Print Fact SheetOxythrips ajugae

Distinguishing features

Both sexes fully winged. Body weakly bicoloured, abdomen brown but head and thorax slightly paler, tarsi and apices of tibiae yellow; distal antennal segments brown, segments I–III paler; fore wings weakly and evenly shaded. Antennae 8-segmented, III and IV each with slender forked sense cone. Head wider than long; 3 pairs of ocellar setae, pair III just anterolateral to ocellar triangle, as long as one side of triangle; maxillary palps 3-segmented. Pronotum transverse, with one pair of posteroangular setae; discal area weakly striate/reticulate. Mesonotum with paired anterior campaniform sensilla, median setae on posterior half of sclerite. Metanotum reticulate medially; median setae posterior to anterior margin; campaniform sensilla present on anterior half of sclerite. Mesothoracic furca with spinula, metafurca with no spinula. Fore tarsal pulvillus with apical claw. Fore wing first vein with 3 widely spaced setae distally, second vein with at least 12 setae. Abdominal tergites with neither craspedum nor ctenidia; tergites V–VIII discal area with no sculpture medially; VIII with no posteromarginal comb; IX with 2 pairs of campaniform sensilla; X subequal in length to IX, with long median split. Pleurotergites irregularly reticulate, without discal microtrichia or setae. Sternites II–VI each with about 6 discal setae; setae S1 on VII arise submarginally.
Male similar to female but smaller; tergite IX with 2 pairs of short stout setae; sternites without discal setae, III–VI with small pore plate.

Related species

There are 39 species listed in the genus Oxythrips, mainly from the Holarctic region, together with a further 12 species known only as fossils. A key to 18 species from Europe is provided by zur Strassen (2003), but some of these species remain poorly defined, including three of the five recorded from Britain. However, ajugae is distinguished by the presence of a small tooth on the apex of the fore tarsal pulvillus, although this species appears to interbreed with bicolor in the Aberdeen area judging from the production there of gynandromorph individuals (Mound, 1970). These two species appear to differ in the sculpture of the abdominal pleurotergites, and the presence or absence of discal setae on sternite VII. The genus is probably related to Anaphothrips, but is distinguished because all of the species have a single pair of pronotal posteroangular setae (Masumoto & Okajima, 2017a).

Biological data

Feeding and breeding in flowers and pupating at ground level, but apparently specific to the male cones of species of Pinus [Pinaceae].

Distribution data

Known in Britain from Surrey to Caithness, and also recorded from the Republic of Ireland (Mound et al., 1976), this species is widespread across Europe from Norway to Turkey.

Family name

THRIPIDAE - THRIPINAE

Species name

Oxythrips ajugae Uzel

Original name and synonyms

Oxythrips ajugae Uzel, 1895: 136
Oxythrips ajugae bicolor Uzel, 1895: 136
Oxythrips pernicis Bagnall, 1926: 283
Oxythrips flavus Morison, 1928: 160

References

Masumoto M & Okajima S  (2017a) Anaphothrips genus-group: key to world genera, with two new species and three new records from Japan (Thysanoptera, Thripidae). Zootaxa 4272 (2): 201–220.

Mound LA (1970) Sex intergrades in Thysanoptera. Entomologist's Monthly Magazine 106: 186–189.

Mound LA, Morison GD, Pitkin BR & Palmer JM (1976) Thysanoptera. Handbooks for the Identification of British Insects 1 (11): 1–79.

zur Strassen R (2003) Die terebranten Thysanopteren Europas und des Mittelmeer-Gebietes. Die Tierwelt Deutschlands 74: 1–271.