Parachironomus Lenz, 1921

Cranston, Peter S., 2007, The Chironomidae Larvae Associated With The Tsunami-Impacted Waterbodies Of The Coastal Plain Of Southwestern Thailand, Raffles Bulletin of Zoology 55 (2), pp. 231-244 : 241

Parachironomus Lenz

( Figs. 29, 30, 33 )

The genus Parachironomus is widespread, but it is never abundant in the region: no species was found in Sulawesi by Ashe (1990). Parachironomus tobaquartus Kikuchi & Sasa (1990) was described in the adult stage from Lake Toba , Sumatra .

Two species occured as larvae in post-tsunami pools and both belong to the arcuatus group (Pinder & Reiss, 1983) having simple SI setae and a convex mentum with dark teeth. One is identical to P. ‘K1’ ( Cranston, 2000) reported from northern Australia, having numerous small teeth laterad to a typical mentum ( Fig. 30 ). This larval type was found only on three consecutive sampling occasions at one site (Hard Klong Luang) in Krabi. The other, a single individual from a dilute and unimpacted pool, differs in having a typical mentum for Parachironomus but with very narrow ventromental plates and a strongly scalloped anterior margin ( Fig. 33 ) .

Figures

Figs. 26–36. Thai post-tsunami Chironomidae. Zavreliella sp.: 26, posterior body. Conochironomus sp.: 27, mentum; 28, antenna. Parachironomus ‘K3’: 29, labrum; 30; mentum. Kiefferulus sp.: 31, antenna. Chironomus sp.: 32, mandible. Parachironomus sp.: 33, ventromental plate. Chironomus javanus: 34, epipharynx; 35, premandible. Chironomus sp.: 36, premandible. Abbreviations: ll, labral lamella; LO, Lauterborn organ; pmd, premandible; SI, SII, labral setae I, II; vmp, ventromental plate.