Introduction

The Idiostolidae a family of three genera and four species, are found in the cool temperate regions of south-eastern Australia, Chile and Argentina (Slater 1964; Woodward 1968a; Zoological Record 1968–2001). Two genera and three species occur in Australia.

Scudder (1962) erected the Idiostolinae as a new subfamily of Lygaeidae, for Idiostolus Berg and Trisecus Bergroth, both of which had been previously placed in the Heterogastrinae. He indicated that idiostolids have an isolated position within the Lygaeidae sensu lato, but share similarities with the Pachygronthinae, Heterogastrinae and Rhyparochrominae. He also reported that the presence of abdominal trichobothria, separate radial and medial veins, and the absence of gonoplacs firmly establish their position within the Pentatomomorpha.

Štys (1967) elevated the group to family rank, within its own superfamily. He considered the family to be plesiomorphic based on features of hind wing venation and the abdominal trichobothrial number and patterns, and that it lacks any synapomorphies with other lygaeoid groups. Schaefer (1966a, 1966b, 1993) and Schaefer & Wilcox (1969) also concluded that the Idiostolidae are a plesiomorphic group, based primarily on character states of the abdominal trichobothria and female genitalia (absence of spermatheca), but maintained the group within the Lygaeoidea sensu lato. Woodward (1968b), in describing the new lygaeid subfamily Henicocorinae, indicated a clear relationship between it and idiostolids, based on the arrangement of abdominal trichobothria and the absence of a spermatheca.

Most heteropterists have accepted the isolated position of the Idiostolidae (Štys & Kerzhner 1975; Schuh 1986; Carver et al. 1991; Schuh & Slater 1995). Henry (1997) established the Idiostolidae + Henicocoridae as a monophyletic group, the Idiostoloidea.

Woodward (1968a) described the Australian fauna. He recognised two species of Trisecus Bergroth from Tasmania and montane areas of New South Wales, and a monotypic genus, Monteithocoris Woodward, which is endemic to Tasmania.

The Australian idiostolids are found in moss associated with species of Nothofagus Blume. The South American species, Idiostolus insularis Berg, is also found in association with Nothofagus (N. betuloides (Mirb.)Oerst). This habitat and distribution is reminiscent of that of peloridiid species (Heteroptera: Coleorrhyncha). Scudder (1962) indicated that the distribution patterns of idiostolids resemble those of Isodermus Erichson (Aradidae), and proposed a vicariance explanation for their distribution. Unlike Isodermus, idiostolids are not presently known from New Zealand. Woodward (1968a) noted that all the Australian species are found in montane regions and suggested that these taxa differentiated during interpluvial periods of the Pleistocene. Schaefer & Wilcox (1969) provided a dispersalist argument for idiostolid distribution.

Little is known of the biology of idiostolids aside from their habitat associations. Schuh & Slater (1995) suggested that the group is most likely to be phytophagous. There is no evidence to support this contention, nor are there any obvious supporting morphological characters.

Diagnosis

Idiostolids are medium-sized, elongate-ovoid insects. The head is porrect and lygaeoid-like, with no sulci. Ocelli are present. The antennae and labium are 4-segmented. The bucculae are short. The pronotum is divided into collar and disc regions. The hemelytral membrane has four longitudinal veins. The corium has numerous longitudinal veins. The hind wings possess a hamus. The metathoracic glands are reduced, without evaporative areas and any raised peritreme. The abdomen bears numerous trichobothria on sterna III to VII. The abdominal terga and sterna are fused. All abdominal spiracles are ventral. The ovipositor is laciniate and the spermatheca is absent. The male phallus is simple and lacks a vesica. (Schaefer 1966a, 1966b; Woodward 1968a; Schaefer & Wilcox 1969; Slater 1982; Schuh & Slater 1995)

Diagnosis References

Schaefer, C.W. 1966. Some notes on heteropteran trichobothria. Michigan Entomologist 1: 85-90

Schaefer, C.W. 1966. The morphology and higher systematics of the Idiostolinae (Hemiptera: Lygaeidae). Annals of the Entomological Society of America 59: 602-613

Schaefer, C.W. & Wilcox, D. 1969. Notes on the morphology, taxonomy, and distribution of the Idiostolidae (Hemiptera-Heteroptera). Annals of the Entomological Society of America 62: 485-502

Schuh, R.T. & Slater, J.A. 1995. True Bugs of the World (Hemiptera: Heteroptera). Classification and Natural History. Ithaca : Cornell University Press xii 336 pp.

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.

Woodward, T.E. 1968. A new subfamily of Lygaeidae (Hemiptera-Heteroptera) from Australia. Proceedings of the Royal Entomological Society of London B 37: 125-132

Woodward, T.E. 1968. The Australian Idiostolidae (Hemiptera: Heteroptera). Transactions of the Royal Entomological Society of London 120: 253-261

General References

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.

Henry, T.J. 1997. Phylogenetic analysis of family groups within the infraorder Pentatomomorpha (Hemiptera: Heteroptera), with emphasis on the Lygaeoidea. Annals of the Entomological Society of America 90(3): 275-301

Schaefer, C.W. 1966a. The morphology and higher systematics of the Idiostolinae (Hemiptera: Lygaeidae). Annals of the Entomological Society of America 59: 602-613

Schaefer, C.W. 1966b. Some notes on heteropteran trichobothria. Michigan Entomologist 1: 85-90

Schaefer, C.W. 1993. The Pentatomomorpha (Hemiptera: Heteroptera): an annotated outline of its systematic history. European Journal of Entomology 90: 105-122

Schaefer, C.W. & Wilcox, D. 1969. Notes on the morphology, taxonomy, and distribution of the Idiostolidae (Hemiptera-Heteroptera). Annals of the Entomological Society of America 62: 485-502

Schuh, R.T. 1986. The influence of cladistics on Heteropteran classification. Annual Review of Entomology 31: 67-93

Schuh, R.T. & Slater, J.A. 1995. True Bugs of the World (Hemiptera: Heteroptera). Classification and Natural History. Ithaca : Cornell University Press xii 336 pp.

Scudder, G.G.E. 1962. Results of the Royal Society expedition to southern Chile, 1958–1959: Lygaeidae (Hemiptera), with the description of a new subfamily. The Canadian Entomologist 94: 1064-1075

Slater, J.A. 1964. A Catalogue of the Lygaeidae of the World. Storrs : University of Connecticut xviii 1668 pp.

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.

Štys, P. 1967. Monograph of Malcinae, with reconsideration of morphology and phylogeny of related groups. (Heteroptera, Malcidae). Acta Entomologica Musei Nationalis Pragae 37: 351-516

Štys, P. & Kerzhner, I. 1975. The rank and nomenclature of higher taxa in recent Heteroptera. Acta Entomologica Bohemoslovaca 72: 65-79

Woodward, T.E. 1968a. The Australian Idiostolidae (Hemiptera: Heteroptera). Transactions of the Royal Entomological Society of London 120: 253-261

Woodward, T.E. 1968b. A new subfamily of Lygaeidae (Hemiptera-Heteroptera) from Australia. Proceedings of the Royal Entomological Society of London B 37: 125-132

History of changes

• Monteithocoris Woodward, T.E. 1968. The Australian Idiostolidae (Hemiptera: Heteroptera). Transactions of the Royal Entomological Society of London 120: 253-261 [257].

  Type species:

   Monteithocoris hirsutus Woodward, 1968 by monotypy.

Distribution

States

Tasmania

IBRA

Tas: Ben Lomond (BEL), Flinders (FLI), King (KIN), Tasmanian Central Highlands (TCH), Tasmanian Northern Midlands (TNM), Tasmanian Northern Slopes (TNS), Tasmanian South East (TSE), Tasmanian Southern Ranges (TSR), Tasmanian West (TWE)

History of changes

• Monteithocoris hirsutus Woodward, T.E. 1968. The Australian Idiostolidae (Hemiptera: Heteroptera). Transactions of the Royal Entomological Society of London 120: 253-261 [259].

  Type data:

   Holotype QM T6598 ♂, Mt Barrow, via Launceston, TAS.
  Paratype(s) ANIC 2♂ 8♀; BMNH; EUQ; CSLAT; USNM.

Distribution

States

Tasmania

IBRA

Tas: Ben Lomond (BEL), Flinders (FLI), King (KIN), Tasmanian Central Highlands (TCH), Tasmanian Northern Midlands (TNM), Tasmanian Northern Slopes (TNS), Tasmanian South East (TSE), Tasmanian Southern Ranges (TSR), Tasmanian West (TWE)

Ecological Descriptors

Litter, terrestrial, volant.

Extra Ecological Information

Nothofagus forest.

History of changes

• Trisecus Bergroth, E. 1895. Contributions to a knowledge of the Rhynchota of Australia. Proceedings of the Royal Society of Victoria ns 7: 287-302 [296].

  Type species:

   Trisecus pictus Bergroth, 1895 by monotypy.

Distribution

States

New South Wales, Tasmania, Victoria

IBRA

NSW, Tas, Vic: Australian Alps (AA), Ben Lomond (BEL), Flinders (FLI), King (KIN), Murray Darling Depression (MDD), Naracoorte Coastal Plain (NCP), NSW North Coast (NNC), Sydney Basin (SB), South East Coastal Plain (SCP), South East Corner (SEC), South Eastern Highlands (SEH), South Eastern Queensland (SEQ), Tasmanian Central Highlands (TCH), Tasmanian Northern Midlands (TNM), Tasmanian Northern Slopes (TNS), Tasmanian South East (TSE), Tasmanian Southern Ranges (TSR), Tasmanian West (TWE), Victorian Midlands (VM), Victorian Volcanic Plain (VVP)

General References

Scudder, G.G.E. 1962. Results of the Royal Society expedition to southern Chile, 1958–1959: Lygaeidae (Hemiptera), with the description of a new subfamily. The Canadian Entomologist 94: 1064-1075 [1069] (key)

Woodward, T.E. 1968. The Australian Idiostolidae (Hemiptera: Heteroptera). Transactions of the Royal Entomological Society of London 120: 253-261 [254] (description)

History of changes

• Trisecus armatus Woodward, T.E. 1968. The Australian Idiostolidae (Hemiptera: Heteroptera). Transactions of the Royal Entomological Society of London 120: 253-261 [256].

  Type data:

   Holotype QM T6599 ♂, Pt Lookout, via Ebor, NSW.
  Paratype(s) EUQ ♂.

Distribution

States

New South Wales

Extra Distribution Information

NSW—Barrington Tops.

IBRA

NSW: NSW North Coast (NNC), Sydney Basin (SB), South East Corner (SEC), South Eastern Queensland (SEQ)

Ecological Descriptors

Closed forest, ground dweller, herbivore, litter, temperate, terrestrial, volant.

Extra Ecological Information

Ex Nothofagus forest, female unknown.

History of changes

• Trisecus pictus Bergroth, E. 1895. Contributions to a knowledge of the Rhynchota of Australia. Proceedings of the Royal Society of Victoria ns 7: 287-302 [297].

  Type data:

   Holotype NMV ♂ (depository uncertain), TAS.

Distribution

States

Tasmania, Victoria

Extra Distribution Information

TAS—Arve River, Cynthia Bay, Florentine River, Franklin River, Hellyer Gorge, Mt Barrow, Queenstown, Waratah, VIC—Cement Creek.

IBRA

Tas, Vic: Australian Alps (AA), Ben Lomond (BEL), Flinders (FLI), King (KIN), Murray Darling Depression (MDD), Naracoorte Coastal Plain (NCP), South East Coastal Plain (SCP), South East Corner (SEC), South Eastern Highlands (SEH), Tasmanian Central Highlands (TCH), Tasmanian Northern Midlands (TNM), Tasmanian Northern Slopes (TNS), Tasmanian South East (TSE), Tasmanian Southern Ranges (TSR), Tasmanian West (TWE), Victorian Midlands (VM), Victorian Volcanic Plain (VVP)

Ecological Descriptors

Closed forest, ground dweller, herbivore, litter, temperate, terrestrial, volant.

General References

Horváth, G. 1926. La distribution geographique des Hemipteres. International Congress of Entomology 3: 323-330 [328] (distribution)

Scudder, G.G.E. 1962. Results of the Royal Society expedition to southern Chile, 1958–1959: Lygaeidae (Hemiptera), with the description of a new subfamily. The Canadian Entomologist 94: 1064-1075 [1069] (key)

Slater, J.A. 1964. A Catalogue of the Lygaeidae of the World. Storrs : University of Connecticut xviii 1668 pp. [1496] (catalogue)

Woodward, T.E. 1968. The Australian Idiostolidae (Hemiptera: Heteroptera). Transactions of the Royal Entomological Society of London 120: 253-261 [254] (key, description)

History of changes