Family REDUVIIDAE
Introduction
The Reduviidae, or assassin bugs, are a family of predaceous cimicomorphan bugs which have a cosmopolitan distribution. The family presently comprises 961 genera and 6601 species, including the Phymatinae and Elasmodeminae (Maldonado Capriles 1990; Froeschner & Kormilev 1989; Zoological Record 1988–1994).
Assassin bugs are small to very large, with the body form varying from elongate and slender to robust and ovoid. The head has a transverse furrow on the vertex, often with a postocular constriction. The eyes are large, mesally placed, and removed from the pronotum. Ocelli are usually present behind the eyes but are lacking in the Emesinae, Saicinae and Tribelocephalinae. The antennae are 4-segmented and usually slender. The characteristic labium is most often short, robust, conspicuously arcuate, and removed from the body. These states are secondarily lost in the Triatominae and some harpactorines, which have the labium more elongate and flexible. The pronotum is variable, often with lateral constrictions, and/or modifications, such as processes or swellings. The scutellum is triangular and sometimes has processes. The prosternum generally has a transverse stridulatory groove. The metathoracic glands are either absent, reduced or are divided without accessory glands. Two other types of exocrine glands may be present: Brindley's glands of the first abdominal segment, and ventral glands which are small sac-like glands at the junction of the thorax and abdomen (Aldrich 1988). The forewings do not have a corial fracture and the membrane usually has two cells. Wing polymorphism is common with aptery, brachyptery and microptery known in most subfamilies. The hind wings are variable but are usually characterised by a distinct subcostal vein and two secondary veins (Davis 1961). In some reduviids, the fore- and sometimes mesotibiae, have spongy, setose pads known as fossulae spongiosae. The tarsi are usually 3-segmented, although Physoderinae and the extralimital Phymatinae have 2-segmented tarsi. The abdomen has connexiva and the first abdominal spiracle is usually present. The male pygophore is often withdrawn and not visible from above. In the male, the phallus is membranous with a pair of basal struts. The females have a plate-like ovipositor and pseudospermathecae—a pair of ectodermal glands at the base of the common oviduct that store sperm (Slater 1982).
The Reduviidae and the extralimital Pachynomidae belong to the superfamily Reduvioidea (Schuh 1986). Carayon & Villiers (1968) originally proposed this classification on the basis of the divided metathoracic glands and the male genitalia. Cobben (1978) considered the pachynomids as most closely related to the Nabidae, and placed the Reduviidae in their own infraorder, the Reduviomorpha. Schuh & Stys (1991) placed the Reduviidae (plus Pachynomidae) as the most basal group of Cimicomorpha, on the basis of characters of the antennal trichobothria, pseudospermathecae and labium.
The suprageneric classification of the Reduviidae is conjectural. Maldonado Capriles (1990) lists 32 known subfamily names but recognised only 25 as valid. Much of the modern work follows the classification of China & Miller (1959). Putshkov & Putshkov (1985) recognised only 21 subfamilies in their catalogue of the world's genera. The classification of Maldonado Capriles (1990) is mostly followed in the Catalogue, but the Visayanocorinae, synonymised with the Saicinae by Maldonado Capriles (1990), are retained in the Catalogue, following Carver et al. (1991).
Thirteen reduviid subfamilies, 100 genera and 226 species are represented in the Australian fauna. The subfamilies are: Ectrichodiinae (7 genera/7 species), Emesinae (19/45), Harpactorinae (33/72), Holoptilinae (5/16), Peiratinae (3/20), Physoderinae (1/2), Reduviinae (14/27), Saicinae (2/7), Stenopodainae (11/24), Tegeinae (1/1), Triatominae (1/1), Tribelocephalinae (1/2) and Visayanocorinae (2/2). A useful key to these subfamilies is provided by Carver et al. (1991).
The Ectrichodiinae are one of the most speciose reduviid subfamilies, with 111 genera and 643 species worldwide (Maldonado Capriles 1990). The subfamily is known from all major zoogeographic regions but has its greatest diversity in the Old World tropics and the Neotropical Region. Cook (1977) revised the Oriental ectrichodiines and provided keys and a checklist. In Australia, the Ectrichodiinae are represented by seven monotypic genera, mostly described by Miller (1952, 1957). They are often strikingly coloured, most are nocturnal and ground-dwelling.
The Emesinae, or thread-legged bugs, are a cosmopolitan subfamily which has received considerable taxonomic attention. Maldonado Capriles (1990) recognised 92 genera and 918 species worldwide. Wygodzinsky (1966) monographed the world fauna, including species descriptions, keys, phylogenetic discussion, and extensive illustrations. Wygodzinsky (1956) also reviewed the Australian emesine fauna. Wygodzinksy (1966) recognised six tribes, four of which are represented in Australia. Eighteen genera and 45 species of emesines occur in Australia, with species of Stenolemus Signoret, Ploiaria Scopoli and Pseudobargylia Wygodzinsky commonly encountered. The Emesinae are nocturnal; most live on plants, although some species are known from caves, spider webs and psocid webs. Wygodzinsky (1966) reported emesines as predators of insects and spiders. Hickman (1969) recorded Stenolemus edwardsii Bergroth and Empicoris rubromaculatus (Blackburn) feeding on psocids, and spiders and associated with their webs.
The Harpactorinae are the most diverse reduviid subfamily with 288 genera and 2059 species worldwide (Maldonado Capriles 1990). They are best characterised by the quadrate cell of the forewing and the elongate first antennal segment. The tribal classification of the Harpactorinae remains conjectural (Davis 1969) and Maldonado Capriles (1990) did not use a tribal classification. Malipatil (1988) recognised the Dicrotelini as a harpactorine tribe, represented in Australia by seven genera (Arrilpecoris Malipatil, Barlireduvius Malipatil, Dicrotelus Erichson, Karlacoris Malipatil, Nyllius Stål and Paranyllius Miller). Due to the present inadequacies of the harpactorine tribal classification no tribes are used in the Catalogue. The Australian Harpactorinae are represented by 33 genera and 72 species. Malipatil (1991) provided a generic overview of Australian Harpactorinae, including 31 genera and 68 species, keys, checklists and new synonymies. In a series of papers, Malipatil, revised the species of Helonotus Amyot & Serville (Malipatil 1986a), Pristhesancus Amyot & Serville (Malipatil 1986b) and the Dicrotelini (Malipatil 1986c). Harpactorines are diurnal, sit-and-wait predators, and are frequently found on angiosperms. Pristhesancus and Helonotus species are known to feed on lepidopteran larvae as well as on other heteropterans. Pristhesancus plagipennis Walker feeds on bees and causes notable mortality in commercial apiaries (McKeown 1942). Hawkeswood (1990) described the biology of this species, extending its host range to include butterflies, buprestids and flies.
The Holoptilinae comprise 15 genera and 76 species worldwide and are most diverse in the Old World tropics (Maldonado Capriles 1990). Wygodzinsky & Usinger (1963) revised the world classification and recognised two tribes, the Aradellini and Holoptilini, both of which are represented in Australia. They are diagnosed by a depressed body with thick rigid setae. Malipatil (1985) revised the Australian Holoptilinae and recognised five genera and 16 species. Holoptiline biology is poorly known, although a number of species are known to feed on ants. Ptilocnemus Walker species attract and paralyse ants with trichome secretions (Miller 1956).
The Peiratinae are a cosmopolitan subfamily, presently comprising 31 genera and 47 species (Maldonado Capriles 1990). The peiratines are represented in Australia by the genera, Ectomocoris Mayr, Peirates Serville and Sirthenea Spinola. The classification of Peirates is conjectural, with numerous authors recognising subgenera, some of which are considered to be separate genera (Maldonado Capriles 1990). In the Catalogue, we have included these subgenera in the generic synonymy, but have not utilised them in the arrangement of species. Peiratine species usually have a robust body form and are mostly ground dwelling.
The Reduviinae are a large cosmopolitan subfamily of 138 genera and 977 species (Maldonado Capriles 1990). It is a composite group presently defined by a combination of character states, including the absence of a discal cell in the forewing. The subfamily is represented in Australia by 14 genera and 27 species, most of which were described by Miller (1951, 1957, 1958, 1959). Most reduviines are generalist predators and some are associated with humans and stored products (Miller 1956).
The Saicinae are tropicopolitan, fragile and have long legs. The subfamily presently comprises 24 genera and 139 species worldwide (Maldonado Capriles 1990). Malipatil (1990) revised the Australian fauna which includes representatives of two genera, Polytoxus Spinola (4 species) and Micropolytoxus Elkins (3 species).
The Stenopodainae are a large subfamily of 114 genera and 724 species worldwide, and are found in all major zoogeographic regions (Maldonado Capriles 1990). Stenopodaines are narrow, small to large species. Two tribes, the Dulitocorini and Stenopodaini, 11 genera and 24 species are represented in the Australian fauna. The cosmopolitan genus Oncocephalus Klug is the most speciose genus and is represented Australia by nine species. Maldonado Capriles (1990) transferred the Australian endemic genus Centrogonus Bergroth to Reduviinae. This is not followed in the Catalogue and Centrogonus is retained in the Stenopodainae, pending a much needed revision of the subfamily in Australia.
The remainder of the described Australian reduviid fauna is placed in five subfamilies: Physoderinae (two species of Physoderes Westwood from Christmas Island); Tegeinae (Tegea atropicta Stål, a specialised termite predator); Tribelocephalinae (two species of Opistoplatys Westwood); Visayanocorinae (Carayonia Villiers and Wardamanocoris Malipatil); and Triatominae. The latter subfamily is found mainly in the Neotropical Region where some species transmit a trypanosome, Trypanosoma cruzi, which causes Chagas' disease (Lent & Wygodzinsky 1979). Triatoma leopoldi (Schouteden), which is known from Iron Range (Queensland), is the only known Australian triatomine (Monteith 1974).
General References
Aldrich, J.R. 1988. Chemical ecology of the Heteroptera. Annual Review of Entomology 33: 211-238
Carayon, J. & Villiers, A. 1968. Étude sur les Hémiptères Pachynomidae. Annales de la Société Entomologique de France ns 4: 703-739
Carver, M., Gross, G.F. & Woodward, T.E. 1991. Hemiptera (bugs, leafhoppers, cicadas, aphids, scale insects, etc.) [with contributions by Cassis, G., Evans, J.W., Fletcher, M.J., Hill, L., Lansbury, I., Malipatil, M.B., Monteith, G.B., Moulds, M.S., Polhemus, J.T., Slater, J.A., Štys, P., Taylor, K.L., Weir, T.A. & Williams, D.J.]. pp. 429-509 in CSIRO (ed.). The Insects of Australia. A textbook for students and research workers. Melbourne : Melbourne University Press Vol. 1 xiii 542 pp.
China, W.E. & Miller, N.C.E. 1959. Check-list and keys to the families and subfamilies of the Hemiptera-Heteroptera. Bulletin of the British Museum (Natural History) Entomology 8: 1-45
Cobben, R.H. 1978. Evolutionary Trends in Heteroptera. Part II. Mouthpart-structures and feeding strategies. Wageningen : H. Veenman & B.V. Zonen 407 pp.
Cook, M.L. 1977. A key to the genera of Asian Ectrichodiinae (Hemiptera: Reduviidae) together with a check-list of genera and species. Oriental Insects 11: 63-88
Davis, N.T. 1961. Morphology and phylogeny of the Reduvioidea (Hemiptera: Heteroptera). Pt 2. Wing venation. Annals of the Entomological Society of America 54: 340-354
Davis, N.T. 1969. Contribution to the morphology and phylogeny of the Reduvioidea. Part IV. The Harpactoroid complex. Annals of the Entomological Society of America 62: 74-94
Hawkeswood, T.J. 1990. Some notes on three species of Australian Reduviidae (Hemiptera). Victorian Entomologist 20: 99-102
Hickman, V.V. 1969. The biology of two emesine bugs (Hemiptera: Reduviidae) on nests or webs of spiders. Journal of the Entomological Society of Australia (N.S.W.) 6: 3-18
Lent, H. & Wygodzinsky, P. 1979. Revision of the Triatominae (Hemiptera, Reduviidae), and their significance as vectors of Chagas' disease. Bulletin of the American Museum of Natural History 163: 125-520
Maldonado Capriles, J. 1990. Systematic Catalogue of the Reduviidae of the World (Insecta: Heteroptera). Puerto Rico : University of Puerto Rico 694 pp.
Malipatil, M.B. 1985. Revision of Australian Holoptilinae (Reduviidae: Heteroptera). Australian Journal of Zoology 33: 283-299
Malipatil, M.B. 1986. Revision of Australian Coranus Curtis (Heteroptera: Reduviidae: Harpactorinae). Occasional Papers of the Northern Territory Museum of Arts and Sciences 3: 29-50
Malipatil, M.B. 1986. Revision of Australian Helonotus Amyot and Serville (Heteroptera: Reduviidae). Journal of the Australian Entomological Society 25: 171-175
Malipatil, M.B. 1986. Revision of Australian Pristhesancus Amyot and Serville (Heteroptera: Reduviidae). Australian Journal of Zoology 34: 601-610
Malipatil, M.B. 1988. Revision of the Australian Dicrotelini with the description of three new genera (Hemiptera: Reduviidae). The Beagle, Records of the Museums and Art Galleries of the Northern Territory 5: 135-145
Malipatil, M.B. 1990. First record of Visayanocorinae (Hemiptera: Reduviidae) from Australia with descriptions of a new genus and two new species. Journal of the Australian Entomological Society 29: 31-36
Malipatil, M.B. 1991. The generic classification of the Australian Harpactorinae (Hemiptera: Reduviidae). Invertebrate Taxonomy 4: 935-971
McKeown, K.C. 1942. Australian insects. The bugs—order Hemiptera-Heteroptera, I. Australian Museum Magazine 8: 27-31
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Miller, N.C.E. 1956. The Biology of the Heteroptera. London : Leonard Hill Ltd x 162 pp.
Miller, N.C.E. 1957. New genera and species of Ethiopian, Mascarene and Australian Reduviidae (Hemiptera-Heteroptera) in the British Museum (N.H.), London. Bulletin of the British Museum (Natural History) Entomol. 5: 29-81
Miller, N.C.E. 1958. New genera and species of Australian Reduviidae (Hemiptera-Heteroptera-Reduviidae). Revue Française d'Entomologie 25(3): 233-239
Miller, N.C.E. 1959. A new subfamily, new genera and new species of Reduviidae (Hemiptera-Heteroptera). Bulletin of the British Museum (Natural History) Entomol. 8: 47-117 pls 1-4
Monteith, G.B. 1974. Confirmation of the presence of Triatominae (Hemiptera: Reduviidae) in Australia, with notes on Indo-Pacific species. Journal of the Australian Entomological Society 13: 89-94
Putshkov, V.G. & Putshkov, P.V. 1985. A catalogue of the assassin bugs genera of the world (Heteroptera, Reduviidae). Vestnik Zoologii 1985: 1-112
Schuh, R.T. 1986. The influence of cladistics on Heteropteran classification. Annual Review of Entomology 31: 67-93
Schuh, R.T. & Štys, P. 1991. Phylogenetic analysis of Cimicomorphan family relationships (Heteroptera). Journal of the New York Entomological Society 99: 298-350
Slater, J.A. 1982. Hemiptera. pp. 417-447 in Parker, S.P. (ed.). Synopsis and Classification of Living Organisms. New York : McGraw Hill Book Co
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Wygodzinsky, P. & Usinger, R.L. 1963. Classification of the Holoptilinae and description of the first representative from the new world. (Hemiptera: Reduviidae). Proceedings of the Royal Entomological Society of London B 32: 47-52