Larval morphology of Aspidytidae (Coleoptera: Adephaga) and its phylogenetic implications
2005
Alarie, Y. | Bilton, D.T.
Aspidytidae, or cliff water beetles, are a recently discovered family of Adephaga, which have an apparently disjunct distribution in China and South Africa. The larvae of Aspidytidae are described for the first time, based on material of Aspidytes niobe Ribera, Beutel, Balke & Vogler, 2002, collected together with adults in South Africa. External morphological features, including chaetotaxy, are reported for all three larval instars, and an assessment made of the polarity of larval characters of phylogenetic utility in Adephaga. Larvae of Aspidytidae possess a mixture of primitive and derived character states, and are unique within the Adephaga in retaining the egg-bursters to instar II, and having dorsally orientated spiracles on abdominal segment VIII in instars II and III. Larvae of Aspidytae have retained several character states which are plesiomorphic within the Dytiscoidea: e.g., the abdominal segment IX retained as a small remnant and the primary seta UR9 and the primary pores URd, URe, and URf are present on the urogomphus. A parsimony analysis based on 17 informative larval characteristics was conducted with the program PAUP*. The six most parsimonious trees confirm the Aspidytidae as a relatively basal lineage of the Dytiscoidea.
显示更多 [+] 显示较少 [-]