Leptothrips distalis (Hood)

Haplothrips distalis Hood, 1925: 103 .

Zygothrips californicus Mason, 1926: 156 . Synonymy in Cott, 1956: 101. Leptothrips pristinus Johansen, 1987: 33 . Syn. n.

This is another member of the genus known only from the western States. It is one of the few species in the genus with a small tooth on the inner margin of the fore tarsus, but is distinguished from two other species with this structure by the presence of several duplicated cilia on the fore wing. The pronotum bears transverse striae, the pronotal mid-lateral setae are present as in fasciculatus, but the mesonotum is closely striate in contrast to that species (Fig. 28). Cott (1956: 103) indicated that distalis had been found breeding in large numbers on a species of Atriplex at Firebaugh (near Fresno) in California. He stated that the plants were severely damaged by this thrips, and made no reference to the possibility that it might be predatory. Johansen described pristinus from Baja California, and distinguished it because of the presence on antennal segment IV of a small accessory sense cone on the external margin. However, as discussed above, the presence of these minute sensilla coeloconica appears to be unstable in some species, and examination of a paratype of pristinus (in USNM) suggests that this species cannot be distinguished satisfactorily from distalis .