Rohrthrips breviceps, Ulitzka, 2019

Ulitzka, Manfred R., 2019, Five new species of Rohrthrips (Thysanoptera: Rohrthripidae) from Burmese amber, and the evolution of Tubulifera wings, Zootaxa 4585 (1), pp. 27-40 : 29

Rohrthrips breviceps sp. n.

( Figs 1–2 )

Male. Body slightly contracted; legs retracted under body; wings (except extreme base) missing as well as segments VII–IX of right antenna; tips of anal setae broken off; fore ocellus concealed by a bubble of air.

Colour ( Fig. 1 ) uniformly dark brown including antennae and legs; all major setae dark.

Head ( Fig.1 ) wider than long, with cheeks rounded behind eyes and converging slightly to base; cheeks lacking setae; one strong pair of long ocellar setae clearly visible close to base of antennae, projecting over apex of antennal segment I. Eyes not protruding over base of antennae, slightly prolonged ventrally. Hind ocelli close to compound eyes; far apart from each other. Vertex with two postocular setae far behind eyes. Antennae 9- segmented; segment I barrel-shaped; segment II basally with asymmetric pedicle, distally inverse cone-shaped; III– VII symmetrical, basally with a slender pedicel, then inverse conically shaped and tapering distally from level of sense cones; segment II apparently with a small distal sensorium (not clearly visible); sense cones short, their number difficult to assess but at least one inner and one outer on III, IV, V and one inner only on VI; segment IX style-shaped, at base much narrower than segment VIII distally. Mouth cone short, but rather pointed. Maxillary palps 2-segmented; labial palps not clearly assessable, very likely 2-segmented. Pronotum wider than long, trapezoidal; anteroangular, mediolateral and posteroangular setae long and pointed, anteromarginal and posteromarginal setae minute; epimeral setae long and pointed. Metanotum with a pair of fine setae far apart from the front margin of the plate. Mesopresternum ( Fig. 2 ) complete and flat boat-shaped; trochantin (“mesoinfrapreepisternum” in Bhatti 1988, p. 196; 1994, p. 108) clearly assessable as a separate sclerite; mesosternellum and metasternum fused. Fore wings torn off, their remnants on both sides recognizable including parts of the clavi, and on the left, the base of most likely one wing vein only. Fore legs with femora stout; fore tarsi with at least one tooth (its size/shape due to position of legs not clearly visible). Mid and hind legs slender. All femora with one long ventral and all tibiae with one long dorsal seta; mid and hind tibiae terminally each with two (or three?) strong spines; mid and hind tarsi two-segmented, with hamus. Abdominal tergites with faint reticulate sculpture, without wing-retaining setae; lateral setae long ( Fig. 1 ), pointed; setae s3 on V–VII longer than other lateral setae and conspicuously bent inwards. Abdominal segment I (pelta) not assessable; IX conical, with setae s3 long and protruding tube; sternite IX with subgenital plate. Abdominal segment X (tube) extended at base; basally reticulate sculptured and entirely furnished with tiny setae; apparently without campaniform sensilla; with terminal crown of anal setae.

Measurements. Male (in microns): Body, length 1245 (slightly contracted). Head, length 139; width 195. Eyes, dorsal length 63; ventral length 76; dorsal width 44. Hind ocelli, diameter 14; distance between the hind ocelli 71. Ocellar setae 43. Postocular setae 47. Prothorax, length 171; width 410; anteroangular setae about 20 (difficult to measure); mediolateral setae 63; posteroangular setae 100; epimeral setae 107. Pterothorax, largest width 403. Mesonotal lateral setae about 62; metanotal median setae 53. Abdomen, length 711 (slightly contracted); largest width 359 (segment II); segment X (tube), length 176; basal width 75. Setae s3 on tergite IX 240. Antennae, length 444; length (largest width) of segment I 40 (28), II 56 (26), III 71 (34), IV 68 (31), V 62 (25), VI 50 (22), VII 47 (19), VIII 34 (9), IX 16 (3). Sense cones, length of inner (outer) on segment III 12 (16), IV 16 (16), V 9 (11); VI 9 (–); basal width 3–4.

Material studied. Holotype male MU-Fos-81/1. Inclusion in Burmese amber donated to the author by Patrick Müller.

Syninclusions. Stellate hairs and small particles of plant detritus; asci and fungal spores, some spores attached to body setae of the thrips.

Etymology. The specific epithet breviceps comes from the Latin words brevis, meaning “short”, and ceps, meaning “head”. It refers to the conspicuously short head of this species.

Figures

FIGURES 1–4. Rohrthrips spp. R. breviceps sp. n. holotype male 1–2: (1) dorsal view; (2) pterothoracic sternal plates (green: mesopresternum, yellow: mesosternum, red: trochantin, violet: mesokatepisternum, blue: metasternum). (3) R. jiewenae sp. n. holotype female, dorsal view, indicated: fungal spores. (4) R. maryae sp. n. holotype male, pterothoracic sternal plates.