Both sexes fully winged. Body and legs blackish brown, antennal segment III yellow, IV dark yellow, V–VI variably yellow in basal 0.25 to 0.6; major setae black, setae on tergites VIII–IX pale; fore wing pale with weak shading along margins. Head distinctly longer than wide; post ocular setae longer than dorsal length of eyes with apices softly pointed. Antennae 8-segmented; segment III with one sensorium, IV with three sensoria; VIII slender and slightly constricted at base. Pronotum with five pairs of long major setae with blunt apices, posteroangular setae almost as long as median length of pronotum; epimeral sutures complete; prosternal basantra not developed, ferna present, mesopresternum divided into paired lateral triangles. Fore tarsus without a tooth. Metanotum with narrow elongate reticulation. Fore wing parallel sided, with about 25 duplicated cilia; three sub-basal setae sub-equal in length. Tergite IX setae S1 finely acute, about as long as tube.
Male similar to female, but antennal segment VI brown, V yellow at base; tergite IX setae S2 as long and fine as S1; sternite VIII without a pore plate.
P. perseae is not known from California, but is included here because it is a potential invader given the expanding avocado cultivation in the State. Together with P. avocadis and P. varicornis it was transferred from the genus Liothrips by Mound et al. (2010) because tergite IX setae S2 of males are as long and fine as setae S1, not short and stout as in the males of Liothrips species. P. perseae has the antennae more extensively yellow than in P. avocadis, particularly in females, with shorter sensoria on segments III and IV. The genus Liothrips, with more than 290 described species, is one of the three largest genera of Thysanoptera. However, in comparison to both Thrips and Haplothrips it involves far greater problems for species recognition and systematics. A particularly high proportion of the described species are known from single samples, or even single individuals, resulting in little knowledge of host relationships or of structural variation within and between species. The general assumption that most members of the genus are host-specific requires validation. Stannard (1957) listed 32 species of Liothrips from North America, and subsequently (Stannard, 1968) included 14 of these in his keys to the Illinois fauna. Cott (1957) treated 11 species from California, including two that he placed in Rhynchothrips, but currently from this State there are 13 Liothrips species listed (Hoddle et al., 2004) of which several cannot at present be recognized.
Liothrips perseae Watson
Breeding on leaves and feeding on young fruit
Persea americana (Lauraceae).
Causing severe damage to leaves and fruit of avocado in Guatemala
Honduras, Guatemala [not known from California].