All species-group names of Trachypachidae, Rhysodidae, and Carabidae (including cicindelincs) correctly recorded from America north of Mexico are catalogued with state and province records. Valid names are listed with the author(s), date of publication, and page citation in their current and original combinations while all synonyms are provided in their original combinations. Genus-group names are recorded with the author(s), date of publication, page citation, type species, and kind of type species fixation. Species groups were preferred to subgenera but subscneric names are also listed.The following nomenclatural changes are proposed and discussed: Bembidion neocoerulescens Bousquet, new replacement name for B. coerulescens Van Dyke, 1925; Chlaenius circumcinctus Say, 1830 for C. perplexus Dejean, 1831; Cyclotrachelus dejeanellus (Csiki, 1930) for C. morio (Dejean, 1828); Cyclotrachelus freitagi Bousquet, new replacement name for C. obsoletus (Say, 1830); Dyschirius aeneolus LeConte, 1850 for D. frigidus Mannerheim, 1853; Harpalus laevipes Zetterstedt, 1828 for H. quadripunctatus Dejean, 1829; Harpalus providens Casey, 1914 for H. viduus LeConte, 1865; Harpalus reversus Casey, 1924 for H. funerarius Csiki, 1932; Notiophilus sierranus Casey, 1920 for N. obscurus Fall, 1901; Pseudamara Lindroth, 1968 for Disamara Lindroth, 1976; Pterostichus trinarius (Casey, 1918) for P. ohionis Csiki, 1930; Stenolophus carbo Bousquet, new replacement name for S. carbonarius (Dejean, 1829).Thirty-six new synonyms are established and seven, considered as questionable, are confirmed. They are (with the valid names in parentheses): Agonothorax planipennis Motschulsky, 1850 (= ? Agonum affine Kirby, 1837); Platynus variolatus LeConte, 1851 (= Agonum limbatum Motschulsky, 1845); Agonum nitidum Harris, 1869 (= ? Agonum melanarium Dejean, 1828); Amerinus fuscicornis Casey, 1914 and A. longipennis Casey, 1914 (= Amerinus linearis (LeConte, 1863)); Apristus fuscipennis Motschulsky, 1864 (= Apristus latens LeConte, 1848); Batenus aeneolus Motschulsky, 1865 (= Agonum exaratum (Mannerheim, 1853)); Brachystylus curtipennis Motschulsky, 1859 (= Pterostichus congestus (Ménétriés, 1843)); Brachystylus parallelus Motschulsky, 1859 (= ? Pterostichus californicus (Dejean, 1828)); Cratacanthus cephalotes Casey, 1914, C. subovalis Casey, 1914, and C. texanus Casey, 1884 (= Cratacanthus dubius (Palisot de Beauvois, 1811)); Cymindis comma T.W. Harris, 1869 (= ? Cymindis limbatus Dejean, 1831); Feronia praetermissa Chaudoir, 1868 (= Pterostichus commutabilis (Motschulsky, 1866)); Galerita angusticeps Casey, 1920 (= Galerita janus (Fabricius, 1792)); Gonoderus cordicollis Motschulsky 1859 (= Pterostichus tristis (Dejean, 1828)); Anisodactylus alternans LeConte, 1851 (= Anisodactylus alternans (Motschulsky, 1845)); Hypherpes spissitarsis Casey, 1918 (= Pterostichus tarsalis LeConte, 1873); Lebia brunnicollis Motschulsky, 1864 (= Lebia lobulata LeConte, 1863); Lebia subfigurata Motschulsky, 1864 and L. sublimbata Motschulsky, 1864 (= Lebia analis Dejean, 1825); Lophoglossus bispiculatus Casey, 1913 and L. illini Casey, 1913 (= Lophoglossus scrutator (LeConte, 1848)); Platysma leconteianum Lutshnik, 1922 (= Pterostichus commutabilis (Motschulsky, 1866)); Loxandrus iris Motschulsky, 1866(= Loxandrus rectus (Say, 1823)); Masoreus americanus Motschulsky, 1864 (= Stenolophus rotundicollis (Haldeman, 1843)); Notaphus laterimaculatus Motschulsky, 1859 (= Bembidion approximatum (LeConte, 1852)); Notiophilus cribrilaterus Motschulsky, 1864 (= Notiophilus novemstriatus LeConte, 1848); Omaseus brevibasis Casey, 1924 (= Pterostichus luctuosus (Dejean, 1828)); Notaphus incertus Motschulsky, 1845 (= Bembidion breve (Motschulsky, 1845)); Peryphus concolor Motschulsky, 1850 (= Bembidion platynoides Hayward, 1897); Peryphus erosus Motschulsky, 1850 (= Bembidion transversale Dejean, 1831); Peryphus subinflatus Motschulsky, 1859 (= Bembidion petrosum petrosum Gebler, 1833); Planesus fuscicollis Motschulsky, 1865 and P. laevigatas Motschulsky, 1865 (= Cymindis platicollis (Say, 1823)); Poecilus pimalis Casey, 1913 (= Poecilus diplophryus Chaudoir, 1876); Pterostichus arizonicus Schaeffer, 1910 (= Ophryogaster flohri Bates, 1882); Pterostichus sequoiarum Casey, 1913 (= Pterostichus tarsalis LeConte, 1873); Scaphinotus grandis Gistel, 1857 (= ? Scaphinotus unicolor unicolor (Fabricius, 1787)); Stenocrepis chalcas Bates, 1882 and S. chalcochrous Chaudoir, 1883 (= Stenocrepis texana (LeConte, 1863)); Stenolophus humeralis Motschulsky, 1864 (= Stenolophus plebejus Dejean, 1829); and Stenolophus laticollis Motschulsky, 1864 (= Stenolophus ochropezus (Say, 1823)).Olisthopus iterans Casey, 1913 and Pterostichus illustris LeConte, 1851, listed as junior synonyms of O. parmatus (Say, 1823) and P. congestus (Ménétriés, 1843), respectively, are considered in the present work as valid species.The type species (listed in parentheses) of the following 14 genus-group taxa are designated for the first time: Circinalidia Casey, 1920 (Agonum aeruginosum Dejean, 1828); Evolenes LeConte, 1853 (Oodes exaratus Dejean, 1831); Leucagonum Casey, 1920 (Agonum maculicolle Dejean, 1828); Megaliridia Casey, 1920 (Cychrus viduus Dejean, 1826); Megalostylus Chaudoir, 1843 (Feronia lucidula Dejean, 1828 = Feronia recta Say, 1823); Micragra Chaudoir, 1872 (Micragra lissonota Chaudoir, 1872); Onota Chaudoir, 1872 (Onota bicolor Chaudoir, 1872); Oodiellus Chaudoir, 1882 (Oodiellus mexicanus Chaudoir, 1882 = Anatrichis alutacea Bates, 1882); Oxydrepanus Putzeys, 1866 (Dyschirius rufus Putzeys, 1846); Paranchomenus Casey, 1920 (Platynus stygicus LeConte, 1854 = Anchomenus mannerheimii Dejean, 1828); Pemphus Motschulsky, 1866 (Cychrus velutinus Ménétriés, 1843); Peronoscelis Chaudoir, 1872 (Tetragonoderus figuratus Dejean, 1831); Rhombodera Reiche, 1842 (Rhombodera virgata Reiche, 1842 = Lebia trivittata Dejean, 1831); and Stenous Chaudoir, 1857 (Oodes cupreus Chaudoir, 1843).Two new family-group names are proposed, Cnemalobini (= Cnemacanthini of authors) based on Cnemalobus Guérin-Méneville, 1839 and Loxandrini based on Loxandrus LeConte, 1852.The work also includes a synopsis of all extant world carabid tribes, a bibliography of all original descriptions, a full taxonomic index, and, as appendices, lists of nomina nuda and unjustified emendations, and annotated lists of species incorrectly or doubtfully recorded from America north of Mexico and of new North American records.

The subfamily Inostemmatinae is considered a symplesiomorphic assemblage and the genera currently classified here are reassigned either to the subfamily Platygastrinae or the Sceliotrachelinae. Forty-one genera are treated, of which 15 are classified in the Platygastrinae, viz. Acerotella Masner, Aceroteta Kozlov and Masner, Allostemma gen.nov., Almargella gen.nov., Annettella gen.nov., Inostemma Haliday, Iphitrachelus Walker, Isostasius Foerster, Magellanium gen.nov., Metaclisis Foerster, Orseta gen.nov., Proplatygaster Kieffer, Rao gen.nov., Sacespalus Kieffer, and Zelostemma gen.nov. Twenty-six genera are classified in the subfamily Sceliotrachelinae, viz. Afrisolia gen.nov., Aleyroctonus gen.nov., Alfredella gen.nov., Allotropa Foerster, Amitus Haldeman, Aphanomerella Dodd, Aphanomerus Perkins, Austromerus gen.nov., Calomerella gen.nov., Errolium gen.nov., Fidiobia Ashmead, Helava gen.nov., Isolia Foerster, Nanomerus gen.nov., Neobia gen.nov., Oligomerella gen.nov., Parabaeus Kieffer, Platygastoides Dodd, Platystasius Nixon, Plutomerus gen.nov., Pseudaphanomerus Szelényi, Pulchrisolia Szabo, Sceliotrachelus Brues, Tetrabaeus Kieffer, Zelamerus gen.nov., and Zelandonota gen.nov. The following extant taxa are described: Afrisolia obesa gen.nov., sp.nov. ♀ (South Africa), Aleyroctonus pilatus gen.nov., sp.nov. ♀ ♂ (Java), Alfredella tasmanica gen.nov., sp.nov. ♀ ♂ (Australia),Allostemma fuscum gen.nov., sp.nov. ♀ ♂ (Chile), Almargella cristata gen.nov., sp.nov. ♀ ♂ (Chile), Annettella gracilis gen.nov., sp.nov. ♀ ♂ (New Zealand), Austromerus grandis gen.nov., sp.nov. ♀ ♂ (Australia), Calomerella scutellata gen.nov., sp.nov. ♀ (USA, Canada), Errolium piceum gen.nov., sp.nov. ♀ (New Zealand), Helava alticola gen.nov., sp.nov. ♀ ♂ (Colombia, Venezuela, Peru), Magellanium furviceps gen.nov., sp.nov. ♂ (Chile), Nanomerus spinulus gen.nov., sp.nov. ♀ (Chile), Neobia badia gen.nov., sp.nov. ♀ (Venezuela, Colombia, Ecuador, Trinidad [W.I.]), Oligomerella donnae gen.nov., sp.nov. ♀ (Australia), Orseta ornate gen.nov., sp.nov. ♀ ♂ (Canada), Plutomerus gen.nov. for Platygastoides indicus Mukerjee ♀ (India, Nepal), Rao pselaphus gen.nov., sp.nov. ♀ ♂ (Australia), Zelamerus amicorum gen.nov., sp.nov. ♀ ♂ (New Zealand), Zelandonota kiwi gen.nov., sp.nov. ♀ ♂ (New Zealand), and Zelostemma gen.nov. for Eurytoma oleariae Maskell ♀ ♂ (New Zealand). Fahringeria Kieffer is considered junior synonym of Fidiobia Ashmead; Nasdia Nixon and Platytropa Kozlov are considered junior synonyms of Allotropa Foerster. The above 41 genera are keyed, with separate keys to world genera and genera of America north of Mexico; with generic diagnoses, taxonomic remarks, distribution, biology, bibliography, and list of species described since Kieffer (1926). Higher classification and relationships of the above genera are discussed. Eighty-one plates with 258 figures (line drawings and micrographs) are included.

A great proportion of biodiversity is accounted for by organisms, particularly insects, intimately associated with plants. Knowing whether ecological or phylogenetic factors chiefly influence the evolution of host plant associations is essential to understanding speciation in, and therefore factors influencing diversity of, phytophagous insects. Through examination of known host plant associations in Curculioninae and comparison with available reconstructed phylogenetic relationships of certain taxa of Curculioninae, little, if any, evidence for cospeciation (parallel cladogenesis) is found. In curculionine taxa where sufficient host plant and/or phylogenetic data are available, weevil species are narrowly to broadly oligophagous; a number of related weevil species are associated with a single host plant species; many weevil genera have host plant ranges spanning distantly related plant taxa; and available weevil reconstructed phylogenies are not concordant with plant relationships. Rather, for at least some weevil taxa, evolution appears to be mediated by one or more of a variety of strictly ecological factors, particularly habitat associations. General applications of these results include biological control, pollination biology, conservation and restoration biology, and use of patterns in insect – host plant associations to resolve problems in plant classification.

Four research programmes are investigating the entomopathogenic fungal genera Metarhizium and Beauveria for locust and grasshopper control in Africa. In the LUBILOSA programme, surveys for pathogen isolates revealed a morphologically distinctive Metarhizium flavoviride Gams and Rozsypal attacking acridoids in West Africa, Madagascar, and elsewhere. Metarhizium anisopliae (Metschnikoff) Sorokin isolates with virulence to acridoids were also obtained, including several from non-orthopteran hosts. Natural epizootics of both genera are rare in acridoid populations, but do occur. A standardized screening method discriminated virulent from non-virulent isolates. The great majority of the most virulent isolates were from the acridoid group of M. flavoviride. A Niger isolate chosen for development from this group had low virulence to honey bees and parasitic Hymenoptera and was not infective to insects in several other orders. Field tests were carried out on formulations of oil mixtures, using ULV application rates of 1–2 L/ha and 2–5 × 1012 conidia per hectare. In preliminary tests, target insects were sprayed successfully in small field arenas and in large cages. Trials in 1993 on variegated grasshopper gave an approx. 90% reduction in field populations after 15 days. Trials on various acridids, predominantly Hieroglyphus daganensis Krauss, in dense grass in northern Benin showed slower mortality, although up to 70% population reduction was achieved. Trials using a vehicle-mounted ULV sprayer (the Ulva-Mast) in open grassland in Niger gave >90% mortality in samples of mixed acridids. In Mali, a Malian isolate of M. flavoviride was shown to be slightly more virulent than the standard Niger isolate; both isolates gave significant population reductions against nymphs of Oedaleus senegalensis Krauss and Kraussella amabile (Krauss) in 1-ha plots. Successful small-scale field trials have also been carried out using the standard M. flavoviride isolate in South Africa against brown locust and in Australia using an Australian isolate against wingless grasshopper. In Mauritania, a trial using the Niger isolate against desert locust nymph bands gave up to 90% mortality in caged samples by day 9 after spraying. The uncaged treated bands were completely destroyed by predators while untreated bands fledged. Oil-based ULV formulations of M. flavoviride are capable of causing high mortality in the field populations of all acridoids against which they have been field tested and show great promise for development as components of IPM strategies for these pests.

Assemblages of carabid beetles occurring in anthropogenic habitats in western Canada include native and introduced species. In this study, about 70% of the native species encountered in anthropogenic habitats have their main centres of abundance in native grassland. Twenty species known from British Columbia are of recent European origin. These species were probably introduced in ballast carried by commercial sailing vessels or in shipments of nursery stock. The species that have successfully colonized western Canada cannot be distinguished from a random sample of the estimated source fauna with respect to either taxonomic distribution or body size. However, all introduced species are characteristic of disturbed and/or anthropogenic habitats in Great Britain and are strictly synanthropic in British Columbia. Where they occurred, introduced species were usually numerically dominant members of anthropogenic assemblages. Both flight and human-assisted transport must be invoked to explain the patterns of range expansion observed for introduced species. Although the presence of introduced species was correlated with reduced diversity of native species, the carabid fauna of western Canada has been generally enriched because only one native species is strictly synanthropic.

The species of the genus Ontherus, endemic to Latin America, are revised. A key in English and Spanish for the identification of adults of the 58 recognized species is provided. Three subgenera are recognized (Caelontherus nov., Planontherus nov. and Ontherus s.str.). The following 29 species are described as new: O. hadros, O. magnus, O. gilli, O. ashei, O. politus, O. sanctaemartae, O. tenuistriatus, O. obliquus, O. howdeni, O. diabolicus, O. pilatus, O. sextuberculatus, O. lunicollis, O. monilistriatus, O. pseudodidymus, O. rectus, O. pubens, O. ulcopygus, O. cambeforti, O. raptor, O. planus, O. edentulus, O. rectangulidens, O. lobifrons, O. androgynus, O. amplector, O. atlantidis, O. insolitus, O. stridulator. The following new synonymies are proposed (the first specific name being valid): O. kirschii Harold = O. elongatus Waterhouse; O. alexis (Blanchard) = O. didymus Erichson = O. glaucinus Erichson = O. nevinsoni Waterhouse; O. incisus (Kirsch) = O. thoracicus Waterhouse; O. azteca Harold = O. villosus Luederwaldt = O. strius Howden and Young; O. cephalotes Harold = O. quadrituberculatus Luederwaldt. The variety O. zikani var. carinicollis Luederwaldt is now recognized as a valid species. Species are arranged into groups according to their phylogenetic relationship, with a brief diagnosis given for each of the 11 groups of species. The following information is given for each species, when appropriate: detailed literature review, synonymy, description or redescription, illustration of important morphological characters, data of material studied, and geographic distribution.

In a sense, this book is an expanded version of an earlier work by this author entitled “The Siphonaptera of Canada”, published in 1949. It is extended beyond the political confines of this country and includes treatment of the fauna of Alaska and Greenland, as well as much new distributional information on the fleas of Canada, especially the Canadian north. This latter was made possible by the Northern Insect Survey (1947-1962), mostly directed by the late Dr. T.N. Freeman, which involved the establishment of about 80 field parties in the Arctic and Subarctic Regions of Canada, Alaska and Greenland.A section on flea anatomy in relation to taxonomy is followed by a key to the genera. Then the six families and 15 sub-families, 60 genera and subgenera, and 183 species and subspecies, of fleas are carefully described and illustrated. Under the description of each species is a detailed listing of all specimens available to the author, West to East. This is followed by a host-flea index providing a taxonomic list of all the species of mammals and birds from which fleas have been taken. Distribution maps have been prepared illustrating all the collection records of flea species. Sometimes the known ranges of mammal hosts are included, where there is evidence of a strong host association.

The systematic position of the Piophilidae sens. lat. within a group of nine schizophorous families with tephritid-like ovipositors (Lonchaeidae, Otitidae, Platystomatidae, Pyrgotidae, Tephritidae, Tachiniscidae, Richardiidae, Pallopteridae, and Piophilidae) is elucidated. It is shown to be a sister-group of the Pallopteridae, and these two families together with the Richardiidae comprise a monophyletic suprafamily unit within the larger group of families. The evolutionary changes that occurred within the Piophilidae are analyzed and the supposed phylogeny of its component taxa is portrayed. The family is redefined to include neottiophilids and thyreophorids and is classified into two subfamilies, Neottiophilinae and Piophilinae; the latter is divided into two tribes, Mycetaulini and Piophilini (with subtribes Piophilina and Thyreophorina). Twenty-three genera are recognized and taxonomically defined; this includes description of two new genera, Neopiophila and Parapiophila. Clusina Curran is synonymized withProtopiophila Duda (new synonymy), and four nominal species are placed in synonymy for the first time, i.e. Piophila anomala Malloch and Piophila setosa Melander and Spuler = Parapiophila vulgaris (Fallén) (new synonymy), Piophila flavifacies Brunetti = P. casei (Linnaeus) (new synonymy), and Mycetaulus pulchellus Banks = Mycetaulus longipennis Loew (new synonymy). Six new species, Actenoptera avalona (Newfoundland), Neopiophila setaluna (Northwest Territories), Protopiophila atrichosa (Peru and British Honduras), Protopiophila pallida (Peru and British Guiana), Prochyliza azteca (Mexico), and Prochyliza inca (Peru) are described. The following 20 new combinations are made: Mycetaulus lituratus (Melander and Spuler), Allopiophila testacea (Melander), Protopiophila nigriventris (Curran), Prochyliza lundbecki (Duda), nigricornis (Meigen), nigricoxa (Melander and Spuler) and nigrimana (Meigen), Arctopiophila arctica (Holmgren), Parapiophila atrifrons (Melander and Spuler), calceata (Duda), coerulescens (Zetterstedt), dudai (Frey), flavipes (Holmgren), lonchaeoides (Zetterstedt), nitidissima (Melander and Spuler), pectiniventris (Duda), penicillata (Steyskal), vulgaris (Fallén), and xanthopoda (Melander and Spuler). In all, 67 valid species are placed, their geographic distributions are outlined, and the zoogeographic implications are discussed. A lectotype is designated for Piophila flavitarsis Meigen = Madiza glabra Fallén (Milichiidae).A key to subfamilies, tribes, and genera is provided, and keys to world species are given where needed. An annotated world list of all names referred to the family (sens. lat.) is provided. The paper includes 58 figures, two tables, and 122 literature references.

A revision of the species in the genus Pityophthorus Eichhoff in North and Central America is presented. The limits of Pityophthorus are expanded to include the species previously placed in Gnatholeptus Blackman. This unit is maintained as a subgenus. One additional subgenus is described, Hypopityophthorus, for P. debilis Wood and P. inops Wood. The genus contains 220 species in North and Central America. The principal subgenus Pityophthorus is divided into 47 species groups. New species are: micans (Mexico), sapineus (Mexico), miniatus (Honduras, Guatemala, and Mexico), pubifrons (Mexico), and acceptus (British Columbia, Wyoming). New synonymy is proposed as follows: P. deletus LeConte (= P. dolus Wood); P. exquisitus (Blackman) n. comb. (= P. inceptis Wood); P. intextus (= P. ornatus Blackman and P. limatus Wood); P. balsameus Blackman (= P. angustus Blackman) and P. indigens Wood (= P. irritans Schedl). Five species are given new status as subspecies: P. tuberculatus Eichhoff as a subsp. of P. pulchellus Eichhoff; P. subopacus Blackman as a subsp. of P. segnis Blackman; P. bellus Blackman as a subsp. of P. confusus Blandford; P. agnatus Blackman as a subsp. of P. confertus Swaine, and P. aurulentus Bright as a subsp. of P. murrayanae Blackman.The monograph includes an historical review, a discussion of diagnostic characters, and a discussion of the general biology of species in the genus. Keys to subgenera, species groups, and species are provided. Each species is described and many are illustrated, and all known bionomic and distributional data are included. Distribution records of many species are mapped.

The subfamily Ceratopogoninae (sensu Wirth, 1965a) is probably a natural (monophyletic) group but includes both blood sucking forms (Culicoidini) and predators on small insects. The insectivorous forms consist of a diversified array of six tribes and many genera represented in moist habitats throughout the world and especially abundant at lake margins.Many predator/prey observations are recorded. The prey consists almost exclusively of the males of other Nematocera or the smaller Ephemeroptera, which the female captures in flight by entering the male (mating) swarms of these insects and hovering until in a position to strike. The initial response is to the swarm-determining landmark, and the female hovers there whether or not potential prey is in flight; groups of hovering females can be induced artificially by suitable markers. These midges themselves form male swarms which the female enters for mating, and the unique method of hunting thus follows a pattern of behaviour already established in relation to another function. The insectivorous tribes have probably been derived from the more plesiomorphic Culicoidini, but the stages in the development of their radically different manner of hunting are not clear.The characteristic form of the mouthparts in the insectivorous genera is described and figured. The prey, after capture in flight, is usually held by the raptorial legs and quickly perforated by the mandibles. A proteolytic saliva is injected and the cellular tissue, except in the longer appendages, is liquefied and sucked out. In most species a single prey individual is not sufficient for one ovarian cycle, and the midge feeds several times. There is some degree of prey specificity, based at least in part on specific responses to the swarm-marker. In several genera there are long tubular "glands" in the abdomen, often everted in flight, whose function is not clearly established. Mobbing of the predator by the intended prey (mosquitoes) is described.The distinctive feature of mating is that the female, in addition to her other prey, often eats the male during mating. Nearly all the records come from the three tribes Heteromyiini, Sphaeromiini, and Palpomyiini. In these tribes (which probably form a relatively apomorphic monophyletic group) the male is usually a dwarf, and the plumose (auditory) antenna is more or less strongly reduced. It is suggested that the female remains in hunting phase when entering her conspecific swarm and captures the male as prey, and that the typical auditory recognition of female by male has become reduced or vestigial. In the more plesiomorphic tribes Ceratopogonini and Stilobezziini the male is normal in size and the antennal plume is fully developed, as in Culicoides, and there are only two records, at most, of the male being eaten during mating.The males eaten during mating are pierced through the head and reduced to an empty cuticle by the action of the lytic saliva. The terminalia however retain their hold, perhaps because of the early destruction of the suboesophageal ganglion, and the dry male cuticle often breaks away leaving the terminalia still attached. The structure of the terminalia and the mating position is described and discussed. Insemination is by spermatophore, which if the male is eaten never leaves the male duct. The terminalia of the male are inverted during mating and in some genera become so permanently early in adult life.An attempt is made throughout to view the phenomena in a phylogenetic context.Numerous illustrations are provided.

A revised generic classification of world Syrphini is proposed. It is based on a study of characters of the adults of 318 described species plus approximately 85 more species as yet either undescribed or unidentified. Thirty-seven genera are recognized; keys to these genera, and to the smaller number of genera known from each of the major zoogeographic regions (except the eastern Palaearctic and Oriental) are presented. Eight new genera, Notosyrphus (South America), Exallandra (Ethiopian Region), Citrogramma (Oriental Region and Australia), Dideomima (Mexico), Hermesomyia (Ecuador), Pseudoscaeva (North and South America), Antillus (Haiti), and Giluwea (New Guinea), and two new subgenera, Melangyna (Austrosyrphus) (Australia and New Zealand) and M. (Melanosyrphus) (New Guinea), are described. Nine new species, in Melangyna (Melanosyrphus), Citrogramma, Hermesomyia, Antillus, and Giluwea, are described. The genus Orphnabaccha is transferred from the tribe Bacchini to the Syrphini, and the genus Toxomerus (including Mesograpta) is referred to the tribe Toxomerini. Maps showing the world distribution of each genus and subgenus, and figures of the male terminalia of the type-species of almost all genera and subgenera, are presented.The peculiar nature of the Neotropical fauna of Syrphini, with almost all species belonging to two large and very diverse genera, is compared with the situation in the rest of the world, where in most major regions the Syrphini consist mostly of a moderate number of medium-sized genera each of which shows much less diversity. Possible reasons for this difference, and for the great preponderance of more primitive Diptera among those with apparent transantarctic relationships, are suggested.