Leptothrips larreae Hood, 1939

Mound, Laurence & O’Donnell, Cheryle, 2017, Predation, phytophagy and character state confusion among North American species of the genus Leptothrips (Thysanoptera: Phlaeothripinae), Zootaxa 4294 (3), pp. 301-315 : 308

Leptothrips larreae Hood

Leptothrips larreae Hood, 1939: 207 .

Described from Arizona, with paratypes from California, all associated with Larrea tridentata [ Zygophyllaceae ], this species probably feeds on mites within cecidomyiid galls on this plant ( Wiesenborn 2015). More than 100 slide mounted specimens from Larrea have been studied (from ERMR), mainly collected in California. When the head is truly horizontal, the compound eyes are clearly longer ventrally than dorsally (but see caveat above). The postocular setae are short, 20–25 microns in length, scarcely reaching the posterior margin of the eye. The number of duplicated cilia on the fore wing is variable within any given population, with bilateral asymmetry in the number being common. At least 10% of adults have no duplicated cilia on one or both fore wings. Antennal segment IV usually has three sense cones, but a very few specimens have been seen with only two on one antenna. Moreover , the small ancillary sense cone (= sensillum coeloconicum) on the external margin of segment IV is present in most examined specimens, but cannot be seen on one or both antennae of a substantial minority of specimens. Despite this variation, the specimens from Larrea consistently have antennal segments III and IV rather short, and antennal segment III with no sense cone. However , not all Leptothrips individuals collected from Larrea are identifiable as larreae . Three specimens from Larrea at Banning , California, have a sense cone on antennal segment III, and antennal segments III+IV more than 160 microns long; the two females have four sense cones on segment IV but the male only three, and the number of duplicated cilia varies from 1 to 4 on these three specimens.