Iotatubothrips Mound & Crespi, 1992

Mound, Laurence A., Tree, Desley J. & Wells, Alice, 2022, Convoluted maxillary stylets among Australian Thysanoptera Phlaeothripinae associated mainly with Casuarinaceae trees, Zootaxa 5190 (3), pp. 301-332 : 326-327

Iotatubothrips Mound & Crespi

Iotatubothrips Mound & Crespi, 1992: 400 .

Type species Iotatubothrips crozieri Mound & Crespi , by monotypy.

The two species previously described in this genus, plus the new species described below, are all known to induce woody galls on the stems of Casuarina species. Within these galls the species develop large colonies, mainly of micropterous females with relatively few males and even fewer macropterae. The majority of character states observed on these species are subject to extreme reduction. Many body parts are particularly weakly sclerotised, such that it is difficult to recognise relationships to any other genera. Moreover, each of the species has proved difficult to slide-mount, because the body contents are remarkably resistant to chemical treatment. Curiously, the abdomen of females lacks a fustis, the sclerotised rod in segment IX that is usually found in Phlaeothripidae . However, this genus shares more character states with Adrothrips than with any other Phlaeothripinae genus. The structural variation between morphs and its relationship to aspects of the biology of two species was discussed by Mound et al. (1998), together with illustrations of the differences between macropterae and micropterae in setae on the head and pronotum.

Diagnosis. Small, light brown, usually micropterous Phlaeothripinae in woody galls on Casuarina species. Head slightly wider than long; postocular setae short (long in macropterae); maxillary stylets retracted almost to postocular setae, less than one-third of head width apart. Antennae 8-segmented; segments short and wide, III without sense cones, IV with 2 sense cones. Pronotum transverse, with 5 pairs of major setae, these long and slender in macropterae. Prosternal basantra absent; ferna irregular; mesopresternum reduced to lateral triangles that are often fused to mesoeusternal margin; metathoracic sternopleural sutures present but irregular. Metanotum weakly reticulate, with several pairs of small setae medially. Fore tarsal tooth prominent in both sexes; fore tibia with or without tubercle on inner apex. Fore wing broad, without duplicated cilia. Pelta bell-shaped in macropterae, eroded to small sclerite in micropterae; tergites II–VII each with one pair of wing-retaining setae; tergal lateral setae long and slender; segment IX of female without obvious fustis; tube very short, often much shorter than head; in female dorsal apical margin prolonged beyond ventral margin; in male deeply excavate ventrally to about 90% of length in some species. Male without sternal pore plate; phallotheca slender and unusually long, 5 times as long as basal width in micropterae but 10 times as long as basal width in macropterae.

Key to Iotatubothrips species

1. Micropterae with pronotal major setae all capitate; macropterous female uniformly mid to dark brown; tergal wing-retaining setae long, straight to weakly sigmoid.......................................................... daguilari sp.n.

-. Micropterae with pronotal midlateral, epimeral and posteroangular setae finely pointed, about 0.5 as long as median length of pronotum; macropterous female yellowish to light brown; tergal wing-retaining setae distinctly sigmoid................ 2

2. Fore tibiae of all morphs with no tubercle at inner apex; male macroptera with phallotheca no more than 6 times as long as phallobase...................................................................................... crozieri

-. Fore tibia inner apex of all females, also male micropterae, with small sharply pointed tubercle; male macroptera without fore tibial tubercle; phallotheca about 10 times as long as phallobase........................................... kranzae