4/04. 5 Ges G73 EAI BASIN NATURALISi MEMOIRS, umber 10 Brigham Young University 1986 ee A Reclassification of * > Genera of Scolytidae (Coleoptera) Lusi y APR 1 0 1987 GREAT BASIN NATURALIST Editor. Stephen L. Wood, Department of Zoology, 290 Life Science Museum, Brigham Young University, Provo, Utah 84602. . Editorial Board. Kimball T. Harper, Chairman, Botany; James R. Barnes, Zoology; Hal L. Black, Zoology; Stanley L. Welsh, Botany; Clayton M. White, Zoology. All are at Brigham Young University, Provo, Utah 84602. Ex Officio Editorial Board Members. Bruce N. Smith, Dean, College of Biological and Agricultural Sciences; Norman A. Darais, University Editor, University Publications. Subject Area Associate Editors. Dr. Noel H. Holmgren, New York Botanical Garden, Bronx, New York 10458 (Plant Taxonomy). Dr. James A. MacMahon, Utah State University, Department of Biology, UMC 53, Logan, Utah 84322 (Vertebrate Zoology). Dr. G. Wayne Minshall, Department of Biology, Idaho State University, Pocatello, Idaho 83201 (Aquatic Biology). Dr. Ned K. Johnson, Museum of Vertebrate Zoology and Department of Zoology, University of California, Berkeley, California 94720 (Ornithology). Dr. E. Philip Pister, Associate Fishery Biologist, California Department of Fish and Game, 407 West Line Street, Bishop, California 93514 (Fish Biology). Dr. Wayne N. Mathis, Chairman, Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington, D.C. 20560 (Entomology). Dr. Theodore W. Weaver III, Department of Botany, Montana State University, Boze- man, Montana 59715 (Plant Ecology). The Great Basin Naturalist was founded in 1939 and has been published from one to four times a year since then by Brigham Young University. Previously unpublished manuscripts in English of fewer than 100 printed pages in length and pertaining to the biological natural history of western North America are accepted. 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See Notice to Contributors on the inside back cover. 12-86 1200 27830 ISSN 017-3614 EAT BASIN NATURALIST MEMOIRS umber 10 Brigham Young University 1986 te A Reclassification of the Genera of Scolytidae (Coleoptera) CONTENTS JN) BXGSTEL GUN Gil ates ceeaa a cP Se oP ce ae ee ee ge aE 1 LN TRODUGITONG se csse ana s a8 epee vot tis anid ve ee cree eee beer sere ee i ETS HIRO) RAY aa ae decteccusScaracs ier rte shes sca Wala. “ecataicd, Hes GEMS stevens Joun dua oeaas ale hoes samme quake eee atepee 2 RE VAIO HEC EIAIRA GER: Soa trace « sac Sessa ears arate acts dee enceatectia ue aie nena waere 3 DTS GWIS SIO IN aes erences cette cca cc ce theese voter ete gs token cureielicucisneca tint ance ctene ne tuseeseeen see eweesce 6 ESTATE @ (GE Niece ores ete cet sic etsne sean, «eek ste ek ee Ie yee ar eee Mt ae 21 VATE ET IID) S eect eee sene en stevestens ee ncucc es crtehe cae Oocana care tetasarets ol celev a tewetatcee tacit ener eecutaete can eee ea sae 24 SSE SE ClO Niger create caer sik ae eater cey Pk yrs sitet anor 25 Key to the families of Curculionoidea .......... 0.0.0 26 Key to the subfamilies and tribes of Scolytidae ................. 0c cee eee ees 28 Suibtamulyalhylesiminaer1ea eter a ceencrsrecrer oecneeo nian teree eres eee acento arenes 34 iiriberbiylastiniuesee sre cece es estes See eer oe ene Ie 34 Miri bepehylesininitgenrss creer pe eke vate eke eee teen See ee ee ete ya 36 ‘Trad ove [Najost ited meanest ote heats aOR ot en uae aoa eto ae ' 40 ‘Maloy PMevab onto nibilles eee eae can oe oem uae oaomae aaG es aca oliae 43 Mribescyormnymemini" gees aan cere atyo seve e avers nae cee aarcesye oonseeaten nc evans & yeas 43 Ibsloys Dieta Wagener ede ane oun dae nee aaa onen eee nana ade es ateo 44 mbar othrosterminipe ere eee ce ie een ee eee 46 ltrabes el OO tri it sevarccereres sere cy cnaeye eevee cous siet cleaves eet cneseas «ther evan eh eienseeane necneese an 48 Thaloya AN eco Ntanee ance Rad ovomconeedn damon canocscekeucedaesotucn bone 49 lini beverly pObonininnecm erat er ea cee Ec tse a eee 53 ‘tal oe) |e higeazyo) Wath ema oereen ramet ee a ace oreo coe adem noe cameos 55 Suiokiimihy Seo Mane yo sees moo cow ng Gosek uncon ons oboucus eo mee oboe aes 57 Mir eES COLy tar teeter nex-cvern ese hee erate aoantiree alte af aitye e ease conte aves neo aemecen tt stance 57 halo Clwerotejs) Noho nc wee acon co ore 6 amass concn base een cae con an On ecu 59 riberScolytoplatypodiniva. nas. ome adeno e se a ean aen ye cel oeiae icra ee 61 ribesViicracinise mer yiter entre se roe re eke ree ee Pek nee eer sree 61 aloe (Cercvoyitint cee e aeonu ea nme Sree anna nadome keen eaes aceon oa 65 MnbelGarphodicicini 4: s case.5 sees oe ee eters eee cre eueere eta eee tee 66 ‘Wir oes ey i ater reer ere et relate tae Peer rece ere re eee a eae 67 MinibeOrnvOCoctini mere tet cates rea ere ce arin re tee 70 MnibA@rypuLcinimyyagee.b cee ema eee Rao ou ck re crn ere ee: 75 mi berXxylOteriniamemr ree ee Ate Act eee a ee ee Lee yaya ene 76 ibe vleborniuer tere cite eel ert cae ee cat coe ee ee 79 Miri DEEXvIOCtOHINI Merete ce cnt ak GR eRe Ome: Seine nner acre 84 Miter @ ry alin apee eens eerasonstn racetteee cack creer ean eevee Meee Meee atege oe ements ocr 85 Mri be Gorthviinigee eee aoe tas ate eee ee eo ee eee ee 93 Subtmbe@onthylinag eer sre hee te ee mile eee ee ee ee eee eee eee 97 Subtrbeaityoplthonmawe acme: meee ercesche ice atest eee tery een te eee 98 OTB VAC IE CTT eae orc rie, ice eee eons cat mee tac ete ehaker to seese och oapoee teins eee eee 100 INTE) XS ex ayeveygecesre coche eared gees chs ceiel ete eka epee ver au ouene se iecen tienen malaieant pete acitmnemstr aucueaerets 111 GREAT BASIN NATURALIST MEMOIRS A Reclassification of the Genera of Scolytidae (Coleoptera) 1986 No. 10 Brigham Young University, Provo, Utah Stephen L. Wood! ABSTRACT.— A taxonomic revision of the genera of Scolytidae (Coleoptera) in the world fauna is presented. Included are 215 valid genera and 273 invalid generic and subgeneric names. The type-species for each genus-group name was examined, including the type-specimen of the type-species in those taxa where a holotype, lectotype, or neotype has been designated—with the exception of four contemporary genera, the type-series of which are lost, and six fossil genera for which no effort was made to locate the types. Taxonomic keys to the families of the Curculionoidea, and to the subfamilies, tribes, and genera of Scolytidae are presented. Descriptions and citations of the original validations of the two subfamilies and 25 tribes of Scolytidae are included. For each genus-group name there is a citation of its original validation, type-species, and synonymy. For each valid genus there is an indication of its distribution, the approximate number of valid species, basic feeding and mating habits, and citations of published keys for the identification of species. Of general interest to coleopterists is a review of the status and position of the families Platypodidae and Scolytidae within the Curculionoidea, including several characters not previously presented. These two families are entirely distinct from one another and from Curculionidae. The phyletic position of Platypodidae and Scolytidae is near the more primitive families of Curculionoidea and quite remote from specialized Curculionidae. Because of their immense economic impact on world forests, forest products, and certain aspects of agriculture, considerable attention has focused on the Scolytidae. Although the literature is filled with reports of the economic ravages and of efforts made to manipulate their populations, comparatively little atten- tion was given to other aspects of their study prior to 1960. Since then, there has been a virtual explosion of information about many other facets of their existence. Although advances in basic communication involving nomenclature and classification nor- mally preceded the expansion of knowledge in other groups of organisms, this was not the case with the Scolytidae. There appear to be several reasons for this delay. The sheer num- ber of species and the urgency to do some- thing with the management of populations compelled local foresters to act. The un- availability of trained taxonomists apparently caused practical foresters to enter the fields of naming and identifying species to meet their own limited needs. With two pre-1960 excep- tions, taxonomic work on Scolytidae was done by senior foresters who lacked a fundamental interest or training in the study of diversity, phylogeny, or evolution. These exceptions were Chapuis, who produced a classical work on Platypodidae (Chapuis 1865) and was start- ing to work on Scolytidae (Chapuis 1869) be- fore jurisdictional problems arose, and Hage- dorn, whose brief career (1904-1912) ended tragically. The unwillingness to accept and apply the concept of evolution and to abandon the typological (morphological) species con- cept by more recent influential workers also delayed progress. The present study had its origin in a conver- sation with C. D. Michener, at Logan, Utah, in August 1949, during which he suggested a reclassification of the genera of Scolytidae in 'Life Science Museum and Department of Zoology, Brigham Young UniVersity, Provo, Utah 84602, USA 2; GREAT BASIN NATURALIST MEMOIRS the world fauna as an appropriate subject for my doctoral dissertation. Fortunately, for me and for science, a more limited topic was cho- sen, but the suggestion was never forgotten and has remained a lifelong objective. In 1981, when I was asked by colleagues to final- ize a comprehensive world catalog of Scolyti- dae, completion of the generic study became mandatory and urgent. Although this presen- tation is a bit premature, its basic objectives are achieved. More thoughtful selection of illustrations and greater detail in their presen- tation would have been helpful to the user. The Scolytidae are among the more difficult insects to classify; yet their tremendous eco- nomic importance is so great that immediate and precise identification is demanded by those industries threatened by the activities of these insects. Although my attraction to the Scolytidae was to their fundamental struc- ture, diversity, ecology, and behavior from theoretical and other points of view, as knowl- edge began to accumulate, my rural back- ground and religious philosophy made me sensitive to the economic interests of others and to aneed for me to assist them with what I had learned. Another need was also para- mount. Among the great frustrations in learn- ing are those resulting from errors that have been transmitted from one generation to the next and, once learned, must be unlearned and corrected before progress can continue. Biological nomenclature and _ classification have been profoundly impeded in their pro- gress by this problem. Therefore, the primary objectives of this study are (1) to review the holotypes or syntypes of the type-species of all named genera and subgenera to make certain that they are correctly placed in appropriate genera, then find the correct generic names for them, and review as many species as possi- ble and group them in those genera, and (2) to devise a scheme of classification such that oth- ers can identify those genera. If these objec- tives are achieved in at least some measure, it is hoped that the constant name changing and duplication of effort (resulting from = syn- onymy) that has impeded taxonomic progress in my generation will be reduced to a mini- mum. This classification of categories above the species level will be the framework on which the catalog of species, now in prepara- tion, will be organized. No. 10 HISTORY Linnaeus (1758) included five species of Scolytidae in his Systema Naturae, edition 10, all under the name Dermestes (typographus , micrographus, poligraphus, piniperda, do- mesticus). Fabricius (1801) expanded this to include 52 species under the generic names Apate (5), Bostrichus (21), and Hylesinus (26). Gemminger and Harold (1872) list 535 species in 60 genera. Hagedorn (1910a, b) lists 1,234 species in 115 genera. There has been no comprehensive classification or catalog of the family on a worldwide basis since the work of Hagedorn, but it is estimated that more than 6,000 biological species are currently recog- nized. The first generic name erected for a member of this family was Scolytus Geoffroy (1762; China 1962, International Commission on Zoological Nomenclature 1963). Since then, 488 generic and subgeneric names have been proposed for the group, of which 215 are treated below as valid. In an attempt to estimate the number of species remaining to be named from America north of Mexico, White (1975), in his example using Scolytidae, recognized 592 species in 1970 and projected that there would be 650 named by the end-point year of 2040, when 100% would be known. That estimate was made prior to publication of my monograph (Wood 1982). In the monograph, numerous species were placed in synonymy and others were named or they extended their distribu- tions into the United States and Canada, leav- ing about the same total number of species and projection as before. Meanwhile, more than half of the scolytid fauna of Mexico and Central America was named from 1960. to 1982. This rapid expansion of the fauna south of the United States made a projection for the larger area meaningless at the present time. Few attempts to classify the higher cate- gories of Scolytidae on a worldwide basis have been published. Perhaps the first contribu- tion worthy of note was that of Ferrari (1867), who listed and described the genera of Tomi- cides (my Scolytinae with Scolytini deleted). There was no attempt to actually classify the genera by Ferrari. Eichhoff (1878a) published a classical monograph of this same group in which he presented keys and descriptions to all known genera and species. His family 1986 Tomicini included 40 genera that were dis- tributed among the subfamilies Crypturgidae (Crypturgus, Dolurgus, Aphanarthrum, Trio- temnus, Pycnarthrum), Cryphalidae (Li- parthrum, Hypoborus, Triarmocerus, Cry- phalus, Glyptoderus, Stephanoderes, Cos- moderes), Problechilidae (Problechilus), Xy- loctonidae (Xyloctonus, Scolytogenes), Pity- ophthoridae (Pityophthorus, Eidophelus, Taphrorychus), Tomicidae (Thamnurgus, Xylocleptes, Tomicus, Lepicerus, Dryocoe- tes), Hylocuridae (Hylocurus), Micracidae (Micracis), Araptidae (Araptus), Hexacolidae (Hexacolus ), Xyleboridae (Coccotrypes, Xyle- borus, Premnobius, Gnathotrichus ), Xylote- ridae (Trypodendron), Corthylidae (Corthy- lus, Brachyspartus, Anchonocerus, Phtho- rius, Trypocranus, Pterocyclon), and Amphi- cranidae (Steganocranus, Amphicranus ). Hagedorn (1910a, b) treated 115 genera and 1,234 species in the entire family worldwide. He divided Scolytidae (Ipidae, in his usage) into four non-Linnean subfamilies, based on the detailed structure of the mouthparts, that contained the tribes indicated: Pilidentatae (Phloeotrupinae), Spinidentatae (Eccoptogas- rinae, Diamerinae, Crypturginae, Hylocuri- nae, Hylesininae, Ipinae, Cryphalinae), Sae- tidentatae (Xyleborinae, Corthylinae), and Mixodentatae (Spongicerinae). Hopkins (1915a, b), in two papers, (a) re- classified the subfamilies and tribes of Scolyti- dae and (b) reclassified the genera and species of Cryphalinae. He elevated the group to su- perfamily rank, Scolytoidea, and recognized four families within it (Ipidae, Scolytidae, Scolytoplatypodidae, and Platypodidae). His Ipidae included the subfamilies Cryphalinae, Ipinae, Micracinae, Webbinae, Xyloctoni- nae, Crypturginae, Phloeotribinae, Hylesini- nae, and Phloeoborinae. His Scolytidae in- cluded the subfamilies Coptonotinae, Hexa- colinae, Bothrosterninae, Camptocerinae, and Scolytinae. His Scolytoplatypodidae in- cluded the subfamily Scolytoplatypodinae, and Platypodidae the subfamilies Platypodi- nae, Genyocerinae, and Chapuisinae. It ap- pears to have been the intention of Hopkins to follow his basic classification with a series of papers treating in detail the various divisions of his classification, but only one paper was published. Hopkins (1915a) reviewed the sub- family Cryphalinae, in which he included 48 Woob: GENERA OF SCOLYTIDAE 3 genera that are currently distributed (below) among the tribes Cryphalini, Dryocoetini, and Xyleborini. Wood (1978) reviewed 15 major published classifications of the higher categories of Scolytidae, including all of those cited above, and presented a revised and expanded classifi- cation of subfamilies and tribes and tenta- tively assigned 404 nominate genera and sub- genera to his 25 tribes. That classification was adapted to his monograph of the North and Central American Scolytidae (Wood 1982), which listed 1,433 species in 94 genera. The present contribution is an expansion of that classification to the genus level for the entire world. REVIEW OF CHARACTERS Characters Shared by Platypodidae and Scolytidae In the early stages of this study, I was thor- oughly convinced that Platypodidae could be no more than a well-marked, primitive sub- family of Scolytidae. Shared characters that led to this premature conclusion included: (1) clearly formed pregular sutures extend from the anterior end of the median gular suture to or near the anterior tentorial pits; these su- tures are reinforced internally by a massive internal inflection of the cuticle that occurs nowhere else in the Curculionoidea; (2) the mandible lacks the horizontal cylinder that rotates on the anterior and (heavily rein- forced) posterior condyles, with its cutting edge apical; instead, the posterior condyle is in a different position, the axis of the mandibular hinge is transverse, and the cut- ting edge is mesal (as in Anthribidae and Nemonychidae); (3) the rostrum is short to nonexistent; (4) the tibiae totally lack corbels, but they share a common basic structure and are armed on the apical and lateral margins by a characteristic series of spines; (5) the eyes are essentially flat against the head; (6) the antennae are mostly of the same basic genicu- late type, with some members of several primitive tribes having a short scape (little if any longer than the pedicel); (7) the visible abdominal sterna | and 2 are weakly connate, except all are free in all primitive genera of Platypodidae; (8) the elytral interstriae 10 ex- 4 GREAT BASIN NATURALIST MEMOIRS Fig. 1. Outline of cephalic aspect of the head of Pseudo- hylesinus sericeus (Mannerheim), with frontal rectangle indicated by the square of dash lines. tends to near the apex in all Platypodidae and in some primitive representatives of virtually all tribes of Scolytidae; (9) the larval characters are basically the same except as noted below; and (10) they share the same basic ecological niche. Characters Not Shared with Other Curculionoids Curculionoidea, excluding Anthribidae, Nemonychidae, Platypodidae, and Scolyti- dae, share a unique mandibular character in which the basal half forms a cylinder that ro- tates on a horizontal axis between the two articulating condyles (Fig. 8). The hypostomal area adjacent to the posterior condyle is en- larged and strengthened to accommodate a new mode of action; the cutting edge is apical and usually takes the form of a large cusp on the side of the basal cylinder. In the four families identified above, the mandibular condyles are closer together, the oblique ac- tion is more like that of a hinge, the cutting edge is mesal, the mandible ends in an acute point, and the hypostomal area is minimal. The Anthribidae and Nemonychidae have an adult labrum. It is lost in all other Cur- culionoidea; however, in most primitive tribes of Scolytidae (most Hylesininae, Cten- ophorini, etc.) there is an epistomal lobe that resembles a small, fused labrum and is proba- No. 10 Fig. 2. Cephalic aspect of the head of a female Chaetas- tus tuberculatus (Chapuis) (Platypodidae) showing a con- spicuous “labrum” in the median area just below the epistomal margin arrow. (Re-drawn from Strohmeyer (1920: 15, Fig. 5). bly homologous to it (Fig. 1). In Platypodidae the epistomal lobe is more generally present, and in Tesserocrerus and Chaetastus (Fig. 2) a suture separating this lobe from the epistoma is evident in some species. Comparable struc- tures are unknown in the remainder of the Curculionoidea. In general, beetles have two gular sutures that are separated by a median gular sclerite. In Nemonychidae (Fig. 3) and some Belidae (Fig. 3B, and Crowson 1967) two gular sutures are clearly indicated from the margin of the foramen magnum to the point of invagination of the tentorium (posterior tentorial pit) where they end. In Anthribidae, the entire tentorial structure is lost and the gular sutures are usually reduced to little more than lateral irregularities on the margin of the foramen magnum. In Belidae there is variation from two widely separated gular sutures that end in two separate posterior tentorial pits (Fig. 3B) to convergence to a single median pit, with consequent reduction in size of the gula, to formation of a single median gular suture of variable length (Fig. 3C). The allies of Belidae (Aglycyderidae and Oxycorynidae including Rhopalotria) share at least part of this same variability. The only other known members of the Curculionoidea that share in similar vari- ability are members of the neotropical scoly- tid genus Gnathotrupes. Of the 23 species of 1986 WoobD: GENERA OF SCOLYTIDAE 5 Fig. 3. Diagrams of the ventral surface of the head of (A) Cimberis attelaboides (Nemonychidae), (B) Belus sp. (Belidae, from Australia), and (C) an unidentified female Belidae from Australia. Note the convergent postgular sutures and remnants of pregular sutures from the level of the antennal insertion to (or toward) the anterior tentorial pits. gs = gular suture, ptp = posterior tentorial pit. Gnathotrupes examined for this character by me, 5 had two complete gular sutures that extended to and were continuous with the pregular sutures, 8 had the pregula elongated and extending most of the distance to the postgula, and 10 had the pregula more or less normal. Most Platypodidae (Fig. 4) have an unusually large pregula and a short to very short median gular suture. Pregular sutures are totally absent in all curculionoids, except for Platypodidae (Fig. 4) and Scolytidae (Fig. 5-G) and for their par- tial presence in females of two (unidentified) Australian Belidae (Fig. 3C). In these two belids the pregular sutures extend only from near the anterior tentorial pits to near the point of antennal articulation; they are not represented from the area of antennal articu- lation to the anterior end of the median gular suture (the point marked externally where the tentorial apparatus invaginates). The pregular sutures illustrated by some writers on Cur- culionidae (Hopkins 1911:Fig. 1) do not exist; they represent irregular undulations in the cuticle that serve to strengthen the posterior (or ventral) wall of the rostrum and do not qualify as sutures in any acceptable usage of that term. Mouthparts have been used extensively in fundamental divisions of the Curculionoidea (Crowson 1967). For example, in Anthribidae and Nemonychidae the maxillary lacinea and 6 GREAT BASIN NATURALIST MEMOIRS Fig. 4. Posterior aspect of head of a female of Doliopygus chapuisi (Duvivier) (Platypodidae). Note the very short median gular suture and the prominent pregular sutures. galea form separate elements (Ting 1936:Fig. 78). The only other curculionoids sharing this character are the Tesserocerini (Platypodidae) (Fig. 6), Attelabidae, and Rhynchitidae (Ting 1936:Fig. 78). Similarly, the Anthribidae and Nemonychidae have a 4-segmented maxillary palpus (Crowson 1967, Ting 1936). This char- acter is shared by all Attelabidae (Crowson 1967, Ting 1936), some Rhynchitidae, and one Platypodidae (Austroplatypus) (Browne 197]a). The costate lateral margins of the pronotum in primitive tribes of Scolytidae (Diamerini, Ctenophorini, Scolytini, etc.) is another indi- cation of primitive origin of this family within the Curculionoidea. The tibial structure of Platypodidae and Scolytidae is unique. It appears to have been derived from a structure resembling that of Protohylastes (Fig. 7), in which the median member of three apical spines became the terminal mucro of Platypodidae and the mesal spine became the terminal mucro in Scolyti- dae (Wood 1973a). The lateral margin is armed by one or more spines in primitive tribes; these may be replaced in specialized groups by socketed denticles (teeth) of setal origin (Wood 1978). The tibial structure of Scolytus and Camptocerus is a specialized de- viation from the basic scolytid structure that only superficially resembles the cossonine No. 10 tibia. Similar structure occurs in Histeridae, Bostrichidae, Brenthidae, or other coleopter- ous groups having a long history of occupancy of insect tunnels bored in wood. The tibial spines of Araucarini (Cossoninae) that have been suggested as ancestral to those of Scolytidae (Kuschel 1966) also are of indepen- dent origin; in fact, the scolytid denticles to which they were compared are socketed and bear no structural similarity to them what- ever. The elytral locking mechanism is basically the same throughout the Curculionoidea, ex- cept that it is radically modified in Attelabidae and Rhynchitidae in an obvious specialization (Wood 1978, and unpublished drawings). A minor departure occurs in Scolytidae (Cor- thylini) (Wood 1978). Visible abdominal sterna 1 and 2 are en- tirely free in all primitive genera of Platypodi- dae but are weakly connate in the higher Platypodidae, all Scolytidae, and in most higher Curculionoidea. The larvae present an enigma. Except in the most primitive genera, the frons and clypeus are usually fused in Platypodidae (Browne 1972), as in Nemonychidae (Crow- son 1967), thus making them easily distin- guishable from those of Scolytidae. However, characters have not yet been found that distin- guish some Scolytidae from some Curculion- idae (Viedma 1963). The difficulty may come more from reduction and simplification to ac- commodate small size than from real differ- ences. Browne (1972) reported urogomphi- like structures in two species of Platypodidae; if correct, this is the only known occurrence of these structures in the Curculionoidea. DISCUSSION Scolytidae and Platypodidae as Families A position within the Curculionoidea is uni- versally accepted for Platypodidae and Scolytidae, except for Sched] (1939), who gave them superfamily status without explanation. For more than a century, it was traditional to list Platypodidae and Scolyltidae as separate families next to Curculionidae until Crowson (1967:164) combined both families with Cur- culionidae, primarily on the basis of the ab- sence of convenient larval characters that could separate them from that family. How- 1986 Woob: GENERA OF SCOLYTIDAE vi D Hylurgops Stenoscelis Hylurgops Hylurgops Stenoscelis Stenoscelis L B Cc Fig. 5 A-F. Head structure of Curculionidae (Stenoscelis, Rhyncolus) and Scolytidae (Hylurgops, Ips); Stenoscelis brevis (Boh.) (Curculionidae), A, lateral, B, dorsal, and C, caudal, with internal tentorial and associated structure indicated by broken lines; Hylurgops rugipennis (Mannerheim), D, lateral, E, posterior, F, dorsal, internal structure as above. 8 GREAT BASIN NATURALIST MEMOIRS No. 10 |. Rhyncolus Fig. 5 G-I. Ips woodi Thatcher, G, ventral, H, lateral; Rhyncolus knowltoni Thatcher (Curculionidae), I, ventral. Abbreviations: ai = antennal insertion; aps = apodeme formed internally by pregular suture; dat = dorsal arm of tentorium; dfm = dorsal margin of foramen magnum; e = cervical membrane attachment; gs = gular suture; mgs = internal apodeme formed by the median gular suture; mtp = median tentorial pillar that invaginates from the combined posterior tentorial pits; p = pregula; pap = paired apodemal plates that branch dorsad from mgs and bears the tentorial apparatus at its anterior extremities; pg = postgula; ps = pregular sutures; ptb = posterior tentorial bridge; ptp = posterior tentorial pit. Fig. 6. Maxilla of Platypodidae: Periommatus bispinus Strohmeyer (left); Chaetastus tuberculatus (Chapuis) (center); and Tesserocerus insignis (Saunders) (right). Note the separate galea and lacinea. Re-drawn from Strohmeyer (1914: pl. 1). ever, following more than 30 years of study of _ best, and warrants much closer examination. the comparative anatomy of the Curculion- Platypodidae and Scolytidae universally share oidea, I find that position untenable and sug- _ with one another: (1) well-developed pregular gest that the relationship of Platypodidae and _ sutures that are reinforced internally by mas- Scolytidae to Curculionidae is remote, at sive apodemal inflections of the entire cuticle, 1986 Coptonotus Tricolus Scolytodes Woob: GENERA OF SCOLYTIDAE 9 ~N i \\ p Mecopelmus rotoplatypus Schedlarius Diamerus Camptocerus Fig. 7. Posterior face of prothoracic tibia: Protohylastes annosus Wood (Coptonotinae), Protoplatypus vetulus Wood (Coptonotinae), Mecopelmus zeteki Blackman (Coptonotinae), Schedlarius mexicanus (Dugés) (Coptonotinae), Cop- tonotus cyclops Chapuis (Coptonotini), Tricolus peltatus Wood (Scolytinae, Corthylini), Scolytodes sp. (Scolytinae, Ctenophorini), Diamerus impar Chapuis (Hylesininae, Deamerini), Camptocerus auricomus Blandford (Scolytinae, Scolytini). Each drawing made at different scale so as to reproduce at a uniform size. extending from the posterior tentorial pit (at the anterior end of the median gular suture) to or near the anterior tentorial pit adjacent to the anterior articulation of the mandible (Figs. 4-5), and (2) a primitive mandible that is articulated and functions (about as in An- thribidae and Nemonychidae) in a manner entirely different from that of higher cur- culionoids (Fig. 8). In view of these universally present primi- tive characters, relict retention of other ances- tral features in one or more genera of these two families takes on added significance. For example: (1) The platypodid genus Austro- platypus clearly has a 4-segmented maxillary palpus (Browne 197la) (known elsewhere only in Anthribidae, Nemonychidae, Attelabidae, and some Rhynchitidae). (2) The platypodid tribe Tesserocerini has the maxilla clearly di- vided into separate lacinear and galear ele- ments (Fig. 6); elsewhere in the Cur- culionoidea this character is shared by the same four families (cited here in No. 1). (3) An adult labrum within the Curculionoidea oc- curs only in Anthribidae and Nemonychidae; however, an epistomal lobe resembling a fused labrum is widely represented among primitive Scolytidae (Fig. 1) and is usually present in Platypodidae (in Tesserocerus and Chaetastus , Fig. 2, it is even separated from the epistoma by a suture). (4) A complete gula, with two gular sutures continuous with the pregular sutures, is present in at least five Gnathotrupes (Scolytidae) species (Wood 1973a), and the pregula is greatly prolonged in eight other species of this genus; the pregula is greatly enlarged and the median gular su- ture is short to very short in most Platypodi- dae (Fig. 4). (5) In most Platypodidae and many scolytid Hylesinini, Scolytini, Mi- 10 GREAT BASIN NATURALIST MEMOIRS Belidae Rhyncolini No. 10 Brenthidae Sphenophor ini Scolytidae Fig. 8. Lateral aspect of apex of rostrum of a representative of: Belidae, Brenthidae, Sphenophorini (Curculionidae), Rhyncolini (Curculionidae), Platypodidae, and Scolytidae. The arrows mark the approximate position of the concealed anterior and posterior articulations of the mandible. cracini, etc., the scape is very short, little if any longer than the pedicel and definitely not geniculate, and in other groups (some Phloeo- tribus, some Micracini, etc.) the club is poorly formed; very little imagination is needed to see the possibility of independent origin of the geniculate, clubbed antenna from that of other curculionoids. (6) The costate lateral margins and concave pleura of scolyiid Diamerini, Ctenophorini, and some Scolytini occur elsewhere in the Curculion- oidea only among the most primitive families. (7) The platypodid-scolytid tibiae totally lack corbels. Their lateral margins bear true spines in Platypodidae and some primitive Scolyti- dae. These are replaced in all higher Scolyti- dae by socketed denticles of setal origin that occur nowhere else in the Curculionoidea (Wood 1978); true spines also occur in some Histeridae, Bostrichidae, and other families that frequent the tunnels of woodboring in- sects. (8) Although the literature states that visible abdominal sterna 1 and 2 are connate in all Platypodidae, this is not true. These segments are entirely free in all primitive gen- era; they are weakly connate in the higher Platypodidae and in all Scolytidae. An inde- pendent origin of this feature is probable. (9) The platypodid-scolytid body habitus most certainly is not of the Curculionidae type, although there is superficial resemblance to it in the Hylastini. Family Scolytidae In the early stages of this study, I was thor- oughly convinced that Platypodidae could be no more than a well-marked, primitive sub- family of Scolytidae. In view of the often in- finitesimally minute features used to charac- terize other families, that position must be reexamined. Although most characters are shared by some members of each group, a sharp demarkation remains. For example, the male spiculum gastrale is undeveloped in Platypodidae, but it is well-developed in Scolytidae (Wood 1982): tarsal segment 1 is greatly elongated in all Platypodidae (Fig. 9), except for Protoplatypus and Scolytotarsus , but it is intermediate in Protohylastes and Coptonotus (These four genera contain a total of five rare, tropical species). The shape and structure of the head, eye, antenna, prono- tum, scutellum, elytra, and tibiae are almost equally distinctive. Details of platypodid be- 1986 Fig. 9. Posterior aspect of protibia of Platypus parallelus (Fabricius) (Platypodidae). havior are too poorly known to add conclusive supporting evidence. The higher Platypodi- dae appear to have been the most primitive segment of this phyletic line to take up the woodboring ambrosial habit, which drasti- cally affected their morphology; this habit ap- pears to have arisen independently in at least eight tribes of Scolytidae (Hyorrhynchini, Phloeosinini, Scolytini, Scolytoplatypodini, Xyloterini, Xyleborini, Cryphalini, Corthy- lini) (Wood 1982). The Platypodidae universally lack socketed tibial denticles (derived from setae) (Figs. 7, 9); these structures are present in all higher groups of Scolytidae (Fig. 10) but are lacking in at least some genera of several primitive tribes. In all primitive genera of Platypodidae visible abdominal segments (sterna) 1 and 2 are free; in the higher Platypodidae and in all Scolytidae they are weakly connate. The pos- terior half of elytral interstriae 10 is univer- sally present in Platypodidae; it is present in primitive members of most tribes of Scolyti- dae (Fig. 12), but it is lost in the higher mem- bers of almost all tribes (Fig. 11). The apical protibial mucro of Platypodidae appears to have been derived from the middle apical spine of a tibia resembling that of Protohy- lastes (Wood 1973a); it appears to have been derived from the inner (mesal) spine in Scolytidae (Fig. 7). In larval Platypodidae (ex- cept Protoplatypus and Schedlarius) the clypeus is fused to the frons (Browne 1972); in Scolytidae it is a separate sclerite. The list could go on, but the above should indicate a close relationship between the two families and the limited overlap of many characters. Woop: GENERA OF SCOLYTIDAE 11 Fig. 10. Lateral margin near apex of protibia of Polygra- phus rufipennis (Kirby). Note the socketed denticles. Subfamilies and Tribes A review of characters usable in classifica- tion of the higher categories of Scolytidae was presented by Wood (1978). Several trends were reported in that study: (1) the primitive head is more or less truncate on its posterior face, the dorsomedian area is progressively prolonged caudad in specialized groups (Figs. 13-14, and Wood 1982:Fig. 14); (2) the primi- tive frons is convex in both sexes (in the higher Hylesininae the male frons is variously im- pressed and the female frons is usually con- vex); the reverse is usually found in the Scolytinae; (3) the primitive eye is oval, en- tire, and finely faceted; specializations in- clude elongation, emargination (including complete division into two parts) (Fig. 15), and enlargement of facets (apparently corre- lated with nocturnal flight habits); (4) the an- tennal scape primitively may have been short, little longer than the pedicel, it is elongate or triangular in most groups; (5) the antennal funicle primitively contains seven segments, and there is a more or less orderly reduction to a minimum of one segment as specialization increases; (6) the antennal club varies from almost nonexistent (three movable segments no longer than those of the funicle in primitive Phloeotribus) to a simple cone-shaped struc- ture with transverse sutures to large and 12 GREAT BASIN NATURALIST MEMOIRS Figs. 11-12. Lateral aspect of Scolytidae: 11, above, in- terstriae 10 unites with interstriae 9 before the level of the hind coxae in Eupagiocerus dentipes Blandford; 12, be- low, interstriae 10 continues to near apex of the elytra in Scolytodes plumeriae Wood. strongly flattened or obliquely truncate, with or without sutures; it is probably the most variable major structure found throughout the family; (7) the prothorax may have (a) the coxae widely separated in primitive groups to fully contiguous in specialized ones; (b) the pleuron concave, with the lateral margins acutely costate in primitive genera (Figs. 11- 12), to convex, with the lateral margin un- marked in specialized genera; (c) the prono- tum longitudinally straight in dorsal profile and unarmed by crenulations in primitive groups to strongly arched and armed by crenulations or asperities in specialized ones; No. 10 Figs. 13-14. Lateral aspect of head in Scolytidae: 13, Hylastes nigrinus Mannerheim, with the posterior face approximately truncate; 14, Xylosandrus retusus (Eich- hoff), with the occipital area greatly extended. (8) the basal margins of the elytra tend to be costate primitively, with the Hylesininae be- coming procurved and crenulate (Fig. 16), the Scolytinae transversely straight and longitudi- nally rounded (Fig. 17); (9) several complex changes occur in the meso- and metathorax that will be discussed below; (10) the male tergum 8 is visible and pubescent in most groups (Fig. 22), but it is telescoped beneath 7 and without pubescence in Carphodicticini, Ipini, Dryocoetini, Xyloterini, and Xylebor- ini; (11) the venter of the abdomen has (a) segments 3 and 4 (visible segments 1 and 2) free in all primitive Platypodidae but weakly connate in the higher Platypodidae and all Scolytidae and (b) limited specialized groups in which specialized features are very impor- Woop: GENERA OF SCOLYTIDAE 13 2 JIU Fig. 15. Variations in eye shape (left to right): shallowly sinuate (Hylesinus crenatus Fabricius); narrowly and shallowly emarginate (Ernoporicus caucasicus Lindemann); strongly sinuate or broadly, shallowly emarginate (Phloeosinus bicolor Brulle); deeply emarginate (Phloeosinus thujae Perris); completely, equally divided (Polygraphus poligraphus Linnaeus); and completely, unequally divided (Sphaerotrypes globosus Blandford). Figs. 16-21. Thoracic structure of Scolytidae: 16, elevated crenulations (arrow) on procurved basal margins of elytra of Phloeotribus setulosus Eichhoff; 17, weakly subcostate basal margins of elytra in Scolytodes plumeriae Wood; 18, metatergum of Hylastes nigrinus Mannerheim, arrows mark intersegmental line (left) and scutoscutellar suture (right); 19, metapleuron of Hylastes nigrinus Mannerheim, upper arrow marks pleural suture, lower arrow marks anterior end of groove that receives costal margin of elytron; 20, ventrolateral aspect of prothorax, arrow marks acutely elevated precoxal ridge (or costa); 21, metatergum of Eupagiocerus dentipes Blandford, pn = postnotum, is = fused interseg- mental line, ss = scutoscutellar suture (compare to Fig. 18). tant (Scolytus , Scolytomimus , etc.); and (12) the tibiae are unusually variable and require special treatment below. Most of the above character states are utilized in the following key to subfamilies and tribes to indicate phyletic trends in the family, subfamily or tribe in which they are involved. However, two of them are sufficiently complicated and im- portant that elaboration is appropriate. These occur on the metathorax and the tibiae. Three primary characters of the metathorax show important features that exhibit phyletic 14 GREAT BASIN NATURALIST MEMOIRS female Fig. 22. Abdominal terga of Cryphalus ruficollis Hop- kins: male, with segments 7 and 8 visible; female, with segment 7 visible (segment 8 is reduced in size, tele- scoped beneath 7, and hidden from view). trends. First, in Curculionoidea generally, in- cluding Platypodidae and primitive Scolyti- dae, the pleural suture follows a zigzag course from the pleural wing process ventrad to the point where the costal margin of the elytron touches the body. It then turns abruptly cau- dad to a point just before reaching the poste- rior limits of the segment, where it turns mesad and continues to the pleural coxal pro- cess. On the metepisternum at the anterior or first angle (below the pleural wing process) a carina or small, flattened spine is present that fits into a small groove on the inner (costal) margin of the elytron just behind the humeral angle. This character state within Scolytidae is best seen in the Hylastini (Fig. 23, parts 43- 44) and in some Hylesinini. The trend is for No. 10 the suture to progressively straighten out whereas the metepisternal spine remains sta- tionary but becomes more remote in position from the changing suture (Fig. 23, part 42). The matching groove on the elytron moves somewhat dorsad and caudad, suggesting that the costal margin of the elytron extends far- ther ventrad than primitively. In Cryphalini the metepisternal spine is considerably re- duced in size, and its function in locking the elytra in closed position is partly assumed by a new diagonal groove on the metepisternum (Fig. 31). In Corthyulini, the spine is entirely lost and the groove is enlarged and extends to amore ventral position (Figs. 23, part 47, and 32). The result is that the closed elytron in this tribe now covers all but a small anterior por- tion of the metepisternum. A second significant feature of the metathorax involves progressive changes in position of the scutoscutellar suture. In Curculionoidea gener- ally, Platypodidae, and primitive Scolytidae (Hylastini and Hylesinini are examples), this su- ture reaches the margin of the scutellar groove near the anterior limits of the groove and contin- ues parallel to and very near its lateral crest for about two-thirds of the length of the groove, then the suture curves abruptly laterad to follow its usual course to the posterior margin of the segment (Fig. 23, part 43). In more advanced tribes this suture progressively straightens out, meeting the marginal crest of the groove only briefly, ifat all (Fig. 23, part 41). The third significant metathoracic feature that is usable in phylogeny occurs only in the Hylesininae. A significant feature of insect flight is the intersegmental line between the metathorax and its postnotum (derived primi- tively from the anterior portion of the first abdominal segment but functionally part of the thorax), which must flex with each stroke of the metathoracic wings. This suture is present in all insects, including Platypodidae, Scolytinae, and primitive Hylesininae (Fig. 23, parts 43, 45). In the more advanced Hylesininae, the median two-thirds of this intersegmental line is lost by complete fusion of the postnotum to the metathorax (Fig. 23, part 41). This fusion is progressive, leaving a weak suture primitively, but it is totally oblit- erated in advanced groups of this subfamily. The tibiae exhibit remarkable variation in constant, conservative patterns that are valu- 1986 Woop: GENERA OF SCOLYTIDAE 15 Fig. 23. Diagrams of terga and pleura of Scolytidae: 41, metatergum and 42, pleuron of Chramesus hickoriae LeConte, arrow points to remnant of intersegmental suture in 41, to metepisternal spine in 42; 43, metatergum and 44, pleuron of Hylastes nigrinus Mannerheim, arrows as above; 45, metatergum and 46, pleuron of Cnemonyx panamensis (Bland- ford), arrows as above; 47, pleuron of Pityophthorus crotonis Wood, metepisternal spine is lost and is replaced by a small groove (arrow). Abbreviations: is = intersegmental suture, mn = metepimeron, ms = metepisternum, pn = postnotum, ps = pleural suture, s = metepisternal spine (part of locking mechanism for elytra), sg = scutellar groove, ss = scutoscutellar suture. able in following trends in phylogeny. Appar- derived resembles that of Protohylastes (Fig. ently, the primitive model from which the 7). The protibia of Protohylastes is slender, tibiae of Platypodidae and Scolytidae were with three rather small spines at the apex and 16 GREAT BASIN NATURALIST MEMOIRS a very minute spine on the posterior face im- mediately basad from the tarsal insertion. Comparative studies (Wood 1973, 1978) sug- gest that the mesal (inner) apical spine be- came the apical spine in Scolytidae and that the middle spine became the apical spine in Platypodidae (Figs. 7, 9). This middle spine in Scolytidae is bent laterad and is a major, iden- tifiable element that projects beyond the level of the tarsal insertion in one or more members of several tribes (Hyorrhynchini, Diamerini, Bothrosternini, Phloeotribini, Phloeosinini, Hypoborini, Polygraphini, Scolytini, Cten- ophorini, Scolytoplatypodini). All tibial spines in Platypodidae (Fig. 9), Hyorrhynchini, Scolytini (Fig. 7), and, apparently, Cten- ophorini (Fig. 7) are true spines. In all higher Scolytidae these spines are either intermixed with or replaced by socketed denticles of setal origin (Fig. 10). The patterns of possession and replacement within the family suggest that socketed denticles had an early mono- phyletic origin within the Scolytidae, with dif- ferential survival of this character in the pos- terity, and do not suggest polyphyletic origins. Many other characters that are not men- tioned above are useful in classification and phylogeny in more limited groups. Several of these are employed in the keys. Conclusions As stated above, the traditional place of Scolytidae in classification has been as a family next to the Curculionidae. However, as Cur- culionidae became fragmented into several families, the position of Scolytidae within the Curculionoidea changed. Sched! (1939c) made a separate superfamily to contain Platy- podidae and Scolytidae. Crowson (1967:164) reduced both to the rank of subfamily within Curculionidae. In reviewing this topic, our first point has been to establish that Platypodidae and Scolytidae are closely related to each other and are derived from the same parental stock. Evidence for this, as stated above, comes from the following: (1) Pregular sutures that extend from the anterior tentorial pit (adjacent to the anterior articulation of the mandible) to meet the anterior end of the median gular suture occur only in these two groups. These sutures are reinforced internally by massive apode- No. 10 mes. Remnants of pregular sutures found in females of two species of Belidae extend from the anterior tentorial pit toward the antennal insertion and never converge or approach the gular suture (or sutures). (2) In these two families, the mandibles come to an apical point and have the cutting edge mesal as in Nemonychidae; furthermore, the articulating condyles are comparatively close together, with the posterior one more nearly lateral in position, and the hypostomal area behind the posterior condyle is minimal in size to almost nonexistent. In most Curculionoidea, except for these two families and Nemonychidae and Anthribidae, the basal half of the mandible forms a horizontal cylinder that rotates on the two condyles, and the cutting edge of the mandible is apical; the posterior condyle is posterior in position and is supported by an enlarged hypostomal area. (3) The subcortical habit in which mated pairs enter vital host tissues to oviposit is shared by Platypodidae, Scolytidae, and some Cossoninae (Curculion- idae); however, the mode of excavation and several structural features (gular area, tento- rium, mandible, etc.) indicate that the latter group exhibits an evolutionary parallelism, not a fundamental relationship. (4) Six genera (Protohylastes, Coptonotus, Scolytotarsus, Protoplatypus, Mecopelmus, Schedlarius ) are structurally and biologically intermediate be- tween the Platypodidae and Scolytidae and could be placed in either family. The charac- ters, reviewed in this paragraph, with primary stress placed upon true pregular sutures, indi- cate a fundamental close relationship between Platypodidae and Scolytidae that is not shared with other groups. A second point of significance has to do with the position of Platypodidae and Scolytidae within the Curculionoidea. Their traditional position in classification has been next to the Curculionidae; however, close examination suggests that such a placement is based on superficial resemblance, not on fundamental structure. As indicated above, pregular su- tures are shared, in part, only with females of two species of Belidae, and the mandibular- hypostomal structure is shared only with An- thribidae and Nemonychidae. These indica- tions suggest a relationship of Platypodidae and Scolytidae to the segment of Curculion- oidea having two gular sutures, rather than 1986 one. However, close inspection of Belidae discloses at least three genera with only one median gular suture and an elongated post- gula, and an entire segment of Oxycorynidae (Rhopalotria) with one gular suture and a postgula of variable size. Furthermore, one genus of Scolytidae (Gnathotrupes) contains at least five species with a complete gula con- necting pregular and postgular elements, and at least eight more in which the connection is almost complete. In many Platypodidae, the pregula is enlarged and is scarcely separated from the postgula. Because such a situation does not occur elsewhere among those cur- culionoids having one gular suture, wisdom suggests that a search be continued for addi- tional clues to phyletic relationships. A movable labrum occurs among. cur- culionoids only in Anthribidae and Nemonychi- dae. Remnants of a labrum are found in many primitive Scolytidae (particularly Hylesininae), and a fused labrum, complete with a transverse suture, occurs in Platypodidae (especially Tesse- rocerini). [ am unaware of similar remnants in other curculionoid families. A 4-segmented maxillary palpus occurs in Australoplatypus (Browne 1971a:49), a fea- ture restricted to only the most primitive cur- culionoids (see family key below). A lacinia separate from the galea is charac- teristic of all Tesserocerini (Platypodidae); this is another feature that is restricted to the most primitive curculionoids (see family key below). The antenna has been used extensively in the classification of curculionoid families, par- ticularly character states of orthocerous vs. geniculate, apex filiform vs. clubbed (or capi- tate), etc. In no curculionoid are segments | and 2 without some degree of enlargement; furthermore, in many of those traditionally referred to as geniculate, the scape is not longer than it is in some Anthribidae. In a large segment of Platypodidae and many Scolytidae, the scape is short, little if any longer than the pedicel, and often it is broadly triangular in shape. In virtually all cur- culionoids (except most Anthribidae), the three apical segments of the antenna are at least slightly enlarged; although the literature generally states otherwise, a few Anthribidae have an abruptly enlarged club. In the genus Phloeotribus (Scolytidae), the club is usually Woop: GENERA OF SCOLYTIDAE Li sublamellate, with the three segments freely movable upon one another (Fig. 16). In primi- tive members of this genus (acaciae , rhodo- dactylus, etc.) the three segments are no longer or wider than are the funicular seg- ments and are as movable. I see no possibility that the Phloeotribus antenna could have been derived from a solid club of the type found in most other Scolytidae. Since this is the only deviant character found in this genus, could it not be a relict reminder that the scolytid club was derived on an independent, parallel line from a common ancestor, and not from other curculionoid groups having clubbed antennae? Much has been said and written of the simi- larity of the tibiae between Scolytus (Scolyti- dae) and many Cossoninae (Curculionidae) in curculionoid family classifications. However, it has never been pointed out that similar tibiae occur in Histeridae, Brenthidae, and other coleopterous families containing groups with a long history of subcortical existence. Within the Scolytidae, the Scolytus tibia is unique and apparently does not represent a truly primitive condition. The truly primitive character state of the tibia on this phyletic line oceurs in Protohylastes, with Platypodidae and Scolytidae derived along separate phylet- ic lines from the basic structure. Larval characters, thus far, have not been very helpful in answering questions about scolytid phylogeny. In fact, reliable means have not yet been found for separating all Scolytidae from all Curculionidae (Viedma 1963, Lekander 1968). Whether this is due to the absence of characters or to the lack of diligence in the search for characters among groups not found in Europe needs to be an- swered. Primitive larval Platypodidae have the frontal sutures extending to the articulat- ing membrane of the mandibles, a fact not previously noted. Browne (1972) suggested that structures found on two platypodid larvae could be relicts of urogomphi. Ifso, this is the only evidence of the existence of urogomphi in the Curculionoidea. Larval Scolytidae and Platypodidae are easily separated from each another by the separate (Scolytidae) or fused clypeus and frons (Platypodidae). It is of inter- est that this same character separates larval Nemonychidae and Anthribidae (see family key below). 18 GREAT BASIN NATURALIST MEMOIRS Lower Jurassic curculionoids with a long rostrum have been referred to the Curculion- idae by Crowson (1983), although they bear a very strong resemblance to Belidae or, per- haps, Eobelidae. Arnoldi (1977) named the extinct family Eobelidae from 14 species that were placed in 7 tribes in 4 subfamilies, taken from Upper Jurassic deposits of South Kaza- khstan (Karastan) in the USSR. In this family the head is similar to modern Belidae except that it is more broadly oval and the rostrum is shorter, as in some modern male Brenthidae. The mandibles are large, with a single apical point and a mesal cutting edge as in modern Nemonychidae. The antennae attach either to the middle or near the apex of the rostrum and are orthocerous, with the three apical seg- ments slightly enlarged but not forming a defi- nite club. Arnoldi did not mention gular su- tures or a labrum. The body resembled modern Belidae except that the lateral mar- gins of the prothorax were acutely elevated as in modern Oxycorinidae and the elytra were much less strongly sclerotized than in modern Belidae. From the above, two fundamental conclu- sions emerge. First, the Platypodidae and Scolytidae are very closely related to one an- other and, in fact, they intergrade to a limited extent. At the same time, these two families are quite distantly related to other families in this superfamily. Second, in spite of the ap- parent absence of larval characters, there are enough discordant adult characters to conclu- sively demonstrate that the Platypodidae- Scolytidae, as one unit, do not belong to and probably are not even closely allied to Cur- culionidae. It is my contention that their preg- ular sutures (and accompanying internal apodemes) prevented elongation of the ros- trum and forced them into an entirely differ- ent mode of existence from other cur- culionoids (parent adults had to bore into vital host tissues to oviposit because they had no rostrum and, consequently, could not follow the curculionid habit of using the rostrum to form oviposition pits). They could have been derived in the Jurassic from a short-rostrumed Eobelidae-like ancestor that had fully formed pregular sutures. Belidae and _ related families, and all other curculionoids having one gular suture, branched off later or from other segments of Eobelidae or its deriva- No. 10 tives. Rostrum length among Jurassic cur- culionoids was diverse, varying from short and broad (Arnoldi 1977) to long and slender (Crowson 1983). The presence of obvious, so- phisticated scolytid tunnels in Lower and Middle Cretaceous conifer bark suggests that the Platypodidae-Scolytidae phyletic line had its origin at least in Upper or Middle Jurassic. The exact phyletic positions of known Jurassic and Cretaceous “curculionid” fossils are diffi- cult to determine, because details of labrum, mandibles, gular sutures, etc., are not suffi- ciently well preserved to permit analysis. I seriously doubt that any true Curculionidae existed prior to the Cretaceous. Habits and Classification Although the Platypodidae are established above as a family, separate from Scolytidae, they are significant because they represent the first major paraphyletic branch from the platypodid-scolytid line of specialization. Their adoption of the xylomycetophagous habit appears to have accelerated their struc- tural and biological deviation. Only the inter- mediate genera Protoplatypus, Mecopelmus , and Schedlarius lack the ambrosial habit (Pro- tohylastes, Scolytotarsus, and Coptonotus are unknown biologically). Schedlarius (mon- ogamous) and Protoplatypus (polygynous) place their eggs in sealed niches; all other known platypodids are monogamous and dis- tribute the eggs loosely in the parental gal- leries or carry them on the female frons. Mecopelmus makes a cave-type nuptial cham- ber (without oviposition galleries) in the cam- bium region of its host and deposits the eggs in clusters therein, and the larvae form indepen- dent mines in the cambium at least for the latter part of their development. Protoplaty- pus forms stellate or radiate tunnels, with a central nuptial chamber in the cambium re- gion, and the eggs are placed in regular, alter- nate, sealed niches along the linear egg gal- leries; the larvae form independent mines throughout their development. Schedlarius is xylophagous (Wood 1957a), places its eggs in randomly organized niches that are sealed with frass, and the larvae form long, indepen- dent mines that wander aimlessly through the wood. An obvious association with fungi is apparent in the vicinity of adult and larval activity, although no mycelial growth in the 1986 mines could be seen at magnification of 20X. The habits mentioned in this paragraph also form the basis of habits for the more diverse Scolytidae. In my review of characters usable in distin- guishing subfamilies of Scolytidae (Wood 1978), only one significant character gap was found that was supported by numerous fea- tures. These characters are summarized in the key to tribes below. The presence or absence of pronotal asperities, the ambrosial habit, and several features used traditionally by past workers to separate multiple subfamilies of Scolytidae either have no value in characteriz- ing subfamilies or have no value in phylogeny. For these reasons, only two subfamilies were recognized. Because the Hylesininae are structurally and biologically less diverse and their specializations more conservative, they are treated here as more primitive than the Scolytinae. Tribes of Hylesininae In general, the Hylesininae are phloeo- phagous. Exceptions include the twig- or small-branch (pith)-boring mycetophagous Hyorrhynchini (all three genera), Bothroster- nus (Bothrosternini), and Hyleops (Phloeo- sinini; last half of larval stage only); xyloph- agous Dendrosinus and three known species of the large genus Chramesus (Phloeosinini); the myelophagous Cnesinus, Eupagiocerus , and Sternobothrus (Bothrosternini),; and the spermophagous Pagiocerus (Bothrosternini) and one species of Phloeotribus (Phloeotrib- ini). The usual mating system in this subfamily is monogamy, with the female initiating the new parental gallery. Departures from this system include (a) apparent male haploidy (arrhenotocous parthenogenesis accompanied by consanguineous polygyny) in Sueus (Hyor- rhynchini); (b) monogamy, with male initia- tion of parental galleries in some Phloeosinus and Olonthogaster (Phloeosinini); and (c) het- erosanguineous (superficially resembling harem) polygyny in at least two species of New Guinea Olonthogaster (Phloeosinini), and in all Carphoborus and many Polygraphus (Polygraphini). These basic habits appear to be correlated with (1) a conservative evolutionary departure from the ancestral structure; (2) a more com- Woob: GENERA OF SCOLYTIDAE 19 pact (stout) body; (3) the body compaction that appears to have resulted in the development of a row of coarse crenulations on the basal margins of the elytra (their function is evi- dently to add resistance when a predator at- tempts to pull from a tunnel the beetle that is blocking the entrance), and (4) the straighten- ing of the pleural suture. The compaction of the body apparently also had an effect upon the mechanism of flight and permitted fusion of postnotum 2 to the metathorax. Although use of these characters requires further study and refinement, a definite trend from the Hy- lastini-Hylesinini to Phloeosinini is indicated. There appears to be a gradual transition in characters from the Hylastini to Hylesinini to Tomicini. The Hyorrhynchini and Phrixoso- mini appear to be relicts of an earlier radiation of primitive stock and are quite unrelated to the other three tribes. The remaining hylesinine tribes have the postnotum partly to entirely fused to the metanotum and fall into three units. The first includes the Old World Diamerini and New World Bothrosternini that probably contain the most primitive spe- cies of this subfamily. Their protibial, prono- tal, and base of elytral structure is much more primitive than the Hylastini-Hylesinini. Their antennal structure is much more similar to Coptonotus-Protohylastes (Platypodidae), although the Hylastini-Hylesinini club is probably more similar to the ancestral struc- ture. The second tribal unit within the more highly evolved segment of this subfamily in- cludes the Phloeotribini and Phloeosinini. Tibial structure of at least a few representa- tives of each suggests an ancient origin. Ex- cept for the aberrant structure of the antennal club of Phloeotribini, they probably could not be separated from one another at the tribal level. They include species bearing the great- est departures from the primitive forms in the pleural and scutoscutellar suture patterns. The absence of socketed protibial teeth in Aricerus and the movable segments in the antennal club suggest that Phloeotrinini is the more primitive of these two tribes. The Polygraphini and Hypoborini are obvi- ously specialized ancient groups that are un- related to one another but of uncertain affinity to other groups. The superficial appearance of the body form of Phloeographus (Poly- 20 GREAT BASIN NATURALIST MEMOIRS graphini) suggests a relationship to Tomicus , but the protibial structure of Serrastus sug- gests a much more ancient origin of this group. The Hypoborini could be a.specialized paraphyletic line that branched from the Phloeosinini. Tribes of Scolytinae The tribes of Scolytinae are easily clustered into five major groups on the basis of several anatomical characters. The most primitive, composed of Scolytini, Ctenophorini, and Scolytoplatypodini, share primitive protibial structure without socketed denticles, a 6- or 7-segmented antennal funicle, a head without a caudal extension of the dorsal occipital area, rather widely separated procoxae, etc. This group contains members (Cnemonyx, Scoly- todes ) with the greatest structural similarity of all Scolytinae to primitive Platypodidae (Pro- toplatypus, in this instance) and to Hylesini- nae. In fact, some Cnemonyx (galeritus and its allies) have coarse crenulations on the basal margins of the elytra; also, Protohylastes was thought to be allied to Pseudohylesinus (Tomicini) until the legs and antennae were studied. The Ctenophorini habits include phloeophagy, xylophagi, and myelophagy; monogamy and polygyny (heterosanguineous only); egg chambers of the cave, linear and radiate types; and deposition of eggs in loose clusters in parental chambers or in individual niches sealed by frass. The monogamous, xy- lomycetophagous Scolytoplatypodini appear to be a specialized Old World geographical replacement of the Ctenophorini. The Scoly- tini are monogamous (except for a few bigy- nous Scolytus) and phloeophagous (except for the xylomycetophagous Camptocerus ). Cne- monyx (Scolytini) and Scolytodes (Ctenoph- orini) could have been derived from a com- mon ancestor. Pycnarthrum (Ctenophorini) could easily be placed as a primitive tribe of Hylesininae on both anatomical and biological bases. The second cluster of tribes within the Scolytinae includes the Micracini and Cac- topinini. Advances include a more efficient body form (cylindrical compaction), slightly extended dorsal occipital area of the head, reduction of funicular segments to six (rarely five), universal occurrence of pronotal asperi- ties, common occurrence of xylophagy and No. 10 bigyny, etc. Xylomycetophagy and males nor- mally associated with more than two females are unknown. Scalelike pronotal and elytral setae are a common occurrence. The evolu- tionary connection between this group of tribes and the more primitive Scolytini- Ctenophorini-Scolytoplatypodini is remote; however, a connection to the more advanced Xyloctonini-Cryphalini is clearly evident. The third cluster of tribes within the Scolytinae includes the Carphodicticini, Ip- ini, Dryocoetini, Crypturgini, Xyloterini, and Xyleborini. In this group, male abdominal tergum 8 is reduced in size and telescoped beneath 7, as in the female. In addition, the procoxae are almost always contiguous, the occipital area of the head attains its greatest prolongation, the obliquely truncate antennal club is developed and exploited, both het- erosanguineous and consanguineous polyg- yny are common, and xylomycetophagy is universal in two tribes. Carphodicticini and some Dryocoetini are obviously very primi- tive, but their connection to other primitive Scolytinae is remote and not reflected in the modern known fauna. The basal margins of the elytra are elevated and costate in Dendro- dicticus (Carphodicticini) as in some Hylesini- nae. The fourth cluster of tribes within the Scolytinae includes Xyloctonini and Cryphalini. In these tribes the procoxae are entirely contiguous, and the antennal club is flat, with the sutures on the posterior face moderately displaced toward the apex. The small metepisternal spine that functions in locking the elytra in the closed position is reduced and partly replaced by a small groove (Fig. 31). Segmentation of the antennal funi- cle is reduced, ranging from a maximum of seven to a minimum of three. Monogamy is the general habit, with consanguineous polyg- yny universal in four genera of Cryphalini (Cryptocarenus, Hypothenemus, Trischidias, Periocryphalus ). There appears to be a close connection between Micracini and this group of tribes. The elytral locking mechanism also suggests a remote connection between this group and the Corthylini (Figs. 23, 31-32). The final cluster of tribes includes the Cor- thylini. The flattened antennal club, with the sutures equal on both sides, the unique elytral locking mechanism, tibiae, eyes, elytra, etc., 1986 characterize this unique tribe. Phloeophagy is almost universal in the primitive half of the tribe, xylomycetophagy in the advanced half. Both monogamy and heterosanguineous poly- gyny are common. Consanguineous polygyny apparently occurs in three species of Araptus . There may be a remote phylogenetic connec- tion to the Cryphalini. Geographical Origin of Tribes For a discussion on this topic to have any semblance of objectivity, certain premises must be established. First, it is assumed that continental drift did occur and, due to that phenomenon, South America and Africa were either connected at their southern ends or were at least close enough to permit faunal exchange by island-hopping until earliest Ter- tiary. At that time, Australia was close enough to the southern end of South America to per- mit at least limited faunal exchange. Second, it is assumed that South America was an island during most of the Tertiary. In addition to the assumed connection to Africa in earliest Ter- tiary, South America was connected to North America in early Tertiary and again in late Tertiary either by a land bridge, as presently exists, or by a series of islands that were close enough to permit faunal exchange. Third, it is assumed that faunal exchange between Africa, Europe, and Asia has been no problem except as it has been affected by climate. Fourth, it is assumed that climate has fluctuated as evi- denced by fossil remains of magnolia trees in Alaska and of tropical forests where the Sahara Desert is now located. Finally, it is assumed that scolytid beetles have had habits through- out their history that were essentially as seen at present. That is, groups presently re- stricted to the tropical forests have always been so restricted, and groups now in more temperate climates have been able to occupy cooler climates for a long time. In the first column of Table 1 are listed all tribes of Scolytidae presently recognized in the world fauna. From each tribe, those gen- era were selected that now are restricted to tropical climates. If those genera are now rep- resented in both Africa and South America or if they have a very closely related geographi- cal replacement genus on both continents, but are not found outside the tropics else- where, then those tribes were considered to Woob: GENERA OF SCOLYTIDAE vAll have a pre-Tertiary origin (Table 1, column 2). If the tribe at that time was local in distribu- tion and was represented on only one land mass, it was not included as pre-Tertiary even though it could have been present. A faunal connection from South America to Australia was regarded as early Tertiary, not just pre- Tertiary. It is noted (1) that 6 of 11 tribes of Hylesininae and 7 of 14 tribes of Scolytinae are judged on this basis to be of pre-Tertiary origin, and (2) that the only pre-Tertiary group containing species with the xylomyce- tophagous habit is Xyleborini. (Hylesinini is excluded, because its only xylomycetopha- gous genus, Hyleops, has not yet fully adopted that habit.) This does not mean that other xylomycetophagous groups were not present, but only that, if they were present, they were local in distribution (on only one land mass) at that time. It is further noted (3) that all tribes judged as pre-Tertiary were phloeophagous except for Xyleborini and part of Micracini. This suggests that xylophagy and xylomycetophagy are of comparatively recent origin. The significant point is that the family Scolytidae was a well-established, diversified group by the beginning of the Tertiary. The fossil engravings of scolytids in coniferous bark from Upper Cretaceous illustrated by Brongniart (1877) and described from Lower Cretaceous by Blair (1943) are evidence of a much longer family history of the group than is usually recognized. It is probable that the beetles that made those engravings were much more similar to the Ctenophorini or, possibly, Protoplatypus than to modern Hylesininae. PHYLOGENY As stated above, the Platypodidae-Scolyti- dae group are members of the Cur- culionoidea. Within that superfamily, they form a distinctive unit that is characterized by the presence of fully developed pregular su- tures. Because the only other known pregular sutures within the Curculionoidea are the api- cal remnants found in females of two species of Belidae, the possibility of an ancient common ancestor should be examined. Three genera of Belidae and an entire segment of Oxyco- rynidae (Rhopalotria), a supposed derivitive 299. GREAT BASIN NATURALIST MEMOIRS No. 10 TABLE 1. Estimated age of the tribes of Scolytidae, based on genera known to be restricted to tropical areas. Tribes are considered pre-Tertiary if a tropical genus or a close geographical replacement genus occurs in Africa and also in South America (Column 3). More recent postseparation (of Africa and South America) distribution is added as indicated (Column 4). Ancient Distribution added after Tribe Pre-Tertiary! origin early Tertiary Hylastini 0 Holarctic No change Hylesinini + Old World South America (from Africa), North America (from Asia) Tomicini a. Xylechinus + South America Worldwide allies b. Dendroctonus + Worldwide in Worldwide allies Araucaria Prixosomini + Africa—South America No change Hyorrhynchini 0 Oriental No change Diamerini 0 Africa Southern Asia to Australia Bothrostornini 0 South America North America Phloeotribini 0 South America Australia (from South America); North America to Eurasia, from South America. Phloeosinini + Africa—South America Ancient to Eurasia; modern to North America Hypoborini : Worldwide (or Africa— Relicts South America) Polygraphini 0 Africa Europe and Asia, then to North America Scolytini 0 South America North America then to Eurasia Ctenophorini Ts South America North America Scolytoplatypodini 0 Africa Southern Asia Micracini =f South America—Africa North America to Asia Cactopinini 0 North America No change Carphodicticini a ? South America—Southern Asia Ipini + South America—Africa Worldwide Dryocoetini 4 Africa Worldwide Crypturgini 0 Africa North America, Eurasia Xyloterini 0 Asia North America Xyleborini + Africa—South America Worldwide Xyloctonini 0 Africa Asia Cryphalini + Africa—South America Worldwide Corthylini 0 South America Worldwide (African segment) ‘Marked (+) if present in recognizable form prior to the beginning of the Tertiary on more than one land mass. Marked (0) if represented at the beginning of the Tertiary by a local representative or a precursor that was present on only one land mass. of Belidae, have only one gular suture, not two as in other members of the Belidae- Oxycorynidae-Aglycyderidae (Proterhinidae) group. Because such a placement would be a radical departure from the traditional position of Platypodidae-Scolytidae within the Cur- culionoidea (which has been next to the Cur- culionidae), additional supporting evidence was sought. The following summary of infor- mation presented in the above sections was found. A functional, but degenerate, adult labrum occurs in Curculionoidea only in An- thribidae and Nemonychidae. Rudiments of a labrum are well marked in many Platypodidae and obscurely indicated in some primitive Scolytidae, but they are not indicated in other curculionoids known to me. Anthribidae and Nemonychidae have a maxillary lacinia sepa- rate from the galea; this character is shared by Platypodidae (Tesserocerini), Attelabidae, and Rhynchitidae; the lacinia and galea are fused in all other curculionoids. Most of those curculionoids having two gular sutures have a 4-segmented maxillary palpus; Attelabidae, some Rhynchitidae, and one Platypodidae share that character. In Anthribidae, Nemonychidae, Eobelidae (fossil), Scolyti- dae, and Platypodidae the mandible is api- cally pointed, the cutting edge mesal, the condyles are closer together and differently positioned, and the apical part of the hypos- toma is of minimal size. In all other cur- 1986 culionoids, the basal half of the mandible forms a cylinder that rotates on a horizontal axis between the condyles, the dentate cut- ting edge is distal and moves through a difter- ent arc, and the hypostoma is enlarged to give greater strength to the posterior condyle. Whereas the preponderance of adult charac- ters support the suggested relationship, larval characters have not been found that separate some Curculionidae from some Scolytidae. The larvae of Platypodidae and Scolytidae are easily separated; however, it is by the same primary character that Anthribidae and Nemonychidae larvae are separated (see key to families below). Obviously the Platypodi- dae-Scolytidae are not part of the Curculion- idae and occupy a more primitive position in phylogeny. Exactly where they branch from the main curculionoid stem is not yet clear, but it could be from an Eobelidae-like ances- tor. Within the Platypodidae-Scolytidae, three major phyletic units are evident. The smallest and most distinctive paraphyletic line is the Platypodidae (about 1,000 species). They lack socketed tibial denticles, have the terminal, protibial mucro formed from the middle one of three apical spines (as compared to Proto- hylastes), always have the posterior half of elytral interstriae 10 present, always have a primitive mechanism for locking the elytra in closed position, lack a spiculum gastrale, and contain members having the primitive charac- ters cited in the above paragraph. The Scolyti- dae contain partial or complete departures from these characters. As indicated above, six rare tropical genera (containing a total of seven species) are intermediate between these families. The other two major phyletic lines include the Hylesininae (about 2,000 species) and the Scolytinae (about 4,000 species). Although the most primitive members of the family un- doubtedly are members of the Scolytinae, that subfamily also contains far more and greater specializations than do the Hylesini- nae. Because the Hylesininae are less diverse and depart less drastically from the primitive form, they are considered more primitive and paraphyletic; the Scolytinae are more special- ized and contain the major evolutionary thrust of the family. Hylesinine evolution appears to have been oriented toward a bodytype that is Woob: GENERA OF SCOLYTIDAE DiS subspherical to take advantage of the row of crenulations on the bases of the elytra; scolytine evolved toward cylindrical com- paction that is more effective in deeper host tissues where the ambrosial habit was ex- ploited. Progess toward a more nearly spherical body form in Hylesininae was accompanied by straightening out (somewhat) the scu- toscutellar and pleural sutures on the meta- thorax. This apparently modified the mecha- nism of flight such that flection between the metathorax and its postnotum was no longer necessary and that the intersegmental line (membrane) was lost, at least in the median area. Accompanying that change were: a re- duction in the number of segments of the antennal funicle from seven to as few as three and changes in the antennal club from cone- shaped, with simple, transverse sutures, to flattened and with or without sutures in’ nu- merous combinations. The primitive mating system was monogamy, with the female ini- tiating the new parental gallery. Limited de- partures from that system include male ini- tiated monogamy and_heterosanguineous polygyny (many Polygraphini) and consan- guineous polygyny (Sueus in Hyorrhynchini). A recognizable phyletic sequence appears to progress from the primitive Hylastini through Hylesinini to Tomicini. Hyorrhynchini and Phrixosomini appear to have been derived independently on separate lines from the same basic stock as that group of tribes. Among those tribes with a fused postnotum, Bothrosternini and Diamerini appear to be geographical replacements of one another that arose from a common ancestor that was much more closely allied to the Ctenophorini- like ancestor of Scolytinae than to the immedi- ate ancestral stock of the Hylastini- Hylesinini-Tomicini. Although the Phloeo- tribini and Phloeosinini are closely related to one another, they (as one unit) were probably derived from the Bothrosternini-Diamerini ancestral stock independently from the unre- lated Polygraphini and Hypoborini. Differen- tiation of phyletic lines in the Hylesininae has progressed slowly; consequently, they are dif- ficult to detect. In general body habitus, Pro- tohylastes (Platypodidae) resembles primitive hylesininae very closely, but the legs and an- tennae do not. Pycnarthrum (Ctenophorini) 24 GREAT BASIN NATURALIST MEMOIRS would be placed in Hylesininae except for its legs. A primitive relationship of Hylesininae to primitive Scolytinae and Platypodidae is clearly indicated in these genera. ° Among the Scolytinae, the Ctenophorini, Scolytini, and Scolytoplatypodini are closely related to one another and were almost cer- tainly derived from a common Ctenophorini- like ancestral stock. The Ctenophorini more nearly resemble Protoplatypus (Platypodi- dae) than do other members of this subfamily. Some Cnemonyx (allies of galeritus, Cten- ophorini) have crenulations on the basal mar- gins of the elytra as in Hylesininae. The four remaining clusters of tribes were probably derived from a Ctenophorini-like ancestor in the following pattern. Although there is no clear primitive connection to an ancestral group, Micracini and Catopinini are anatomi- cally and biologically allied to one another. An advanced member of Micracini probably gave rise to the Xyloctonini-Cryphalini group, then a Cryphalini-like member gave rise to the Corthylini. The remaining tribes, Carphodic- ticini, Ipini, Dryocoetini, Crypturgini, Xylo- terini, and Xyleborini (listed in ascending or- der of anatomical and biological complexity) were probably derived from another Mi- cracini-like ancestor along the same (one) phyletic line of descent. Active major evolu- tionary thrusts appear to be in progress within the Dryocoetini, Xyleborini, Cryphalini, and Corthylini, which combined contain more than half the living species of Scolytidae. METHODS Although this project was conceived in 1949, serious work on it was not started until 1955. From 1955 to 1965, comparative anatomical studies were made of representa- tives of more than 100 selected genera of Cur- culionoidea, in addition to more than 60 gen- era of Scolytidae and Platypodidae. As the patterns of evolution began to emerge from those studies, a major effort was made to col- lect specimens and to gather behavioral and ecological data on species not previously known to me. More than 2,000 species of Scolytidae and 300 species of Platypodidae were collected from North and South Amer- ica, Europe, Asia, Australia, and New Guinea. In addition, visits were made for the No. 10 purpose of studying types and comparing them and other specimens to my material at museums in the United States, Canada, Mex- ico, Venezuela, England, Austria, Finland, USSR, India, Japan, Australia, and Papua- New Guinea. There visits included stays of a month or more at the British Museum (Natu- ral History), the Schedl Collection (both at Lienz with Sched] in 1965 and at Vienna in 1983), and the Forest Research Institute, Dehra Dun, India (where more than 40,000 Indian specimens were sorted to species in addition to studies of the types). It is esti- mated that well over 400,000 specimens of Scolytidae and Platypodidae were examined. From those museums not visited in person by me, types and other specimens were obtained for study through loan. Except as noted below under Incertae Sedis, all existing type-species for all named genera and subgenera were ex- amined and, where type-specimens have been designated, the type-specimen of those species were also studied. The basis for recog- nition is given under each species and syn- onym below. Except at Helsinki (Finland), Leningrad and Moscow (USSR), Bulolo (Papua-New Guinea), and Sydney (Australia), where local museum equipment was used, the studies were made using an American Optical Com- pany stereoscopic microscope, model 25, equipped with an occular grid, at magnifica- tions of 10, 40, 80, and 160X. All measure- ments were made at 10X and excluded the head (in measurements of body length). Authentic specimens of the type-species of several genus-group names assigned to the Scolytidae. were not examined during the course of this study. These species fall into two categories: (1) those for which the types or other authentic specimens could not be found and are presumed lost, and (2) fossil species. The types of four genera could not be found. These included: 1. Allarthrum Hagedorn (1912:355), based on A. kolbei Hagedorn (1912:355), from Pe- terhafen, Deutsch New Guinea. The type(s), 1.5 mm in length, was deposited in the Kgl. Zoolog. Museum Berlin but cannot now be found. The illustration of the antenna (Hage- dorn 1912:Fig. 5) is ofa Cryphalus species. It is provisionally listed as a synonym of Cryphalus. 1986 2. Bufonus Eggers (1919:231), based on B. obscurus Eggers (1919:231) from Amani, Ost- Afrika. The unique holotype, 1.5mm, was lost with the Hamburg Museum in 1944. The an- tennal funicle was described as 2-segmented, the club elongate, with three transverse su- tures; the scutellum was not visible, the basal margins of the elytra were sharply rounded, and the elytral sculpture was pronounced and unique. Except for the absence of crenula- tions on the basal margins of the elytra, this genus would be placed in Hypoborini. A more detailed knowledge of the fauna of East Africa is needed before it can be correctly placed in classification. 3. Toxophorus Eggers (1920b:119; preoc- cupied, renamed Toxophthorus Wood), based on T. africanus Eggers (1920b:119) from Deutsche-Ostafrika. The unique holotype, 3.0 mm, was lost with the Hamburg Museum in 1944. The antennal scape was elongate, the funicle was 5-segmented, the club was flat- tened, with a suture near the apex, and the frons was impressed above the eyes. This genus almost certainly is in the Dryocoetini, possibly near Tiarophorus or Xylocleptes . 4. Pseudomicracis Eggers (1920a:36), based on P. elsae Eggers (1920a:36) from Dares- Salaam, Ostafrika. The unique female holo- type, 1.5 mm, was lost with the Hamburg Museum. The frons was impressed, the an- tenna was similar to Micracis, the scape was triangular, with long hair on the outer angle, and the sutural apex of the elytra mucronate. Because only one known genus bears the com- bination of characters described by Eggers, his name is associated with those African spe- cies previously referred to the American genus Micracis. As such, this genus is recog- nizable and is treated below under the name Pseudomicracis . Of the six fossil genera that have not been previously placed in synonymy under older names of modern genera, four are from Baltic amber, one is from Burmese amber, and one is from sedimentary deposits. These include: 1. Carphoborites Sched] (1947:32) was based on C. keilbacki Sched] (1947:32) and C, posticus Sched] (1947:33), both from Baltic amber (Charphoborites was a lapsus calami). From the descriptions, I see no reason to separate these species from Carphoborus; however, I have not examined the specimens. Woob: GENERA OF SCOLYTIDAE 25 2. Hylescierites Sched] (1947:29) was based on H. granulatus Sched] (1947:30) from Baltic amber. From the photograph of the holotype and the original description, I see no reason for separating this species from Hylurgops. 3. Taphramites Sched] (1947:41) was based on T. gnathotrichus Schedl (1947:42) from Baltic amber. From the description, it ap- pears that this species should be placed in Dryocoetini, probably in or near Dryocoetes . I have not examined the specimen. 4. Xylechinites Hagedorn (1907:120) was based on X. anceps Hagedorn (1907:120) from Baltic amber and was redescribed and illus- trated by Sched] (1947:30-32). The descrip- tions and photograph of the holotype indicate that this species is a Tomicini near or in Xylechinus. I have not examined the speci- men. 5. Cryphalities Cockerell (1917:368) was based on C. rugosissimus Cockerell (1917: 368) from Burmese amber. Because no usable characters were included, the original de- scription gives no clue as to where this species should be placed. It is assumed that Cockerell was correct in assigning it to Cryphalini. I have not examined the specimen. 6. Xyleborites Wickham (1913:26) was based on X. longipennis Wickham (1913:26) from the Wilson Ranch near Florissant, Colo- rado. The author indicated that this species, 2.2 mm in length, resembled Xyleborus pubescens. Essential characters were not de- scribed. The specimen was not examined by me. Pityophthoridea Wickham (1916:18) and Adipocephalus Wickham (1916:16) are not considered to be members of the Scolytidae. SYSTEMATIC SECTION Although some obvious unanswered ques- tions remain as to the exact position of Platy- podidae and Scolytidae within the Cur- culionoidea, the following key is presented for the identification of families. The presence of complete pregular sutures and the mandible structure of Platypodidae and Scolytidae are obviously more primitive than the absence of these sutures and the specialized mandibular structure of Belidae and Oxycorynidae, but the single gular suture and presence of larval epipharyngial rods are more advanced than 26 GREAT BASIN NATURALIST MEMOIRS the two gular sutures and absence of the rods in Belidae. The long subcortical history and very small body size of Platypodidae and Scolytidae have had an obvious effect on their anatomy that complicates interpretation of their position in phylogeny. This key to families of the Curculionoidea is tentative. A thorough reexamination of the Belidae-Aglycyderidae-Oxycorinidae groups is needed to determine the significance of single vs. double gular sutures, the precise position of character gaps that separate families, etc. Another area of concern is the section of the key in couplets 11 and 12. Char- acters to separate these three taxa are weak, but, in view of the large number of species to be classified herein, perhaps the recognition of these three families is justified. Among more than 150 genera of Curculionidae (in the sense used here) dissected by me, I saw three possible divisions of this family. These in- cluded (1) the Cossoninae-Rhynchophorinae, (2) the broadnose weevils, and (3) all others. It is recognized that some equally distinct groups may exist that were not seen by me, but a thorough comparative anatomical study should precede their recognition. Following my study, I seriously doubt that even one- third of the 75 or more subfamilies that have been recognized within Curculionidae de- serve this rank; most are worthy of no more than tribal status. Key to the families of Curculionoidea 1. Adult: two gular sutures present or rudiments of them evident (only one gular suture and a postgula present in several Belidae and Rho- palotria of Oxycorynidae); maxillary palpi 4- segmented; abdominal segments free (except 3-6 connate in Anthribidae); antennae usu- ally orthocerous, scape little longer than suc- ceeding segments, club loosely 3-segmented. Larva: epipharyngeal rods absent; maxillary palpi 3-segmented, rarely 2-segmented; tho- racic legs present; frontal sutures reaching articulating membrane of mandible; two folds in each abdominal tergum ................ 2 — Adult: one gular suture extending from minute postgula at margin of foramen mag- num to posterior tentorial pits (usually where base of rostrum meets head); maxillary palpi 1- to 3-segmented (4-segmented in one Platy- podidae, some Rhynchitidae, and all Atte- labidae); abdominal segments free or partly connate in some groups; antennae frequently geniculate, a definite club usually present (or- thocerous in Brenthidae; intermediate in Ithyceridae, Apionidae, some Platypodidae, and a few Sc. 'ytidae). Larva: epipharyngeal rods present; maxillary palpi 1- or 2-seg- mented (3-segmented in Brenthidae and Rhynchitidae); thoracic legs absent (present in Brenthidae and Ithyceridae); frontal su- tures not reaching articulating membrane of mandible (except Brenthidae, Apionidae, Ithyceridae, some Platypodidae); two to four folds in each abdominal tergum ............ Adult: labrum distinct and separate (except absent in Bruchela of Anthribidae); maxillary palpi flexible, lacinia forming a distinct ele- ment (see also Rhynchitidae and Tessero- cerini in Platypodidae). Larva: mandibles withiaidistinct mola wis. ssa ener Adult: labrum fused or lost; maxillary palpi rigid; maxilla without a separate lacinia. Larva: mandibles without a distinct mola .... Adult: gular sutures rudimentary, repre- sented only at margin of foramen magnum or totally lost; tentorium largely or entirely obso- lete; proventriculus developed; lateral mar- gins of pronotum acute (rounded in Bruchela); inner margin of elytra with a flange near costal margin; cavities of mesocoxae broadly closed outwardly by sternum, visible abdominal sterna 1—4 connate. Larva: clypeus distinct from frons, or head deeply retracted; mandibles without ventral process in addition to mola (includes the distinct subfamily Bruchelinae) Adult: gular sutures extending from margin of foramen magnum to posterior tentorial pits; tentorium present; proventriculus indistinct; inner margin of elytra without a flange near costal margin; mesocoxae not or imperfectly closed outwardly by sternum; abdominal sterna free. Larva: clypeus usually fused to frons; head not deeply retracted into protho- rax; mandibles with a ventral process in addi- tiomitommolareren veawectsrcteriae Adult: gular sutures longer, extending to pos- terior tentorial pits; partial pregular sutures occasionally present in female near apex of rostrum; at least three genera with large post- gula and short median gular suture; antennae filiform or nearly so, inserted laterally remote from base of rostrum; inner margin of elytra with a flange near costal margin; wing with five anal veins in main group complete to base; tarsi normal, pseudotetramerous; lat- eral margins of pronotum _ transversely rounded. Larva: maxillary palpiger well de- veloped; thoracic spiracle intersegmental . . . ERO Mi aR re ATU Re Conet EN 3 Wier Aes bos 5c Belidae Adult: gular sutures usually short (a large postgula and one median gular suture in some Oxycorynidae), externally visible near fora- men magnum or else lateral margins of prono- tum acute; antennae inserted at or near base of rostrum; either antennae clubbed or tarsi pseudotrimerous; inner margin of elytra with- No. 10 Mie EOS one 6 Anthribidae Nemonychidae 1986 5(4). 7(6). Woob: GENERA OF SCOLYTIDAE out a flange near costal margin; wings with fewer than five anal veins or else bases of elytral veins incomplete. Larva: maxillary palpiger usually not evident; thoracic spiracle in mesothorax Adult: tarsi pseudotrimerous, segment 2 bilobed; antennal insertion at base of rather short rostrum; antenna filiform, not clubbed; proventriculus well developed. Larva: maxil- lary palpiger not distinct ................. MOA en SE sic Aglycyderidae (= Proterhinidae) Adult: tarsi pseudotetramerous, segments 2 and 3 bilobed; antennal club 2- or 3-seg- mented; (a large postgula and at least a partial median gular suture present in at least Rho- palotria ); lateral margins of pronotum acute; antennal insertion at base of long rostrum, on ventral face; proventriculus poorly devel- oped. Larva: palpiger distinct .. Adult: pregular sutures present and rein- forced internally by massive apodemal ridges; rostrum short to nonexistent; tibiae armed on apical or lateral margins by a series of spines and/or socketed teeth of setal origin, corbels never present; hypostomal area small, never armed by a large spine, posterior mandibular condyle more anterior in position; axis of mandibular hinge oblique to transverse, cut- ting edge on mesal margin (Fig. 8); some members (Tesserocerini) with a separate acinar te Meee Percy ey se ene: Adult: pregular sutures absent, with no indi- cation of supporting internal apodemal struc- ture (longitudinal ridges giving rigidity to ros- trum are not reinforced internally and should not be confused with true pregular sutures); rostrum variable, long to very short; lateral margins of tibiae unarmed (except for simple spines in some Cossoninae), corbels com- monly present; hypostomal area larger, com- monly armed by a large spine, posterior mandibular condyle more posterior in posi- tion (Fig. 8); axis of mandibular hinge parallel to body axis, cutting edge on apical margin; separate lacinia never present (except some Rhynchitidae and all Attelabidae) .......... Adult: tarsal segment 1 elongate, usually longer than 2-5 combined (except shorter in Protoplatypus, Protohylastes, Coptonotus, Scolytotarsus ); tibiae armed on apical and/or lateral margins by one or more spines, never by socketed denticles, apical mucro formed by middle apical spine (as compared to Proto- hylastes); male spiculum gastrale absent; an- tennal club solid, unmarked by sutures (fee- bly indicated in Coptonotus); head about as wide as pronotum; pronotum with distinct lateral constriction near middle; when visible, scutellurm often reduced, declivous, usually with not more than apex attaining (flush with) elytral surface; metepisternum very elongate, its anterior margin straight, its anteroventral angle neither displaced caudad nor extended Oxycorynidae 8(6). ventrad; mesepimeron flat, vertical; mese- pisternum moderately to greatly enlarged, varying from flat to inflated; eyes convex, never truly emarginate; pronotum never armed by asperities. Larva: clypeus fused to frons in all except primitive genera; frontal sutures reaching articulating membrane of mandible or not .........-.-.-- Platypodidae Adult: tarsal segment 1 about equal in length to 2 or 3; tibiae armed on apical and/or lateral margins either by spines or socketed denti- cles, apical mucro formed by mesal element (compared to Protohylastes structure); male spiculum gastrale present; antennal club vari- able, with or without sutures; head narrower than pronotum; pronotum almost never with constriction near middle; when visible, scutellum usually flush with elytral surface, often flattened; metepisternum stout to elon- gate, its anterior margin usually procurved, its anteroventral angle displaced slightly cau- dad and distinctly extended ventrad; mese- pimeron flat, oblique; |» mesepisternum smaller, declivous cephalad; eyes more nearly flat against head, often emarginate to divided; pronotum often asperate. Larva: clypeus dis- tinct, separate from frons; frontal sutures never reaching articulating membrane of MANGiblesic 2a. acca woken neces Scolytidae Adult: labial palpi inserted ventrally on men- tum; head frequently constricted behind eyes; antennae never geniculate, inserted dorsally or laterally at base or middle of ros- trum, club absent to moderately distinct; proventriculus without sclerotized plates. Larva: frontal sutures reaching articulating membrane of mandibles .................. Adult: labial palpi inserted apically; antenna straight or geniculate, inserted laterally at middle or near apex of rostrum, club 1- to 3-segmented, loose to compact, small to large. Larva: frontal sutures either reaching or not reaching articulating membrane of MAN GID LES tenner et niet tema er Adult: maxillary palpi 4-segmented, galea and lacinia distinct; mandibles often dentate on outer margin; labial palpi 1- or 3-segmented (rarely absent); elytra with a scutellary striole; notosternal suture short, laterally reflexed; hind wing usually with four anal veins, radial cell well developed; sterna 3-6 rarely free, 3-4 connate in some, 3-6 connate in most; cap piece of male tegmen simple, setose; malpighian tubules grouped three on each side of alimentary canal; more than two ovari- oles in each ovary. Larva: legs absent, two or more stemmata present on each side of head; antenna usually 2-segmented; maxillary palpi 2- or 3-segmented; abdominal terga with two folds Adult: maxillary palpi 3-segmented, galea and lacinia fused; mandibles never dentate on outer margins; elytra never with scutellary 10 Attelabidae 10(8). 11(10). 12(11). GREAT BASIN NATURALIST MEMOIRS striole; notosternal suture well developed and usually extending almost to anterior margin; hind wing with three or fewer anal veins, radial cell not evident; sterna 3-4 connate and much longer than 5-6; cap piece of tegmen bilobed. Larva: rudimentary, segmented legs present; stemmata absent; antenna 1-seg- mented; maxillary palpi 3-segmented; ab- dominal terga with three to four folds Adult: maxillary galea and lacinia distinct, palpi 3- or 4-segmented; metepimeron sub- transversely carinate and interacting with humeral angles of elytra to aid in locking ely- train position, metepisternal locking element not developed and its interlocking flange at this point on inner costal margin of elytra absent; antenna straight, club loosely 3-seg- mented; abdominal sterna 3 and 4 connate, suture distinct. Larva: median area on poste- rior part of head overlapped by prothorax; maxillary palpi 2- or 3-segmented; two basal sensillae on labrum; frontal sutures complete but indistinct; abdominal terga with two folds Adult: maxillary lacinia usually fused to galea, palpi 2- or 3-segmented; metepisternum cari- nate, fitting flange on inner margin of elytra near humeral angle, metepimeron not cari- nate; antenna straight or geniculate, clubbed or not. Larva: posterior part of head free in median area; maxillary palpi | to 3-seg- mented; no basal sensillae on labrum Adult: abdominal tergum 8 longitudinally grooved for reception of inwardly raised ele- vation at suture near apex of elytra; tergum 8 bearing a pair of spiracles; maxillary palpi 3- segmented, but largely retracted into palpifer; antenna not geniculate. Larva: rudi- mentary, segmented legs present; maxillary palpi 2-segmented; 3 stemmata present .... Adult: abdominal tergum 8 not grooved, spir- acle absent; maxillary palpi 2- or 3-seg- mented, usually not retracted into palpifer Adult: either antenna not geniculate, or if geniculate then trochanters long, cylindrical, femur remote from coxa, attached to apex of trochanter; ventral surface of mentum usually with projecting setae; proventriculus poorly developed. Larva: frontal sutures extending to articulating membrane of mandibles; ab- dominal terga with two folds Adult: antenna usually geniculate; troch- anters triangular, femur attached to side of trochanter, sometimes almost touching coxa; ventral surface of mentum without projecting setae; proventriculus usually well developed. Larva: frontal sutures not reaching articulat- ing membranes; abdominal terga with two to four folds Rhynchitidae ll Ithyceridae 12 Apionidae Curculionidae No. 10 Family Scolytidae Latreille Scolytarii Latreille [1807:273, Type-genus: Scolytus Ge- offroy 1762, see also China 1962] The family Scolytidae is comprosed of a group of more than 6,000 small to minute species. Whereas the preponderance of spe- cies are tropical, a few of them reach the northern and southern limits of tree distribu- tion near the polar regions. They are unique in that loosely pair-bonded adult parents bore into subcortical tissues of their host (usually) before mating or oviposition occur. Eggs are variously placed in the galleries, and the lar- vae either expand the parental mines or form individual galleries while the parents defend the outer entrance to the tunnel. Thus, the beetles are essentially internal plant parasites that spend virtually their entire lives secreted within the tissues of the host. The ephemeral habitat they occupy is the unthrifty, weak- ened, or dying tissue of woody plants; only one generation is completed in each host un- less a large tree that is succumbing progres- sively is involved. Because of the very brief period this habitat is open to them, efficient means of locating a host, recruiting a popula- tion to subdue it, and overcoming host resis- tance are mandatory. This is accomplished through sensitivity to odors emitted by trees under stress, by a complex system of phero- mones, and by mutualistic relationships with fungi. Several of the most efficient species, with respect to meeting these challenges, compete with man for timber and horticul- tural resources and present a very real threat to human economy. Most woody plants, a few herbaceous plants, and many fruits and nuts are infested by these insects. The adjustments they have made in their mating systems, uti- lization of food resources, and adaptive radia- tion form a classic example of biological diver- sity. Key to the Subfamilies and Tribes of Scolytidae (Modified from Wood 1978) Each basal margin of elytra procurved and armed by a series of marginal crenulations (Fig. 16) (or less commonly by a continuous elevated costa in some Bothrosternini, Di- amerini, Polygraphini), usually with a scutel- lar emargination between them, scutellum usually small and rounded or depressed, ab- sent in some groups; pronotum weakly if at all declivous on anterior half, usually unarmed . tees a aS es c" Woop: GENERA OF SCOLYTIDAE Re » x * Fig. 24. Eupagiocerus dentipes Blandford, protibia: A, posterior face showing the bifid spine on the lateral, apical angle and small socketed denticle; B, an enlargement of the socketed denticle. 2(1). but crenulations sometimes present on anterolateral areas; head usually visible from above, somewhat wider; protibia usually wider; scales or deeply divided setae a com- mon feature (subfamily HYLESININAE).... Basal margins of elytra forming a straight, transverse line across body (Fig. 17), un- armed, rarely (some Scolytini, Ctenophorini, Cryphalini) with a weakly elevated continu- ous line; scutellum usually large, flat (rarely absent or highly modified in some Xyle- borini); pronotum weakly to strongly de- clivous on anterior half and usually armed by many asperate crenulations, particularly on median half (Figs. 31, 46, 52); head usually partly or entirely concealed from dorsal as- pect, somewhat narrower; protibia usually narrower; scales or deeply divided setae an uncommon feature (subfamily SCOLYTI- NAE) Scutellar area of metanotum and its postno- tum separated by a suturelike intersegmental membrane (Fig. 23, pts. 43, 45); posterior part of scutoscutellar suture strongly curved mesad to a point near crest of scutellar groove then continuing cephalad parallel to this costa for about two-thirds of metanotum length (Fig. 23, pt. 43) (except much less in Phrixoso- mini and Hyorrhynchini), metapleural suture descending subvertically from pleural wing process to metepisternal groove formed to receive corresponding costal groove and flange of elytron then abruptly angled and continued caudad along this groove to a point near pleural coxal process (Figs. 18, 23 pt. 44); scutellum visible; funicle 6- or 7-segmented or if 5-segmented (Sueus) then eye divided, male frons not impressed, and antennal club symmetrical bo Scutellar area of metanotum and its postno- tum completely fused on at least median third, intersegmental suture usually obsolete (Figs. 21, 23 pt. 41); scutoscutellar suture less strongly curved, approaching costa of scutel- lar groove more gradually and continuing cephalad parallel to it for less than half length of metanotum (Fig. 23, pt. 41) (it never reaches margin of this groove in some groups; metapleural suture sometimes as described above, but more commonly running a more direct route from pleural wing process to pleural costal process, often remote from locked position of costal margin of elytra for most or all of its course (Figs. 21, 23 pt. 41); scutellum either not visible or if visible then funicle 5-segmented and male frons im- pressed (Bothrosternini with 6-segmented fu- nicle but with a distinctive protibia, Fig. 24) Eye entire to feebly emarginate; scutoscutel- lar suture parallel to costa of scutellar groove for two-thirds length of notum; precoxal ridge on prothorax present (Fig. 20) or absent; an- tennal funicle 5- to 7-segmented Eye completely divided by an emargination, halves widely separated; scutoscutellar suture remote from costa of scutellar groove; crenu- lations on basal margins of elytra low, often poorly formed; precoxal ridge on prothorax never present; antennal funicle usually 6-seg- mented (5-segmented in Sueus) Prothoracic precoxal area rather large, its lat- eral margins strongly, sharply elevated from anterior margin to coxae (Fig. 20); crenula- tions on elytral bases usually poorly devel- oped; antennal funicle 7-segmented, club conical, segment 1 often as long as others combined; head somewhat prolonged, sub- rostrate, frons never sexually dimorphic; eyes GREAT BASIN NATURALIST MEMOIRS No. 10 Fig. 25. Mesal aspect of elytral base: A-B, Pseudohylesinus nebulosus (LeConte), groove nearest pubecent surface continues to base without interruption (ignore the tiny grain of frass trapped in the groove in A); C, Phloeosinus cristatus (LeConte), groove near base interrupted by a series of interlocking nodules and cavities. x = entire, rather short; Northern Hemisphere, except introduced elsewhere; in Pinaceae Rie Uric ie siteeeeraes RENCE eRe oe eee Hylastini Prothoracic precoxal piece small, short, its lateral areas elevated or not; crenulations on elytral bases more conspicuously elevated, forming a definite row (except confused in Dactylipalpus); antennal funicle variable, 5- to 7-segmented, club weakly to moderately flattened; head less distinctly rostrate, male frons usually impressed, eye oval to elongate, entire to feebly emarginate ............... 5 Pronotum asperate on anterolateral areas (ex- cept Hylastinus); prothorax with elevated costate ridge from coxa to anterior margin (weaker than in Fig. 20); antennal funicle 6- or 7-segmented; mesal surface of elytra at base of suture immediately behind scutellum with an interlocking series of nodules and cavities (Fig. 25-C), this lock interrupts groove and flange of suture (not visible when elytra in locked position); worldwide ........ Hylesinini Anterolateral areas of pronotum unarmed; precoxal costa on prothorax absent; funicle 5- to 7-segmented; mesal surface of elytra at su- ture with interlocking groove and flange con- tinuted to base without a series of nodules or cavities immediately behind scutellum (Fig. I5-A-B) Aworldwideser cree Tomicini Protibia armed on outer apical margin by sev- eral socketed denticles of approximately equal size; procoxae contiguous; frons convex, not sexually dimorphic; antennal scape elon- gate, suture | of club partly septate; prono- tum never armed by asperities; America, /Nigterleed aa ape naiciga Geo oreo ae Phrixosomini Protibia with outer apical angle produced into one conspicuous spine reaching level of tarsal insertion, outer margin without any socketed teeth; procoxae rather widely separated; male frons broadly impressed (except in dwarfed Sueus), female frons convex; antennal scape either long or short, club aseptate; pronotum either with or without asperities in anterolat- eral areas; southeast Asia ...... Hyorrhynchini Lateral margins of pronotum usually sub- acutely elevated, costate (as in Fig. 12); mesepimeron moderately to very large, its dorsal portion usually grooved for reception of elytral base; scutellar shield under base of elytra large, extending posteriorly beyond visible scutellum (Fig. 26); scutoscutellar su- ture remote from costa of scutellar groove to its base; outer apical angle of protibia often with only one major recurved spine (Fig. 7); Africa, southeast Asia to Australia .. Diamerini Lateral margins of pronotum rounded (Fig. 16) (subcostate in a few neotropical Both- rosternini, Fig. 11); mesepimeron not en- larged or grooved (feebly grooved in Aricerus), scutellar shield beneath elytra small if present, not extended caudad beyond visible scutellum (Figs. 18, 21); scutoscutellar suture near and parallel to costa of scutellar groove on at least anterior fourth of metan- ObUM HES, «Solas Atel cee eo eer 8 Outer apical angle of protibia with a curved bifid process, meso- and metatibiae with one or two (usually smaller) curved spines on outer apical angle extending beyond level of spine on inner apical angle (Fig. 24); prono- tum smooth or longitudinally strigose; funicle 6-segmented; lateral prosternal area usually subacutely elevated from coxa to anterior margin; anterior coxae rather widely sepa- rated; crenulations on elytral bases rather small or (rarely) replaced by a continuously elevated costa; eye entire; America ........ Pea neo nen eaccm one to age Bothrosternini Outer apical margin of protibia armed by sev- eral teeth of about equal size (except Aricerus in Phloeotribini), none of them extending be- 1986 Woop: GENERA OF SCOLYTIDAE 31 Fig. 26. Diagram of Sphaerotrypes globosus Blandford, with elytra removed, showing enlarged scutellar plate that lies below the base of the elytra. 10(9). 11(9). LCD: yond tarsal insertion; funicle 4- to 7-seg- mented; prosternal area with margins rounded, costa obsolete; eye varying from en- tire to emarginate to divided .............. Scutellum visible, elytral bases notched for its reception; tarsal segment 3 stout, usually somewhat bilobed (except slender in Chramesus ); mesal surface of elytra at suture immediately behind scutellum with a series of interlocking nodules and cavities (Fig. 25-C) MOT trier y a cacloks ais Gyausaie tun suehy stot prem ncc ers 10 Scutellum obsolete, elytral bases only slightly if at all emarginate at suture (Fig. 17); tarsal segment 3 slender; mesal surface of elytra at suture usually without a special lock, groove and flange extend to base at position of scutel- lum (degenerate in Fig. 25-A-B) Antennal club constricted at sutures and mov- able at intersegmental lines (Figs. 16, 27); Holarctic, Neotropical, and Australian ..... MPR ees Aza cvisyeute 1) Sutya & tnila'e aces Phloeotribini Antennal club immovably, broadly fused at sutures, sutures often partly or entirely obso- lete; worldwide ................ Phloeosinini Eye emarginate or entirely divided; prono- tum never armed by asperities; crenulations at bases of elytra more widely distributed, extending laterad beyond interstriae 5 (Fig. 16); funicle 5- or 6-segmented; scutoscutellar suture passing near and parallel to costa of scutellar groove on anterior fourth of meta- notum; Northern Hemisphere and Africa . . . Polygraphini Eye sinuate or entire; pronotum armed by a few scattered or clustered asperities; crenula- tions at bases of elytra restricted to area be- tween suture and interstriae 5; funicle 3- to 6-segmented; scutoscutellar suture remote from costa of scutellar groove on anterior fourth of metanotum; almost worldwide ... . Hypoborini Lateral margins of pro- and metatibiae un- armed except for a single, apical, spinelike process that curves toward and extends be- Fig. 27. Antenna of Phloeotribus: A, rhododactylus (Marsham):; B, caucasicus Reitter. yond process of inner apical angle (Fig. 7, Camptocerus); lateral margins of pronotum subacutely elevated, costate; pleural suture descending subvertically from pleural wing process to groove receiving groove and flange on costal margin of elytra, at this point suture turns abruptly and follows groove caudad to metapleural coxal process (Fig. 23, part 46); funicle 7-segmented, sutures of antennal club strongly procurved or obsolete; Holarctic and Neotropical acstae recta sete avaeatts Scolytini — Lateral margin of protibia armed by more than one denticle, none of which exceed or curve toward inner apical process; pleural su- ture less strongly angulate, groove receiving flange of costal margin of elytra displaced ven- trad from course followed by pleural suture (Fig. 23, part 42); lateral margins of pronotum subacutely raised or not, antenna variable .. 13 13(12). Metepisternum visible throughout its length, slightly more than its dorsal half covered by elytra when in locked position, either with a conspicuous groove for reception of costal flange throughout its length or else groove represented at its anterior end by a denticula- tion or costate remnant near anterior end of metepisternum (Fig. 23, parts 42, 44, 46); antennal club varying from flat to obliquely truncate (Hig: (29) soo se wasas selene stra tegen 14 — Metepisternum largely covered by elytra, its groove for reception of costal flange obsolete, asmall, transverse callus (Cryphalini, Fig. 31) ora small transverse groove (Corthylini, Figs. 23, part 47, and 32) at anterior end of met- episternum; antennal club strongly flattened; antennal club never obliquely truncate ... . . 24 14(13). Lateral margins of pronotum subacutely ele- vated, basal margins of elytra usually finely elevated; procoxae rather widely separated except contiguous in Xyloctonini; protibia 32 GREAT BASIN NATURALIST MEMOIRS No. 10 Figs. 28-32. Scolytidae parts: 28, Ips woodi Thatcher, ventral aspect of prothorax showing contiguous coxae, left coxa removed (ignore the plant fiber between the coxae); 29, obliquely truncate antennal club of Dryocoetes confusus Swaine; 30A, posterior face of protibia of Scolytoplatypus papuanus Eggers showing unsocketed spines on lateral margin, B, enlargement of spines 1 and 2; 31, dorsal aspect of posterolateral area of prothorax of Cryphalus ruficollis Hopkins, with left elytron removed to expose anterolateral area of metathorax (arrow points to the groove that is partially replacing the metepisternal spine; 32, left pleuron of Corthylus panamensis Blandford, with elytron removed; upper arrow points to pleural suture, lower one to the groove that has entirely replaced the metepisternal spine. 1986 15(14). 16(15). 17(14). 18(17). 19(18). Woop: GENERA OF SCOLYTIDAE with prominent outer apical process recurved (Fig. 7, Scolytodes), usually extending be- yond tarsal insertion, posterior tibia tapered on apical third and armed by several small socketed denticles; funicle 6- or 7-segmented; tarsi often retractible into tibial grooves .... 15 Lateral and basal margins of pronotum rounded (except Cnestus); procoxae subcon- tiguous (except most Micracini and a few Xyleborini); protibia with outer apical angle inconspicuous, armed by several small sock- eted denticles; funicle 2- to 6-segmented; tarsi not retractible (except in Eccoptopterus ) 17 Eye divided or nearly so by a very deep emar- gination; antennal club flat, usually enlarged, with sutures strongly procurved; abdomen conspicuously ascending toward apex (not al- ways clear in Ctonoxylon); tarsi always re- tractible into tibial grooves; Africa and south- ern Asia Xyloctonini Eyes entire to shallowly sinuate on anterior margin; antennal club flat, usually smaller, more slender, sutures variable, if present; ab- domen horizontal; tarsi retractible or not ... 16 Antennal club with one or more sutures indi- cated by grooves, setae, or septae; scutellum large, flat; America; mostly phloeophagous, never mycetophagous Ctenophorini Antennal club unmarked by sutures; prono- tum with sides strongly constricted on poste- rior half; scutellum absent (a small scutellum present in Scolytoplatypus congonus ); Africa to Asia and New Guinea; mycetophagous .. . Scolytoplatypodini Procoxae moderately separated; protibia with sides parallel, armed by denticles only on api- cal margin or posterior face; funicle 6-seg- mented (5-segmented in one African genus); female frons often concave, male frons rarely concave (except two Pseudothysanoes ); Africa and America, one species in Asia .... Micracini Procoxae contiguous (except Carphodicticini, some Xyleborini); protibia much wider api- cally, armed on lateral margin by several den- ticles; female frons rarely concave (a few Dry- ocoetini), male frons often concave; funicle 2- to 5-segmented, 6-segmented in Tiarophorus 18 Male frons strongly excavated, epistoma armed by a pair of (usually) fused horns of enormous size (Fig. 47); funicle 5-segmented, club often small and feebly flattened; eye small, entire; pronotum with summit near basal margin, projecting back over scutellum in some species; western United States and Mexico Cactopinini 19 Not fitting above combination of characters. . Meso- and metathoracic tibiae more slender, more abruptly narrowed on apical fourth, lat- eral and apical margins armed by fewer, coarser teeth; eye sinuate to shallowly emar- 20(19). 21(20). ginate (divided in Tiarophorus , Dryocoetini, Africa); pronotum sometimes with a raised line on basal or lateral margin; pregular area not depressed; sexes of similar size and body form (except male dwarfed and deformed in Coccotrypes and Ozopemon); habits varied but never woodboring or mycetophagous . . . If eye completely divided into two parts and antennal funicle 4-segmented then male frons deeply excavated and male equal in size to female; if eye emarginate (or if divided and funicle 5-segmented) then male dwarfed, de- formed, and flightless and female meso- and metathoracic tibiae expanded to just beyond middle then arcuately tapered to apex, its apical two-thirds on outer margin armed by a row of numerous small, closely set teeth of equal size, these usually supplemented in same row by submarginal hair on posterior face; male pronotum highly modified; pregu- lar area depressed (except Premnobius); woodboring, mycetophagous Pronotum rather strongly, laterally con- stricted on posterior half, anterior half not declivous and never armed by asperities; anterior coxae moderately separated; anten- nal club strongly flattened, marked by two sutures, sutures on posterior face almost equal to those on anterior face; South America and India to Ceylon (Sri Lanka) Pronotum not constricted, sides straight to arcuate, anterior half usually declivous, usu- ally armed; anterior coxae contiguous; anten- nal club obliquely truncate or with sutures on posterior face strongly displaced toward apex (rarely with sutures obsolete) Eye shallowly sinuate (shallowly emarginate in some Acanthotomicus), its lower half dis- tinctly narrower than above; protibia with 3-4 socketed teeth; antennal club rarely obliquely truncate (Pityokteines, Orthotomicus); pro- coxae contiguous, intercoxal piece longitudi- nally emarginate to absent, never complete; elytra moderately sulcate to elaborately exca- vated, with lateral margin usually armed by tubercles or spines; pronotum more strongly declivous on anterior third, asperities usually larger; worldwide Eye sharply, rather deeply emarginate (sinu- ate in Deropria), lower half usually almost equal in width to upper half; protibiae usually with four or more socketed teeth (most excep- tions with lateral margins of pronotum acutely elevated); procoxae either contiguous or dis- tinctly, narrowly separated; elytral declivity flattened to convex, unarmed by spines or large tubercles; pronotum either evenly arched from base to anterior margin or less strongly declivous on anterior third, asperi- ties, when present, usually fine and abundant (a few exceptions) 20 21 Ipini 34 GREAT BASIN NATURALIST MEMOIRS . Antennal funicle 4- to 6-segmented, club ei- ther obliquely truncate or with sutures on posterior face strongly displaced toward apex; anterior half of pronotum more strongly de- clivous and rather coarsely asperate (unarmed in Tiarophorus); worldwide ..... . Dryocoetini oe Antennal funicle 2- or 3-segmented, club with sutures on posterior face about equal to those on anterior face; pronotum feebly declivous on anterior half and unarmed (minutely gran- ulate in some Aphanarthrum), reticulate in many species; size small; Northern Hemi- sphere and Africa............... Crypturgini 23(19). Eye always completely divided into two parts; antennal funicle 4-segmented, base of club feebly to moderately corneous, usually pubescent to base; male subequal in size to female, his frons flattened or excavated and anterior margin of his pronotum more broadly rounded; male joins female in parental gallery, reproduction always bisexual, Hol- arctic and Oriental................ Xyloterini — Eye emarginate except divided in some Amasa; funicle 5-segmented (3- or 4-seg- mented in a few Asiatic forms); males flight- less, dwarfed, deformed, anterior slope of pronotum variously excavated; male head convex; male absent from parental gallery ex- cept as progeny; partly parthenogenetic, male haploid; almost worldwide ........ Xyleborini 24(13). Costal margin of elytra slightly to moderately ascending from base of declivity to apex; basal end of metepisternum armed by a callus or partial groove of degenerating metepisternal spine (Fig. 31); sutures on posterior face of antennal club more strongly displaced toward apex; funicle 3- to 5-segmented; tibiae more strongly flattened, usually armed by more than four denticles; vestiture commonly in- cludes scales; eye usually entire, less com- monly emarginate; worldwide ..... Cryphalini = Costal margin of elytra descending toward apex (except Brachyspartus); basal end of metepisternum with a small, transverse groove (Fig. 32) (concealed when elytra in locked position), elytra in locked position more completely cover metepisternum (Fig. 52 part 5, and 53); sutures on posterior face of antennal club only slightly displaced toward apex; funicle 1- to 5-segmented; tibiae more slender, rarely armed by more than four sock- eted denticles; vestiture rarely includes scales (in tropical forms only); eye emarginate; al- most worldwide except Australia .... Corthylini Subfamily Hylesininae Hylesinen Erichson [1836:46, Type-genus: Hylesinus Fabricius, 1801] Most previous classifications have recog- nized the Hylesininae as a major division of the taxon treated here as Scolytidae; however, No. 10 there has been variability in the taxonomic rank assigned to it. Most of the distinguishing characters employed previously are not found consistently throughout the group and, conse- quently, have little or no taxonomic value. The most consistent and reliable character available for the recognition of this subfamily is the procurved basal margins of the elytra that are armed by a row of crenulations, and the scutellar notch between them. The heav- ier, more coarsely armed tibiae are distinctive but less reliable as a distinguishing feature. The more primitive Bothrosternini, Diame- rini, and a few other isolated examples lack the specialized elytral crenulations and have the basal margins elevated along a continuous costa reminiscent of some Platypodidae. This same character also occurs in Dendrodicticus (Carphodicticini) and, in a greatly reduced form, many Scolytini, Ctenophorini, and Cryphalini. On the other hand, a few Cnemonyx (allies of galeritus, Scolytini) have fully formed basal crenulations that suggest an affinity with the Hylesininae. Even though the demarkation between subfamilies is not as sharp as some would like, the division of sub- families is simple and the characters are reli- able. Tribe Hylastini Hylastes LeConte [1876:387, Type-genus: Hylastes Erichson, 1836] DESCRIPTION.—Frons not sexually dimor- phic; eye oval, entire; antennal scape elon- gate, funicle 7-segmented; precoxal ridge on prothorax strongly, acutely elevated; protibia very broad, with rather numerous lateral socketed teeth; scutellum visible; crenula- tions at base of elytra poorly developed, usu- ally net forming a definite row; declivital in- terstriae 10 sometimes present (Scierus); declivital sculpture usually simple; vestiture usually includes scales (some exceptions); scu- toscutellar suture parallel to costa of scutellar groove for two-thirds length of pronotum; metapleural suture descending subvertically from pleural wing process to metepisternal groove (this groove interlocking with groove on costal margin of elytron) then continuing caudad along this groove to a point near pleural coxal process; tarsal segment 3 wider than 1 or 2. 1986 BioLoGy.—All species are monogamous. They breed in coniferous hosts, usually at the base or in the roots of large trees, although some species prefer the lower surface of pros- trate logs that are in contact with the ground. Parental galleries are monoramous or bi- ramous, usually entirely in the phloem, but exposed on peeled bark. Eggs are placed in niches and are sealed in with frass. Larval mines are comparatively long and wander ir- regularly in the phloem. The species are not agressive, usually preferring unthirfty or felled trees after they have been attacked by other bark beetle species, except a few species of Hylastes have been reported to kill seedlings in nursery stock. Their role in the primary destruction of roots is unstudied. TaxONOMy.—Members of this tribe are the most common fossil Scolytidae in Baltic am- ber (Oligocene). They are not always clearly separable from the Hylesinini to which they are obviously closely related phylogeneti- cally, and they appear to be of ancient origin in the family. Their specialized habits appar- ently have resulted in evolutionary paral- lelism and superficial similarity of appearance with certain Cossoninae (Curculionidae), re- sulting in an erroneous supposition that the two groups are closely related. The generic limits within the Hylastini are not sharp. Indi- vidual variation within species and the simi- larity of species within genera make specific identification in the group rather difficult. They are strictly holarctic in distribution, if introductions to southern Africa, New Zealand, and Australia are ignored, and they are confined to the Pinaceae. Key to the Genera of Hylastini 1. Anterior coxae rather widely separated by an intercoxal piece, its width at least equal to half width of a coxa; striae 9 and 10 both indepen- dently continued at least to level of abdominal sternum 4; elytral vestiture sparse, recumbent, yellow, hair- or bristlelike, never including scales; general surface of elytra and pronotum rather dull; body color reddish brown; North America; Picea, Abies, Pinus; 2.7-4.3mm .... Scierus — Anterior coxae contiguous or at most with inter- coxal piece narrower than one-fourth width of a coxa; striae 10 obsolete behind level of posterior coxae, only striae 9 continuing caudad; elytral vestiture longer, more abundant, usually in- cluding at least some small scales. ............ 2 Woob: GENERA OF SCOLYTIDAE 35 Fig. 33. Hylastes macer LeConte, dorsal aspect (After Bright 1976: 206). 2(1). Third tarsal segments broad, bilobed; pronotum usually constricted anteriorly, usually about equal numbers of small and large punctures in- termixed on disc; North America, N Africa, Eu- rope, Asia; Abies, Cedrus, Pinus; 3.3-5.7 mm ON eee a ee ee PERT Tan Hylurgops — Third tarsal segments narrower, emarginate; pronotum not noticeably constricted anteriorly (Fig. 33), punctures uniformly large or small, rarely intermixed with a few smaller ones; North America, N Africa, Europe, Asia, Canary Is- lands; Abies, Cedrus, Picea, Pinus; 2.0-5.5 mm Hylastes Scierus LeConte [1876:390, Type-species: Scierus annectens LeConte, monobasic]. Dis- tribution: 2 species in N and W North Amer- ica where Picea grows. Both are monogamous and breed in phloem of roots, butts, and stumps of standing trees or next to the ground in the lower bole of prostrate trees. Keys: Bright (1976:41), Wood (1982:79). Hylurgops LeConte [1876:389, Type-spe- cies: Hylastes pinifex Fitch =Hylurgops rugi- 36 GREAT BASIN NATURALIST MEMOIRS pennis pinifex (Fitch), subsequent designa- tion by Hopkins 1914:123. Synonyms: Hyle- sinites Germar 1813:15, Type-species: Hyle- sinites electrinus Germar, monobasic; Hyla- stites Hagedorn 1907:117, Type-species: Hy- lastites schellwieni Hagedorn, monobasic; Myelophilites Hagedorn 1907:118, Type-spe- cies: Myelophilites dubius Hagedorn, mono- basic; Hylescierites Schedl 1947:29, Type- species: Hylescierites granulatus Sched, monobasic]. Distribution: 7 species, 2 with subspecies, in North America; 2 in N Africa; 18 nominate species in Europe and N Asia; 7 nominate fossil species including 1 from North America and 6 in Baltic amber (Oligocene). All are monogamous and breed in phloem tissues of Pinaceae; most are in roots, butts, and stumps of standing hosts, some in logs, and at least one may occur in smaller material. Keys: Wood (1982:82) for North America, Pfeffer (1944) for Europe and N Africa, Tsai and Huang (1964b) for China, Murayama (1963) for NE Asia. Hylastes Erichson [1836:47, Type-species: Bostrichus ater Paykull, subsequent designa- tion by Westwood 1838:39 and Thomson 1859:146]. Distribution: 16 species in North America; | in Jamaica; 17 nominate species in Europe and N Asia; 1 in N Africa; 1 in the Canary Islands; fossil species include 2 from Baltic amber (Oligocene), 1 from Miocene of Colorado. All are monogamous and breed in phloem tissues of Pinaceae; most are in roots, butts, and stumps of standing trees, a few in the bole of prostrate trees next to the ground; seedlings are sometimes infested, apparently under emergency stress, for the purpose of maturation feeding or to wait for a suitable host. Keys: Wood (1982:93), and Blackman (1941) for North America, Pfeffer (1944) for Europe, Murayama -(1963) and Tsai and Huang (1964a) for NE Asia. Tribe Hylesinini Hylesinen Erichson [1836:46, Type-genus: Hylesinus Fabricius, 1801] Phloeotrupides Chapuis [1866:357, Type-genus: Phloeo- trupes Erichson, 1836 =Phloeoborus Erichson, 1836] Phloeobori Blandford [1893:426, Type-genus: Phloeo- borus Erichson, 1836] Dactylipalpi Blandford [1893:426, Type-genus: Dactyli- palpus Chapuis, 1869] Hylastinides Niisslin [1912b:273, Type-genus: Hylasti- nus Bedel, 1888] No. 10 Alniphagini Murayama [1963:iii, 29, Type-genus: Alniph- agus Swaine, 1918] DEscrIPTION.—Frons obscurely to deeply and extensively impressed in male, female flat to variously convex; eye oval to elongate, en- tire to feebly sinuate on anterior margin; an- tennal scape very short to very elongate, fun- nicle 6- or 7-segmented (except 5- to 7- segmented in Hylesinopsis), club conical to moderately flattened, symmetrical or nearly so, two or more sutures indicated, except su- tures absent in Dactylipalpus ; procoxae nar- rowly to moderately separated, precoxal ridge on prothorax moderately to very strongly, acutely elevated; pronotum armed by a few asperities, except absent in Hylastinus; metascutellar area separated from postnotum by a distinct suture; mesal surface of sutural groove of elytra just behind scutellum inter- rupted by a series of interlocking nodules and cavities; tarsal segment 3 usually wider than 2, often bilobed. BroLocy.—All species are monogamous. Allare phloeophagous except the xylophagous Phloeoborus and Dactylipalpus. Parental gal- leries are biramous or, if a well-developed turning niche is present, they may be mono- ramous. Eggs are deposited in niches and are sealed in with frass. Larval mines usually fol- low a definite course away from the parental mine and rarely cross one another. Phloeo- borus and Dactylipalpus appear to have a symbiotic relationship with fungi, but not in a mycetophagous sense (old parental mines are stained black and wood adjacent to larval mines is discolored and in a more advanced state of decay). TaxoNomy.—The occurrence of this tribe in the Eocene and its almost worldwide distri- bution suggest an ancient origin. The strictly neotropical Phloeoborus and ethiopian (ex- cept for two oriental species) Dactylipalpus suggest that these unique but related genera were derived from a common ancestral African stock at or before the time of separa- tion of South America and Africa. The remain- ing American Hylesinini include representa- tives of Hylesinus and Alniphagus, both of which occur in Asia and appear to have reached North America in comparatively re- cent time. The one Hylesinus in South Amer- ica (antipodius Schedl) is quite similar to liv- ing Australian species and was apparently 1986 derived from Australian stock anciently. This suggests that Hylesinus is very old. The African genera Hylesinopsis and Rho- palopselion appear to be comparatively young, and they are now going through a pe- riod of rapid evolutionary change. It could easily be argued that they should be grouped into a single genus and also that both should be fragmented into many small genera. How- ever, it appears that only a small fraction of the African species have been discovered. It is anticipated that when more species are known most of the apparent character gaps will have disappeared, leaving only two major clusters of species. Hylesinus and Ficicis have been grouped into one genus by most workers. However, when all species are examined, it is apparent that two distinct clusters of species are formed on both anatomical and_ biological (host choice) bases. Since these two cannot be com- bined without also including a third cluster of species (Alniphagus ), I have elected to recog- nize all three as genera. Alniphagus appears to be more nearly allied to Ficicis than to Hylesinus. The three clusters of genera mentioned above, together with the comparatively unre- lated Hylastinus, Kissophagus, Pteleobius, Cryptocurus, and Neopteleobius, appear to represent remnants of a previous phyletic ra- diation that took place anciently. Although they cluster conveniently into one tribe, the extinction of intermediate forms makes com- ments on phylogenetic relationships difficult at this time. Key to the Genera of Hylesinini 13 Antennal club subconical to strongly flattened, with three sutures clearly indicated, funicle 6- or 7-segmented (5-segmented in some Hyle- sinopsis ); posterior face of protibia flattened to weakly convex, smooth, punctures with their lateral margins feebly or not at all tuberculate, lateral margin armed by socketed teeth; female pronotum never with a visible mycetangium; smaller, phloeophagous species, rarely larger thant: Qimin ts getter olestcites hogs seu y sete ia 2 _ Antennal club conical, either without sutures or with sutures | and 2 rather weakly indicated, funicle 7-segmented; posterior face of protibia moderately to strongly convex, rather coarsely, closely tuberculate, lateral margin without socketed teeth; female pronotum or pro- pleuron with a conspicuous mycetangium; larger, xylophagous, tropical species, 5.0-16.0 2(1). 3(2). 4(3). 6(3). 7(6). Woop: GENERA OF SCOLYTIDAE 37 Antennal club subconical, elongate, at least 1.5 times as long as wide, sutures straight to feebly procurved; eye shorter, less than 3.0 times as long as wide (3.3 in Hylastinus ); interstriae 10 never represented on posterior third of elytral length; body usually more slender........... a Antennal club rather strongly flattened, stouter, less than 1.5 times as long as wide, sutures weakly to rather strongly procurved (if almost straight, then scutellum not visible), some species appear to have four or more su- tures; eye elongate, at least 4.0 times as long as wide; interstriae 10 often narrowed and cari- nate on posterior third of elytra; body usually stoutersAtnica 24. once uaeetens stan 10 Frons convex in both sexes, not sexually dimor- phic, sometimes marked by a fine, median carina; antennal funicle 6-segmented (except 7-segmented in Hylastinus which lacks prono- tal asperities) Male frons moderately to very strongly im- pressed, female frons convex (or impressed in Neopteleobius), median carina absent or poorly represented; antennal funicle 7-seg- mented (except 6-segmented in Neoptele- obius); pronotal asperities always present .... 6 Frontal rectangle (Fig. 1) conspicuously longer than wide; pronotum unarmed by asperities; antennal funicle 7-segmented; elytral ground vestiture of short, rather stout hair (not sub- plumose); Europe to W Asia, introduced al- most worldwide; herbaceous to shrubby legumes; 2.0-2.5 mm Hylastinus Frontal rectangle conspicuously wider than long; pronotum armed on anterolateral areas by a few fine asperities; antennal funicle 6-seg- mented; elytral ground vestiture of either plumose or scalelike setae Frons with a fine, long, median carina; elytral ground vestiture of abundant, short, plumose setae of uniform color; pronotum more slen- der, 0.95 times as long as wide; Europe, N Africa, W Asia; Hedra; 2.0-2.2 mm . Kissophagus Frons without a carina; elytral ground vestiture of abundant scales, their margins entire, usu- ally forming patterns of light and dark color; pronotum stouter, less than 0.85 times as long as wide; Europe, N Africa, W Asia; Ulmus, Sorbus, etc.;1.8-2.2mm ........... Pteleobius Male frons very strongly, extensively exca- vated to well above upper level of eyes; male declivity truncate and armed above and below by large, blunt processes; apical segments of male funicle each ornamented by one or more very long, coarse setae; Africa (Nigeria to Tan- ganyika); Piptadenia; 2.3-2.5mm_.. Cryptocurus Male frontal impression less profound, rarely extending above eyes; declivity convex, one or more interstriae sometimes elevated and armed by smaller tubercles Funicle 6-segmented; male and female frons impressed, strongly in male, moderately in fe- 38 GREAT BASIN NATURALIST MEMOIRS Fig. 34. Alniphagus aspericollis (LeConte), dorsal aspect (After Bright 1976: 207). male, impression not extending above upper level of eyes; eye shallowly emarginate, elytral ground vestiture scalelike, costal margin near apex descending; E Asia; 2.2-2.8mm ....... Neopteleobius _ Funicle 7-segmented; female frons flat to con- vex; male frons, if strongly concave, with exca- vation extending above eyes; eye less strongly to not emarginate 8(7). Eye entire, oval, less than 3.0 times as long as wide; protibia armed on lateral margin of apical fourth by six or more closely set, socketed teeth; body stouter; declivity more gradual, abdomen distinctly ascending to meet elytral apex; elytral vestiture of uniform length, mostly of scales (except almost subglabrous in crenatus); almost worldwide; Fraxinus and other Oleaceae; 1.7-4.8mm......... Hylesinus — Eye shallowly emarginate, somewhat elon- gate, at least 3.3 times as long as wide; protibia armed by 2-5 socketed teeth; body more slen- der; declivity shorter, more abrupt, abdomen horizontal, not rising to meet elytral apex; ely- tral vestiture of ground cover of short hair or No. 10 scales, and interstrial rows of longer, erect bris- thes: 255 anie esl eee eee 9 9(8). Male frons weakly, very shallowly impressed; protibia armed by five socketed teeth, outer apical angle only moderately abrupt; antennal club more nearly subconical; setae in elytral ground vestiture subplumose; Japan to W North America (Fig. 34); Alnus; 2.1-3.4mm . PORE PORT eee ae ld 8 aio bc Alniphagus — Male frons moderately to extensively exca- vated; protibia armed by no more than four socketed teeth, outer apical angle abrupt; an- tennal club more strongly flattened, its apex less narrowly rounded; setae in elytral ground vestiture undivided, abundant to absent; Aus- tralia to Japan and China; Ficus, rarely other hosts: 6-5:0imm' 2 Aas chee Ficicis 10(2). Pronotum subtriangular, scutellum small to absent; funicle 5-, 6-, or 7-segmented; striae often impressed, punctures usually larger; Africa:1/3-3:O0immise. a 2h cee Hylesinopsis — Pronotum subquadrate, scutellum _ rather large; funicle 6-segmented; striae usually weakly impressed, narrow, punctures fine to obsolete; Africa; 1.5-4.5mm_ ... Rhopalopselion 11(1). Antennal club with two sutures (often obscure); female proepisternum with a large myce- tangium ornamented by hair; metatarsus re- tractible into tibial groove; Central and South America; 5.0-16.0mm ........... Phloeoborus — Antennal club unmarked by sutures; female pronotum with a median, transverse, slitlike mycetangium on anterior third; metatarsus not retractible, tibial groove absent; Africa, SE Asia, Philippines; 6.0-14.0 mm ... Dactylipalpus Hylastinus Bedel [1888:388, Type-species: Ips obscurus Marsham, original designation]. Distribution: 2 in Europe, 1 in N Africa; one of these (obscurus) has been introduced into most temperate areas of the world. One is phloeophagous in Cytisus; one (obscurus) breeds in the roots of various clovers. Keys: Reitter (1913:45). Kissophagus Chapuis [1869:34, Type-spe- cies: Hylesinus hederae Schmitt, monobasic]. Distribution: 4 in Europe and neighboring areas. All are phloeophagous and monoga- mous. Key: Reitter (1913:44). Pteleobius Bedel [1888:392, Type-species: Bostrichus vittatus Fabricius, subsequent designation by Hopkins 1914:128]. Distribu- tion: 2 in Europe, one of these is recorded from N Africa. They are phloeophagous in Ulmus and Sorbus and are monogamous. Keys: Reitter (1913:42), Balachowsky (1949: 94). 1986 Cryptocurus Sched] [1957c:869, Type-spe- cies: Cryptocurus spinipennis Schedl, mono- basic. Synonym: Hyloperus Browne 1970: 546, Type-species: Hyloperus bicornis Browne =Cryptocurus spinipennis Schedl, original designation]. Distribution: 1 in Africa (Nige- ria to Tanganyika). It was attracted to light and was also taken from a Piptadenia buchananii log. Neoptelobius Nobuchi [1971:125, Type- species: Hylesinus scutulatus Blandford, orig- inal designation]. Distribution: 1 species in E Asia and Japan. Phloeophagous in several broadleaf hosts. Alniphagus Swaine [1918:73, Type-spe- cies: Hylesinus aspericollis LeConte, mono- basic. Synonym: Hylastinoides Spessivitzey 1919:249, Type-species: Hylastes alni Ni- isima, monobasic]. Distribution: 2 in W North America, 1 in Japan and E Asia. All are phloeophagous in Alnus and are monoga- mous. Keys: Bright (1976:74) and Wood (1982:119) for North America. Hylesinus Fabricius [1801:390, Type-spe- cies: Hylesinus crenatus Fabricius, subse- quent designation by Westwood 1838:39. Synonyms: Leperisinus Reitter 1913:41, Type-species: Bostrichus fraxini Panzer = Bostrichus varius Fabricius, subsequent des- ignation by Swaine 1918:70]. Distribution: 10 in North America, 1 in South America, 5 in Europe, 9 in Asia, 1 in Africa (Uganda). More than 20 additional nominate species occur in S Asia, Australia, and neighboring areas. All are phloeophagous and are common in Fraxinus or other Oleaceae hosts; they are monoga- mous. Keys: Wood (1982:110) for North America, Murayama (1963:6) for NE Asia. Ficicis Lea [1910:147, Type-species: Ficicis varians Lea, subsequent designation by Hop- kins 1914:122. Synonym: Ficiphagus Mu- rayama 1958:930, Type-species: Ficiphagus goliathoides —Hylesinus porcatus Chapuis, original designation]. Distribution: About 16 nominate species in the area from India and Japan to Australia. All are monogamous and phloeophagous in Ficus, rarely in other hosts (particularly Artocarpus ). Hylesinopsis Eggers |1920a:40, Type-spe- cies: Hylesinopsis dubius Eggers, monobasic. Synonyms: Pseudohylesinus Eggers 1919: 234, Type-species: Pseudohylesinus togonus Eggers, monobasic, preoccupied; Metahylesi- Woob: GENERA OF SCOLYTIDAE 39 nus Eggers 1922:165, Type-species: Pseudo- hylesinus togonus Eggers, automatic; Pseudo- phloeotribus Eggers 1933b:18, | Type- species: Pseudophloeotribus africanus Eg- gers, monobasic; Trypographus Schedl 1950e:213, Type-species: — Trypographus joveri. Schedl, monobasic; Chilodendron Sched] 1953a:74, Type-species: Chiloden- dron planicolle Schedl, monobasic; Glo- chicopterus Schedl 1954b:75, Type-species: Glochicopterus baphiae Schedl, monobasic; Hapalophloeus Sched| 1966b:363, Type-spe- cies: Metahylesinus brinckei Sched, original designation; Hemihylesinus Sched] 1967:224, Type-species: Hemihylesinus — endroedyi Schedl, monobasic]. Distribution: About 38 species in Africa (Considerable synonymy is anticipated). Apparently all are phloeo- phagous and monogamous. Rhopalopselion Hagedorn — [1909:740, Type-species: Rhopalopselion bitubercula- tum Hagedorn, monobasic. Synonym: Hapa- logenius Hagedorn 1912:352, Type-species: Hapalogenius globosus Hagedorn, monoba- sic]. Distribution: About 30 African species. Apparently all are phloeophagous and monog- amous. Phloeoborus Erichson [1836:54, Type-spe- cies: Phloeoborus rudis Erichson, subsequent designation by Hopkins 1914:126. Synonym: Phloeotrupes Erichson 1836:53, Type-spe- cies: Phloeotrupes grandis Erichson, subse- quent designation by Hopkins 1914:127]. Dis- tribution: About 24 species, S Mexico to N Argentina. All are xylophagous in rather large host material and are monogamous; they are occasionally attracted to light. They have an intimate association with fungi, but are not mycetophagous. Keys: Blandford (1897:150, Eggers (1942:267), Wood (1982:122). Dactylipalpus Chapuis [1869:12, Type- species: Dactylipalpus transversus Chapuis, subsequent designation by Hopkins 1914: 120. Synonyms: Dactylopselaphus Gem- minger & Harold 1872:2678, Type-species: Dactylipalpus transversus Chapuis, auto- matic; Ethadopselaphus Blandford 1896:321, Type-species: Ethadopselaphus cicatricosus Blandford, original designation]. Distribu- tion: LO African and 2 Philippine and SE Asian species. Apparently xylophagous in large host material; occasionally attracted to light. Key: Eggers (1933c¢:200). 40 GREAT BASIN NATURALIST MEMOIRS Tribe Tomicini Tomicidae Thomson [1859: 145, Type-genus: Tomicus Latreille, 1802/3] Hylurgini LeConte [1876: 373, Type-genus: Hylurgus Latreille, 1807] Dendroctonides Niisslin [1912b: 273, Type-genus: Den- droctonus Erichson, 1836] Xylechinides Niisslin [1912b: 273, Type-genus: Xylechi- nus Chapuis, 1869] DESCRIPTION.—Frons very weakly to mod- erately sexually dimorphic, male usually im- pressed, female convex; eye oval to ovate, entire; antennal scape elongate, funicle 4- to 7-segmented, club symmetrical, feebly to moderately flattened, three sutures usually indicated; pronotum unarmed, except a few very small asperities sometimes present in Xylechinosomus and some Xylechinus; pro- coxae contiguous to moderately separated, precoxal lateral costa absent; metascutellar area separated from postnotum by a distinct suture; sutural groove on mesal surface of ely- tra continuing to base without a series of inter- locking nodules and cavities; tibiae armed by socketed denticles. BioLocy.—All species are monogamous; all are phloeophagous except for the xylophagous Pachycotes (and Hylurgonotus?). The parental galleries are usually biramous, ex- cept in Dendroctonus, Hylurgus, and some Tomicus they are monoramous. Those of Sinophloeus, Hylurgonotus, and Pachycotes are not known to me. The eggs are placed in niches and packed in frass except that some Dendroctonus have modified the niches into elongate grooves into which numeraus eggs are packed in single or double rows. The larval mines usually show on the inner surface of peeled bark and are oriented in a direction away from the parental mine. Symbiotic rela- tionships with fungi may occur in all genera, but they are adapted toward overcoming re- sistance of the host and are not of a myce- tophagous type. TAXONOMY.—The worldwide distribution of this diversified tribe suggests an ancient origin, although only one Tertiary fossil has been reported (Xylechinus, Oligocene). The most conspicuous division of the group is that presented in couplet 1 of the key, except that Xylechinus should be placed with the first group of genera. The Tomicini represent the most highly evolved segment of an evolution- No. 10 ary trend that began in the Hylastini, contin- ued in the Hylesinini, and reached its greatest specialization in the Tomicini. Two major clusters of genera appear within the tribe: first, the Xylechinus group of genera (Xylechinus, Chaetoptelius, Xylechinosomus, Sinophloeus, Dendrotrupes, Hylurgopinus, Pseudoxylechinus , and Pseudohylesinus ) and, second, the Dendroctonus group of genera (Hylurgus, Tomicus, Dendroctonus, Hylur- drectonus , and Pachyucotes ). The first group appears to have radiated in a wide variety of hosts from South America and Australia since the beginning of the Tertiary. The second group appears to have been associated an- ciently with Araucaria hosts and is sparsely, uniformly represented in major geographical areas, except for Africa, in modern Araucaria and other Pinaceae. Key to the Genera of Tomicini iN Metepisternal setae scalelike or plumose; an- tennal funicle 7-segmented ............... 2 — Metepisternal setae usually hairlike (bifid in one Hylurgonotus having a 6-segmented funi- cle, and scalelike in Xylechinus having a 5- segmented funicle); antennal funicle 4- to 7- segmented is. ...a. nse oae OeeOee 8 Anterolateral areas of pronotum distinctly as- perate (minute in India species); antennal club apparently with either two or four trans- verse sutures; male frons strongly impressed . 3 = Anterolateral areas of pronotum unarmed; an- tennal club with three sutures clearly marked; male frons impressed or not ............... 4 Antennal club more strongly flattened, more slender, at least 2.0 times as long as wide, apparently with two sutures; frontal rectangle at least as wide as long (0.8-1.0 times); Europe and Asia to Australia and New Zealand; mostly in broadleaf hosts; 1.8-5.0mm...... Recess ae ieee Gio. Chaetoptelius — Antennal club less strongly flattened, stouter, less than 1.5 times as long as wide, apparently with four sutures; frontal rectangle longer than wide (about 1.2 times); South America; Araucaria; 1.5-3.4mm....... Xylechinosomus Male frons strongly impressed; median fron- tal carina present; pronotum either without a constriction affecting dorsal profile (Sino- phloeus ) or with a moderate lateral constric- tion on anterior third (Dendrotrupes) ....... 5 — Male frons convex to modestly flattened, me- dian carina present or absent; pronotum with a conspicuous transverse constriction on ante- rior third affecting dorsal profile Antennal club elongate, 2.0 times as long as wide, apparently with four or five sutures; 1986 Woop: GENERA OF SCOLYTIDAE 4] Fig. 35. Xylechinus montanus Blackman, dorsal aspect (After Bright 1976: 206. 7(6). declivital interstriae 2 impressed, 3 (some- times 1-7) armed by rounded _ tubercles; pronotum conspicuously wider than long (0.7 times as long as wide); larger; South America; Nothophagus ; 2.3-3.0mm ....... Sinophloeus Antennal club more compact, less than 1.5 times as long as wide, with three sutures; declivity variable; pronotum almost as long as wide (0.9 times); New Zealand; hosts not coniferous; 1.5-2.0mm........ Dendrotrupes Elytral vestiture hairlike, ground vestiture moderately stout; frontal carina absent; an- tennal club slightly flattened, segment 1 one- fourth of its length; North America; Ulmus ; PROD Simimecepeine ea r-yeveisyenoue ie nt Hylurgopinus Vestiture of abundant, conspicuous scales (one exception with no ground setae); median frontal carina usually present; antennal club MMIOLEICOMICAMl = aye meresagaeie che eccacels eases neecieesn at df Strial punctures small, close; interstriae two or more times as wide as striae, unarmed (except coarsely tuberculate and without ground vestiture in rugatus), erect setae closer and coarser; elytral ground setae more slender and appically pointed, variegated pat- 12(10). terns obscure; antennal club somewhat more flattened and apex less pointed; China; broadleaf hosts; 1.8-3.0 mm . Pseudoxylechinus Strial punctures coarse; interstriae less than 1.5 times as wide as striae, often armed by tubercles of moderate size; elytral ground se- tae usually stout, apically rounded, and form- ing conspicuous variegated patterns; antennal club more nearly conical, segment 1 usually conspicuously longer; North America; conif- erous hosts; 2.2-5.8 mm Pseudohylesinus Ground vestiture on elytra scalelike, metepisternal setae scalelike (Fig. 35); anten- nal funicle 5-segmented; median frontal carina present (except absent in a few South American species); procoxae rather widely separated; North and South America, Eu- rope, Asia, Africa, Australia; coniferous and broadleaf hosts; 1.5-3.5mm ....... Xylechinus Ground vestiture on elytral disc hairlike, metepisternal setae hairlike (except some Hy- lurgonotus , female Hylurdrectonus ) Protibiae armed by five or more socketed teeth on distal and lateral margins; male frons convex except in Hylurdrectonus; phloeo- DHAGOUS) neva ee mm memminnete secneeec seine? 10 Protibiae armed by three socketed teeth (four in two Hylurgonotus) on distal margin; male frons feebly to strongly, extensively exca- vated; xylophagous in Araucaria .......... 13 Antennal funicle 6-segmented, club conical . 11 Antennal funicle 5-segmented, club moder- atelVflativgn. gages Cre ttzess abe cunemitied sais 12 Procoxae contiguous; pronotum more slen- der, 0.95-1.1 times as long as wide, only slightly constricted on anterior thrid; erect interstrial setae abundant, confused; a short median carina from epistomal margin to level of antennal insertion; Europe, W Asia; Pinus; MCD Bik ceccicasn suns aheveeeS epotecaer tetas Hylurgus Procoxae moderately separated; pronotum stouter, less than 0.85 times as long as wide, strongly constricted on anterior third; erect interstrial setae in uniseriate rows (except confused in puellus); a fine median carina from epistoma to middle of frons (absent in puellus); Europe, Asia, N Africa; 2.5-4.5 mm Tomicus Antennal club with sutures somewhat pro- curved; procoxae contiguous; male frons con- vex to weakly impressed; vestiture never scalelike in either sex; North America, Eu- rope, Asia; Pinus, Picea, Larix, Pseudotsuga; 2)5-O:OMM versace gee yen ers Dendroctonus Antennal club with sutures straight, trans- verse; procoxae moderately separated; male frons rather strongly concave; female elytra with some scales (except araucariae); Aus- tralia, New Guinea; Araucaria; 1.3-1.8 mm Pr i RE RO Hylurdrectonus 42 GREAT BASIN NATURALIST MEMOIRS 13(9). Declivital vestiture hairlike (except scalelike in tuberculatus);, protibiae with either three or four socketed teeth; male frons rather shal- lowly impressed (except deeper in an- tipodius), South America; Araucaria; 2.7-4.6 fet tdnen eine merece naa ier Hylurgonotus — Declivital vestiture always includes scales (sparse in male peregrinus); protibiae with three socketed teeth; male frons strongly, more extensively impressed (except weak in peregrinus ); Australia, New Zealand, and ad- jacent islands; Araucaria; xylophagous; 2.3- A= DAMM ate Opal deena eee a ere ete Pachycotes Chaetoptelius Fuchs [in Reitter 1913: 43, Type-species: Hylesinus vestitus Mulsant & Rey, automatic. Synonyms: Homarus Broun 1881: 740, Type-species: Homarus mundulus Broun, automatic, preoccupied; Acrantus Broun 1882: 409, Type-species: Homorus mundulus Broun, automatic, preoccupied; Chaetophorus Fuchs 1912: 46, Type-species: Hylesinus vestitus Mulsant & Rey, monoba- sic, preoccupied]. Distribution: 1 species in Europe and W Asia, 1 in New Zealand, about 8 in Australia and New Guinea. All are phloeophagous and monogamous. Xylechinosomus Schedl [1963a: 209, Type- species: Xylechinus taunayi Eggers, original designation]. Distribution: About 9 species in South America. All are phloeophagous in Araucaria. Sinophloeus Bréthes [1922b: 433, Type- species: Sinophloeus porteri Bréthes, mono- basic]. Distribution: 2 species in South Amer- ica. Apparently phloeophagous in Notho- fagus. Dendrotrupes Broun [1881: 741, Type-spe- cies: Dendrotrupes costiceps Broun =Den- drotrupes vestitus Broun, subsequent desig- nation by Hopkins 1914: 120]. Distribution: 3 species in New Zealand. Phloeophagous. Hylurgopinus Swaine [1918: 43, 74, Type- species: Hylastes rufipes Eichhoff, original designation]. Distribution: 1 species in North America. Phloeophagous in Ulmus and mon- ogamous. Pseudoxylechinus Wood & Huang [1986: 465, Type-species: Pseudoxylechinus uni- formis Wood & Hwang, original designation]. Distribution: 7 species in Asia. All are phloeophagous and monogamous in broadleaf trees. Pseudohylesinus Swaine [1917: 11, Type- species: Pseudohylesinus grandis Swaine Hylurgus sericeus Mannerheim, original No. 10 designation]. Distribution: 11 species in North America. Phloeophagous in Abies, Picea, Pinus, Pseudotsuga, and Tsuga and monogamous. Keys: Blackman (1942a: 5), Bright (1969: 15), Wood (1982: 130). Xylechinus Chapuis [1869: 36, Type-spe- cies: Hylesinus (Dendroctonus) pilosus Ratzeburg, monobasic. Synonyms: Prunipha- gus Murayama 1958: 930, Type-species: Pruniphagus gummensis Murayama, original designation; Squamasinulus Nunberg 1964: 431, Type-species: Squamasinulus chiliensis Nunberg, original designation, Xylechinops Browne 1973: 283, Type-species: Xylechinus australis Sched], original designation]. Distri- bution: 19 species in Central and South Amer- ica, 2 in North America, 2 in Africa, 5 in Asia, and 1 in Europe. All are phloeophagous and monogamous. Keys: Blandford (1897: 157), Wood (1982: 143) for North and Central America. Hylurgus Latreille [1807: 274, Type-spe- cies: Hylesinus ligniperda Fabricius, monoba- sic]. Distribution: 3 species in Europe, W Asia, N Africa. All are phloeophagous in conif- erous hosts and monogamous. Tomicus Latreille [1802/3: 203, Type-spe- cies: Hylesinus piniperda Fabricius =Der- mestes piniperda Linnaeus, monobasic. Syn- onyms: Blastophagus Eichhoff 1864: 25, Type-species: Dermestes piniperda Lin- naeus, preoccupied, subsequent designation by Lacordaire 1866: 360; Myelophilus Eich- hoff 1878c: 400, Type-species: Dermestes piniperda Linnaeus, automatic]. Distribu- tion: 8 species in Europe and Asia. All are phloeophagous in Pinus and are monoga- mous. Keys: Murayama (1963: 35) for the Far East, Balachowsky (1949: 135) for France, Sched] (1946b: 52) for the genus. Dendroctonus Erichson [1836: 52, Type- species: Bostrichus micans Kugelann, subse- quent fixation by International Commission on Zoological Nomenclature 1974: 230]. Dis- tribution: 16 species in North America and 2 in Eurasia. All are phloeophagous in Pinus, Picea, Larix, and Pseudotsuga and are monogamous. Keys: Hopkins (1909: 69), Wood (1963: 26, 1982: 151). Hylurdrectonus Schedl [1938b: 40, Type- species: Hylurdrectonus piniarius Sched, monobasic. Synonym: Xylogopinus Schedl 1972: 64, Type-species: Xylogopinus araucar- 1986 iae Schedl =Hylurdrectonus corticinus Wood, monobasic]. Distribution: 3 species in Australia and New Guinea. Phloeophagous in Araucaria except one in central axis of leaflet; monogamous. Hylurgonotus Sched] [195le: 448, Type- species: Hylurgonotus brunneus Schedl =Hylurgus tuberculatus Eggers]. Distribu- tion: 4 species in South America. In Arau- caria, possibly xylophagous and apparently monogamous. Pachycotes Sharp [1877: 10, Type-species: Pacycotes ventralis Sharp =Hylesinus pere- grinus Chapuis, monobasic]. Distribution: 8 species in Australia, New Zealand, and New Guinea. All are xylophagous in logs and monogamous. Tribe Phrixosomini Phrixosomini Wood [1978: 111, Type-genus: Phrixosoma Blandford, 1897] DESCRIPTION.—Frons not sexually dimor- phic, frequently with a fine, median carina; eye completely divided; antennal scape elon- gate, funicle 6-segmented, club rather strongly flattened, slightly asymmetrical, un- marked by sutures, except 1 partly septate; pronotum unarmed by asperities, procoxae contiguous; scutoscutellar suture remote from scutellar groove, postnotum separated from scutoscutellar area of metanotum by a com- plete suture; tibiae armed on lateral margin by socketed denticles. BioLoGy.—These monogamous, phloeo- phagous, tropical species are restricted to hosts of the Guttiferae. The parental galleries are usually biramous, although a third egg tunnel is not uncommon, with the galleries either longitudinal, transverse, or without definite orientation. The eggs are deposited in niches and sealed in by frass. The larval mines show on the inner surface of peeled bark, but they are almost entirely in the bark and usu- ally wander indiscriminantly without respect to the grain of the wood. TAxXONOMY.—Only one genus is known (Fig. 36). It is apparently very old and repre- sents a group that is otherwise extinct. They are unknown in the fossil record. The one genus in South America and Africa in Gut- tiferae has changed so little since separation of these land masses that division into species groups is not recommended. Although more Woop: GENERA OF SCOLYTIDAE 43 \ \ RON ASE ty \ VS ea dyad \ S RACER Ss ss At Fig. 36. Phrixosoma magna Blackman, antenna. closely allied to Hylesinini than to other tribes, this genus is quite unique. Phrixosoma Blandford [1897: 148, Type- species: Phrixosoma rude Blandford, mono- basic. Synonyms: Bothryperus Hagedorn 1909: 742, Type-species: Bothryperus psaltes Hagedorn, monobasic; Neohylesinus Eggers 1920b: 118, Type-species: Neohylesinus quadrioculatus Eggers, monobasic; Sphaero- sinus Eggers 1929: 40, Type-species: Sphaerosinus striatus Eggers, monobasic]. Distribution: 13 species in Central and South America and 9 in Africa. All are phloeo- phagous in Guttiferae and are monogamous. Key: Wood (1982: 204). Tribe Hyorrhynchini Hyorrhynchinae Hopkins [1915b: 225, Type-genus: Hy- orrhynchus Blandford, 1894] Sueinae Murayama [1958: 7, Type-genus: Suews Mu- rayama, 1951] DESCRIPTION.—Frons sexually dimorphic, male slightly to strongly impressed, female convex; eye completely divided; antennal scape either long or short, funicle 5- or 6-seg- mented, club aseptate and either unmarked by sutures or with two sutures; pronotum armed or not; procoxae moderately to widely separated, precoxal ridge obsolete; scu- toscutellar suture remote from scutellar groove; scutoscutellar area separated from postnotum by a distinct suture; tibiae without socketed denticles. BroLocy.—The species are myelomyce- tophagous or xylomycetophagous and form simple, monoramous tunnels in the pith or xylem of twigs or small branches. Only two larvae were seen (Sueus niisimai) and these were in the parental chamber. Males of Sueus are very rare, dwarfed, and deformed; repro- duction in this genus is apparently by 44 GREAT BASIN NATURALIST MEMOIRS arrhenotocous parthenogenesis. In Hyor- rhynchus and Pseudohyorrhynchus the males are similar in size, shape, and abundance to the females, suggesting a normal bisexual re- lationship. TaxoNomMy.—A dozen species assigned to three genera are listed in the literature. All occur in the area from India and Japan to New Guinea. They form an aberrant, relect group of uncertain affinity but are considered to be among the most primitive of the Hylesininae. Although definitely members of the Hylesini- nae, they share more primitive characters with primitive Scolytinae and Platypodidae than with other members of their own sub- family. Key to the Genera of Hyorrhynchini 1. Antennal funicle 5-segmented, club rather weakly compressed; male dwarfed, rare, flight- less; male frons convex, with median carina; tarsal segment 3 entire; Sri Lanka (Ceylon) and New Guinea to Japan; female 1.6-2.0 mm, male LO ibelnaod mma oo como Moos onan Sueus — Antennal funicle 6- or 7-segmented, club rather strongly flattened; male subequal in size to fe- male, shares parental gallery; male frons con- cave or not, with or without a carina; tarsal seg- ment 3 emarginate to bilobed ............... 2 2(1). Antennal funicle 6-segmented, club with two clearly marked sutures; male frons concave, without a carina; tarsal segment 3 emarginate; interstrial tubercles minute; India to Japan; 2.7- DEOMI ete coped ete ee eles Hyorrhynchus — Antennal funicle 7-segmented, club without su- tures; tarsal segment 3 deeply bilobbed; male frons not impressed, with a median carina; inter- strial tubercles on declivity rather coarse; Japan; 325-3 OMMMey ptaauaeiee hele Pseudohyorrhynchus Sueus Murayama [1951: 1, Type-species: Sueus sphaerotrypoides Murayama =Hyor- rhynchus niisimai Eggers, original designa- tion. Synonym: Neohyorrhynchus Schedl 1962e: 202, Type-species, Hyorrhynchus ni- isimai Eggers, original designation]. Distri- bution: 2 species from Sri Lanka (Ceylon) and New Guinea to Japan. Xylomycetophagous in small branches and, apparently, at least partly parthenogenetic (only one series of males known). Hyorrhynchus Blandford [1894a: 58, Type- species: Hyorrhynchus lewisi Blandford, monobasic]. Distribution: About 10 species from India to Japan. Habits have not been reported except host species include Acer, Fagus, and Macaranga; the species are xy- No. 10 lomycetophagous and monogamous (Nobu- chi, pers. comm.). Pseudohyorrhynchus Murayama [1950b: 61, Type-species: Pseudohyorrhynchus wa- dai Murayama, original designation]. Distri- bution: 1 species from Japan. Specimens of this monogamous species attack living Cornus twigs where they are xylomycetophagous. Tribe Diamerini Diameridae Hagedorn [1909: 734, Type-genus: Di- amerus Erichson, 1836] Strombophorini Sched] [1959e: 75, Type-genus: Strom- bophorus Hagedorn, 1909] Sphaerotrypini Murayama [1963: 5, Sphaerotrypes Blandford, 1894] Type-genus: DESCRIPTION. —Frons dimorphic, feebly to very strongly impressed in male, flattened to convex in female; eye entire to completely divided; antennal scape usually elongate, fu- nicle 6- to 7-segmented, club flattened, su- tures variable, one to several (five or more, mostly pseudosutures); procoxae moderately to widely separated; scutoscutellar suture re- mote from scutellar groove, postnotum fused to scutoscutellar area of metanotum, interseg- mental suture obsolete on median half. BIoLOGy.—These monogamous, phloeo- phagous species are largely restricted to tropi- cal and subtropical areas of the eastern hemi- sphere. The parental galleries are mostly biramous and either longitudinal or trans- verse. The eggs are deposited in niches and sealed in by frass. The larval mines show on the inner surface of peeled bark and tend to radiate away from the parental tunnel without respect to the grain of the wood in most spe- cies; the latter parts of the tunnels in some species are parallel to the grain of wood. TAXONOMY.—Seven genera represented by about 122 species occur in Africa and south- eastern Asia to Australia. Pseudodiamerus, Pernophorus, and Strombophorus occur only in Africa. They appear to form a sister group derived from the same ancestral stock as Both- rosternini and, if this is the case, these groups have differentiated and radiated since early Tertiary. Features used to characterize this tribe vary and tend to intergrade with Phloeosinini. Although future study may re- quire combination of these two tribes, their division gives a convenient break in a large and diverse group. 1986 bo = A(3). UU r= Key to the Genera of Diamerini Eye oval, neither strongly reduced on lower half nor completely divided; antennal club with fewer than three sutures, funicle 5-, 6-, or 7-seg- Mente Cuenepee ts cases etiaerniese cit mange navies 2 Eye either strongly narrowed on lower half or entirely divided into two parts; antennal club apparently with five or more sutures marked by constrictions and/or rows of setae, funicle 6-seg- mented (except 7-segmented in Pernophorus) . 5 . Costal margin on basal fourth of elytra normal, not emarginate, metepisternum not expanded; median anterior area of pronotum usually finely asperate; antennal funicle 6-segmented; club elongate, sutures 1 and 2 feebly indicated (straight) to absent; Africa, SE Asia to Australia; EDP OMIM sale ace sree te ec eschc ns scue's. ie Acacicis Costal margin on basal fourth of elytra either normal or deeply, abruptly emarginate, when emarginate metepisternum expanded into this emargination; pronotum never asperate (feeble lateral asperities in Bothrosternoides) 2). Costal margin on basal fourth of elytra deeply emarginate (Fig. 37); suture | on antennal club strongly, subangulately procurved; Africa, SE Asia to Australia; 3.0-5.0 mm Diamerus Costal margin on basal half of elytra almost nor- mal, straight to weakly emarginate; basal mar- gins of elytra either costate or armed by a row of coarse crenulations; protibia with two to four curved spines; male frons shallowly impressed; suture 1 on antennal club weakly indicated (Straight)ionabsentic.-..5 ct cise cence enna 4 Eye more than 3 times as long as wide; funicle 7-segmented; club with suture 1 straight, fee- ble; protibia with two apical and two lateral spines; costal margin not emarginate; basal mar- gins of elytra crenulate; pronotum without lat- eral granules; Africa (Angola); 2.2-3.0 mm Pseudodiamerus Eye twice as long as wide; funicle 5-segmented, club unmarked by sutures; protibia with two apical and one small posterior subapical spine and several lateral posterior granules; costal margin shallowly emarginate at base; basal mar- gins of elytra strongly costate; some prothoracic granules or small asperities in lateral areas; male with median epistomal tubercle; body very stout; Malaya;2.3mm......... Bothrosternoides Eye completely divided; scutellum visible, longer than wide; pronotum unarmed by asperi- ties; body very stout, subglobular; Africa, SE Asia; 1.5-5.0 mm Sphaerotrypes Eye strongly constricted on lower half to about one-third width of upper half; pronotum at least partly asperate; scutellum not visible; body elongate-oval . Antennal funicle 7-segmented; elytral vestiture hairlike to subplumose; Africa; 4.0mm...... Pernophorus Woop: GENERA OF SCOLYTIDAE 45 Fig. 37. Diamerus curvifer Walker, lateral aspect of fe- male. — Antennal funicle 6-segmented; elytral vestiture with ground cover scalelike; Africa; 1.5-3.5 mm Strombophorus Acacacis Lea [1910: 149, Type-species: Acacacis abundans Lea, monobasic. Syn- onyms: Trogloditica Sampson 1922: 148, Type-species: Trogloditica trahax Sampson, monobasic; Pseudoacacacis Sched] 1963c: 477, Type-species: Acacacis borneensis Browne, original designation; Neodiamerus Sched] 1971b: 282, Type-species: Neodi- amerus granulicollis Schedl, original designa- tion]. Distribution: 5 species in Africa, 2 in Sri Lanka, 2 in Malaya, 1 in Borneo, 1 in New Guinea, and 2 in Australia. All are phloeophagous and monogamous. Pseudodiamerus Eggers [1933b: 18, Type- species: Pseudodiamerus striatus Eggers, monobasic]. Distribution: 3 species in Africa. Allare apparently phloeophagous and monog- amous. Bothrosternoides Sched [1969: 210, Type- species: Bothrosternoides malayensis Sched], monobasic]. Distribution: 1 species in Malaya. Three specimens intercepted in Japan and 4 in China in imported Nyatoh logs. Diamerus Erichson [1836: 57, Type-spe- cies: Hylesinus hispidus Klug, monobasic. Synonyms: Acanthurus Ejichhoff 1886: 24, Type-species: Acanthurus spinipennis Eich- hoff = Hylesinus curvifer Walker, subsequent designation by Hopkins 1914: 116; Lissoclas- tus Schaufuss 1905: 71, Type-species: Lisso- clastus pimelioides Schaufuss, monobasic]. Distribution: About 11 species in Africa and 28 in the Indo-Australian and Oriental areas. All are phloeophagous and monogamous. Sphaerotrypes Blandford [1894a: 61, Type- species: Sphaerotrypes pila Blandford, subse- quent designation by Hopkins 1914: 129. Syn- 46 GREAT BASIN NATURALIST MEMOIRS onym: Parasphaerotrypes Murayama 1958: 933, Type-species: Sphaerotrypes controver- sae Murayama, original designation]. Distri- bution: 8 nominate species in Africa and about 35 in the Indo-Australian and Oriental areas. Pernophorus Strohmeyer [1910b: 92, Type-species: Acanthophorus — brevicollis Strohmeyer, automatic. Synonym: Acan- thophorus Strohmeyer 1910a: 69, Type-spe- cies: Acanthophorus brevicollis Strohmeyer, monobasic, preoccupied]. Distribution: 5 nominate species in Africa. They are appar- ently phloeophagous and monogamous. Strombophorus Hagedorn [1909: 740, Type-species: | Strombophorus — crenatus Hagedorn, subsequent designation by Hop- kins 1914: 130]. Distribution: About 34 spe- cies in Africa. They are phloeophagous and monogamous. Tribe Bothrosternini Bothrosterni Blandford [1896a: 120, Type-genus: Both- rosternus Eichhoff, 1868] DESCRIPTION.—Frons usually sexually di- morphic; eye entire to slightly sinuate; funicle 6-segmented, club symmetrical, moderately flattened, sutures indicated; procoxae moder- ately separated; protibia bearing a bifid pro- cess on outer apical angle exceeding inner apical angle; pronotum unarmed; crenula- tions on basal margins of elytra poorly devel- oped, sometimes represented by a continuous costa; at least part of scutoscutellar suture par- allel to margin of scutellar groove; postnotum fused to scutoscutellar area of metanotum, suture obsolete. BioLocy.—All species are monogamous, except that a form of parthenogenesis proba- bly exists in Bothrosternus. All are myeloph- agous, except that Bothrosternus and, possi- bly, Eupagiocerus ater Eggers are myelo- mycetophagous. In Cnesinus annectens Wood typical transverse, biramous egg gal- leries are formed in the cambium region of the host by parent beetles, complete with egg niches, and the larvae feed briefly in the cam- bium region before following the parent beetles to the pith region. Typically, the parental pith tunnel is biramous; the eggs are deposted in clusters in the loose frass in this cavity; and the larvae feed in congress while extending the parental pith tunnel. Pupation occurs in the larval frass. No. 10 TaxONOMY.—The tribe is restricted to the American tropics, with two species extending into the southern United States. It appears to be the New World counterpart of the closely allied Diamerini. The genera of Bothrostern- ini differ anatomically from one another only slightly and may be recognized with difficulty in some instances. The protibial and antennal structure and the costate basal margins of the elytra in at least some members suggest a very primitive position in classification. Though primitive as a group, modern representatives appear to have evolved since the beginning of the Tertiary to their present ecological and structural status, because clearly identifiable related groups are not known outside of the neotropical realm. They appear to be more nearly allied to Diamerini and Hyorrhynchini than to any American groups. Key to the Genera of Bothrosternini 1. Lateral margins of pronotum rounded ........ 2 — Lateral margins of pronotum marked by a sharply elevated, costate to subcostate line .... 3 2(1). Sutures of antennal club transverse, straight; rostrum distinctly wider than distance between eyes; pronotum either longitudinally strigose or punctured; pith borers of twigs and other small stems; SE USA to South America; 1.6-3.5 mm SAO MON NODAME Me CUA HOMO DI "0:06 0 Cnesisnus — Sutures of antennal club strongly procurved; rostrum width at tip equal to distance between eyes; frons excavated in both sexes, with a me- dian tubercle just above epistoma; body oval; seed borers; SE USA to South America, inter- cepted elsewhere in maize, etc.; 1.9-2.6 mm . . TA Ser An MESA Rene taba mas cia.a to 0 Pagiocerus 3(1). Sutures of antennal club strongly procurved; pith borers in twigs and woody vines; Central and South America; 2.1-3.8mm_ ... Eupagiocerus — Sutures of antennal club transverse, straight ... 4 4(3). Proepisternal area partly excavated, with cavity densely filled by yellow pubescence, particu- larly in female; prothoracic intercoxal piece with a transverse, subcarinate ridge; elytral inters- triae usually not strongly carinate; ambrosia beetles in axial tunnels of woody vines; Central and South America; 1.9-3.3mm_ .. Bothrosternus — Proepisternal area normal, not densely pubes- cent; prothoracic intercoxal ridge absent; elytral interstriae narrowly carinate from posterior part of disc to apex; pith borers in branches and twigs; Central and South America; 2.2-3.6 mm Bue tn Teta aroha as tas Oct OO: Sternobothrus Cnesinus LeConte [1868: 171, Type-spe- cies: Cnesinus strigicollis LeConte, monoba- sic. Synonym: Nemophilus Chapuis 1869: 27, 1986 Woop: GENERA OF SCOLYTIDAE 47 Fig. 38. Bothrosternini: 1-8, Cnesinus spp., (1) cubensis Blackman, dorsal aspect, (2) same, fernale head, (3) panamen- sis Blackman, dorsal aspect, (4) same, male head, (5) robai Blackman, male head, (6) setulosus Blandford, female head, (7) costulatus Blandford, dorsal aspect, (8) same, female head, (12) blackmani Schedl, dorsal aspect; 9-11, Bothroster- nus foveatus Blackman, (9) dorsal aspect of fernale, (10) female head, (11) propleuron of female. (After Blackman 1943: pl. 15). 48 GREAT BASIN NATURALIST MEMOIRS Type-species: Nemophilus strigillatus Cha- puis =Cnesinus strigicollis LeConte, subse- quent designation by Hopkins 1914: 125]. Distribution: About 101 species from the USA to Argentina. All are monogamous and myelophagous except that one is partly phloeophagous. Keys: Wood (1968b: 88, 1982: 209). Pagiocerus Eichhoff [1868a: 148, Type- species: Pagiocerus rimosus — Eichhoff =Bostrichus frontalis Fabricius, subsequent designation by Hopkins 1914: 126]. Distribu- tion: About 5 species are known from the USA to Argentina, 1 is occasionally intercepted worldwide in large seeds, including maize. All are monogamous and spermophagous. Eupagiocerus Blandford [1896d: 133, Type-species: Eupagiocerus dentipes Bland- ford, monobasic. Synonym: Nemopagiocerus Schedl 1962a: 85, Type-species: Eupagio- cerus nevermanni Schedl =Eupagiocerus ater Eggers, monobasic]. Distribution: 4 spe- cies from Mexico (Chiapas) to Venezuela and Peru. All are monogamous and myelophagous in woody vines. Keys: Wood (1965: 31, 1982: 249). Bothrosternus Eichhoff [1868a: 150, Type- species: Bothrosternus truncatus Eichhoff, monobasic]. Distribution: About 12 species from Mexico (Veracruz) and Jamaica to Peru and Brazil. Monogamous and some species apparently with a type of parthenogenesis (in- volving consanguineous polygyny), and myelophagous in woody vines. Key: Wood (1982: 247). Sternobothrus Eggers [1943: 372, Type- species: Bothrosternus cancellatus Chapuis, original designation]. Distribution: About 10 species from Costa Rica to Bolivia and Brazil. Monogamous and myelophagous, three spe- cies breed in Nectandra branches. Key: Wood (1982: 254). Tribe Phloeotribini Phloeotribidae Chapuis [1869: 42, Type-genus: Phloeo- tribus Latreille, 1796] Phthorophloeides Niisslin [1912b: 273, Type-genus: Ph- thorophloeus Rey, 1883] DEsSCRIPTION.—Frons sexually dimorphic, male variously impressed, female flat to con- vex; eye entire; funicle 5-segmented, club al- most non-existent to strongly asymmetrical, deeply divided into three movable, sub- No. 10 "po 0 009 ©00be fe e Be J i R Ld t! B ry Bs B Fig. 39. Phloeotribus pilula Erichson, dorsal aspect of male. (After Sched] 1953: 80). lammelate segments; procoxae contiguous; pronotum armed or not, its lateral margins rounded; metatergum fused to its postnotum. BroLocy.—All are monogamous and phloeophagous. Parental galleries are bi- ramous and engrave the wood rather deeply. Eggs are deposited in niches packed in frass. Larval mines follow a rather definite course away from the parental tunnels and usually do not cross one another; in the latter stages they may engrave the wood rather deeply. A few species bore rather deeply into subsurface tis- sues of woody vines; one species breeds in the fruiting pods of its host (Inga). TaxoNoMy.—The tribe apparently origi- nated in South America, where a majority of the species now occur. Aricerus and one very primitive Phloeotribus apparently reached Australia very early; much later a few species of Phloeotribus reached North America and then spread from there to northern Asia, Eu- 1986 rope, and North Africa. The tribe apparently was derived from the same parental stock as the Phloeosinini, although the relationship is not close. The distribution, freely movable antennal club segments (Fig. 39), and the tib- ial structure of Aricerus and at least one spe- cies of Phloeotribus suggest an origin in early Tertiary or late Cretaceous while it was still possible to spread to Australia, but not into Africa. The one Australian and a few Eu- ropean Phloeotribus (Fig. 27) have virtually no club on the antenna, suggesting the possi- bility that the club of Scolytidae could have been derived independently from that of other curculionoids. Key to the Genera of Phloeotribini 1. Lateral margin of protibia without socketed teeth, outer apical angle rather strongly produced, with few (about three) major serrations; lateral margin of pronotum acutely elevated, subserrate; anten- nal club rather slender, almost symmetrical, ven- tral margins of segments not noticeably extended; phloeophagous; Australia to New Guinea; 3.1-4.6 AYMARA RP Gps cS SS che us hfe si 2gc aventneeeredeser Daktieis Aricerus — Lateral margin of protibia with several socketed teeth, none strongly projecting beyond others (one exception); lateral margins of pronotum rounded; ventral or lateral margin of each antennal club segment weakly to profoundly extended into a sublamellate process except in very primitive species; phloeophagous; North and South Amer- ica, Europe, N Asia, N Africa, Australia ........ .. Phloeotribus Aricerus Blandford [1894b: 133, Type-spe- cies: Aricerus chapuisi Blandford, subse- quent designation by Hopkins 1914: 117. Syn- onym: Hylesinosoma Lea 1910: 143, Type- species: Hylesinus fici Lea =Aricerus eich- hoffi Blandford, monobasic]. Distribution: 3 species from Australia to New Guinea. Monogamous and phloeophagous in Ficus limbs. Phloeotribus Latreille [ 1796: 50, Type-spe- cies: Hylesinus oleae Fabricius —Scolytus scarabaeoides Bernard, monobasic. Syn- onyms: Phloiotribus Latreille, 1796: 50, inad- vertent error in original spelling amended in Latreille 1804: 108, ruled by International Commission on Zoological Nomenclature 1979: 132; Phloeophthorus Wollaston 1854: 299, Type-species: Phloeophthorus perfolia- tus Wollaston, monobasic; Dryotomus Cha- puis 1869: 46, Type-species: Dryotomus pu- berulus Chapuis, monobasic; Phthorophloeus Rey 1883: 128, Type-species: Phloeophthorus Woob: GENERA OF SCOLYTIDAE 49 spinulosus Rey, monobasic; Elzearius Guille- beau 1893: 64, Type-species: Elzearius crena- tus Guillebeau, monobasic; Eulytocerus Blandford 1897: 161, Type-species: Eulyto- cerus championi Blandford, monobasic; Comesiella Del Guercio 1925: 218, Type-spe- cies: Comesiella sicula) Del Guercio Bostrichus brevicollis kolenati, monobasic; Neophloeotribus Eggers 1943: 349, Type-spe- cies: Phloeotribus nubilus Blandford, desig- nated by Wood 1983: 648; Dryotomicus Wood 1962: 76, Type-species: Dryotomus pu- berulus Chapuis, automatic]. Distribution: About 58 species in South America, 27 in North and Central America, 10 in Europe, 4 in N Africa, 1 in Australia. All are monoga- mous and phloeophagous. Keys: Pfeffer (1972: 31) for Europe, Blandford (1897: 162) for Cen- tral America, Wood 1982: 257) for North and Central America. Tribe Phloeosinini Phloeosinides Niisslin [1912b: 273, Type-species: Phloeo- sinus Chapuis, 1869] DEscriPTION.—Frons usually dimorphic, male impressed, female flat to convex; eye varying from entire to emarginate to com- pletely divided; antennal funicle 5- to 7-seg- mented, club flattened, slightly to strongly asymmetrical, with or without sutures; prono- tum armed or not; tarsal segment 3 com- pressed to broad and bilobed; scutellum visi- ble or not; metanotum fused to postnotum. BioLocy.—All are monogamous except for a few species of polygynous Olonthogaster and one bigynous Chramesus. Most are phloeophagous, although Dendrosinus and three species of Chramesus are xylophagous and Hyleops larvae become xylomyce- tophagous in the later stages. The parental tunnels are mostly monoramous, with a con- spicuous turning niche, a few are rather prim- itively (unequally) biramous. Eggs are placed in niches and packed in frass. Larval mines tend to follow a definite course away from the parental tunnel and rarely cross one another. TaxONoMy.—This tribe appears to consist of a diverse assemblage of somewhat distantly related genera or clusters of genera that ap- pear to be relicts from a former much larger group. Their worldwide distribution, diverse structure, and possession of several primitive traits suggest an ancient origin that extends 50 GREAT BASIN NATURALIST MEMOIRS Fig. 40. Phloeosinus punctatus LeConte, dorsal aspect of male. (After Bright 1976: 207). well into the Cretaceous. Within the tribe, two clusters of genera are apparent. Pseu- dochramesus and Chramesus (America) are closely related to one another and are the most highly evolved from a structural point of view. Cladoctonus, Phloeosinopsoides, Olon- thogaster, and Phloeosinus (Fig. 40) form a second cluster of genera to ‘which Phloeo- cranus (Fig. 41) and Phloeodictica might form a primitive base. All are Old World genera except that about half of the Cladoctonus spe- cies occur in tropical America and a segment of Phloeosinus has extended into North Amer- ica in comparatively late Tertiary time. The Cladoctonus species of the Philippines (1), Africa (8), and tropical America (6) have appar- ently changed only slightly since attaining their present generic distribution (perhaps early Tertiary). The American Dendrosinus and Carphotoreus and the Australian Hyleops are not closely related to one another or to the other known generic groups of this tribe. No. 10 Fig. 41. Phloeocranus bruchoides Sched, lateral aspect of female (tibial denticles omitted). Key to the Genera of Phloeosinini 1. Interstriae 10 continued to declivity (to level of visible sternum 3); protibia with lateral apical angle produced slightly and armed by three socketed teeth; humeral angles of elytra strongly produced cephalad, largest crenula- tions at humeral angles; eye deeply emarginate (three-fourths divided); funicle 5-segmented; scutellum not visible; phloeophagous; India to Malaya;:2:5-3:5imm\ ).3 22 east Phloeocranus — Interstriae 10 not continued behind level of metacoxae; lateral apical angle of protibia not produced (except Phloeoditica) ............. 2 Protibia slender, outer apical angle armed by two closely set, projecting, socketed denticles, one smaller tooth on lateral margin; procoxae rather widely separated by distance equal to width of coxa; funicle 5-segmented, club sym- metrical to moderately asymmetrical; prono- tum unarmed; scutellum not visible; elytral ground vestiture of circular (rounded) scales; metathoracic wings apparently absent in male of at least one species; phloeophagous; SE Asia; 229-9 SMM ghee omits eben Pane Phloeoditica — Protibia more strongly flattened, armed by three or more socketed teeth of equal size; with other combination of characters ............- 3 Antennal club symmetrical to rather weakly asymmetrical (Fig. 42); eye emarginate, or di- vided when funicle 5-segmented; procoxae ei- ther separated or contiguous; body usually morejslenden tan)... oc} tenn Sere 4 oe Antennal club very strongly asymmetrical (Fig. 43), sutures strongly procurved when present; eye entire; funicle 5-segmented; procoxae rather widely separated; body usually very stout; American species Eye entire; funicle 6- or 7-segmented; prono- tumlarmed(ornotias.ciscna ie cee 5 — Eye weakly emarginate to completely divided; funicle 5-segmented (6-segmented in some Cladoctonus); pronotum unarmed by asperi- ties (except weakly armed in Phloeosinop- soides) 1986 10(9). Woop: GENERA OF SCOLYTIDAE Funicle 7-segmented; bases of elytra produced anteriorly, each strongly procurved; scutellum visible, elytral notch for its reception very deep, narrow; procoxae very widely separated; pronotum armed or not; body stout, usually black; xylophagous; Mexico to South America; SUOLDIOMNM ee erga ses aye skeen mere Dendrosinus Funicle 6- or 7-segmented; elytral bases not produced; scutellar notch at sutural base of elytra not unusually deep or narrow; procoxae contiguous to moderately separated; smaller .. 6 Procoxae contiguous; pronotum unarmed; fu- nicle 7-segmented; scutellum obsolete; tarsal segment 3 broad, strongly bilobed; phloeo- phagous except larvae xylomycetophagous in later stages; Australia; Araucaria; 2.4-4.0 mm Rr etn bere ei corre cegilepeabto Serre go artes Bitte Hyleops Procoxae separated by about half width of a coxa; funicle 6-segmented; pronotum armed by fine asperities; scutellum visible; tarsal seg- ment 3 narrow; phloeophagous Body more slender, 2.1 times as long as wide; antennal club almost symmetrical, three su- tures indicated, 1 partly septate; posteromesal margin of pronotum almost straight; Mexico; Alnus 2°522074MM, ..002e eres: Carphotoreus Body stout, 1.6 times as long as wide; antennal club strongly asymmetrical, suture | septate, others not indicated; posteromesal margin of pronotum slightly extended toward scutellum; Congo; 1.8 mm Catenophorus Antennal club subglobular, sutures obsolete or indicated by sparse setae; funicle 5- or 6-seg- mented; procoxae contiguous; scutellum visi- ble or not; phloeophagous; tropical America, Africa, Philippines; 1.4-2.5mm .... Cladoctonus Club flattened, sutures transverse to oblique when present; funicle 5-segmented; procoxae moderately separated; scutellum _ visible; phioeophagousia. a.c.csees sqcdese en eer 8 Pronotum finely asperate at least in lateral ar- eas; sutures 1 and 2 on antennal club trans- verse; eye coarsely faceted, anterior margin shallowly, broadly emarginate; elytral ground vestiture almost obsolete, erect setae in rows, flattened, almost scalelike; Taiwan to New Guinea; 1.3-2.5 mm Phloeosinopsoides Pronotum unarmed; sutures | and 2 on anten- nal club oblique; eye more finely faceted, emargination at least one-third as deep as eye width (completely divided in some Asian spe- cies); elytral ground vestiture usually more abundant, erect setae slender when ground SEtAG SPATSOl a 30 si atanstatete. «ass eis teteuans's-e aus etene, tes 10 Eye usually completely divided by an emar- gination (several exceptions), tarsal segment 3 slender; protibia with two (rarely one to three) apical and subapical socketed teeth, one or two others sometimes on lateral margin; vestiture usually less abundant; male frons usually con- cave; female frons concave to convex, usually ornamented by a conspicuous brush of hair; 51 above Phloeosinus thujae (Perris); 43, below, Chramesus hicko- riae LeConte. Fig. 42-43. Antennae of Phloeosinini: 42, color usually reddish brown; SE Asia to New Guinea; mostly in nonconiferous hosts; 1.4-5.5 mm..... Olonthogaster — Eye less than one-half divided by an emargina- tion; tarsal segment 3 broad, emarginate to bilobed; protibia with three or more socketed denticles on apical and subapical margin, four or more smaller teeth on lateral margin, vesti- ture more abundant; male frons usually shal- lowly impressed; female frons convex, often with a median carina, vestiture inconspicuous in both sexes; color brown to dark brown; N Africa to N Asia, North America, Australia; mostly in coniferous hosts; 1.4-4.1) mm (Phloeosinites Hagedorn presumably fits near here) Phloeosinus 11(3). Antennal club with sutures strongly pro- curved, clearly marked by rows of setae and grooves; phloeophagous; S America; 1.3-2.0 mm Pseudochramesus — Antennal club without sutures; mostly phloeophagous; North and South America; 1. 2- 2.7mm Chramesus Phloeocranus Schedl [1942: 7, Type-spe- cies: Phloeocranus bruchoides Schedl, mono- basic. Synonym: Diamerides Browne 1949: 893, Type-species: Diamerides _ litseae Browne =Phloeocranus bruchoides Schedl, original designation]. Distribution: 1 species from India to Indonesia in Litsea. This species is monogamous and phloeophagous. 52 GREAT BASIN NATURALIST MEMOIRS Phloeoditica Sched [1962d: 189, Type-spe- cies: Kissophagus curtus Eggers, present des- ignation]. Distribution: One species in SE Asia. It breeds in Pongamia glabra. Dendrosinus Chapuis [1869: 28, Type-spe- cies: Hyulesinus globosus Eichhoff, monoba- sic]. Distribution: 10 species from USA (Flor- ida) and Mexico (Jalisco) to Argentina. All are monogamous and xylophagous. Key: Wood (1982: 283). Hyleops Schedl [1938b: 35, Type-species: Hyleops glabratus Schedl, monobasic]. Dis- tribution: 1 species in Australia in Araucaria branches. It is monogamous and_ partly phloeophagous. The later larval stages pene- trate the xylem and become xylomyce- tophagous. Parental tunnels are transversely biramous and without apparent symbiotic fungi. Carphotoreus Wood [1973b: 171, Type- species: Chaetophloeus alni Bright, original designation]. Distribution: 1 species in Mex- ico (Oaxaca). It is monogamous and phloeo- phagous. Catenophorus Nunberg [1956b: 195, Type- species: Catenophorus congonus Nunberg, original designation]. Distribution: 1 species in the Congo. The habits are unknown. Cladoctonus Strohmeyer [1911: 17, Type- species: Cladoctonus affinis Strohmeyer, monobasic. Synonyms: Hoplites Eggers 1923: 140, Type-species: Hoplites banosus Eggers, monobasic, preoccupied; Hoplitontus Wood 1961: 2, Type-species: Hoplites banosus Eg- gers, automatic; Hoplitophthorus Wood 1961: 2, Type-species: Hoplitophthorus sentosus Wood =Hoplites interruptus Eggers, original designation]. Distribution: 8 species in Africa, 6 in Cuba to Brazil and Bolivia; 1 in the Philip- pine Islands. The two species for which habits are known are monogamous and_phloeo- phagous. Phloeosinopsoides Schedl [1964c: 317, Type-species: Phloeosinopsis _ triseriatus Schedl, automatic. Synonym: Phloeosinopsis Schedl 1964b: 297, Type-species: Phloeo- sinopsis triseriatus Schedl, original designa- tion, preoccupied]. Distribution: About 8 species from Taiwan to New Guinea. All are monogamous and phloeophagous. Phloeosinus Chapuis [1869: 37, Type-spe- cies: Hylesinus thujae Perris, subsequent des- ignation by Hopkins 1914: 126]. Distribution: No. 10 29 species in North America, about 30 in Asia and adjacent islands, 5 in Europe, 2 in N Africa, and 2 in Australia. All are monogamous and phloeophagous. Most are in coniferous hosts, especially Cupressineae. Keys: Black- man (1942c: 400) and Wood (1982: 287) for North America, Sched! (1950a: 36) for Eu- rope, Murayama (1963: 22) for Japan. Olonthogaster Motschulsky [1866: 401, Type-species: Olonthogaster nitidicollis Mot- schulsky, subsequent designation by Hopkins 1914: 126. Synonyms: Holonthogaster Gem- minger & Harold 1872: 2676, Type-species: Olonthogaster nitidicollis Motschulsky, auto- matic; Hyledius Sampson 1921: 35, Type-spe- cies: Hyledius asper Sampson, monobasic; Hylurgulus Eggers 1927c: 392, Type-species: Hylurgulus summatranus Eggers, monoba- sic; Phloeosinopsis Sched] 1936a: 23, Type- species: Phloeosinopsis armatus Sched] =Phloeosinus spinifer Schedl, original desig- nation]. Distribution: About 25 species from SE Asia to Australia. All are phloeophagous and monogamous except for 2 polygynous species from New Guinea. Hosts include Lyt- sea, Myristica, etc. Phloeosinites Hagedorn [1907: 119, Type- species: Phloeosinites rehi Hagedorn, subse- quent designation by Hopkins 1914: 126]. Distribution: 8 fossil species in Baltic amber (Oligocene). The relationship of this genus to Phloeosinus was not determined. Pseudochramesus Blackman [1939: 87, Type-species: Chramesus — acuteclavatus Hagedorn, original designation]. Distribu- tion: 11 species in South America. The habits have not been reported. Key: Blackman (1939: 88). Chramesus LeConte [1868: 168, Type-spe- cies: Chramesus hicoriae LeConte, monoba- sic. Synonyms: Rhopalopleurus Chapuis 1869: 46, Type-species: Rhopalopleurus tu- berculatus Chapuis, subsequent designation by Hopkins 1914: 128; Thaumasinulus Reitter 1913: 39, Type-species: Dendrosinus bon- nairei Reitter =Chramesus rotundatus Cha- puis, monobasic; Prochramesus Wood 1956b: 254, Type-species: Prochramesus annectans Wood, original designation]. Distribution: 39 species in South America, 40 in North and Central America and adjacent islands. All are monogamous, except for the bigynous C. in- comptus, and all are phloeophagous except 1986 Woop: GENERA OF SCOLYTIDAE D3 Fig. 44. Liparthrum spp.: 1, outline of dorsal aspect of arizonicum Wood; 2, outline of dorsal aspect of albosetum Bright; 3, outline of antenna of albosetum. (After Bright 1968: 639). for the myelophagous C. quadridens and three xylophagous species. Keys: Blackman (1938c: 536), Wood (1982: 316). Tribe Hypoborini Hypoborinae Niisslin [1911: 376, Type-genus: Hy- poborus Erichson, 1836] DEscCrIPTION.—Frons dimorphic or not, male impressed, female convex or less strongly impressed, except in some Li- parthrum species this feature is reversed; eye entire; funicle 3- to 6-segmented, club with up to three sutures, sometimes absent; prono- tum variously armed in restricted areas; pro- coxae contiguous; tarsal segment 3 narrow; scutellum not visible; crenulations on elytral bases not continued laterad from interstriae 5; postnotum fused to metatergum (remnants of suture sometimes visible). BioLocy.—All are monogamous and phloeophagous. In all except Chaetophloeus the parental gallery is a simple, oval cave. Eggs are packed in frass in niches on the mar- gins of the central cave (Liparthrum) or of the egg tunnels (Chaetophloeus). Larval mines radiate out from the parental chamber and rarely cross one another; they are visible on the inner surface of peeled bark. TAXONOMY.—This tribe is sparsely and widely distributed in the warm climates around the world. Except for Liparthrum (Fig. 44), which is almost worldwide in the warm areas, the remaining genera are of lim- ited distribution. One is American, 1 Aus- tralian, 2 Madagascaran, and 4 African (1 of these reaches nearby areas of Europe and Asia in cultivated fig). It appears to be a relict group that once enjoyed much greater distri- bution and diversity than at present. The American genus, Chaetophloeus, is quite different structurely and_ biologically from the remaining closely related genera. Members of this tribe apparently prefer arid or semiarid areas or habitats and tend to be rare. Since they breed in shrubs or small trees of marginal economic importance, it is sus- pected that a majority of the species await discovery. Key to the Genera of Hypoborini 1. Funicle 6-segmented, club small, conical, with two straight sutures; Australia; Acacia; 1.3 mm Posie e caa a etaeehyn aici em ae oota Zygophloeus — Funicle with 3- to 5-segments; club flattened, sutures present or absent ................--. 2 . Protibia strongly flattened, rather broad, lateral apical half armed by a row of 7-10 closely set, socketed teeth; pronotal asperities confined to two or three paired clusters on lateral thirds, each cluster containing 1-5 denticles; funicle 5- segmented, club clearly marked by three su- tures; phloeophagous; North and South Amer- ieas 20-2 Simm as. seas as a ate Chaetophloeus 54 GREAT BASIN NATURALIST MEMOIRS — Protibia slender, lateral margin armed by about four rather widely spaced, socketed teeth; pronotal asperities mostly on median third, more abundant; funicle 3- to 5-segmented ..... 3 3(2). Antennal funicle 5-segmented, club rather broad, sutures very broadly procurved; protibia slender, with one large spine on outer apical angle and four small, socketed denticles on lat- eral margin; crenulations on basal margins of elytra feeble; body subglabrous; Madagascar; LPS MLM getatecever cate ists tere cee teat von peioreiece Glochiphorus — Protibia not armed on outer apical angle by a major spine; antenna variable; elytra bearing CoE) ed aarp Pee rns Eee Cid Oishi Eeear noe 4 . Funicle 4- or 5-segmented, club with sutures obscure, club more broadly oval ............. 5 — Funicle 3-segmented, club usually more slen- (GLeTE oeetrcrain ahi Aus Gens teat ore mine ee tale ae 7 5(4). Antennal funicle 4-segmented (appearing 3-seg- mented, but 4- or possibly 5-segmented on slide mount), club unmarked by sutures; basal mar- gins of elytra a continuous costa, individual crenulations feebly indicated; anterior half of pronotum asperate; striae not impressed, punc- tures coarse, deep, wider than interstriae; Madagascar; 1.6mm ......... Cryphyophthorus — Funicle 4- or 5-segmented; crenulations on basal margins of elytra well-formed; strial punc- tures smaller; pronotal asperities often present, butlessiconspicuous: 4.20 osccsa-ei sche ete 6 . Funicle 4-segmented, club devoid of sutures; meso- and metatibiae slender, about equal to protibia; phloeophagous; S USA to N South America, S Europe and N Africa to China and Micronesia; 0.8-1.5mm ........... Liparthrum — Funicle 5-segmented, club with three obscure sutures; meso- and metatibiae rather strongly flattened, much wider and more coarsely serrate than protibia; phloeophagous; S Europe, N Africa to Asia Minor; 1.1-1.4mm..... Hypoborus A eS . Antennal club with three distinct sutures; meso- and metathoracic tibiae slender, about equal to protibia; phloeophagous; Africa; 1.2-1.8 mm . . eal EOD Lectin A TNL cies Styracoptinus — Antennal club long and slender, sutures not in- dicated; scape ornamented by a tuft of long hair; discal interstriae 2 on basal fourth with one tu- bercle greatly enlarged in male, 3 with four tubercles on posterior half and upper half of declivity; phloeophagous; Africa; 1.6-2.0 mm Dacryostactus Zygophloeus Schedl [1958b: 215, Type- species: Zygophloeus australis Schedl, mono- basic]. Distribution: 1 species in Acacia in Australia. Glochiphorus Strohmeyer [1910c: 126, Type-species: Glochiphorus globosus Stroh- meyer, monobasic]. Distribution: 1 species in Madagascar. No. 10 Chaetophloeus LeConte [1876: 382, Type- species: Hylesinus hystrix LeConte, monoba- sic. Synonyms: Renocis Casey 1886: 257, Type-species: Renocis heterodoxus Casey, monobasic; Pseudocryphalus Swaine 1917: 20, Type-species: Pseudocryphalus brittaini Swaine = Renocis heterodoxus Casey, original designation]. Distribution: 17 species in North America and adjacent islands, 2 in South America. All are monogamous and phloeophagous. Keys: Blackman (1940: 376), Wood (1982: 349). Cryphyophthorus Sched] [1953c: 294, Type-species: Cryphyophthorus — eggersi Schedl, original designation]. Distribution: 1 in Sumatra (Indonisia), 1 in Madagascar. Liparthrum Wollaston [1854: 294, Type- species: Liparthrum bituberculatum Wollas- ton, original designation. Synonyms: Lei- parthrum Wollaston 1854: 294, invalid error in spelling, amended by Wollaston (1864: 265), International Commission on Zoological Nomenclature (1981: 64) ruled this to be an invalid spelling; Erineosinus Blackman 1920: 53, Type-species: Erineosinus squamosus Blackman, monobasic; Phloeochilus Schedl 1953c: 292, Type-species: Phloeochilus pala- quius Schedl, original designation, Phloeo- trypetus Wood 1960a: 16, Type-species: Phloeotrypetus palauensis Wood, original designation; Dacryophthorus Schedl 1971b: 281, Type-species: Dacryophthorus brincki Schedl, original designation]. Distribution: 2 species in South America, 7 in North and Central America; 11 in the Canary and other Atlantic islands, 6 in Europe, | in China, 4 in the Indo-Malayan area, and 1 in Micronesia. All are monogamous and_ phloeophagous. Keys: Sched] (1959a: 36) for the genus, Wood (1982: 364) for North and Central America. Hypoborus Erichson [1836: 62, Type-spe- cies: Hypoborus fici Erichson, monobasic]. Distribution: 1 species from S Europe, N Africa, and SW Asia in cultivated fig. Monoga- mous and phloeophagous. Styracoptinus Wood [1962: 77, Type-spe- cies: Styracopterus murex Blandford, auto- matic. Synonyms: Styracopterus Blandford 1896c: 323, Type-species: Styracopterus murex Blandford, monobasic, preoccupied; Afrotrypetus Bright 1981b: 113, Type-spe- cies: Afrotrypetus euphorbiae Bright, original designation]. Distribution: About 5 species in 1986 S Africa. All are apparently monogamous and phloeophagous. Dacryostactus Schaufuss [1905: 79 (reprint p. 3), Type-species: Dacryostactus kolbei Schaufuss, monobasic]. Distribution: 1 spe- cies in Africa. Monogamous and_phloeo- phagous. Tribe Polygraphini Polygraphidae Chapuis [1869: 48, Type-genus: Polygra- phus Erichson, 1836] Carphoboridae Niisslin [19]1: 376, Type-genus: Car- phoborus Eichhoff, 1864] DEsCRIPTION.—Frons_ dimorphic, male variously impressed and sparsely pubescent, female concave to convex and usually orna- mented by conspicuous setae; eye emarginate to completely divided; antennal funicle 5- or 6-segmented, club slightly to strongly flat- tened, symmetrical to strongly asymmetrical, with or without sutures; procoxae contiguous; tarsal segment 3 slender; pronotum unarmed; scutellum not visible; crenulations on bases of elytra either individual (separate) or repre- sented by a continuous costa (Serrastus ), con- tinued to humeral angle; metanotum fused to its postnotum. BroLocy.—All are phloeophagous. Car- phobius and some Polygraphus are monoga- mous; apparently Chortastus and Serrastus share this habit; Carphoborus (Fig. 45) and most Polygraphus are polygynous. Parental tunnels are monoramous or biramous_ in monogamous forms and radiate in polygynous forms. The nuptial chamber is unusually large in most species. Eggs are packed in frass in niches. Larval mines wander considerably and have a greater tendency to cross one an- other than in most other tribes. TAxONOoMy.—In my initial study of the tribes of Scolytidae (Wood 1978), the Poly- graphini were reluctantly given tribal status only after much hesitation and the pondering of many questions. Since then, all reserva- tions have been dismissed. Although quite specialized in several respects, representa- tives of two genera (Serrastus, Polygraphus ) have the outer apical angle of the protibia produced beyond the tarsal insertion and are armed as in primitive representatives of other unspecialized tribes. The tribe generally ap- pears to have been derived from the same ancestral stock as the Phloeosinini, but Woob: GENERA OF SCOLYTIDAE 59 Fig. 45. Carphoborus pinicolens Wood, dorsal aspect of female. (After Bright and Stark 1973: 155). the one known species of Phloeographus bears a remarkable superficial resemblance to certain Tomicus species (Hylesinini). The genera form a rather compact unit without conspicuous divisions. Four small genera are exclusively African (Serrastus, Chortastus, Phloeographus, Cardroctonus), one is Malayan (Bothinodroctonus), and one is American (Carphobius ). The larger genus Carphoborus is primarily North American and probably originated there from stock derived from Asia. European and Asian spe- cies of Carphoborus appear to have been derived from the more primitive and diverse American fauna. The largest genus, Polygra- phus, is largely African, with strong represen- tation in Europe and Asia, and with three species in northern North America. The ab- sence of this group in South America suggests either an origin since early Tertiary, if Africa were the site, or else an origin in tropical Eurasia. Polygraphus reached North America in comparatively recent time, Carphoborus and Carphobius much earlier. Eurasian Car- 56 GREAT BASIN NATURALIST MEMOIRS phoborus were probably derived from a sec- ondary radiation that moved from North America to Asia. Carphobius apparently rep- resents a relict from a very early ancestral stock not now represented elsewhere. Key to the Genera of Polygraphini 1. Basal margins of elytra armed by a continuous costa; protibia very slender, its median apical mucro bent laterad, about one lateral denticle present, posterior face asperate; funicle 5-seg- mented; club strongly flattened, moderately asymmetrical, sutures not indicated; phloeo- phagous; Africa; 1.8-2.0 mm.......... Serrastus — Basal margins of elytra serrate, armed by a row of crenulations; protibia more broadly flattened, lateral margin armed by several socketed denti- CLES Re ee RT RIED Ghee 2 bo = . Funicle 5-segmented (5- or 6-segmented in Polygraphus, if 6-segmented then eye com- pletely divided); male frons armed by a median pair of tubercles near upper level of eyes; vesti- ture of abundant scales (except glabrous in some Bothinodroctonus) 2) -cr eects ee 3 — Funicle 6-segmented; eye never divided into two parts; male frons unarmed by median tuber- cles; vestiture hairlike or sparse if scalelike ci 3(2). Eye completely divided by a deep emargination (some Asian and African species only emar- ginate); antennal club rather strongly flattened, asymmetrical, devoid of sutures; phloeo- phagous; North America, Asia, Europe, Africa; P5-5 OMe een senate Polygraphus — Eye less than half divided by an emargination; antennal club symmetrical (or nearly so), clearly markediby/sutunesecys-naneeeee ten rier 4 4(3). Sutures of antennal club procurved; vestiture sparse, in uniseriate rows on interstriae; tropical ATTICA upacm ener ee ta ee ea Mone tae 5 — Sutures of antennal club straight or nearly so; vestiture much more abundant; northern hemi- SDHELE eee tei cite Hecate 6 5(4). Antennal club with three weakly procurved su- tures indicated, apex strongly acuminate; vesti- ture sparse, of uniseriate rows on declivity; de- clivital interstriae 2 slightly impressed, unarmed, | and 3 armed by small tubercles; SW Africas 25 2:mmi\ eaters serve cnet Phloeographus — Antennal club with suture 1 partly septate, | weakly, 2 moderately procurved; strial punc- tures very fine; Africa; 1.3-2.0mm_ . Cardroctonus 6(4). Male frons shallowly impressed below upper level of eyes, female usually convex; vestiture of abundant scales; antennal club moderately large, flattened; phloeophagous; North Amer- ica, N Asia, Europe, N Africa; 1.4-2.6mm .... Santen eer i eer aed Prertrnaieha hs coe tac Carphoborus — Male frons profoundly excavated from eye to eye from epistoma to well above eyes, female simi- larly but less strongly excavated; antennal club No. 10 small, more nearly conical; vestiture confined to a few interstrial setae on and near declivity; phloeophagous; India to Malaya; 1.8-2.5mm . . NA rete sesame dere ey tee Bothinodroctonus 7(3). Antennal club symmetrical, with three trans- verse sutures indicated; vestiture abundant, hairlike; phloeophagous; North America; 1.6- DUNG oe aEn bs cer enoacn bh ei.0 ¢ Carphobius — Antennal club rather strongly asymmetrical, part of suture 1 indicated, strongly oblique; vestiture usually confined to declivity, scalelike; phloeophagous; Africa; 2.5-5.3 mm ... Chortastus Serrastus Nunberg [1969: 392, Type-spe- cies: Serrastus ivoriensis Nunberg =Chor- tastus similis Eggers, monobasic]. Distribu- tion: 2 species in Africa (Ghana to Zaire). They are monogamous and phloeophagous. Phloeographus Wood [1984: 229, Type- species: Phloeographus mamibiae Wood, original designation]. Distribution: 1 species in Africa (apparently Namib Desert, SW Africa). Cardroctonus Schedl [1966b: 361, Type- species: Cardroctonus orientalis Schedl, orig- inal designation]. Distribution: 2 species in Africa. Polygraphus Erichson [1836: 57, Type-spe- cies: Hylesinus pubescens Fabricius =Der- mestes poligraphus Linnaeus, monobasic. Synonyms: Lepisomus Kirby 1837: 193, Type- species: Apate (Lepisomus ) rufipennis Kirby, subsequent designation by Hopkins 1914: 124; Spongotarsus Hagedorn 1908: 372, Type-species: Spongotarsus quadrioculatus Hagedorn, monobasic; Pseudopolygraphus Seitner 1911: 105, Type-species: Polygraphus grandiclava Thomson, subsequent designa- tion by Hopkins 1914: 128; Ozophagus Eggers 1919: 234, Type-species: Ozophagus camer- unus Eggers, subsequent designation by Wood 1982: 386; Urdugraphus Beeson 1941: 301, nomen nudum]. Distribution: 3 species in North America, about 45 in Asia and adja- cent islands, 6 in Europe, about 45 in Africa and Madagascar. Most are polygynous, al- though monogamy occurs in some Asian and African species. All are phloeophagous. Keys: Sched] (1955a: 5) for Europe and part of Asia, Murayama (1956: 278) for Japan, Wood (1982: 387) for North America. Carphoborus Eichhoff [1864: 27, Type- species: Hylesinus minimus Fabricius, mono- basic. Synonym: Estenoborus Reitter 1913: 58, Type-species: Hylesinus perrisi Chapuis, 1986 monobasic]. Distribution: 21 species in North America, 14 in Europe and Asia, 2 in N Africa. All are polygynous and phloeophagous. Keys: Pfeffer (1914: 169) for Europe, Balachowsky (1949: 143) for France, Wood (1954a: 507, 1982: 372) for North America. Bothinodroctonus Sched [1969: 208, Type- species: Bothinodroctonus bicinctus Sched, monobasic]. Distribution: 4 species from In- dia to Borneo and China. One species is phloeophagous in Odina. Carphobius Blackman [1943c: 398, Type- species: Carphobius arizonicus Blackman, original designation]. Distribution: 3 species in North America (Arizona to Guatemala). All are monogamous and phloeophagous in conifers. Key: Wood (1982: 369). Chortastus Schaufuss [1905: 15 (reprint p. 8), Type-species: Chortastus camerunus Schaufuss, monobasic. Synonym: Afrochram- esus Sched] 197la: 197, Type-species: Afrochramesus baguenai Schedl,_ original designation]. Distribution: 7 species in Africa. Apparently all are monogamous and phloeo- phagous. Subfamily Scolytinae Scolytarii Latreille [1807: 273, Type-genus: Scolytus Ge- offroy, 1762] In previous classifications, this subfamily has been divided into two or more major divi- sions equivalent to subfamilies. However, it appears that this unit contains both the most primitive elements of the family that are most closely related to primitive Platypodidae and also the main evolutionary thrust of the platy- podid-scolytid group. This diversity makes characterization of the subfamily rather diffi- cult. Members of this subfamily have the bases of the elytra simple, forming a straight, trans- verse line across the body. A large, flat scutel- lum is usually visible. The elytral bases are weakly subcostate in some Scolytini, Ctenophorini, and Cryphalini. The body tends to be more elongate, with specialization directed toward cylindrical compaction and the xylomycetophagous habit. A broadly oval body outline is usually confined to primitive, phloeophagous genera. Armed elytral bases that suggest a relationship to the Hylesininae occur in Ctenophorini (Cnemonyx, allies of galeritus ). Woop: GENERA OF SCOLYTIDAE eye Five clusters of relationship are recognized within the subfamily. Progressing from primi- tive to the more specialized, these include: (1) Ctenophorini, Scolytini, and Scolytoplatypo- dini; (2) Micracini and Cactopinini; (3) Carphodicticini, Ipini, Dryocoetini, Cryp- turgini, Xyloterini, and Xyleborini; (4) Xyloc- tonini and Cryphalini, and (5) Corthylini. Of these, the Corthylini are by far the most dis- tinctive from an anatomical point of view. Tribe Scolytini Scolytarii Latreille [1807: 273, Type-genus: Scolytus Ge- offroy, 1762] Camptoceridae Chapuis [1869: 49, Type-genus: Campto- cerus Latreille, 1829] DESCRIPTION.—Frons usually strongly di- morphic, male variously impressed, female flat to convex, one or both often ornamented by hair; posterior face of head truncate; eye oval, entire; scape short to elongate, funicle 7-segmented, club rather large, flattened, su- tures present or not; pronotum unarmed, its lateral margins costate; protibia (usually all three tibiae) unarmed on lateral margin, outer apical angle extended into a spine curving toward and exceeding inner apical angle, socketed denticles never present; meta- pleural suture descending subvertically to groove receiving groove on costal margin of elytra then turning abruptly and continuing parallel to groove to near metacoxal process; in two genera venter of abdomen ascends con- spicuously to meet apex of weakly declivous elytra. BioLocy.—All are monogamous except for a few neotropical and one European bigynous Scolytus. Camptocerus species are xylomyce- tophagous; those in the other three genera are phloeophagous. Parental galleries are bi- ramous, except for a few that are mono- ramous. In Camptocerus, a biramous, trans- verse tunnel without niches is usually made in the cambium region, then a radial egg tunnel (sometimes branched) is extended from it into the xylem. Eggs are deposited in niches in this radial tunnel. The larval mines of phloeo- phagous species follow a definite course and rarely cross one another. Camptocerus larvae enlarge the egg niche into a cradle just large enough to accommodate the mature beetle, somewhat similar to some other ambrosia beetles. 58 GREAT BASIN NATURALIST MEMOIRS TAXONOMY.—Except for the Eurasian ele- ment of Scolytus, members of this tribe are exclusively American. Their obvious origin is neotropical. Some members of this group re- semble the primitive ancestral line that prob- ably gave rise to the Hylesininae; in fact, some Cnemonyx have crenulations on the basal margins of the elytra. They also appear closely allied to the stock from which Platypodidae diverged. The four genera assigned here form a compact group, although the Cnemonyx ap- pear more primitive and, in some respects, overlap the other three. Scolytus appears to have reached North America from South America by the begin- ning of the Tertiary, when a secondary radia- tion occurred. Elements of this radiation then reached Eurasia, where another radiation oc- curred that was based on a progressively re- duced gene pool. The number of Eurasian species in this genus now may equal or exceed the American component, although the anatomical and biological diversity there is greatly reduced. Key to the Genera of Scolytini 1. Scutellar area of interstriae 1 not depressed, scutellum flush (even) with elytral bases; basal margins of elytra with a fine raised line (some Cnemonyx with crenulations instead), outline of anterior margins form a continuous, straight, transverse line with scutellum; ventral profile of abdomen ascending gradually ............... 2 — Scutellum depressed, subtriangular, apically (posteriorly) pointed; elytral bases depressed in scutellar area, appearing emarginate in median area; ventral profile of abdomen usually ascend- ing abruptly at segment 2 .............0..04. 3 2(1). Antennal club usually with two or three sutures clearly marked by setae; scutellum small, longer than wide, often convex; apical rhargin of meso- and metathoracic tibiae commonly bearing tu- bercles on anterior edge in addition to inner and outer apical spines; usually more coarsely sculp- tured; phloeophagous; USA and Mexico to Ar- gentina; 1.0-3.9 mm Cnemonyx — Antennal club with suture | (only) marked inter- nally by a partial septum; scutellum flat, 1.5 or more times as wide as long; meso- and metatho- racic tibiae acutely margined on apical anterior edge, without supplemental denticles; usually very finely sculptured; xylomycetophagous; Central and South America; 2.6-8.5 mm... ... nopdieos Seon oans deewandrnebdnad Camptocerus 3(1). Basal portion of costal margin of elytra deeply, broadly excised, metepisternum conspicuously expanded into this notch (Fig. 46); abdomen abruptly flexed upward at posterior margin of No. 10 Fig. 46. Scolytopsis puncticollis, female. Note emar- ginate costal margin of elytron. segment 2; phloeophagous, tropical; Mexico (Oaxaca) and Cuba to Argentina; 1.6-3.5mm . . RT ORGULEG DRS RUSH E Oe Tau oo Scolytopsis — Costal margin of elytra normal (straight) and overlapping metepisternum; abdomen flexed upward from anterior margin of segment 2; phloeophagous; North and South America, Eu- rope, N Asia, N Africa; 1.3-5.5mm ..... Scolytus Cnemonyx Eichhoff [1868a: 150, Type- species: Cnemonyx galeritus Eichhoff, monobasic. Synonyms: Ceratolepis Chapuis 1869: 52, Type-species: Ceratolepis jucundus Chapuis, monobasic; Loganius Chapuis 1869: 52, Type-species: Loganius flavicornis Cha- puis, monobasic; Minulus Eggers 1912b: 206, Type-species: Minulus barbatus Eggers, monobasic; Coptodryas Schedl 1948b: 262, Type-species: | Coptodryas — hylurgoides Schedl. monobasic; Coptosomus Schedl 1952a: 363, Type-species: Coptodryas hylur- goides Schedl, automatic]. Distribution: 19 species in USA (Florida), Mexico, and Central America, about 27 in South America and adja- cent islands. All are monogamous and phloeophagous. Keys: Blandford (1896d: 128) for Central America, Wood (1982: 394) for North and Central America. Camptocerus Latreille [1829: 91, Type- species: Hylesinus aeneipennis Fabricius, monobasic]. Distribution: 19 species from Central and South America. All are monoga- mous and xylomycetophagous. Key: Wood 1982: 412 for Central America. Scolytopsis Blandford [1896d: 120, 123, Type-species: Scolytopsis puncticollis Bland- ford, monobasic]. Distribution: 7 species from Cuba and Mexico (Oaxaca) to Argentina. All are phloeophagous and monogamous. Key: Wood (1982: 417) for Central America. Scolytus Geoffroy [1762: 309, Type-spe- cies: Bostrichus scolytus Fabricius, desig- 1986 nated by the International Commission on Zoological Nomenclature (China 1962: 3). Synonyms: Ekkoptogaster Herbst 1793: 124, Types-species: Bostrichus scolytus Fabricius, designated by Hopkins 1914: 121; Copto- gaster Illiger 1807: 321, Type-species: Bostrichus scolytus Fabricius, designated by Hopkins 1914: 118; Eccoptogaster Gyllenhal 1813: 346, an isotypical emendation of Ekkop- togaster Herbst; Scolytochelus Reitter 1913: 23, Type-species: Ips multistriatus Marsham, designated by Wood 1982: 419; Ruguloscoly- tus Butovitsch 1929: 20, Type-species: Bostrichus rugulosus Miller, designated by Wood 1982: 419; Archaeoscolytus Butovitsch 1929: 21, 23, Type-species: Scolytus claviger Blandford, monobasic, not a genus-group name, no status; Spinuloscolytus Butovitsch 1929: 21, 24, Type-species: Ips multistriatus Marsham, present designation, not a genus- group name, no status; Tubuloscolytus Bu- tovitsch 1929: 21, 33, Type-species: Eccopto- gaster intricatus Ratzeburg, present desig- nation, not a genus-group name, no status; Pygmaeoscolytus Butovitsch 1929: 21, 28, Type-species: Bostrichus pygmaeus Fabri- cius, present designation, not a genus-group name, no status; Pinetoscolytus Butovitsch 1929: 22, 48, Type-species: Scolytus marawitzi Semenov, monobasic, not a genus- group name, no status; Confusoscolytus Tsai, Yin, & Huang 1962: 4, 14, Type-species: Ec- coptogaster confusus Eggers, monobasic]. Distribution 28 species in North and Central America, about 29 in South America, 47 in Asia, Europe, and N Africa. Monogamous, except for 1 European and about 20 Central and South American bigynous species, and all are phloeophagous. Keys: Blackman (1934: 6) for North America, Sched] (1937a: 156) for South America and (1948a: 4) for Europe, Michalski (1973: 137) for Europe and Asia, Wood (1982: 420) for North and Central America. Tribe Ctenophorini Ctenophoridae Chapuis [1869: 49, Type-genus: Ctenophorus Chapuis, 1869 =Scolytodes Fer- rari, 1867] Problechilidae Eichhoff [1878a: 34, 46, 167, 298, Type-genus: Problechilus Eichhoff, 1878 Gymnochilus Eichhoff, 1867] Hexacolidae Eichhoff [1878a: 35, 57, 306, Type- genus: Hexacolus Eichhoff, 1868 =Scolytodes Ferrari, 1867] Woob: GENERA OF SCOLYTIDAE 59 DeEscrIPTION.—Frons usually dimorphic, male impressed and female flat to convex in Pycnarthrum and Gymnochilus , sexual differ- ences obscure in Microborus, male convex and female variously sculptured and orna- mented in Scolytodes; posterior face of head truncate; eye usually elongate, entire to sinu- ate; scape elongate, funicle 6- or 7-seg- mented, club with or without sutures; prono- tum armed or not, its lateral margins costate; procoxae widely separated; protibia with one or more socketed denticles on lateral margin, spine on lateral apical angle usually extending beyond level of tarsal insertion; pleural suture about as in Scolytini. BioLocy.—All are monogamous, except for a few polygynous Scolytodes. All are phloeo- phagous, except for the xylophagous Scoly- todes multistriatus Wood and species that in- fest Cecropia leaf petioles. Parental galleries vary from a simple to an elongate cave to stellate in Scolytodes; they are biramous in Pycnarthrum and Gymnochilus and indefi- nite, nondirectional, and without definite pat- tern in Microborus. The eggs may be scat- tered loosely in the parental chamber or placed in crude niches in Scolytodes ; definite niches are formed in Pycnarthrum and Gym- nochilus; they were not observed in Mi- croborus. The larvae usually feed commu- nally in Scolytodes; they form individual mines that follow a somewhat definite direc- tion in Pycnarthrum and Gymnochilus ; they are individual and without a definite direction in Microborus. Symbiotic relationships with fungi were not observed. Taxonomy.—The tribe is restricted to the American tropics, except that Microborus boops Blandford was introduced into tropical Africa. Scolytodes and Microborus are closely related to one another. Pycnarthrum and Gymnochilus are remotely related to those genera and to one another. Pycnarthrum could easily be placed in Hylesinini. This tribe occupies a position intermediate be- tween the Scolytini and the more highly evolved tribes in this subfamily. In all mem- bers the outer apical angle of the protibia projects beyond the tarsal insertion, a primi- tive feature shared by primitive members of several other tribes. It is the Ctenophorini protibia, not the type found in Scolytini, that appears to resemble the ancestral type of all 60 GREAT BASIN NATURALIST MEMOIRS scolytids. The eye shape, usually unarmed pronotum, presence of interstriae 10, simple sculpture of the elytra, the elytral locking mechanism, and diversity of habits all suggest that, when considered as a whole unit, this is probably the most primitive of all of the tribes of Scolytidae. It is clearly of neotropical origin and has spread into southern North America only recently. This phyletic line is repre- sented in the Old World by Scolytoplatypo- dini, a group that has diverged significantly in both structure and habits. Key to the Genera of Ctenophorini l. Eyes elongate, approximate above and below, coarsely faceted, shallowly emarginate; entire surface of pronotum smooth and punctured, not ALINE Aces es mecas museca eke eesam ayant 2 — Eye oval, enitre, finely faceted; pronotum as- perate anteriorly or, if smooth, then anterior margin of elytra bearing a fine, raised line ..... $} . Antennal club subglobular, about as long as wide, sutures not clearly indicated; pronotum longer than wide, its lateral margins straight or feebly constricted; vestiture hairlike, usually sparse; small, slender species; phloeophagous; Central and N South America, Jamaica, Africa; DIET Sim mehewectusyerscaercrsi dete ote Microborus — Antennal club asymmetrically _ flattened, pointed, at least 1.5 times as long as wide, su- tures | and 2 clearly marked by setae; pronotum wider than long, its lateral margins arcuate; vestiture of abundant, short, bristlelike scales; larger, stouter species; phloeophagous; Florida and Texas to Brazil; 1.3-2.1 mm .... Pycnarthrum 3(1). Antennal funicle 7-segmented, club large, broad, usually with procurved sutures or su- tures obsolete; elytral vestiture consisting of abundant, minute hair and sparse interstrial rows of long, erect, scalelike bristles; summit of pronotum on basal third, asperities on anterior area coarse; elytral base without a fine, raised line; phloeophagous; Mexico (Puebla) to Brazil and Bolivia; 1.5-2:3mm .......... Gymnochilus — Antennal funicle 6-segmented, club small, su- tures present or not; elytral vestiture sparse (usually), hairlike; pronotal asperities fine, if present; summit at middle or indefinite; basal margins of elytra marked by a fine, raised line; mostly phloeophagous; Florida and Mexico to Argentina; 0.9-3.6mm ............. Scolytodes Microborus Blandford [1897: 175, Type- species: Microborus boops Blandford, mono- basic. Synonym: Pseudocrypturgus Eggers 1919: 236, Type-species: Pseudocrypturgus camerunus Eggers =Microborus boops Blandford, monobasic]. Distribution: 8 spe- cies from Jamaica and Mexico to South Amer- No. 10 ica, 1 (boops) was introduced into tropical Africa. All are monogamous and_phloeo- phagous. Key: Wood (1982: 452) for Central America. Pycnarthrum Eichhoff [1878a: 41, 104, Type-species: Pycnarthrum gracile Eichhoft =Hypoborus (?) hispidus Ferrari, subsequent designation by Hopkins 1914: 128. Synonyms: Nemobius Chapuis 1869: 41, Type-species: Nemobius lambottei Chapuis =Hypoborus (?) hispidus Ferrari, subsequent designation by Hopkins 1914: 128, preoccupied; Monebius Hopkins 1914: 125, Type-species: Nemobius lambottei Chapuis =Hypoborus (?) hispidus Ferrari, automatic; Nomebius Navas 1915: 34, Type-species: Nemobius lambottei Chapuis =Hypoborus (?) hispidus Ferrari, automatic]. Distribution: About 15 species in USA (S Florida) and Mexico to Brazil. All are monoga- mous and phloeophagous. Key: Wood (1982: 455) for North and Central America. Gymnochilus Eichhoff [1868b: 399, Type- species: Gymnochilus zonatus Eichhoff, monobasic. Synonyms: Problechilus Eichhoft 1878a: 46, 167, Type-species: Gymnochilus zonatus Eichhoff, automatic; Meringopalpus Hagedorn 1905: 547, Type-species: Meringo- palpus fallax Hagedorn =Gymnochilus zona- tus Ejichhoff, monobasic]. Distribution: About 14 species in Mexico to Brazil and Bo- livia. All are monogamous and_ phloeo- phagous. Key: Wood 1982: 462) for North and Central America. Scolytodes Ferrari [1867: 77, Type-spe- cies: Scolytodes laevigatus Ferrari, mono- basic. Synonyms: Hexacolus Eichhoff 1868b: 399, Type-species: Hexacolus glaber Eich- hoff, monobasic; Ctenophorus Chapuis 1869: 49, Type-species: Ctenophorus laevigatus Chapuis =Hexacolus levis Blackman, mono- basic; Prionosceles Blandford 1897: 177, Type-species: Prionosceles atratus Blandford, subsequent designation by Hopkins 1914: 128; Epomadius Blandford 1897: 179, Type- species: Epomadius culcitatus Blandford, monobasic; Erineophilus Hopkins 1902: 34, Type-species: Erineophilus schwarzi Hop- kins, original designation; Hylocurosoma Eg- gers 1940: 138, Type-species: Hylocurosoma striatum Eggers, monobasic; Hexacolinus Sched] 1963a: 217, Type-species: Hexacolinus minutissimus Schedl =Scolytodes minutis- simus Sched, original designation; Cryphalo- 1986 philus Schedl 1970b: 358, Type-species: Cryphalophilus afer Schedl, monobasic]. Distribution: 57 species in USA (S Florida) to Panama, about 60 in South America. Both monogamy and polygyny are common in the genus; habits are diverse, but include phloeophagy, myelophagy, and one is xy- lophagous. Eggs are usually placed in clusters in galleries; crude egg niches occur in some species, particularly those that make stellate parental tunnels. Key: Wood 1982: 467) for North and Central America. Tribe Scolytopltypodini Scolytoplatypini Blandford [1893: 425, Type-species: Scolytoplatypus Schaufuss, 1890] Taeniocerini Blandford [1893: 428, Type-genus: Taenio- cerus Blandford, 1893 =Scolytoplatypus Schau- fuss, 1890] Spongocerinae Hagedorn [1909: 162, Type-genus: Spon- gocerus Blandford, 1893 = Scolytoplatypus Schau- fuss, 1890] DESCRIPTION.—Frons dimorphic, male concave, female convex; posterior face of head truncate; eye oval, entire; scape elongate, fu- nicle 6-segmented, club flattened, without sutures; pronotum unarmed, usually con- stricted on posterior half, female with median mycetangium; procoxae widely separated; protibia with outer apical process prominent, recurved, outer margin without socketed denticles; scutellum not visible, except small in one species; basal margins of elytra usually slightly elevated along a continuous costate line. BioLocy.—All are monogamous and _ xy- lomycetophagous. Eggs are deposited in niches. Larvae are reared in individual cra- dles somewhat similar to those of other am- brosia beetles. TAXONOMY.—The unique genus Scolyto- platypus appears to be a highly specialized geographical replacement of the neotropical Scolytodes. It appears to be the only Old World representative derived from the same ancestral stock as the Ctenophorini. A careful study of Scolytoplatypus shows quite clearly how the transition from unsocketed tibial spines to socketed tibial teeth (derived from setae) took place (Wood 1978). This transition occurred well after Platypodidae had _ di- verged from the main ancestral line and after family characters for Scolytidae had been fixed. Woop: GENERA OF SCOLYTIDAE 61 Scolytoplatypus Schaufuss [ 1890: 31, Type- species: Scolytoplatypus permirus Schaufuss, monobasic. Synonyms: Spongocerus Bland- ford 1893: 431, Type-species: Scolytoplatypus tycon Blandford, subsequent designation by Hopkins 1914: 129; Taeniocerus Blandford 1893: 431, 437, Type-species: Scolytoplaty- pus mikado Blandford, subsequent designa- tion by Hopkins 1914: 130; Strophionocerus Sampson 1921: 36, Type-species: Scolyto- platypus mikado Blandford, automatic]. Dis- tribution: 9 species in Africa, 3 in Madagascar, 17 from Asia to Indonesia, New Guinea, and the Philippines. All are monogamous and xy- lomycetophagous. Keys: Browne (1971: 113) for Africa, Sched] (1975: 219) for the genus. Tribe Micracini Micracides LeConte [1876: 346, 367, Type-genus: Mi- cracis LeConte, 1868] Hylocuridae Eichhoff [1878a: 298, 306, Type-genus: Hy- locurus Eichhoff, 1872] DEsCRIPTION.—Frons_ usually dimorphic; either sex may be variously impressed, sculp- tured, or ornamented by setae, female frons often concave, male frons rarely concave (two species); dorsomedian occipital area usually extended slightly caudad; eye oval to elon- gate, entire to sinuate; scape very short to elongate, strongly flattened to slender, orna- mented or not; funicle 6-segmented (5-seg- mented in Miocryphalus , Africa), club with or without sutures; pronotum asperate on ante- rior half, lateral margins rounded, protibia usually with sides parallel, socketed denticles usually confined to apical margin; procoxae usually distinctly separated (contiguous in three African genera); subplumose setae al- most always present. BioLocy.—All American genera are bigy- nous, except that Micracisella is monoga- mous; habits of African genera are largely un- reported. Most species occur in broadleaf trees and shrubs in desert or semidesert ar- eas. Stenoclyptus, Phloeocleptus, and most Pseudothysanoes are phloeophagous; Thysa- noes, Micracis, and Hylocurus are xy- lophagous; the species of Micracisella are myelophagous in small twigs. Details of their life cycle are poorly known, except that the development of most species is very slow. TAXONOMY.—The tribe occurs in North and South America and Africa, with one species in 62 GREAT BASIN NATURALIST MEMOIRS TABLE 2. A comparison of American and African gen- era of Micracini arranged in order of structural complex- ity, with the first member in each cluster forming geo- graphical replacements of one another on the same horizontal line. Other genera in each cluster from the same continent are thought to have been derived from the first member of that cluster. American genera African genera Pseudothysanoes Lanurgus Stenoclyptus Traglostus Thysanoes Saurotocis — Miocryphalus Phloeocleptus Phloeocurus Hylocurus Micracis Pseudomicracis Micracisella N Asia (China). Almost every American genus has a closely allied counterpart in Africa; obvi- ously the generic traits were rather well estab- lished before the faunas were separated prior to early Tertiary, but some modification con- tinued after isolation. The Asiatic Pseu- dothysanoes mongolica (Sokanovskii) was ob- viously derived from American stock much more recently. Because most of the species in this group breed in small twigs and branches of trees and shrubs having little or no eco- nomic importance, they are regarded by forest biologists as scientific curiosities and, consequently, are poorly known. As seen in Table 2, three clusters of genera in this tribe are represented in both America and Africa. The first species in each cluster is a geographical replacement of its counterpart on the other continent, and it is considered to have given rise to the other genera within its own cluster on its own continent. Miocry- phalus is unrepresented in America and is thought to have been derived very early from a specialized representative of the ancestral stock. The allies of this genus or its ancestor could possibly have given rise to ancestral Xyloctonini and Cryphalini. Whereas primitive Micracini appear to be allied to the ancestral stock that produced Carphodicticini, I see no clue as to where these groups connect to more primitive Scolytinae, except that it apparently was near the Ctenophorini. The Micracini appear to be the only possible ancestral group for the Cac- topinini; however, the connection is remote and obscure at best. No. 10 Key to the Genera of Micracini Elytra broadly rounded behind (except sub- acuminate in Pseudothysanoes mucronatus); protibia usually much more slender, less strongly flattened (except Thysanoes); lateral margins of antennal club constricted at sutures 1 and (usually) 2, except when sutures absent (American species) or sutures procurved (African'species) |e)... «5 .cccueperacnaie 2 Elytral apices acuminate (partly lost in some Micracisella), usually mucronate; protibia more strongly flattened, at least apically (ex- ceptions in African species); antennal club without constrictions at sutures, sutures always indicated on anterior face in American species, absent in some African species .............. 7 Pronotum longer than wide, its summit less strongly developed; protibia rather broadly flattened, sides parallel, subtruncate apically; xylophagous; USA to Costa Rica; 1.2-2.3 mm Thysanoes Pronotum as wide or wider than long, summit well developed; protibia slender, weakly or not at all flattened; mostly phloeophagous (some exceptions) |: jc -jusncine cia eee 3 Procoxae contiguous; sutures of antennal club, when present, strongly procurved, suture 1 attaining middle of club; antennal scape short, less than twice as long as club, in female usually as broad as long and ornamented by numerous setae: Africa, 08).0..2s.65. 2 2 eae 4 Procoxae moderately separated (a few subcon- tiguous); sutures of antennal club, when present, straight to moderately procurved, never attaining middle of club; scape elongate except subgenus Aphanocleptus (Pseudothysa- noes), its vestiture usually rather sparse; AMERICAN osha wis terior setae eae Ree ee 6 Antennal club with sutures present, marked by setae; female mandibular and declivital spines absent; female frons concave to convex; phloeophagous; Madagascar and Africa; 1.1- PST iieebit ely om ee A AS EU EB aca 6S Lanurgus Antennal club finely, uniformly, rather densely pubescent, sutures obsolete; female fFONS CONCAVE! wi. wise ates Fayre cote eee TCE 5 Antennal funicle 6-segmented; mandible bear- ing one or more very long, slender spines di- rected dorsad; female declivity armed on inter- striae 1 at base of declivity by a prominent spine; Africa; 2.2 mm Traglostus Antennal funicle 5-segmented; mandible nor- mal; declivity unarmed; Africa; 1.3-2.5mm .. Aitiale Coe diesy coe dshapcnn oben seeds ReeeA eRe Miocryphalus Elytral declivity in both sexes variously sculp- tured but never sulcate; antennal scape long or short, club with or without sutures; mostly phloeophagous, a few xylophagous; North and South America, | in China; 0.7-2.0 mm PRT Memo escent ine icc Pseudothysanoes 1986 10(9). 11(9). 12(7). Woop: GENERA OF SCOLYTIDAE Elytral declivity bisulcate, subvertical; anten- nal scape short, flattened, little if any longer than pedicel, club small, widest through basal half, sutures | and 2 straight, indicated by rows of setae; phloeophagous; USA (California) and Mexico (Oaxaca); 1.0-1.5mm...... Stenoclyptus Eye short, oval, not more than 1.5 times as long as wide (except up to 3.0 times in Phloeocurus , Africa), finely faceted; antennal club small, su- tures straight to weakly procurved or bisinuate (South American Hylocurus with strongly pro- curved sutures and with posterior face of pro- tibia tuberculate); protibia rather slender, Wwidemapicall ye mancicd