Both sexes fully winged. Body, legs and antennae brown, except yellow basal half of antennal segment III; fore wing pale with posterior half dark including clavus. Antennae 9-segmented, VII–IX forming a unit with IX much shorter than VIII; sensoria on III–IV linear, on III usually 0.4 as long as segment, on IV more than 0.5. Head and pronotum with no long setae. Fore tarsus with hamus small. Metanotum with one pair of setae at anterior margin and one pair near posterior, sculpture weakly arcuate around anterior margin. Fore wing slender with apex rounded. Abdominal tergites IV–VI without sculpture medially; trichobothria on X very small. Sternites IV–VI each with two pairs of posteromarginal setae and 12 to 14 setae on discal area, chaetotaxy on VII similar with two pairs of supernumerary setae submarginally.
Male similar to female but abdomen more slender; tergite I with pair of short longitudinal ridges.
A total of 12 species is listed currently in the genus Erythrothrips, although two of these (E. bishoppi from Texas and E. fasciculatus from California) cannot at present be distinguished satisfactorily from E. arizonae and these are all likely to represent the same species. Of the remaining nine species, one is from California, one from Argentina, two from Brazil, three from Peru, and two from Mexico (although these last two are also likely to represent a single species) (Mound & Marullo, 1993). The name E. fasciculatus is applied to relatively small specimens in which the sensorium on antennal segment III is scarcely 0.3 as long as the segment, but these specimens have been taken from the same host plant, Adenostoma, as E. arizonae.
Erythrothrips arizonae Moulton
Bailey (1957) indicates that the larva spins a pupal cocoon, and that the adults are found in spring in California. Adults and larvae are possibly predatory on the larvae of other thrips.
Yucca brevifolia (Agavaceae); Adenostoma fasciculatum (Rosaceae)
California, Arizona, Nevada, Mexico.