Enigmathrips, Mound & Tree & Wells, 2022

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 : 316-317

Enigmathrips gen.n.

Type species Enigmathrips carnarvoni sp.n.

Diagnosis. Macropterous or micropterous Phlaeothripinae with convoluted maxillary stylets and elongate pronotum. Antennae 8-segmented ( Fig. 43 ), II with sensorium on basal half of segment, III with one short sense cone, IV with 3 short sense cones; VII pedicillate, VIII small. Head almost twice as long as wide ( Fig. 44 ), posterior margin eroded medially; ocelli small, posterior pair wide apart close to eyes; maxillary stylets retracted to eyes, crossing over each other near eyes but then wide apart and with complex flexures posterolaterally before entering long and pointed mouth cone. Pronotum much narrower than prothorax ( Fig. 46 ), anterior margin strongly eroded between weak anteromarginal setae; remaining setae long and pointed, epimera with second seta well developed; notopleural sutures complete. Prosternal basantra absent; ferna large and wide apart; mesopresternum reduced to small median sclerite ( Fig. 45 ); metathoracic sternopleural sutures long. Meso and metanota weakly sculptured, metanotum with one or more pairs of minor setae medially in addition to small pointed median pair. Fore tarsal tooth stout, longer than tarsal width. Fore wing broad, parallel sided, with closely ciliate margins but without duplicated cilia; with two long weakly capitate sub-basal setae. Pelta triangular with apex truncate; tergite II lateral margins eroded; II–VII with anterior pair of wing-retaining setae absent, only II–IV with posterior pair and these weakly curved; II–VII each with median transverse irregular row of about 20 setae; tergal posterolateral setae long and weakly capitate, but on IX shorter than tube; tube shorter than head.

Comments. The structure of the single species for which this genus is erected is remarkable and the generic relationships are difficult to interpret. The structure of the antennae is typical of species in the Liothrips -lineage, in the number and size of the sense cones on segments III and IV, and the short segment VIII that is broadly joined to segment VII. In contrast, the following character states are more typical of the Plectrothripini : antennal segment II sensorium on basal half of segment, pronotum elongate and narrow, tergite II eroded laterally. A particularly unusual feature is that despite the presence of broad, parallel-sided fore wings there are no sigmoid wing retaining-setae on any of the tergites.

Figures

FIGURES 40–50. Akthethrips, Enigmathrips, Phallothrips, Thaumatothrips. A. strobus 40-42: (40) head; (41) pronotum; (42) metanotum & pelta. E. carnarvoni 43–46: (43) antenna; (44) head; (45) prosternites; (46) pronotum. (47) T. froggatti head & fore legs. P. houstoni 48–50: (48) microptera; (49) macroptera; (50) macroptera tergites V–VII.