Lissothrips discus Mound & Tree, 2015, sp.n.

Lissothrips discus sp.n.

(Figs 2, 9, 14, 18)

Female microptera. Body, legs and antennae brown, tube and antennal segments I–III darkest; major setae pale. Head slightly wider than long, weakly reticulate near posterior margin (Fig. 9); compound eyes small, with about 12 large facets dorsally, also about 8 ventrally narrowing to a single facet at posterior; po setae long and capitate; maxillary stylets retracted to level of po setae, about one third of head width apart medially. Antennae 8- segmented, III short and disc-shaped with no sense cones (Fig. 2), IV with 3 stout sense cones, VIII slender and narrowed to base. Pronotum transverse, without sculpture (Fig. 14); notopleural sutures incomplete; major setae all long and capitate. Fore tarsus with no tooth. Mesonotum with faint transverse sculpture (chaetotaxy of holotype aberrant, Fig. 18); fore wing lobe with 2 capitate setae; metanotum without sculpture, median setae wide apart small and fine. Prosternal ferna not developed; basantra bluntly pointed medially; mesopresternum reduced to slender lateral triangles; anterior margin of mesoeusternum transverse; metathoracic sternopleural sutures not developed. Abdomen with pelta broadly flattened, almost without sculpture, campaniform sensilla present (Fig. 18); tergites with median setae minute, III–VI with 2 pairs of long capitate setae laterally, VII–VIII with external pair acute; tergite IX setae finely acute and longer than tube; anal setae longer than tube. Sternites with 8 to 10 small discal setae, median marginal setae longer than lateral pair.

Measurements (holotype female in microns). Body length 1600. Head, length 150; width 170; po setae 45. Pronotum, length 100; width 220; setae—am 35, aa 35, ml 45, epim 35, pa 45. Fore wing lobe 45. Tergite IX setae S1 125. Tube length 55. Antennal segments III–VIII length, 20, 40, 40, 45, 43, 30.

Material studied. Holotype female microptera, Australia, Queensland, Carnarvon Station [approx. 190km NNW of Roma], from dead wood, 8.x.2014 (DJT 1861).

Comments. This species is distinguished from all other members of the genus by the remarkable disc-like shape of the third antennal segment. Apart from that, it shares with the two new species, corticosus and hypni, the presence of capitate po setae and a well-developed wing lobe. The head of the only known specimen is slightly crushed (Fig. 9), and the natural head width is probably little more than the head length.