Rohrthrips schizovenatus, 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 : 33-34

Rohrthrips schizovenatus sp. n.

( Figs 10–15 )

Female. Body fully extended; head and various antennal segments deformed; right side of thorax slightly bent upwards and partly concealed by remnants of a leaf; body partially translucent showing many fungal spores inside the body (only visible using transmission light; fig. 15); right wings overlapping body, left wings spread; both fore legs and left hind leg folded under body.

Colour ( Fig. 10 ) uniformly brown including legs, antennal segment I, II, VIII and IX; median antennal segments lighter at base; all major setae and wing fringes dark; wing veins uncoloured basally, darkened in the second third and distally broadened to a dark brown spot; wings shaded greyish.

Head crushed at the right anterior half and the left basal part, therefore its original shape difficult to assess; with reticulate sculpture; wider than long and produced in front of anterior margin of eyes; cheeks very likely slightly rounded behind eyes, without setae; ocellar setae broken off. Eyes large; ocelli not visible. Postocular setae missing, their points of insertion far behind eyes. Antennae 9-segmented; segment I long, barrel-shaped; segment II slightly asymmetric, inverse cone shaped; segments III-VIII inverse conically shaped; segment IX style-shaped, at base narrower than segment VIII distally; segment II with a structure interpretable as an apical sensorium; segments III–VIII with long setae; a short sense cone visible on segment III and V. Pronotum crushed, trapezoidal; wider than long; anteroangular setae short, mediolateral setae and posteroangular setae long and pointed, other pronotal setae not developed or missing; epimeral setae rather short, strong and pointed. Pterothorax crushed and partly concealed by the remnants of a leave. Fore wings becoming progressively larger in distal half ( Fig. 10 ); anterior vein distally split in two short branches reaching costa at about three quarters of the wings’ length; each branch ending with a terminal seta ( Fig. 11 ); vein furnished with 6 additional setae (basal setae located on the vein); second vein not developed; membrane without microtrichia. Fore wing clavus with paired setiform processes at tip. Hind wing without microtrichia and without any veins; base with recurved setae. Fore wing fringe cilia straight; arising from sockets ( Fig. 13 ); duplicated cilia present around apical margin of wing ( Fig. 13 ). Hind wing fringe cilia arising from sockets on the anterior margin, these sockets smaller as on fore wing; on hind margin fringes ingrained in the wing membrane without sockets ( Fig. 12 ). Forelegs with femora stout; fore tarsi with teeth; a long seta visible dorsally on the right fore tibia; other setae lacking (broken off?). Mid and hind legs slender; femora with one long ventral and tibiae with one long dorsal seta; mid and hind tibiae terminally each with two visible spines, much smaller on mid tibiae; mid and hind tarsi two-segmented, with hamus. Abdomen without wing retaining setae; lateral setae long, pointed; setae s3 on III–VII longer than other lateral setae and conspicuously bent inwards ( Fig. 10 ). Abdominal segment I (pelta) not assessable; VIII with a spiracle on each side close to the lateral margin of the tergum ( Fig. 14 ); IX conical at base, distally tapering dome-shaped, with setae s3 long, but not protruding tube; sternite IX with structures interpretable as gynosternal plates and fustis (cf. Bhatti 1998b). Abdominal segment X (tube) long and slender, not extended at base ( Fig. 10 ); sculptured reticulate; apparently without campaniform sensilla; with terminal crown of long anal setae.

Measurements. Female (in microns): Body, length 2188. Head, length 233; width about 245. Eyes, length 95; width 57. Prothorax, length about 265; width 410; anteroangular setae 14 (difficult to measure); mediolateral setae 69; posteroangular setae 126; epimeral setae 50. Pterothorax, largest width about 375 (compressed on the right). Abdomen, length 1372; largest width 510 (segments III); X (tube), length 343; basal width 67. Setae s3 on tergite IX 372. Antennae, length 471; length (largest width) of segment I 52 (28), II 68 (28), III 100 (37), IV 84 (31), V 62 (22), VI 50 (22), VII 28 (16), VIII 28 (9), IX 19 (5). Sense cones, length 16; basal width 4–5 (on segment III and V). Fore wings, length 1193; largest width 274. Wing vein, length 872 (measured from wing base).

Material studied. Holotype female MU-Fos-76/1. Inclusion in Burmese amber, donated to the author by Patrick Müller.

Syninclusions. Remnants of a beetle and a springtail; detritus including small coprolites and parts of plants like stellate hairs, fibres and fragments of leaves. Many fungal spores inside the body of the thrips ( Fig. 15 ).

Etymology. The specific epithet schizovenatus comes from the Greek word σχíζω (skhízō), meaning “to split”, and the Latin word venatus meaning “with veins”. It refers to the wing vein of this species, which is distally divided into two short branches.

Figures

FIGURES 9–15. FIGURE 9. Haplothrips haideeae Mound & Minaei (Phlaeothripidae), wing base, s1–s3: subbasal wing setae, indicated white: wing vein, indicated black: rudiment of paired setiform process. FIGURES 10–15. R. schizovenatus sp. n. holotype female: (10) dorsal view; (11) distal part of wing vein; (12) posterior margin of hind wing (fringes embedded in wing membrane); (13) distal margin of fore wing (fringes on sockets); (14) position of spiracles on segment VIII (indicated black); (15) fungal spores (light yellowish dots) inside the body (inverted transmission light image).