Descriptions of larvae of Desmopachria Babington (Coleoptera: Dytiscidae: Hydroporinae): the D. vicina Sharp species group.

MICHAT, M. C. & M. ARCHANGELSKY.

COLEOPTERISTS BULLETIN

The Coleopterists Society

Año: 2007 vol. 61 p. 264 - 276

0010-065X

Larval morphology of the Desmopachria vicina Sharp species group is investigated. Forthis purpose, the three larval instars of Desmopachria concolor Sharp and Desmopachriapunctatissima Zimmermann are described and illustrated for the first time, with an emphasison the morphometry and chaetotaxy. Both species have the setae LA3, LA4 and LA5inserted proximally on the prementum and the seta LA10 inserted distally on the secondlabial palpomere, the two larval autapomorphies that define the genus DesmopachriaBabington. They are also characterized by the presence of secondary setae on the ventralsurface of the siphon of third-instar larva; this character state is a synapomorphy ofDesmopachria + Hyphydrus Illiger. Desmopachria concolor and D. punctatissima are verysimilar morphologically, suggesting that they could be closely related phylogenetically.Larvae of the D. vicina species group differ from those of the Desmopachria convexa (Aube´)species group in the presence of one additional seta on the dorsal surface of the prementum,the more distal insertion of the seta LA2 on the prementum, and the absence of one of thedistal pores (LAb or LAd) on the first labial palpomere.