Body brown, paler medially, legs yellow; fore wings yellowish. Antennae 8-segmented with terminal segment fully divided, or 7-segmented with terminal segment entire; segment III shorter than IV, both with forked sense cones. Head longer than wide, ocellar setae pair I present, pair III on anterior margins of ocellar triangle; median pair of postocular setae absent. Pronotum longer than wide, with two pairs of posteroangular setae; metanotal median setae arising at anterior margin. Abdominal tergites without ctenidia, tergite X with a median longitudinal split. Sternites without 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 longicollis is one of only two species in the genus that have a pair of setae in front of the first ocellus, but unlike P. sculpticollis there are no transverse striae on the pronotum. A key to Plesiothrips species is given by Mound et al. (2016).
Hood JD (1954) Brasilian Thysanoptera IV. Proceedings of the Biological Society of Washington 67: 17–54.
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
