Scirtothrips inermis Priesner

Hoddle, Mark S. & Mound, Laurence A., 2003, The genus Scirtothrips in Australia (Insecta, Thysanoptera, Thripidae), Zootaxa 268, pp. 1-40 : 22

Scirtothrips inermis Priesner

[ Figs 12 , 44 ]

Scirtothrips inermis Priesner, 1933: 186 ­188.

Described from the Canary Islands, this species has been recorded from California, New Zealand and South Australia ( Palmer & Mound, 1983), and has been taken from a wide range of unrelated trees and herbs. It is similar to the tropical species S. dobroskyi in having unusually long posteromarginal setae S2 on the pronotum, but the ocellar setae pair III are longer than in any endemic Australian species. S. inermis usually has at least one more discal seta on the tergal microtrichial fields than in other members of the genus. The male is described as lacking drepanae on the ninth tergite, but no males have been seen from Australia. The second instar larvae have the pronotum with reticulate sculpture, much as in S. aurantii . Several females have been studied from near Adelaide (ix.1994) on Viburnum [ Caprifoliaceae ], also females and larvae from cultivated Gerbera [ Asteraceae ] at Silvan in Victoria (x.2002).

Female macroptera. Colour: Yellow, antecostal ridges on tergites and sternites dark; forewings shaded near base but pale distally; antennal segment I pale, II – VIII darker.

Structure: Vertex closely striate, ocellar region with several transverse lines; ocellar setae pair III about twice as long as diameter of one posterior ocellus, close together between midpoints of posterior ocelli; two pairs of post­ocular setae. Pronotum with transverse striae not closely spaced, distance between lines about equal to diameter of a discal setal pore; 2 anteromarginal setae, about 10 discal setae; 4 pairs of posteromarginal setae, S2 50 – 65 microns long, more than twice diameter of antennal segment II. Metanotal reticulation arcuate anteriorly but almost equiangular on posterior half, median setae close to margin. Forewing scale with 4 marginal setae; first vein setae with about 10 setae; second vein 2­3 setae; all posteromarginal fringe cilia straight. Tergite I without long discal setae, III­V median setae longer than distance between bases; tergal microtrichial fields with 4 – 6 discal setae; VIII with discal microtrichia anteromedially, posteromarginal comb complete; IX without discal microtrichia. Sternites III­VI with 3 pairs of posteromarginal setae; microtrichial fields extending just mesad of S2.

Figures

FIGURES 11 ­ 20. Scirtothrips heads and pronota. 11, frondis; 12, inermis; 13, kirrhos; 14, longipennis; 15, litotes; 16, moneres; 17, pilbara; 18, tenor; 19, quadriseta; 20, solus.

FIGURES 38 ­ 44. Scirtothrips abdominal tergites. 38, akakia; 39, albomaculatus VI­IX; 40, australiae VI­IX; 41, drepanofortis I­IV; 42, kirrhos IV­VI; 43, moneres IV­VI; 44, inermis IV­VIII.