Both sexes micropterous, fully winged adults not seen. Body dark brown with abdominal segments III–VI slightly paler; tarsi yellow, tibiae variably yellowish brown; antennal segments I-III yellowish, IV–VIII brown. Head transversely reticulate in ocellar triangle, striate posterior to occipital ridge; occipital apodeme close to but not confluent with posterior margin of eyes; ocellar setae III on margins of ocellar triangle; maxillary palps 3-segmented. Pronotum with transversely anastomosing striae, closely spaced on median "blotch", but no fine sculpture lines between the main striae. Mesonotum with transverse striations. Metanotum transversely striate on anterior two-thirds, posterior with about six rows of closely spaced microtrichia; median metanotal setae arising about 0.5 times their length from the anterior margin. Metasternal plate with anterior margin weakly emarginate. Tergites fully covered with densely spaced microtrichia, bearing three pairs of large discal setae; tergite IX with 2 pairs of mid-dorsal setae and no campaniform sensilla; sternites II–VI with lobed craspedum bearing microtrichia, absent medially on VII.
Male similar to female but smaller, sternite VIII with postero-marginal setae S1 more than 100 microns long.
The monophyly of Thripidae subfamily Sericothripinae was recently confirmed by Lima & Mound (2016), and the current concept of three valid genera within the subfamily follows Wang (2007) and Mound & Tree (2009). The genus Sericothrips currently comprises eight species that occur mainly in the northern hemisphere, but only two species are known from Europe (zur Strassen, 2003). These two species are similar to each other in colour and structure, but are readily distinguished by the position of the median metanotal setae, the distribution pattern of microtrichia on the metanotum, and the number of mid-dorsal setae on tergite IX of females. Species of Sericothrips have the abdominal tergites fully covered with rows of microtrichia, in contrast to species of Hydatothrips and Neohydatothrips.
Apparently feeding and breeding on leaves rather than in flowers, this species is associated in Europe with the Fabaceae species Lotus corniculatus and Trifolium repens.
Collected infrequently in Britain, but across a wide area from South East England to several parts of northern Scotland (Mound et al., 1976, as S. abnormis). It is widespread in Europe and on to western Siberia and Georgia. This species has a complex nomenclatural history (Collins, 2010a); the current species concept follows zur Strassen (1980).
THRIPIDAE - SERICOTHRIPINAE
Sericothrips bicornis (Karny)
Rhytidothrips bicornis Karny, 1910: 50
Collins DW. (2010a) Thysanoptera of Great Britain: a revised and updated checklist. Zootaxa 2412: 21–41.
Lima EFB & Mound LA (2016) Systematic relationships of the Thripidae subfamily Sericothripinae (Insecta: Thysanoptera) Zoologischer Anzeiger 263: 24–32.
Mound LA, Morison GD, Pitkin BR & Palmer JM (1976) Thysanoptera. Handbooks for the Identification of British Insects 1 (11): 1–79.
Mound LA & Tree DJ (2009) Identification and host-plant associations of Australian Sericothripinae (Thysanoptera, Thripidae). Zootaxa 1983: 1–22.
Wang C-L (2007) Hydatothrips and Neohydatothrips (Thysanoptera, Thripidae) of East and South Asia with three new species from Taiwan. Zootaxa 1575: 47–68.
zur Strassen R (1980) Die west-paläarktischen Fransenflügler-Arten von Sericothrips Haliday 1836, Hydatothrips Karny 1913, und Neohydatothrips John, 1929 (Thysanoptera, Thripidae). Polskie Pismo Entomologiczne 50: 195–213.
zur Strassen R (2003) Die terebranten Thysanopteren Europas und des Mittelmeer-Gebietes. Die Tierwelt Deutschlands 74: 1–271.