Body dark brown, tibiae and tarsi yellow; fore wings greyish brown. Antennae 7-segmented, segment III shorter than IV, both with forked sense cones. Head longer than wide, clearly projecting in front of eyes; ocellar setae pair I absent; postocular setae in a transverse row. Pronotum with two pairs of posteroangular setae; metanotal median setae behind anterior margin. Abdominal tergites without ctenidia, tergite X with a median longitudinal split. Sternites II–VII with 4 to 16 discal setae.
Male not known.
Intraspecific variation
Not recorded.
Genus and similar species information
There are 17 species listed in Plesiothrips, mostly light brown to yellowish brown with grey fore wings. All of them live on grasses, and the genus represents a radiation that is unique to the American continent. They all have the ovipositor weak with serrations almost absent, which suggests that they possibly deposit their eggs within grass flowers, rather than into plant tissues. Possibly related to the genus Thrips due to having a similar position of the rudimentary ctenidia on tergites VI & VII, and absence of ocellar setae pair I. Plesiothrips setiventris is unique in the genus in having discal setae on the abdominal sternites. A key to Plesiothrips species is given by Mound et al. (2016).
Hood JD (1950) Brasilian Thysanoptera II. Revista de Entomologia 21: 1–113.
Mound L, Lima E, O’Donnell C, Cavalleri A (2016) New World grass thrips of the genus Plesiothrips (Thysanoptera: Thripidae). Austral Entomology 55: 340–346.
Published in: 30/12/2016 Posted by: Mariana Lindner
