Female fully winged or hemimacropterous. Body and femora dark brown, tarsi and apices of tibiae yellow; antennae brown with segment III almost yellow, and IV light brown; fore wings shaded but slightly paler medially and pale at base. Antennae 7-segmented; segments III–IV each with short forked sense cone; III 2.0–2.5 times as long as wide, VII short. Head wider than long, with two pairs of ocellar setae; pair III small, arising on anterior margins of ocellar triangle near the first ocellus, pair II longer than III; postocular setae pair II displaced posterior to this row of setae; maxillary palps 2-segmented. Pronotum with 2 pairs of long posteroangular setae, with no discal setae. Metanotum with irregular longitudinal reticulate lines; median setae arising well behind anterior margin; campaniform sensilla present. Fore wing first vein with 3 (sometimes 2) setae on distal half; second vein with row of 7–10 setae. Abdominal tergite II with 4 lateral marginal setae; tergites VI–VIII with paired ctenidia laterally, on VIII posteromesad to spiracles; tergite VIII posteromarginal without a comb; pleurotergites without discal setae. Sternites II–VII with three pairs of marginal setae, S1 arising well in front of posterior margin; sternites without discal setae.
Male smaller than female, micropterous; tergite VIII posterior margin with complete row of weak triangular teeth; sternites III–VII each with slender transverse pore plate.
Three species are now placed in the genus Baliothrips (Bhatti & Mound, 1980; Collins, 2010a; Zhang et al., 2018). Two of these occur in Britain, and they share the unusual character state of setal pair S1 on sternite II arising sub-marginally. Together with Stenothrips graminum, these three species possibly represent a European radiation of grass-living species from the genus Thrips, in which there is a tendency for reduction of the maxillary palps to a 2-segmented condition. This contrasts with the Asian radiation of grass-living species derived from Thrips that are placed in the genera Stenchaetothrips and Fulmekiola, all of which have 3-segmented palps. B. dispar differs from kroli in that the head does not project forward of the eyes, campaniform sensilla are present on the metanotum, and there are transverse pore plates on sternites III–VII in the male.
Feeding and breeding on leaves of various species of Poaceae and Cyperaceae, usually in damp areas.
Widespread in Britain, recorded from Kent to Inverness, and also from Northern Ireland as well as County Dublin in the Republic of Ireland (Morison, 1973b; Mound et al., 1976; O'Connor, 2008). The species is found across the northern Palaearctic, and also in North America (zur Strassen, 2003).
THRIPIDAE - THRIPINAE
Baliothrips dispar (Haliday)
Thrips dispar Haliday, 1836: 449
Thrips brevicornis Haliday, 1836: 449
Thrips sibirica Trybom, 1896: 622
Baliothrips basalis Shull, 1909: 224
Bagnallia agnessae Bagnall, 1911: 7
Bagnallia halidayi Bagnall, 1911: 8
Baliothrips ustulatus Priesner, 1919: 128
Platythrips badius John, 1924: 142
Baliothrips petzi Priesner, 1925: 151
Baliothrips sibiricus Priesner, 1925: 151
Baliothrips exilis Bagnall, 1928: 154
Bhatti JS & Mound LA (1980) The genera of grass and cereal-feeding Thysanoptera related to the genus Thrips (Thysanoptera: Thripidae). Bulletin of Entomology 21: 1–22.
Collins DW (2010a) Thysanoptera of Great Britain: a revised and updated checklist. Zootaxa 2412: 21–41.
Morison GD (1973b) Observations and records for some British Thysanoptera. XVII Thripidae, Baliothrips dispar (Haliday). The Entomologist 106: 157–164.
Mound LA, Morison GD, Pitkin BR & Palmer JM (1976) Thysanoptera. Handbooks for the Identification of British Insects 1 (11): 1–79.
O’Connor JP (2008) A review of the Irish thrips (Thysanoptera). Irish Naturalists’ Journal 29: 20–24.
Zhang SM, Wang ZH, Li YJ & Mound LA (2018) One new species, two generic synonyms and eight new records of Thripidae from China (Thysanoptera). Zootaxa 4418 (4): 370–378.
zur Strassen R (2003) Die terebranten Thysanopteren Europas und des Mittelmeer-Gebietes. Die Tierwelt Deutschlands 74: 1–271.