Sesquithrips, 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

Sesquithrips gen. n.

Type species: Sesquithrips rostratus gen. et sp. n.

Diagnosis. Abdominal segment X tubiform. Antennae nine-segmented, with segments VIII and IX broadly joined. Fore wings broadened in basal half, distally with parallel margins and with broadly rounded tip; first vein complete, bearing setae; second vein present but ending approximately in the middle of the wing with a distinct terminal seta ( Fig. 22 ). Fore wings with fringe cilia embedded into wing membrane; duplicated cilia present; wing coupling not assessable. Hind wings distally with posterior margin of wing membrane serrate into small teeth, each carrying a fringe cilium at tip attached on a tiny socket ( Fig. 23 ). Abdomen without sigmoidal wing retaining setae.

Sesquithrips shows modern tubuliferan character states in combination with plesiomorphic features like ninesegmented antennae and fore wings with longitudinal veins. It therefore is allocated to Rohrthripidae . Similar as mentioned for Adstrictubothrips gen. n., the fringes in Sesquithrips gen. n. are embedded for the most part into the wing membrane ( Fig. 22 ). Only at the serrate posterior margin of the hind wings are they clearly attached on tiny sockets ( Fig. 23 ). Sesquithrips gen. n. differs from Rohrthrips and Gemineurothrips gen. n. with regard to the narrow shape of the wings. Furthermore, the dorsolateral sutures found in members of Rohrthrips and Paralleloalathrips gen. n. at abdominal segment II (see below) are not developed in this new genus. Moreover, Sesquithrips gen. n. is easily distinguished from the latter genus and from Adstrictubothrips gen. n. by the second wing vein, which ends in the middle of the fore wing with a stout terminal seta ( Fig. 22 ).

Etymology. The name of the new genus derives from the Latin prefix sesqui, meaning “one and a half”, and thrips, the usual term for a genus within Thysanoptera . It refers to the wing venation with a complete first vein and a second vein extending only half the length of the fore wing ( Fig. 22 ).

Figures

FIGURES 21–23. Sesquithrips rostratus gen. et sp. n. holotype female. (21) dorsal view, mouth cone outlined white; (22) left wings, indicated: distinct seta at distal end of second wing vein; (23) serrate hind margin of left hind wing.