Family PTILODACTYLIDAE
Compiler and date details
31 December 1999 - Andrew A. Calder, CSIRO Entomology, Canberra, Australian Capital Territory, Australia
Introduction
The Australian Ptilodactylidae is represented by two genera and five described species in two subfamilies, Anchytarsinae (Byrrocryptus Broun) and Cladotominae (Austrolichas Lawrence & Stribling), compared to a relatively abundant world fauna of 37 genera and 309 species (Lawrence & Stribling 1992; recent literature). Five subfamilies (Lawrence & Newton 1995) are recognised in the family. However, a comprehensive phylogenetic analysis may find the Anchytarsinae to be paraphyletic. The family is very diverse and four of the Australian species formerly included in the Dascillidae by Carter are now considered to be true Ptilodactylidae. The family's distribution in Australia is confined to coastal eastern Australia extending from the Atherton Tableland, north Queensland south to the ranges east of Melbourne, Victoria.
The first Australian ptilodactylid to be named was Dascillus serraticornis by Carter (1929) who incorrectly placed it in the family Dascillidae. Carter (1930) described a second species Dascillus obongus from the Dorrigo region, New South Wales also in Dascillidae while two more species variegatus and nigrinus (Carter 1935, 1936) were described in the ptilodactylid genus Epilichas White. Carter (1935) reassigned his D. serraticornis and D. oblongus to the same genus although still incorrectly retaining all four species in Dascillidae. Lawrence (1987) noted that all of these species lacked membranous lobes on tarsal segments 2-4 typical of true Epilichas and considered that all four species were better accommodated in the New Zealand genus Byrrocryptus. Recently, Lawrence & Stribling (1992) decribed the only Australian representative of the subfamily Cladotominae from North Queensland erecting a new genus Austrolichas to accommodate it. A few undescribed species of Ptilodactyla Illiger are also known from North Queensland (Lawrence & Stribling 1992). The Epilichadinae that Lawrence & Stribling (1992) used is a nomen nudum, the correct available subfamily name being Anchytarsinae.
Very little is known regarding the biology of the Australian species. The adults however, are commonly found along the banks of streams and rivers from where they are easily beaten from foliage and being nocturnal also readily come to light. Ptilodactylid larvae occur in wetter habitats and have been collected from leaf litter and rotten wood, while a number of North American genera are known to be aquatic (Stribling 1986; Lawrence 1991). Larvae are reported to feed on rotting vegetation or rotten logs (Lawrence 1991) and the aquatic larvae of the New World Anchytarsus feed on submerged decaying wood (LeSage & Harper 1976).
Lawrence & Stribling (1992) recognised four larval types based on the structure of the mandibles, mouthparts, antennae, abdominal apex, abdominal sterna and respiratory modifications. The first type is represented by Anchytarsus Guérin-Meneville of which the larvae are usually aquatic and lack functional spiracles in all but the last instar (Hinton 1947). The second type is seen in Ptilodactyla with larvae that occur in leaf litter and rotten wood and lack special respiratory modifications. The third type occurs only in Araeopidius Cockerell that is found in gravel and sand at stream edges and is able to withstand periods of inundation (Hinton 1961); and a fourth type represented by the Australian Austrolichas and Holarctic Paralichas White with a spiracular siphon on segment 8 and complex hydrofuge vestiture. These species presumably occur in litter and rotten wood near streams subject to periodic flooding.
Diagnosis
Ptilodactylid adults are soft-bodied, oval to elongate, pubescent beetles with moderately long, 11-segmented antennae. Adults range from 2.5 to 8.5 mm in length. Some species have articulated appendages attached to the bases of antennal segments 4 to 10. The head is strongly deflexed with large protruding eyes and is usually not visible from above. Antennal insertions may be present or absent. The labrum is distinct and the mandible has a thin incisor lobe parallel to the plane of movement. The maxillae and labium are often modified with enlarged or divided setose lobes. The palps are often enlarged apically. The pronotum is transverse, narrowed anteriorly, with sharp lateral carinae that are obsolete anteriorly. There is a well developed basal interlocking mechanism consisting of crenulations or a comb of small teeth. The procoxae are transverse with exposed trochantins and the procoxal cavities are open behind both internally and externally. The prosternal process is narrow. The scutellum is notched anteriorly. The midcoxae are narrowly separated and the cavities are partly closed by the mesepisternum. The elytra are usually striate, never ribbed. The hindwing has an obliquely closed radial cell and the anal (wedge) cell is either present or absent. The tarsi are 5-segmented, usually with ventral brushes or sometimes with a reduced fourth segment and the third with a membranous lobe or appendage ventrally (Lawrence 1982; Lawrence & Britton 1994).
Larvae are typically elongate, cylindrical to slightly flattened or curving ventrally at the apex. The head is prognathous with one large stemmata each side. Spiracles occur on the mesothorax and first eight abdominal segments and are biforous. The mandibles bear brushes of hairs or articulated processes at the base or are simple. The antennae are three-segmented and either very short or long. Tergite 8 can have a small pair of defensive eversible glands laterally. Segment 8 can sometimes have the 8th spiracles at the end of a posteriorly projecting process (spiracular siphon). Tergite 9 can form a sclerotised concave plate or not. Segment 9 can have a ventral operculum concealing the anal region. Segment 10 can have a pair of lobes bearing several hooks and usually osmoregulatory papillae or anal gills or it can have no anal papillae and few anal hooks (Lawrence 1991; Lawrence & Stribling 1992; Lawrence & Britton 1994).
General References
Carter, H.J. 1929. Australian Coleoptera, notes and new species. VI. Proceedings of the Linnean Society of New South Wales 54: 65–79, pl. IV [Date published 15 May 1929]
Carter, H.J. 1930. New Guinea and Australian Coleoptera. Notes and new species. Proceedings of the Linnean Society of New South Wales 55: 532-549 [Date published 15 Dec. 1930]
Carter, H.J. 1935. Australian Coleoptera. Notes and new species. No. IX. Proceedings of the Linnean Society of New South Wales 60: 179-193
Carter, H.J. 1936. Australian Coleoptera. Notes and new species. No. X. Proceedings of the Linnean Society of New South Wales 61(3-4): 98-110
Hinton, H.E. 1947. On the reduction of functional spiracles in the aquatic larvae of the Holometabola, with notes on the moulting process of spiracles. Transactions of the Entomological Society of London 98: 449-473
Hinton, H.E. 1961. How some insects, especially the egg stages, avoid drowning when it rains. Proceedings and Transactions of the South London Entomological and Natural History Society 1960: 138-154, pls 5-8
Lawrence, J.F. 1982. Coleoptera. pp. 482-553 in Parker, S.P. (ed.). Synopsis and Classification of Living Organisms. New York : McGraw Hill Vol. 2 vii 1232 pp.
Lawrence, J.F. 1987. Notes on the classification of some Australian Elateriformia (Coleoptera). Journal of the Australian Entomological Society 26(4): 360
Lawrence, J.F. 1991. Order Coleoptera. pp. 144-658 in Stehr, F.W. (ed.). Immature Insects. Coleoptera and Diptera. Dubuque, Iowa : Kendall-Hunt Vol. 2 xvi 975 pp.
Lawrence, J.F. & Newton, A.F., Jr 1995. Families and subfamilies of Coleoptera (with selected genera, notes, references and data on family-group names). pp. 779-1006 in Pakaluk, J. & Ślipiński, S.A. (eds). Biology, Phylogeny and Classification of Coleoptera: Papers celebrating the 80th birthday of Roy A. Crowson. Warszawa : Muzeum i Instytut Zoologii PAN.
Lawrence, J.F. & Stribling, J.B. 1992. A new genus of Ptilodactylidae (Coleoptera: Elateriformia) from north Queensland, with description of the presumed larva. Journal of the Australian Entomological Society 31(1): 19-27
LeSage, L. & Harper, P. 1976. Notes on the life history of the toed-winged beetle Anchytarsus bicolor (Melsheimer) (Coleoptera: Ptilodactylidae). The Coleopterists Bulletin 30(3): 233-238
History of changes
| Published | As part of group | Action Date | Action Type | Compiler(s) |
|---|---|---|---|---|
| 12-Feb-2010 | (import) |