Family HYDROPTILIDAE
Compiler and date details
Arturs Neboiss, Department of Entomology, National Museum of Victoria, Abbotsford, Victoria; updated (2002) by Alice Wells, Australian Biological Resources Study, Canberra, Australia
Introduction
This is a large family, commonly known as the micro-caddis; they are the smallest (wing span 4–12 mm) of all Trichoptera.
The family is known from all faunal regions and there are about 90 genera and 7–800 species. It is known throughout Australia and represented by 14 genera and 139 species. Wells (1992a) compared the microcaddisfly faunas of SE Asian countries, New Guinea and Australia, noting the domination of the Australian fauna by species in the tribe Hydroptilini and apparent absence from Australia of the tribe Stactobiini, which is very diverse throughout SE Asia and New Guinea. One stactobiine species has now been described from north-eastern Queensland, another undescribed species has been found in NE Queensland.
The Australian hydroptilid fauna includes a preponderance of algal feeding species, their larvae feeding on diatomaceous growth on macrophytes or rocky substrates or on filamentous green algae. While some Orthotrichia species share these dietary preferences, many Australian species have been found feeding on eggs of aquatic invertebrates. Species in the Orthotrichia aberrans group, however, are parasitic on other caddisfly pupae, either philopotamids or hydropsychids (Wells 1992b). Larvae of Australian hydroptilids can be identified to genus using the key provided by Wells (1997).
Diagnosis
Adult: ocelli either present or absent according to genus. Maxillary palpi 5-segmented in both sexes, the first two segments very short and the apical segment simple. The antennae are shorter than the forewing; shorter in females that in the males; basal segment shorter than head. Mesoscutum without setal warts, scutellum flat, triangular, pointed posteriorly, margins vertical. Wings elongate, slender, usually acute apically, densely covered with fine pubescence, hindwing fringe with very long hairs, longer than width of wing; wing venation reduced, interpretation of veins often very difficult.
Tibial spurs variable: 0–1: 2–3: 3–4.
Larva: the first four instars are small, slender and free living. In the fifth instar the abdomen becomes enlarged and a purse-shaped case is constructed. Heavily sclerotized plates are on all three thoracic nota; mid- and hind-legs often longer than forelegs; anal claws are small. Larval case is (usually) laterally, but sometimes dorso-ventrally, flattened; it is constructed of small sand grains, algae, other plant material or entirely of silk. Before pupation the larva attaches the case to the substrate.
References
Kelley, R.W. 1984. Phylogeny, morphology and classification of the micro-caddisfly genus Oxyethira Eaton (Trichoptera: Hydroptilidae). Transactions of the American Entomological Society 110: 435–463
Neboiss, A. 2003. New genera and species, and new records, of Tasmanian Trichoptera (Insecta). Papers and Proceedings of the Royal Society of Tasmania 136: 43-82 [dated 2002]
Wells, A. 1992a. The Hydroptilidae (Trichoptera) of the Malay Archipelago: A preliminary report. pp. 244–246 in Tomaszewski, C. (ed.). Proceedings of the 6th International Symposium on Trichoptera. Poznan, Poland : Adam Mickiewicz University Press
Wells, A. 1992b. The first parasitic Trichoptera. Ecological Entomology 17: 299–302
Wells, A. 1979. A review of the Australian genera Xuthotrichia Mosely and Hellyethira Neboiss (Trichoptera: Hydroptilidae), with descriptions of new species. Australian Journal of Zoology 27: 311–329
Wells, A. 1979. A review of the Australian species of Hydroptila Dalman (Trichoptera: Hydroptilidae), with descriptions of new species. Australian Journal of Zoology 26: 745–762 [dated 1978]
Wells, A. 1979. The Australian species of Orthotrichia Eaton (Trichoptera: Hydroptilidae). Australian Journal of Zoology 27: 585–622
Wells, A. 1980. A review of the Australian genera Orphninotrichia Mosely and Maydenoptila Neboiss (Trichoptera: Hydroptilidae), with descriptions of new species. Australian Journal of Zoology 28: 627–645
Wells, A. 1981. The genera Oxyethira Eaton, Gnathotrichia Ulmer and Stenoxyethira Kimmins (Trichoptera: Hydroptilidae) in Australia. Australian Journal of Zoology 29: 103–118
Wells, A. 1982. Tricholeiochiton Kloet & Hincks and new genera in the Australian Hydroptilidae (Trichoptera). Australian Journal of Zoology 30: 251–270
Wells, A. 1983. New species in the Australian Hydroptilidae (Trichoptera), with observations on relationships and distributions. Australian Journal of Zoology 31: 629–649
Wells, A. 1985. Four new species of Hydroptilidae (Trichoptera) from the Alligator Rivers region, Northern Territory. Transactions of the Royal Society of South Australia 109: 97–102
Wells, A. 1985. Larvae and pupae of Australian Hydroptilidae (Trichoptera), with observations on general biology and relationships. Australian Journal of Zoology Supplementary Series 113: 1–69
Wells, A. 1997. A Preliminary Guide to the Identification of Larval Hydroptilidae (Insecta: Trichoptera). Identification Guide No. 13. Co-operative Research Centre for Freshwater Ecology, Albury. 28 pp.