys frontalis (Walckenaer) made a "dis- tinct sound as the tarsal claws (of the legs I of the male) hit the ground...," and by Bristowe and Locket (1926), who had reported earlier on the same species, but had implicated the legs II as the sound producers. In either case, it was not clear if the sound produced by E. frontalis was an integral part of the courtship or incidentally produced by the movement of the legs. Experimental Procedure Four females and 2 males, offspring of P. mystaceus female collected in Oklahoma, were reared to maturity from an eggsac containing 12 eggs. 135 136 The spiders were housed separately in 9 x 1 cm plastic petri dishes; twice a week they were provided with water by moistening a wad of cotton within the dish and were fed larvae of the cabbage looper, Trichoplusia ni (Hubner) . Two different techniques were used for observing courtships: 1) the male was placed directly into a female's petri dish, on the side opposite the female, or 2) the male and female were placed 5-15 cm apart on a 30 x 10 cm section of a live-oak branch, in order to simulate natur- al conditions. Temperature ranged from 24-26 °C for all sessions. Six separate filming and/or recording sessions lasted 10-90 min. each. Films were made using a Beaulieu Super-8-mm movie camera and an Auricon Pro 600 16-rnm movie camera. Sound recordings were made with a Sony TC-756-2 reel-to-reel tape recorder and a Turner S22D microphone. The audiospectrogram was produced on a Kay 7029A Sound Spectrograph. Results Courtships were observed for one of the males (the second male was killed by the first female with which he was placed) . Typically a male placed into the petri dish housing a female almost immediately begins palpating the female's draglines and her abandoned nests, continuing this palpal exploration until he detects the female visually. If the female is not inside a nest when first seen by the male (usually from 3-6 cm), the male begins producing a soft, audible trill that is systematically repeated. By apparently engaging the substrate with enlarged setae (macrosetae) encircling apical, whorled setae on the tips of the palpal cymbia (similar to those observed on lycosids by Rovner, 1975; Figure 6-1), leverage is produced which enables a stridula- tory mechanism on the palpus to be operated. This mechanism consists of a 137 plectrum-like projection of the tibial apophysis which fits into a bowl- shaped area on the cymbium containing a complicated file system. The entire mechanism is located laterally (ectally) ; in lycosids it is located dorsally. Also, lycosids have the file on the tibia facing a cymbial plectrum, the reverse of the condition in J?, mystaceus. The file system of _P. mystaceus consists of 2 types of adjacent file fields which blend into one another. Within the concavity is a fan-shaped file, while along the distal edge of concavity is a linearly-arranged file similar to lycosid files. Neither file is as well-defined as the lycosid files. The individual ridges of P. mystaceus' files are rounded whereas those of lycosids have distinct edges; however, in P_. mystaceus, both types of file are overlaid with numerous short ridges of variable length (Figure 6-2). For each sound sequence, both palpi become engaged nearly simultan- eously by a backward movement in which the palpi appear to be dragged along the surface of the substrate for a distance of about 1 mm. Halfway through the backward movement, the cymbia are bent backward at an angle to the palpal tibiae (Figure 6-3). At the end of the backward movement, the palpi remain stationary for a fraction of a sec. while the cymbia are rotated outward. The palpi may be returned to their most anterior position by reversing the sequence of backward movement. Only when the palpi are in their most anterior position are they clearly off the sub- strate. A single cycle of palpal movement is approximately 0.8 sec. (5 frames at 6 frames per sec). Audiospectrograms indicate that 13-20 (x = 17, n = 8) paired stridu- lations are made consecutively, separated by pauses subequal to the sound sequences (Figure 6-4) . Alternation of stridulations and pauses occurs at the rate of 1.6 sound sequences per second. 138 Simultaneous with the initiation of sound production, the male extends his legs I forward, positioning them just above and parallel to the substrate, and spread approximately 40° apart. The tarsi and meta- tarsi are turned upward about 15° and occasionally flicked upward together. (On one occasion, at a distance of about 1 cm from the female, the tarsi and metatarsi were flicked continuously for several sec. at approximately 2 flicks per sec). The male's approach is usually direct, without the zigzag movement (lateral stepping movement) characteristic of some other Phidippus spe- cies and many other salticids. Forward movement is slow and halting, the male often remaining in one spot for several min. Total courtship time is long compared to the rapid advance of the males of some Phidip- pus species, on 3 occasions lasting approximately 8 min. before the female terminated the courtship by leaving the vicinity. These 3 longest courtships reached an advanced stage, wherein the male brought his legs I closer together, touched the female, and attempted to mount her; howev- er, none of the 4 females allowed their male sibling to mate them. Instead, each raised her legs I to repel him, and, if the male was per- sistent, lunged sharply forward with open fangs, struck downward with the legs I, and forced him backward; the female then left the vicinity. On two occasions, the male performed a zigzag display; once prior to assuming his stridulatory stance, and once in the middle of courtship after several sequences of stridulation. In the first instance, the zigzag display was brief, lasting less than 30 sec. and consisting of 4 changes of direction, with a pause between each lateral move. In the second instance, during mid-courtship, 7 multiple zigzags occurred which included 1-3 changes of direction during each lateral stepping sequence; total elapsed time was about 3 min. 139 If the female is initially in and remains in a nest when the male is introduced into the petri dish, the male continuously palpates the sub- strate, interspersing sequences of stridulation. Upon finding the nest sheltering the female, the male attempts to gain entrance by probing and pulling at the silk with his legs I, interspersing sequences of palpal vibration on the silk. (Note: other species known to use a tactile courtship vibrate their entire body) . I could not determine the movement pattern of this palpal vibration, but the palpi were not in contact with the petri dish and no audible sound was produced. After the preceding research was completed, I collected two ante- penultimate P. mystaceus and reared them to maturity (October, 1979). A courtship and mating was observed for this pair, but it was neither filmed nor recorded. Courtship appeared in all respects to be identical to that of the Oklahoma male, including type of sound, stance, and the rapid upward flicking of the tarsi and metatarsi at less than 1 cm dis- tance from the female. Mating occurred in the female's nest and lasted 87 min. until the female left the nest. Upon separating, the male re- newed courtship, initially showing a single lateral stepping sequence as in the Oklahoma male. The female avoided the male, and the pair was separated. Discussion Known reproductive behavior of the males of species of Phidippus involves a male locating a female by visual or chemotactic means, a visually-oriented courtship by the male consisting of a series of move- ments with the legs I and palpi (usually while advancing in a zigzag path), mounting of the female by the male, and mating. Typically the male is conspicuously marked with bright and/or contrasting colors both 140 anteriorly and dorsally; the anterior patterns are displayed during courtship. Unlike most other species, both males and females of P_. mystaceus are cryptically-colored gray spiders that live in trees (Specht and Dondale, 1960; Warren et al. , 1967, as P. incertus; see Edwards, 1977, for nomenclatorial comments); males have mostly anteriorly- oriented modifications (Figure 6-5). While anterior modifications are probably used by each sex to identify the other (especially the female recognizing the male as a conspecific and potential mate) from distances of a few centimeters, visual identification at longer distances would seem to be severely handicapped by cryptic coloration. A mechanism which increased the male's chances of locating a female could be selected for under these circumstances. The role of acoustic or vibratory signals in the courtship of P. mystaceus probably evolved with cryptic coloration. As selection for cryptic coloration increased in association with exploitation of a new microhabitat (most Phidippus species live in the herb-shrub zone), the role of visual communication was in part supplanted by sound during courtship. The use of sound, whether airborne or substrate-borne, has several advantages over conventional visual courtship, because sound extends the male's communicatory distance from a few centimeters to over a meter (based on the audible component available to the human ear) . Sound is transmitted well through solids, and considering that in this case sound is produced on the substrate, vibrations through this medium may be the most important sound component for female-to-male orientation (as Rovner, 1967, showed to be the case for wolf spiders). By orienting toward the male upon perception of the sound, the female might sooner visually detect and be able to evaluate the male as a prospective mate, and thus sooner choose to wait for or flee from him. The advantages gained by the 141 male by increasing his communicatory distance might be: 1) alerting a receptive female to his presence at a greater distance, possibly causing her to remain in the vicinity for a longer period of time (and perhaps inhibiting her predatory instincts) , so that the male has a greater chance of finding and courting her; 2) based on many observations of P_. mystaceus and of other Phidippus species, non-receptive females usually avoid advancing males; thus, by alerting a female to his presence at a greater distance, a male would reduce the chance of triggering an aggres- sive response by a non-receptive female. As evidence for these probable advantages, analysis of courtships showed that the male began courting a female from 2-4 times further away when unconfined (on the live-oak branch) than did other species of Phi- dippus when observed under unconfined experimental conditions (Edwards, 1975). At the greater distances, only sound was used initially by a _P. mystaceus male upon sighting a female, indicating that this form of communication was important in alerting a female to his presence. Sound was also used alternately with palpal exploration of the silk when the male was in contact with the female's draglines in the petri dish, even though she was not visible. Under natural conditions, a male likely would often encounter a female's dragline prior to locating her; he could maximize his chances of mating by beginning to signal immediately, regardless of whether or not the female was visible to him. The male's initial palpal exploration of the female's silk draglines and nests has been noted for other salticids (Richman, 1977). Hill (1977a, b) demonstrated the presence of whorled setae on the tarsi and palpal cymbia of other species of Phidippus, and, noting the similarity of these setae to insect pheromone receptors, hypothesized that those setae were contact chemoreceptors. Judging from the behavior of the male 142 .P. mystaceus (which has the same type of whorled setae on its palpal cym- bia; Figure 6-1), this hypothesis may well be correct; the presence of a contact pheromone on the silk could indicate to a male that a female was, or had been, in the vicinity. The behavior in _P. mystaceus of engaging the palpi against the sub- strate is probably derived from similar behavior among its relatives. Males of other species of Phidippus move their palpi up and down or back and forth during courtship. This behavior appears to preadapt them for engaging the substrate, since only a slight change in the amplitude and/ or attitude of these movements would bring the palpi into contact with the substrate. The same movement occurs more intensely and rapidly when a male encounters silk made by a female, in association with chemotac- tile exploration; it is likely that this is the evolutionary pathway of the development of the use of sound in _P. mystaceus. The behavioral application of the palpi to the substrate by F_. mys- taceus appears to differ from lycosids in that P. mystaceus moves the tips of the palpi while stridulating during each brief sound sequence, whereas the lycosids apparently remain attached in one place to the substrate for a prolonged sequence of sound production. The presence of a linearly-arranged file on the distal edge of the cymbial bowl was indicated by a few large ridges (at 75X) . Subsequent S.E.M. photomicrographs showed a fan-shaped file system which was barely discernible at 100X. As noted earlier, both files were overlaid with minute ridges. It is possible that the larger ridges are responsible for the lower frequencies observed on the audiospectrogram, and the smaller ridges produce the higher frequency wavelengths. 143 By simulating the direction of palpal movement with a model, it is apparent that the backward movement would cause the fan-shaped file to be drawn across the plectrum, while the rotary movement would bring the linear file into contact with the plectrum. The fan shape of the proxi- mal file would accomodate the arc-shaped movement as the palpus is bent on the backward stroke. Despite the differences in arrangement and shape of the larger ridges, the ultrastructure of the two files is simi- lar and they seem to produce the same sound. The entire sequence appears to be reversible; in fact, the timing of a complete palpal move- ment (approximately 0.8 sec.) is remarkably close to half the number of sound sequences per sec. (1.6), suggesting that two stridulatory actions are made with each palpus, one on the back stroke, and a second by reversing the action on the return stroke. The files appear to be oriented so that they could be stroked from either direction. Examina- tion of Figure 6-4 will show one sound sequence is exactly 0.8 sec, equally divided between sound and pause. The shape and arrangement of the macrosetae at the tip of the cymbium are such that a downward, forward pressure would engage them with the substrate. By dragging the palpus backward, enough leverage is apparent- ly produced to move the fan-shaped file across the relatively stationary plectrum; however, the backward movement and bend of the palpus also may be a prerequisite to positioning the macrosetae into the substrate. Once the palpus is anchored in the substrate, the cymbium is rotated lateral- ly outward, then the direction of movement is reversed. The structure involved in sound production by rotating is the linear file; the cymbium must be rotated sideways due to the lateral position of the file. The mechanics of sound production with the linear file are similar to those 144 of the lycosids with respect to the palpus anchored by macrosetae and the similar file structure, by P. mystaceus differs from the lycosids in the location of the stridulatory organ, the type of movement needed to engage the file, and the reversed positions of the file and plectrum. The stridulatory mechanisms known in other spiders incorporate plec- trum and file systems on opposing faces of the chelicerae and palpi, legs I and II, carapace and legs I, carapace and abdomen (Gertsch, 1979), or between palpal tibia and tarsus (Rovner, 1975). In each of these cases, either the plectrum is moved across a stationary file, or both plectrum and file are moved together. The stridulatory mechanism of P. mystaceus differs from all of these in that the primary moving part is the file. Although the plectrum is passively moved in space during the movement of the palpus to engage the substrate, the cymbium containing the files is actively moved against the plectrum on the tibia. When the palpus is fixed on the substrate with the macrosetae, again it is the cymbium that is moved against the stationary plectrum. Conclusion The use of stridulation to produce sound by P. mystaceus appears to represent a third method of communication for salticids (a fourth method if the tarsal percussion of Euophrys frontalis is a valid communi- catory process) . Despite the fact that females used for the present research failed to respond favorably to courtship by their sibling male, the behavioral and morphological evidence in the male of a functional role for sound production during courtship is substantial. 145 Additional Observations A third method of sound production in spiders, vibration (producing a "buzz" similar to that of a fly) , has been demonstrated for the sparassid spider, Heteropoda venatoria (L.) (Rovner, 1980). In the same paper, low amplitude appendage oscillations resulting in a faint whirring sound were reported for Lycosa rabida Walckenaer. Phidippus whitmani Peckham and Peckham employs entire-body (?) vibration (lacking an audible component, but with a widely-spaced stance similar to H. venatoria) during its Type I visual courtship (Edwards, unpublished). This is probably an adaptation to its microhabitat (mesophytic leaf litter) , the same substrate used for vibratory signalling by many lycosids. I have noted another vibratory behavior that also seems similar to that of H. venatoria during the Type II tactile courtship of Phidippus regius C. L. Koch, while the male is contacting the nest of the female (Edwards, 1975) . Subsequent laboratory observation showed a similar behavior for J?, whitmani, although the timing of vibratory sequences was different than those of P. regius, probably a species-specific difference. Jackson (1977) reported a similar behavior for P. johnsoni (Peckham and Peckham) and suggested a similarity in some respects to the vibratory courtships of web-building spiders. I suspect that the vibratory courtships of Phidippus species, although not producing an audible component that I could detect, may be more like the courtships of H. venatoria than like web-builders (perhaps these latter two are similar?) and should be further investigated. It is curious that all known forms of non-tactile direct inter-individual communication not involving vision in salticids involve the production of acoustic or vibratory signals. In the case of P. mystaceus and P. whitmani, both types of communication are used simultan- eously, although the two species produce vibrations in different ways. 146 Figure 6-1. Distal ectal view of palpus of P. mystaceus, showing macrosetae (M) used to engage substrate (100X) . 147 Figure 6-2. Stridulatory organ of male _P. mystaceus, showing fan- shaped file (F), linear file (L) , and plectrum (P) . 148 Figure 6-3. Diagrammatic illustration of movement of left palpus by male P. mystaceus during stridulation. A. Anterior position. B. Backward movement, during which cymbium is bent backward, moving fan-shaped file across plectrum. C. Rotary movement, during which macrosetae are engaged in substrate and cymbium is rotated outward. F = File cavity, T = Tibial apophysis. 149 CSJ oo LILBJlJlElD.ELrLS_OJU3J3Ja_S_a_ 0)0 a) rj 3-° 60 ^ 150 1 ■ . m& *.' •/ '>*• Figure 6-5. Anterior view of male _P. mystaceus . CHAPTER 7 DIFFERENTIAL ATTACK RESPONSES BY Phidippus SPP. (ARANEAE: SALTICIDAE) TO CONTRASTING PREY TYPES Hollis and Branson (1964) first recorded differential responses by a salticid to different types of live prey. They observed Phidippus audax (Hentz) attempting to capture the salticid Metacyrba undata (DeGeer) by jumping at the intended prey, but not jumping when capturing Tenebrio larvae. Gardner (1965) noted slight differences in the approach of juvenile P. coccineus Peckham & Peckham to Drosophila and Calliphora. Edwards et al. (1974) described different attack methods used by the salticid Corythalia canosa (Walckenaer) (= Stoidis aurata (Hentz)) when attacking various ant species. Field and laboratory observations of prey capture by Phidippus regius C. L. Koch (Edwards 1975) indicated that this salticid utilized different methods of approach and capture for larval Lepidoptera and adult Diptera. These 2 prey types have frequently been reported in the natural diet of foliage-dwelling species of Phidippus (Whitcomb et al. 1963, Warren et al. 1967, Jackson 1977). In the present research, 7 species of Phidippus were analyzed for differences in attack behavior due to these 2 types of prey and to the species of spider. Materials and Methods Adult and subadult Phidippus (Fig. 7-1) were obtained from their natural habitats in Florida, except for 6 P. clarus and 2 P. putnami (captured in Missouri) ; some adults of P. regius, P. otiosus, and P. 151 152 apacheanus were laboratory-reared from eggsacs of females captured in Florida. The spiders were individually housed in 90 X 10 mm plastic petri dishes and were provided with fresh water by means of a small, moist wad of cotton in the dish. Only adult spiders were tested. Proffered prey were 4th and 5th instar larvae of the cabbage looper, Trichoplusia ni (Hubner) , and adults of the house fly, Musca domestica (L.). Individual tests were conducted in the following manner: 1) a single cabbage looper (hereafter referred to as looper) was placed directly into the petri dish housing a spider, or 2) first a spider and then a house fly (hereafter referred to as fly) were placed in a 90 X 20 mm glass petri dish (because the 10-mm-deep petri dishes overly re- stricted the flies' flight). I measured the distance the spider jumped to capture its prey by refering to a sheet of graph paper lined with 1 mm graticules positioned under the petri dish. Measurements were made from the point where the chelicerae of the spider had been located just prior to a jump to the part of the prey nearest the spider. I estimated my accuracy of measurement to be - 1 mm for the capture of loopers and + 2 mm for flies. The position of the spider in respect to the prey at the time of attack was also recorded. The spider was considered to be anterior to a looper if the spider's sagittal plane was in front of the 3rd pair of true legs, posterior to the looper if behind the mid-abdomi- nal prolegs, and lateral if in-between. Similarly, the spider was considered to be anterior to the fly if in front of the cervix, pos- terior to the fly if behind the pedicel, and lateral if in-between. Most spiders were offered both types of prey, but the number of times each type of prey was tested for each spider varied. Capture distances were compared for the 2 types of prey using Students' t test; differences 153 among species of Phidippus were examined by using a 1-way analysis of variance, Duncan's Multiple Range Test for unequal sample size, and Chi- square (p<0.05 for all tests unless otherwise indicated). Results Spiders attacked loopers from significantly shorter distances than they attacked flies (Fig. 7-1). Typically, upon seeing a moving looper, a spider would rapidly approach to within 10-12 mm, then pause and watch the intended prey. If the looper continued to move, the spider would circle until it was directly in the looper' s path, stalk forward a few mm, leap, and then bite the looper in the dorsum of the thorax. If the looper changed its direction of movement as the spider was preparing to jump, the spider would reposition itself. If the looper stopped moving after the spider had already seen it but before the spider approached it, the spider might approach and attack the posterior or the anterior end while the looper was stationary, or might attack any part of the looper that moved. On 5 occasions (out of 225) involving 3 species (P. regius (3) , P. otiosus, P. audax) , a spider walked directly to a looper and captured it without jumping (0 mm). In contrast to captures of loopers, which were predominantly made from anterior to a looper, captures of flies by most species of Phidippus tested occurred with similar frequencies from all directions (Fig. 7-2). Upon seeing the fly (mean distance approx. 60 mm), the spider would move stealthily, although rapidly (approx. 1-2 cm/sec) to within 25-30 mm of the fly. Regardless of the direction of attack, the spider almost always captured the fly by biting it in the thorax near the wing bases. Over 50% of successful attacks on flies were initiated from directions other than anterior to the flies for all Phidippus species tested. 154 P. regius C. L. Koch T=48 P. otiosus (Hentz) T=32 P_„ apacheanus Chamber lin &. Gertsch T=10 P„ audax (Hentz) T=26 P_. clarus Keyserlin^ T=15 P. pulcherrimus Keyserling T=18 P_0 putnami (Peckham & Peckham) T=13 captured prey: cabbage looper * :]_=jo, nj_» * + * house fly #3! ti=38, n,=65 t2=38, n2=50 nb t^-21, nx=22 t2=16, n2=20 ^b t1=9, n,=17 t2=6, n2=18 ^^bc ti=23, nx=40 t2=18, n2=3D be ti-14, nx=23 t2=12, n2=20 £.=17, nj-40 t2=14, n2=30 _-^b t1=ll, n1=18 t2=13, n2=30 distance jumped (mm) Figure 7-1. Comparison of capture of cabbage looper and house fly by Phidippus species. Diagram consists of mean, 95% confidence interval, and range. Diagrams accompanied by the same letter (a,b,c) are not significantly different (Duncan's Multiple Rnage Test, p 0.01). T = total # of spiders of that species tested, t-^ and t2 = total spiders of that species tested for cabbage looper and house fly, respectively. Likewise, n and n„ = total captures of cabbage looper and house fly, respectively. 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