Scirtothrips Shull 1909

Scirtothrips Shull, 1909

Scirtothrips Shull, 1909: 222. Type species Scirtothrips ruthveni Shull.

Sericopsothrips Hood, 1936: 83. Type species Sericopsothrips palloris Hood. syn.n.

Hood described Sericopsothrips for a single species that remains known only from a single female, collected from blueberry flower in 1934 at Canandaigua, New York. He compared the genus to Sericothrips, but curiously made no reference to Scirtothrips. In contrast, based on the description, Stannard (1968) stated that the genus would “key to Scirtothrips ”, although Masumoto and Okajima (2007), also Mound (2009), stated that Sericopsothrips could be distinguished from Scirtothrips by having a pair of long posteroangular setae on the pronotum. Again, however, the comments by these authors were based only on the original description. The holotype female of palloris has now been examined, and the pronotal setae S2 are 50 microns long (Fig. 7). This is not significantly longer than the 45 microns long setae of S. ewarti Bailey from western USA, nor the 30 microns long setae of the common pest species S. citri (Moulton). In other character states, the species palloris is a typical member of Scirtothrips, with the inner dorsal seta on antennal II conspicuously longer than the outer seta, and the genus is here placed into synonymy. The species level taxonomy of North American Scirtothrips species remains unsatisfactory (Hoddle et al. 2012), and comparisons of Scirtothrips palloris comb.n. with other species are currently not possible. However, it is a pale individual, with no obvious darker markings, the ocellar area bears widely spaced irregular transverse striae and setae pair III are closer together than the diameter of the first ocellus, the metanotum has elongate reticulation with the median setae arising far behind the anterior margin, the lateral microtrichial fields on the tergites bear three pairs of setae, and no discal microtrichia are visible on the ninth tergite; the sternites are not visible. As a result of this synonymy, Scirtothrips now comprises 110 species, most of which are found in the warmer parts of the world. Several species have been reported as pests on a range of important crops, including avocado, capsicum, citrus, grapes, mango, strawberry and tea (Hoddle & Mound 2003). As noted in the key above, one recently described species, S. malayensis, is unusual in that the holotype and several (but not all) paratypes lack ocellar setae pair I, a remarkable condition that was not noted in the original description (Ng et al. 2014).