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Thrips of California 2012

Pseudophilothrips varicornis

Recognition data

Distinguishing features

Both sexes fully winged. Body and legs blackish brown, antennal segment III sharply yellow; major setae brown, tergite IX setae paler; fore wing deeply shaded around sub-basal setae, with median longitudinal dark line extending to shaded distal area. Head slightly longer than wide, ocellar region overhanging interantennal projection; maxillary stylets retracted to eyes, close together medially; post ocular setae longer than dorsal length of eyes with apices softly pointed; mouth cone extending between fore coxae. Antennae 8-segmented; segment III with one sensorium, IV with three sensoria; VIII slender and constricted at base. Pronotum with five pairs of long major setae with rounded apices, posteroangular setae almost as long as median length of pronotum, epimera with a second pair of stout setae variable in length; epimeral sutures complete; prosternal basantra not developed, ferna present, mesopresternum divided into paired lateral triangles sometimes meeting medially. Fore tarsus without a tooth. Metanotum reticulate, median setae long. Fore wing parallel sided, with about 18 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; tergite IX setae S2 as long as S1; sternite VIII with an extensive pore plate.

Related and similar species

P. varicornis was transferred from the genus Liothrips by Mound et al. (2010) because the males have setae S2 on the ninth tergite long and slender as in females, whereas all species of Liothrips have this pair of setae short and stout. In this and several other characters it resembles the Central American species, P. avocadis and P. perseae, but differs in the color of the fore wings and length of the antennal segments. Currently, there are 290 species listed in the genus Liothrips, although 30 of these are placed in two sub-genera known only from Asia. As a result, this is larger than either Thrips or Haplothrips, these three being the largest genera of Thysanoptera. However, in comparison to both Thrips and Haplothrips there are far greater problems in Liothrips in species recognition. A particularly high proportion of the described species are known from single samples, or even single individuals, resulting in little knowledge of variation within and between species, and thus the general assumption that most members of the genus are host-specific requires extensive testing. 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, two of which 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.

Taxonomic data

Current valid name

Liothrips varicornis Hood

Original name and synonyms

  • Liothrips varicornis Hood, 1912: 74

Family placement

Phlaeothripidae, Phlaeothripinae

Common names

Hollyhock thrips

Biological data

Life history

The bright red larvae occur in colonies on stems and leaves of hollyhocks, and their activities result in feeding lesions (Bailey, 1938).

Host plants

Multiple records from Althea, Hibiscus, Sida and Sphaeralcea (Malvaceae).

Tospoviruses vectored


Crop damage


Distribution data

Area of origin

Southwest USA


California, Mexico, Bahamas, Hawaii, Tahiti.