Arachisothrips Stannard

(Figs 3, 67)

Three species are currently listed in this genus, each of them with the basal half of the fore wing grossly inflated and reticulate (Fig. 3). The antennae are 8-segmented, with simple sense cones on segments III and IV, and VIII 3.5 times longer than segment II (Fig. 34). The pronotal setae are small, but the metanotum has a pair of long setae. The male of A. millsi may be the smallest known Thysanopteran, with body length about 0.6 mm (Wilson 1975). It lacks ocelli, and in contrast to the female the distal flat portion of the fore wing is shorter with no posterior fringe; abdominal sternites VII and VIII have a broad transverse pore plate. One of the three species, A. latipennis, was described by Wilson (1975) from a single female with two pairs of metanotal setae, whereas Hood (1955) described A. seticornis from a single female with the anterolateral pair of metanotal setae minute and hair-like. In contrast, the many specimens of the type species, A. millsi Hood, recorded by Wilson (1975), also those examined for the present review, lack this anterolateral setal pair (Fig. 67). The host plant remains unknown, but the present authors hypothesize that the wing configuration may provide an advantage in using wind currents to disperse. Laurence Mound (pers.com.) has pointed out that many specimens of A. millsi were taken in February 2013 at Puntarenas, Costa Rica by insecticide fogging of forest canopy. He suggested that this thrips might live in the epiphytic Bromeliads on rain forest trees, and that the curious fore wings might be hygrophobic in that semi-aquatic habitat. In Brazil, A. millsi was previously recorded in Santa Catarina and Rio Grande do Sul States, but further females were collected in Chapada dos Guimarães, State of Mato Grosso (11.ix.2011) (CHNUFPI), from grasses and in Roraima State, in Malaise trap (1–15.ii.2016) (CHNUFPI).