Described from four females, this species has not been studied by the present authors. A yellow species, with no sternal discal setae, it differs from the tropical pest species, T. palmi, in having only three setae on the lateral margins of the second abdominal tergite.
T. helvolus has been compared to two other North American members of the genus (Nakahara, 1994: 67), including T. heraclei. The genus Thrips is the second largest genus in the Thysanoptera, and currently includes, worldwide, about 295 species. All members of the genus lack ocellar setae I on the head, and they all have ctenidia on tergite VIII posteromesad to the spiracles. Other characters, such as number of antennal segments, number of setae on the fore wing veins, and number of discal setae on the sternites are variable between species (Palmer, 1992; Mound & Masumoto, 2005).
Nothing is known of the biology of this species.
Known only from California.
THRIPIDAE - THRIPINAE
Thrips helvolus Nakahara
Thrips helvolus Nakahara, 1994: 67
Mound LA & Masumoto M (2005) The genus Thrips (Thysanoptera, Thripidae) in Australia, New Caledonia and New Zealand. Zootaxa 1020: 1–64.
Nakahara S (1994) The genus Thrips Linnaeus (Thysanoptera: Thripidae) of the New World. United States Department of Agriculture. Technical Bulletin 1822: 1–183.
Palmer JM (1992) Thrips (Thysanoptera) from Pakistan to the Pacific: a review. Bulletin of the British Museum (Natural History) Entomology Series 61 (1): 1–76.