Adstrictubothrips mirapterus, Ulitzka, 2022

Ulitzka, Manfred R., 2022, New genera and species of Rohrthripidae (Thysanoptera: Tubulifera) from Burmese Cretaceous amber, Zootaxa 5162 (1), pp. 1-36 : 4

Adstrictubothrips mirapterus gen. et sp. n.

( Figs 1–2 , 35 )

Female. Head slightly retracted under pronotum, thorax contracted, abdomen fully extended; head partially translucent, therefore maxillary stylets visible; left antenna with distal segments deformed; left wings overlapping body, right wings spread; both fore legs folded under body.

Colour ( Fig. 1 ) brown to greyish brown, legs as well as antennal segments I, II and basal part of III concolourous with body; distal part of antennae dark brown as well as anterior part of head, pterothorax and tube. All major setae light brown, except s1–s3 at tergite IX and all anal setae, which are darker. Wing veins and fringes greyish brown ( Fig. 2 ); fore wings shaded grey, hind wings lighter with a dark median streak.

Head ( Figs 1 , 35 ) retracted basally under pronotum; slightly wider than long, recessed behind eyes; basally sculptured with faint lines of transverse loose reticulation. Cheeks nearly straight, diverging slightly backwards and tapering sharply just before the base; laterally with some sparse and weak setae. Ocellar setae difficult to assess, one short pair visible close to hind ocelli; postocular setae far behind compound eyes, short but pointed. Eyes small, not prolonged ventrally. Hind ocelli close to compound eyes; far apart from each other; fore ocellus on a small hump far in front between antennal insertions. Antennae nine-segmented; segment I conically shaped; II inversely conical, apically with a small sensorium; III–VIII basally with a pedicle, then inverse conically shaped and tapering distally; IX style-shaped, at base nearly as wide as VIII distally. Sense cones difficult to assess; at least one inner and one outer present on III–V. Mouth cone short but pointed. Maxillary stylets ( Fig. 35 ) wide apart but long (without maxillary bridge), their base visible close to hind margin of compound eyes. Pronotum wider than long; pronotal chaetotaxy as well as pterothoracic structure not assessable. Fore wings narrow ( Fig. 2 ); somewhat widened in basal third; distally parallel and slightly bent forwards, tip bluntly rounded; anterior vein complete, with one small and two large setae in the basal two-thirds of the wing, apical setae lacking; second vein not developed; membrane without microtrichia. Fringe cilia straight; distinctly thickened at base; at fore wings embedded into the wing membrane, at hind wings, however, arising from tiny sockets. Duplicated cilia running parallel to normal wing fringes; present around wing apex, distally on posterior wing margin and one duplicated cilium on fore margin of wing. Clavus with paired setiform processes at tip. Hind wing without microtrichia and without any veins ( Fig. 2 ). Fore legs ( Fig. 1 ) with femora not enlarged; fore tibiae and tarsi not clearly assessable, however, fore tarsi with hamus. Mid and hind legs slender; tibiae each with a long dorsal seta and terminally each with a strong spine; mid and hind tarsi two-segmented; with a long recurved hamus. Abdominal tergites without wing-retaining setae; lateral setae weak, slightly curved and pointed. Pelta triangular, much wider than long, sculptured with lines of transverse loose reticulation. Abdominal segment IX dome-shaped; setae s1–s3 long and pointed; s2 slightly longer than tube. Abdominal segment X elongated tubular, but distinctly narrowed in the middle; with a terminal crown of anal setae, these shorter than tube.

Measurements. Female (in microns): Body, length 794 (slightly contracted). Head, length 136; width 146. Eyes, length 50; width 31. Hind ocelli, diameter 9; distance between the hind ocelli 31. Postocular setae about 17 (difficult to measure). Distance between maxillary stylets (at base of head) 62. Pronotum, length 93; width 174. Pterothorax, largest width 174 (at level of mesothoracic spiracles). Abdomen, length 529; largest width 171 (segment VI); segment X (tube), length 99; basal width 28. Pelta, length 43; width 115. Setae on tergite IX, length s1 78; s2 109; s3 47. Antennae, length 255; length (largest width) of segment I 25 (25), II 31 (17), III 37 (22), IV 31 (19), V 31 (16), VI 33 (16), VII 26 (14), VIII 25 (12), IX 16 (6). Sense cones, length of inner (outer) on segment III 16 (15), IV 12 (15), V 12 (9); basal width of inner (outer) about 2 (3). Fore wings, length 498; width in the middle 31.

Material studied. Holotype female MU-Fos-134/1 ( Figs 1–2 , 35 ); inclusion in Burmese amber from Hukawng Valley , Kachin State, Myanmar. The holotype was donated by Patrick Müller and is deposited in the author’s collection.

Syninclusions. Remnants of insect legs, plant detritus and stellate plant hair.

Etymology. The species epithet mirapterus comes from the Latin word mirus, meaning “strange”, and the Greek word πτερόν (pteron), meaning “wing”. It refers to the unusual wings of this species with a single vein bearing setae only in the basal two-thirds but not apically ( Fig. 2 ).

Figures

FIGURES 1–4. Rohrthripidae species. Adstrictubothrips mirapterus gen. et sp. n. 1–2: (1) holotype female dorsal view, indicated: constriction at the tube; (2) right wings, indicated: duplicated cilium on fore wing margin. Gemineurothrips microcephalus gen. et sp. n. syntype female (MU-Fos-145/1) 3–4: (3) dorsal view; (4) left antenna.

FIGURES 35–38. Line drawings of Rohrthripidae. Head, mouthparts and prothorax (md: mandibula, mx: maxillary stylets) 35–37: (35) Adstrictubothrips mirapterus gen. et sp. n. holotype female; (36) Gemineurothrips peculiaris gen. et sp. n. holotype (spa: posteroangular setae, left broken off and lying close to coxa; scx: coxal setae); (37) Rohrthrips rhamphorhynchus sp. n. holotype. (38) Rohrthrips multihamuli sp. n. holotype; left antenna, segment numbers in Roman numerals, indicated: ventral projections on segments V–VII (cs: campaniform sensillum, uncolored trichomes indicate presumptive sense cones).