The immature stages of the genus Trepobates Uhler (Hemiptera: Heteroptera: Gerridae), with an identification key to instars and the description of the nymphs of T, taylori (Kirkaldy)

摘要

The egg and five instars of Trepobates are described based on examined material of T. taylori and published information of T. inermis, T. knighti, T. panamensis, T. pictus, T. subnitidus and T. trepidus. The characters most useful in identifying nymphs I-V of Trepobates are: the width of the head; the lengths of the antennae, femora 1-3, tibiae 2-3 and tarsus 2-3; the Y-shaped ecdysial line of the head; the colour patterns of the pro- and mesonotum; and the urosternites VIII and IX. A key to the fivenymphal instars of Trepobates is provided. The five instars of T. taylori are described and illustrated for the first time, with emphasis on the morphometry and colour pattern of selected structures, and chaetotaxy of the antennae; the egg is figured and redescribed. The characters useful in identifying nymphs I-V of this species are: the colour pattern of the head; the chaetotaxy of the antennal segment I; the lengths of the antennal segment III and mesonotum; and the width of the pronotiim. Differences between sexes in nymphs IV and V are presented.