Polytrichothrips Priesner

Okajima, Shûji & Masumoto, Masami, 2023, Six genera of the subtribe Macrothripina from Southeast Asia to Taiwan (Thysanoptera, Phlaeothripidae, Idolothripinae), Zootaxa 5291 (1), pp. 1-74 : 68

Polytrichothrips Priesner

Polytrichothrips Priesner, 1939: 77 . Type-species: Polytrichothrips pilosus Priesner (= Docessissophothrips laticeps Bagnall ), by monotypy.

The genus Polytrichothrips was described from Sarawak, Borneo, with unique species, P. laticeps . Subsequently, Mound (2007) described additional species, P. geoffri , from Queensland, Australia. The type-species has three pairs of long cephalic setae, the postoculars, postocellars and mid-vertexals, although geoffri has only one pair of long setae, the postoculars. Therefore, a combination of three morphological features seemed to characterise this genus until now: the maxillary stylets are deeply retracted to the level of the compound eyes and close together medially; the head has a pair of ommatidium-like structures on the cheeks ventro-laterally near base; the metanotum and pelta are scarcely sculptured. However, similar maxillary stylets and ommatidium-like structures are also found in Peltariothrips and Tarassothrips , though Peltariothrips has the shorter head with the maxillary stylets somewhat wider apart from each other in the middle of head. Tarassothrips has the ommatidium-like structures situated at the middle of cheeks, and has the unusually long sense-cones on the antennal segments. Moreover, Ethirothrips tenuis has the similar elongate maxillary stylets, and E. ommatus has the similar ommatidium-like structures situated behind the middle of cheeks. As a result, the genus Polytrichothrips is hardly distinguished among the Macrothripina by the peculiar weakly sculptured metanotum and pelta, and its generic status requires re-examining.

Key to Polytrichothrips species

(*: based on the description)

1. Postocellar and mid-vertex setae elongate............................................................ laticeps *

- Postocellar and mid-vertex setae short, at least shorter than 1/3 as long as postocular setae (cf. Fig. 205 )................ 2

2. Prothoracic notopleural suture complete; antennal segments I and II dark brown: head longer, more than 1.3 times as long as wide.......................................................................................... geoffri *

- Prothoracic notopleural suture incomplete ( Fig. 205 ); antennal segments I and II brownish yellow, distinctly paler than head ( Fig. 206 ); head shorter, about 1.1 times as long as wide …………………………………………………….. malayanus sp. n.

Figures

FIGURES 203–210. Polytrichothrips malayanus sp. n., female. (203) Fore tarsus; (204) ommatidium-like structure; (205) head & prothorax; (206) antenna; (207) prosternum & mesopresternum; (208) mesonotum to pelta; (209) abdominal segment IX & tube; (210) abdominal tergites III–IV.