Sesquithrips markpankowskii, Ulitzka, 2022

Ulitzka, Manfred R., 2022, New genera and species of Rohrthripidae (Thysanoptera: Tubulifera) from Burmese Cretaceous amber, Zootaxa 5162 (1), pp. 1-36 : 21-23

Sesquithrips markpankowskii gen. et sp. n.

( Figs 19–20 )

Female (Holotype). Head slightly bent downwards, abdomen contracted ( Fig. 19 ); right wings spread but hind wing hidden by fore wing; left wings partially overlapping body, hind wing covered by fore wing except for tip; left fore leg and right hind leg folded under body.

Colour ( Fig. 19 ) uniformly dark brown, including antennae and legs; all major setae dark as well as wing veins and fringes; fore wings shaded brown, paler from the middle towards base and at the extreme tip; hind wings largely covered by fore wings, at least pale brownish at tip.

Head ( Fig. 19 ) broad, much wider than long; dorsally sculptured with transverse reticulations. Cheeks converging slightly rounded towards base; laterally with spine-like setae arising from small tubercles. Ocellar setae not visible; postocular setae far behind compound eyes, tiny, pointed. Eyes small, longer than wide, not prolonged ventrally. Ocelli large; hind ocelli close to compound eyes and far apart from each other; fore ocellus between antennal insertions, directed forwards. Antennal bases far apart. Antennae nine-segmented; segment I conically shaped; II large, inversely conical, apically with a small circular sensorium; III–VIII basally with a pedicle, then inverse conically shaped and sharply tapering distally; IX style-shaped, broadly attached to VIII. Sense cones difficult to assess; at least one inner and one outer present on III–VI and one outer on VII. Mouth cone short and rounded ( Fig. 19 ). Maxillary palps two-segmented. Pronotum trapezoidal, wider than long; chaetotaxy not assessable. Mesonotum sculptured with fine transverse lines; metanotum reticulate. Fore wings narrow, somewhat broadened in basal half and bluntly rounded at tip; anterior vein complete, bearing seven setae in distal half; second vein ending with a distinct terminal seta in the middle of the wing; wing membrane without microtrichia. Clavus with paired setiform processes at tip. Fringe cilia straight; embedded into wing membrane, except at posterior distal margin of hind wings, where the wing margin is serrate with small teeth, each carrying a fringe cilium at tip attached on a tiny socket. Fore wings with duplicated cilia around wing tip and along distal part of posterior wing margin; running parallel to normal wing fringes. Fore legs with femora not enlarged, apically with external margin sharply curved into a tooth-like protuberance; fore tibiae not clearly assessable; tarsi without tooth but with a recurved hamus. Mid and hind legs slender; tibiae each with a long dorsal seta; mid and hind tarsi two-segmented. Abdominal tergites without wing-retaining setae; lateral setae stout, slightly curved and pointed. Tergite I (pelta) D-shaped, much wider then long, sculptured with lines of transverse loose reticulation. Abdominal segment IX dome-shaped; setae s1 stout and pointed, sharply recurved at tip; s2 and s3 finely pointed, shorter than tube. Abdominal segment X tubular, with margins parallel; with a pair of campaniform sensilla close to apex and with a terminal crown of anal setae, these much shorter than tube; ventral median pair of annal setae stout with cannula-like tips.

Measurements. Female (in microns): Body, length 990 (abdomen contracted). Head, length 105; width 167; distance between antennal bases 22. Eyes, length 47; width 37. Hind ocelli, diameter 16; distance between the hind ocelli 31. Pronotum, length 109; largest width 189. Pterothorax, largest width 226 (at level of mesothoracic spiracles). Abdomen, length 536; largest width 245 (segment II); segment X (tube), length 124; width 31. Pelta, length 56; width about 190 (difficult to measure). Setae at tergite IX, length s1 34; s2 56; s3 74. Antennae, length 249; length (largest width) of segment I 31 (27), II 34 (25), III 37 (22), IV 34 (22), V 34 (22), VI 28 (17), VII 22 (12), VIII 19 (9), IX 10 (5). Sense cones, length of inner (outer) on segment III 6 (9), IV 9 (16), V 6 (12), VI 6 (9), VII – (9); basal width of inner (outer) about 2 (3) (measured on segment III). Fore wings, length 517; width at terminal seta of cross vein 53.

Male (Paratype). Body ( Fig. 20 ) fully distended; wings bent upwards so that they appear shorter in projection than they are in reality, right wings and left hind wing spread, left fore wing overlapping body; all legs folded under head and body, respectively, except for right mid leg; median part of abdomen ventrally hidden by a large air bubble.

Very similar to female but smaller and much more slender. Pronotum with short posteromarginal setae. Fore tarsi without tooth. Abdominal sternite IX with hypandrium and androsternite clearly visible (see Bhatti 1998b). Fore femora not enlarged; fore tibiae not clearly assessable; tarsi without tooth but with a recurved hamus. Fore wings shorter as in female; with less duplicated cilia; first vein of fore wing with less setae; posterior distal margin of hind wings serrate with small teeth, but not as pronounced as in female.

Measurements. Male (in microns): Body, length 853. Head, length 84; width 118; distance between antennal bases 21. Eyes, length 31; width 25. Pronotum, length 72; largest width 130; posteromarginal setae 16. Abdomen, length 559; largest width 152 (segment II); segment X (tube), length 81; width 25. Setae at tergite IX, length s1 34; s2 47; s3 62. Antennae, length 255. Fore wings, length 350; width at terminal seta of cross vein 37.

Material studied. Holotype female MU-Fos-134/1 ( Fig. 19 ); inclusion in Burmese amber; purchased by Mark Pankowski on eBay and donated to the author . Paratype male MU-Fos-141/1 ( Fig. 20 ); inclusion in Burmese amber; purchased by the author on eBay from Terry Su , eBay username “burmite-miner”. Both fossils originate from Hukawng Valley, Kachin State, Myanmar and are deposited in the author’s collection .

Syninclusions. MU-Fos-134/1: Plant detritus, small droplets and brownish stains of unknown origin. MU-Fos-141/1: A springtail (Collembola), parts of a mite, two coprolites, stellate plant hairs (some in a large aggregation), plant detritus, some tiny air bubbles.

Etymology. The new species is dedicated in gratitude to Mark Pankowski for his continuous and invaluable support in my work on fossil Thysanoptera .

Figures

FIGURES 19–20. Sesquithrips markpankowskii gen. et sp. n. (19) holotype female, dorsal view, mouth cone outlined white; (20) paratype male, dorsal view, mouth cone outlined white. (Note: The wings of the male are bent upwards and, therefore, longer than visible on the photo).