Palaeoglaesum bisulcum, Wagner, Rüdiger, 2017

Wagner, Rüdiger, 2017, Synopsis of extinct Bruchomyiinae (Diptera, Psychodidae) from Burmese, Baltic and Dominican amber, with descriptions of new genera and species, Zootaxa 4320 (1), pp. 100-120 : 117

Palaeoglaesum bisulcum sp. nov.

( Fig. 7d )

Etymology. name based on bipartite (bisulcus=divided; latin) gonostylus.

Diagnosis. Palaeoglaesum species with apically bilobed gonostylus.

Material. BUB 583 in coll. Müller

Geological stratum. Burmese amber.

State of preservation. Specimen well preserved, however some sclerites of thorax and abdomen deformed. Right hind leg missing; wing venation not entirely recognizable, left wing folded; distal part of right wing missing. Body covered with a coat of long hairs.

Syninclusion. 1 female of ceratopogonid-like Diptera .

Description. Head in lateral view elongate, eyes oval, no eye-bridge; labium strong, as long as height of head. Relative length of scape, pedicel and flagellomeres of right antenna: 9-10-48 -33-31-29-27-25-23-21-21-21-20-20- 18-21; absolute length: 0.05-0.06-0.27-0.19-0.18-0.17-0.15-0.14-0.13-0.12-0.12-0.12-0.11-0.11- 0.10-0.12 mm. Antennae with coat of equally long setae, ascoids not discernable. Palpus 4-segmented: relative length: 18-29-32- 69; absolute length: 0.10-0.17- 0.18-0.39 mm.

Head length 0.35 mm, length thorax + abdomen 2.84 mm; length genitalia 0.58 mm.

Thorax without specific features; left hind leg missing; remaining legs pubescent, hairs longest at base of femora, shorter towards tarsus. Fore tibia with few ventral bristles.

Wing length 2.30 mm. Sc terminates in C, with sc-r crossvein, R2+3 about 1.3 times longer than R2.

Abdomen with 8 segments and genitalia. Gonocoxites tubular, basally wider than distally, slightly sinuous; gonostyli bifurcated, longer than gonocoxites, distally widest; separation of lobes at approximately 1/3 of gonostylus length. Aedeagus tube shaped with crinkly surface (periaedeagal sheath), tip reaches almost tip of gonocoxite; terminally with an elongate distally forked aedeagus sclerite (distiphallus). Near tip on either side tips of elongate blade shaped parameres visible. Epandrium flat, elongate rectangular, cerci elongate oval. Proctiger oval, vaguely discernable between cerci.

Comments. The new species is distinguished by the hair coat on the entire body, shape of gonocoxites, distally bifid gonostyli, and the shape of the aedeagus with a long distally split distiphallus sclerite (compare P. muelleri and P. quadrispiculatum ); parameres blade shaped. The long and flat epandrium is in common with the other known species of Burmese Amber Bruchomyiinae .

Figures

FIGURE 7. Palaeoglaesum muelleri sp. n. a. genitalia lateral view; b. fore femur; c. fore tibia; Palaeoglaesum notandum sp. n. d. genitalia transverse lateral view; Palaeoglaesum bisulcum sp. n. e. genitalia dorsal view. Abbreviations: ae—aedeagus; ascl—aedeagus sclerite; c—cercus; ep—epandrium; gcx—gonocoxite; gst—gonostylus.