Phylogenetic relationship of seven Dendrolimus (Lepidoptera: Lasiocampidae) species based on the ultrastructure of male moths' antennae and antennal sensilla.

The morphology and ultrastructure of the antennae and antennal sensilla of seven male Dendrolimus species and a male Trabala vishnou gigantina (Yang) (Lepidoptera: Lasiocampidae) were examined by light microscope and scanning electron microscope. Six morphological types of antennal sensilla were identified: Sensilla trichodea, Sensilla chaetica, Sensilla styloconica, Sensilla coeloconica, Böhm bristles, and foot-like sensilla. Six of the Dendrolimus moths and Trabala vishnou gigantina Yang share the same antennal sensilla type, as do various geographic populations of the same species. The exception, Dendrolimus spectabilis Butler, has foot-like sensilla. However, the antennal sensilla subtypes were significantly different among species and/or populations. There were no remarkable differences in the width of the scape, pedicel, subflagellum, and the side-branches between the eight male species studied. However, we observed significant differences in the number of flagellomere and the length of scape, pedicel, subflagellums, and side-branches. The length and basal diameter of various types of antennal sensilla did not vary significantly among Dendrolimus moths. Beyond that, there were no differences among populations of the same kind of species. Hierarchical cluster analysis found two clusters: the first contained D. punctata punctata (Walker), D. punctata wenshanensis (Tsai et Liu), D. tabulaeformis (Tsai et Liu), and D. spectabilis and D. superans (Butler), and the second contained D. grisea (Moore) and D. kikuchii kikuchii (Matsumura). Trabala vishnou gigantina was placed separately from the two clusters. We conclude that D. punctata wenshanensis,D. tabulaeformis, and D. spectabilis are geographic subspecies of D. punctata punctata.