Phylogenetic relationships of Leuronectes Sharp (Coleoptera: Dytiscidae: Agabinae) based on larval morphology and chaetotaxy

MICHAT, M. C. & M. ARCHANGELSKY.

INSECT SYSTEMATICS & EVOLUTION

APOLLO BOOKS

Año: 2009 vol. 40 p. 209 - 228

1399-560X

on a cladistic analysis of seven Agabinae genera and 54 morphological and chaetotaxic characters from larvae. For this purpose, larvae of L. curtulus Régimbart are described and illustrated in detail for the fi rst time, with particular emphasis on morphometry and chaetotaxy. Th e results show that Leuronectes is well placed within Agabinae based on the absence of natatory setae on tibia and tarsus in instars II and III, the urogomphus composed of two urogomphomeres, and the absence of secondary setae on urogomphus.Leuronectes is resolved as part of a basal polytomy along with Platynectes Régimbart and a clade formed by the remaining agabine genera. Leuronectes shares with Platynectes the setae UR2, UR3 and UR4 not inserted contiguously, with Platambus Th omson the anterolateral lobes of frontoclypeus not projected beyond anterior margin, with Hydrotrupes Sharp the seta AB9 inserted dorsolaterally, and with Ilybius Erichson the seta LA10 inserted submedially. Leuronectes is unique within Agabinae in having the apical lateroventral process of the third antennomere not protruding and additional ventroapical pores on third antennomere, and is unique within the dytiscid genera studied in having the seta LA12 inserted submediallyand one additional spine-like seta inserted on the lateral margin of abdominal segment VIII.