Palaeoglaesum quadrispiculatum ( Stebner, Solórzano-Kraemer, Ibáñez-Bernal & Wagner, 2015 ) 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 : 113-114

Palaeoglaesum quadrispiculatum ( Stebner, Solórzano-Kraemer, Ibáñez-Bernal & Wagner, 2015) comb. nov.

( Figs. 6 a–e )

Etymology. In ventral view genitalia with 4 sclerite tips are visible, 2 of the parameres and 2 of the aedeagus sclerite.

Diagnosis. Palaeoglaesum species with long, blade shaped parameres, tips reach the end of the epandrium

Material. BUB 372 and 731 in coll. Müller

Geological stratum. Burmese amber.

State of preservation. Head, thorax, abdomen and details of genitalia recognizable, although many sclerites particularly of thorax and abdomen are deformed. Palpus and antenna complete; wing crumpled.

Features additional to original description based on specimen BUB 731. Antenna with cylindrical scape, oval, slightly asymmetric pedicel, and 14 flagellomeres; antenna length 2 mm (absolute length of scape, pedicel and flagellomeres: 0.05-0.04-0.21-0.14-0.17-0.16-0.16-0.15-0.14-0.13-0.12-0.11-0.11-0.10- 0.10-0.11 mm); relative length proportions: 8-7-36 -25-29-28-28-27-25-22-21-20-20-17-17-20. Mouthparts without functional mandibles; palpus of four segments; absolute length: 0.09-0.19- 0.16-0.30 mm; relative length proportion: 16-33- 28-53; palpus length 0.74 mm. Submentum in lateral view broad elongate.

Wing length 1.7 mm. Sc ends in C, short sc-r crossvein; fork R2/3 near tip of R1 into C. R2+3 2.5 times longer than R2; R5 behind wing apex; crossvein m-cu near fork M3/M4; CuA moderately long, CuP short, almost straight, ending in wing.

Abdomen with 8 segments and inverted genitalia, inversion by segments 8 and 9. Gonocoxite tubular, longer than gonostylus, that is almost straight, waisted in the basal third, with acute apex. Epandrium flat, elongate rectangular, with elongate oval setose cerci. Aedeagus thin, tube-shaped, with single elongate, distally bilobed basiphallus sclerite. The lateral straight spine-like appendages are elongate blade-shaped parameres; in the specimen mentioned they overlap even the cerci.

Comments. Specimens BUB 372 and BUB 731 are without doubt conspecific with P. quadrispiculatum (Stebner, Solórzano-Kraemer, Ibáñez-Bernal & Wagner) . Additional details mentioned here were not visible in the holotype that was prepared in perfect dorsoventral view. Based on the additional specimens, it is evident that the lateral blade-shaped sclerites mentioned in the original description are heavily sclerotized parameres positioned between the epandrium and gonostyli; the split Y-shaped basiphallus sclerite is positioned between gonocoxites, morphologically ventral of the parameres. Amber piece BUB 372 includes a leg, probably of a coleopteran, and few debris particles as syninclusions, BUB 731 without syninclusions.

Figures

FIGURE 6. Palaeoglaesum quandrispiculatum (Stebner, Solórzano-Kraemer, Ibáñez-Bernal & Wagner) a. head lateral view; b. palp segments; c. pedicel and 1 st flagellomere; d. apical antennal flagellomeres; e. genitalia transverse lateral view. Abbreviations: ascl—aedeagus sclerite; c—cercus; ep—epandrium; gcx—gonocoxite; gst—gonostylus; pm—parameres.