Phylogenetic utility of the nuclear gene dopa decarboxylase in noctuoid moths (Insecta : Lepidoptera : Noctuoidea)

Phylogenetic utility for the nuclear gene encoding: dopa decarboxylase (DDC ), little used in systematics, was recently demonstrated within the noctuid moth subfamily Heliothinae. Here we extend the test of the utility of a 70 9-bp DDC fragment to deeper levels, analyzing 49 species representing major groups across the superfamily Noctuoidea. Parsimony, distance, and maximum likelihood analyses recover all or nearly all of a set of "test clades" su pported by clear morphological synapomorphies, spanning a wide range of tax onomic levels. DDC also upholds a recent proposal that the Noctuidae are pa raphyletic. Nt3 contributes a majority of the signal and recovers the basal spit between Notodontidae and all other noctuoids, despite a plateau of nt 3 divergence at this level. However, nonsynonymous changes also support gro ups at all levels, and in contrast to nt3, amino acid divergence shows no p lateau. The utility of DDC promises to extend back to the early Tertiary an d Cretaceous, a time span for which few suitable genes have been identified . (C) 2000 Academic Press.