Belongs within: Chironomidae.
The Tanytarsini are a group of non-biting midges with a long first tarsomere on the fore leg and usually with macrotrichia on the wings (Oliver 1981). Species with fully developed wings have veins r-m and R4+5 forming a straight line or shallow angle (Spies et al. 2009).
Insects never fail to amaze
Published 22 June 2007
Recently I saw my first ever specimen of Archaeognatha. I was going to write on that, so I picked up the lab’s faithful copy of The Insects of Australia (CSIRO 1991) to look up information. Before I found the Archaeognatha chapter, however, I came across something else that just blew me away so much that I had to share it with you all. Meet the freaky little marine midge Pontomyia.
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There are very few marine insects, and only a single genus, the waterstrider Halobates, has species that are actually found on the open ocean (van der Hage 1996). Other marine insects are restricted to inshore habitats. Pontomyia appears to be an inhabitant of tide pools and lagoons in the West Pacific. It belongs to the large family Chironomidae, mosquito-like (but non-parasitic) midges with aquatic larvae
Individuals of Pontomyia spend most of their lives as benthic larvae. After they emerge as non-feeding adults, they only live for a couple of hours (Soong et al. 1999). In this brief time, they must find a mate and produce eggs.
Pontomyia adults emerge at dusk or after sunset. At least one species, Pontomyia oceana, only emerges around the new and full moons (in combination with the specific emergence time, this probably ensures that the females end up laying eggs at low tide). Pupae swim to the surface and emerge as adults. The females are vermiform and structurally degenerate, with seemingly little activity as far as I can tell.
The males are the freaky ones. They skim the water surface film on the tips of the stout second and stilt-like, trailing third pairs of legs. The first pair of legs is immensely long and curve out on either side of the body as a pair of ‘outriggers’, barely skimming the surface and maintaining the animal’s balance. The paddle-like wings propel the midge by flicking the air just above the water surface (Norris 1991).
Females do not complete emergence from the pupa unless males are nearby (Soong et al. 1999). Males generally emerge up to an hour before females, and have been observed stripping the pupal skin from females to help them emerge. Once a male has found a female, he picks her up with the second legs and the base of the third legs and carries her while mating. Males are apparently quick movers, and I was especially taken by this sentence in Soong et al. (1999): ‘They did not appear to slow down after catching females, sometimes climbing the vertical substrate up to 15 cm above the water level while dragging a female along‘. One can’t help wondering what Germaine Greer would make of the verbs in there.
After mating, the male drops the female. She lays her eggs on bits of dead coral or the like sticking up about the water surface in long interconnected strings. And that, as they say, is that.
Systematics of Tanytarsini
Characters (Oliver 1981): Wing membrane usually with macrotrichia; calypter always without fringe; crossvein r-m nearly parallel to R4+5, and continuous with it, or if oblique, then wing apex truncated; crossvein m-cu absent. First tarsomere of foreleg longer than fore tibia; hind tibia with two combs composed of basally fused spines. Gonostylus fused to gonocoxite and directed backward.
<==Tanytarsini
|--Corynocera ambiguaO81, R86
|--Lenziella crusculaO81
|--ZavreliaSA09
|--LauterborniaO81
|--NandevaSA09
|--SkutziaSA09
|--ConstempellinaSA09
|--Neostempellina thienemanniSA09, R86
|--StempellinellaSA09
|--Neozavrelia luteolaSA09
|--ParapsectraSA09
|--SubletteaSA09
|--Virgatanytarsus arduennensisSA09
|--Stempellina Bause 1914SA09, F61
| |--*S. bausei (Kieffer 1911)F61 [=Tanytarsus bauseiF61; incl. S. montivagaR86]
| `--S. australiensis Freeman 1961F61
|--Pontomyia Edwards 1926SA09, F61
| |--*P. natans Edwards 1926F61
| `--P. cottoni Womersley 1937F61
|--ParatanytarsusSA09
| |--P. grimmiiSA09
| `--P. quadratusSA09
|--CaladomyiaSA09
| |--C. pistraSA09
| `--C. riotarumensisSA09
|--Lundstroemia Kieffer 1921F61
| |--*L. roseiventris Kieffer 1921F61
| `--L. parthenogenetica Freeman 1961F61
|--CladotanytarsusSA09
| |--C. furcatus (Freeman 1961) [=Tanytarsus (Cladotanytarsus) furcatus]F61
| |--C. lewisiP09
| |--C. mancus (Walker 1856) [=Chironomus mancus, Tanytarsus mancus]F61
| `--C. viridiventrisO81
|--RheotanytarsusSA09
| |--R. calakmulensisSA09
| |--R. christinaePH10
| |--R. juliaePH10
| |--R. rhenanusR86
| `--R. trivittatusPH10
|--MicropsectraSA09
| |--M. atitlanensis Sublette & Sasa 1994SA09
| |--M. atrofasciataG09
| |--M. bidentataG09
| |--M. junciG09
| |--M. longicristaG09
| |--M. notescensG09
| |--M. pallidulaG09
| |--M. schrankelaeG09
| `--M. subviridaG09
`--Tanytarsus van der Wulp 1874F61
|--T. barbitarsis Freeman 1961F61
|--T. belmorensis Freeman 1961F61
|--T. bispinosus Freeman 1961F61
|--T. communis Skuse 1889 (n. d.)S89
|--T. dissimilisRD77
|--T. ejuncidusR86
|--T. funebrisF61
|--T. fuscithorax Skuse 1889S89
|--T. guatemalensis Sublette & Sasa 1994SA09
|--T. heusdensisG09
|--T. inextentus Skuse 1889S89
|--T. modicus Skuse 1889S89
|--T. ogilbyi Skuse 1889 (n. d.)S89
|--T. pallidicornisG09
|--T. palmatus Freeman 1961F61
|--T. pandusSA09
|--T. semibarbitarsusPH10
|--T. spinosus Freeman 1961F61
|--T. sydneyensis Kieffer 1917F61
`--T. vespertinusB87
*Type species of generic name indicated
References
[B87] Boothroyd, I. K. G. 1987. Taxonomic composition and life cycles of Chironomidae (Diptera) in a northern New Zealand stream. Entomologica Scandinavica Supplement 29: 15–22.
[F61] Freeman, P. 1961. The Chironomidae (Diptera) of Australia. Australian Journal of Zoology 9 (4): 611–735.
[G09] Gerecke, R. 2009. Revisional studies on the European species of the water mite genus Lebertia Neuman, 1880 (Acari: Hydrachnidia: Lebertiidae). Abhandlungen der Senckenberg Gesellschaft für Naturforschung 566: 1–144.
Norris, K. R. 1991. General biology. In: CSIRO. The Insects of Australia 2nd ed. vol. 1 pp. 68–108. Melbourne University Press.
[O81] Oliver, D. R. 1981. Chironomidae. In: McAlpine, J. F., B. V. Peterson, G. E. Shewell, H. J. Teskey, J. R. Vockeroth & D. S. Wood (eds) Manual of Nearctic Diptera vol. 1 pp. 423–458. Research Branch, Agriculture Canada.
[P09] Pape, T. 2009. Economic importance of Diptera. In: Brown, B. V., A. Borkent, J. M. Cumming, D. M. Wood, N. E. Woodley & M. A. Zumbado (eds) Manual of Central American Diptera vol. 1 pp. 65–77. NRC Research Press: Ottawa.
[PH10] Pinder, A. M., S. A. Halse, R. J. Shiel & J. M. McRae. 2010. An arid zone awash with diversity: patterns in the distribution of aquatic invertebrates in the Pilbara region of Western Australia. Records of the Western Australian Museum Supplement 78 (1): 205–246.
[R86] Reiss, F. 1986. Erster Nachtrag zur Chironomidenfauna Bayerns (Diptera, Chironomidae). Spixiana 9 (2): 175–178.
[RD77] Richards, O. W., & R. G. Davies. 1977. Imms’ General Textbook of Entomology 10th ed. vol. 2. Classification and Biology. Chapman and Hall: London.
[S89] Skuse, F. A. A. 1889. Diptera of Australia. Part VI.—The Chironomidae. Proceedings of the Linnean Society of New South Wales, series 2, 4 (2): 215–311, pls 11–14.
Soong, K., G.-F. Chen & J.-R. Cao. 1999. Life history studies of the flightless marine midges Pontomyia spp. (Diptera: Chironomidae). Zoological Studies 38 (4): 466–473.
[SA09] Spies, M., T. Andersen, J. H. Epler & C. N. Watson Jr. 2009. Chironomidae (non-biting midges). In: Brown, B. V., A. Borkent, J. M. Cumming, D. M. Wood, N. E. Woodley & M. A. Zumbado (eds) Manual of Central American Diptera vol. 1 pp. 437–480. NRC Research Press: Ottawa.
van der Hage, J. C. H. 1996. Why are there no insects and so few higher plants, in the sea? New thoughts on an old problem. Functional Ecology 10: 546–547.