Thrips formosanus group

Palmer (1992) listed five taxonomic groups (I–V) for 91 species of genus Thrips from Pakistan and Pacific, primarily based on presence or absence of discal setae on abdominal sternite VII. The species without discal setae on sternite VII were included in groups I, II and III while species with discal setae were included in groups IV and V. Further, group III was distinguished from I and II based on the presence of discal setae on abdominal sternites III–VI. Groups I and II were distinguished from each other based on the metanotal sculpture, which is distinctively reticulate in group I and longitudinally striate with few medial reticulations in group II. Palmer included thirty two species in group II, all of which share absence of discal setae on any of the abdominal sternites and laterotergites except three species ie. xenos Bhatti from India, setosus Moulton and brunneus Ishida from Japan which have at least one discal seta on the laterotergites.

Within this large group II, four species, T. formosanus Priesner from Taiwan, T. obscuripes Priesner and T. rostratus Priesner from Java and T. tanicus Bhatti from India, share the following character states: Body brown; antennae 7–segmented; metanotum with longitudinally reticulate sculpture in middle, median pair of metanotal setae far back from anterior margin; fore wing first vein with 3 setae on distal half; abdominal sternites III–VII and laterotergites without discal setae; tergite VIII with well-developed posteromarginal comb of fine and long microtrichia. However, T. floreus Kurosawa from Japan also shares the above listed characters but was not included in any group by Palmer (1992). Similarly, T. hoddlei Mound and Masumoto from Australia also shares these characters but has the body bicoloured. Therefore, a new species-group ‘ Thrips formosanus group’ is designated here for seven species including a new species, T. moundi. This species-group represents a sub-set of species within the large Group II recognised by Palmer (1992). The phylogenetic significance of species-groups within this genus requires further confirmation; the only sub-group with biogeographical correlation is the four species from New Zealand related to obscuratus that have three, not two, pairs of marginal setae on the second sternite (Palmer 1992).