Palleptocerus grimaldii, WICHARD & MÜLLER, 2022

WICHARD, WILFRIED & MÜLLER, PATRICK, 2022, Palleptoceridae fam. nov., an extinct leptoceroid family in mid-Cretaceous Burmese amber (Insecta, Trichoptera), Palaeoentomology 5 (5), pp. 468-474 : 469-470

Palleptocerus grimaldii sp. nov.

( Figs 1–4 )

Type material. Male holotype and female paratype 1 are next to each other in small amber ( Figs 1A , 3A, 3B ): ZFMK-TRI000831. Female paratype 2: ZFMKTRI000832 ( Fig. 4A ). Male paratype: ZFMK-TRI000833 ( Fig. 4B ).

Bodies partially well preserved; forewings in dorsal view visible, hind wings partially covered by forewings. Long antennae incomplete in length. Head, thorax and abdomen can partially show signs of decomposition. Fore and hind wing venations largely visible, but crossveins are not or often barely visible, which is probably due to the preservation in amber.

In dorsal and lateral views, the genitalia of males and females are usually obscured by the saddle-roofed and moderately transparent wings. In ventral view, the genitalia are more visible when not clouded by unfavourable preservation in amber. In male genitalia, only the anterior paired inferior appendages are often clearly visible ventrally for this reason.

Etymology. The new species is dedicated in honor of David Grimaldi on his 65 th birthday.

Diagnosis. As for the genus.

Description. Head: Laterally protruded compound eyes; the outer eye distance is 0.7 mm. Ocelli not present. Filiform antennae longer than forewings - embedded in amber and truncate, therefore incomplete in length; in paratype male ( Fig. 4B ) antennae twice as long as forewings, subsequently truncated. Scapus conically thickened; flagellomeres cylindrical, elongate. In both sexes, five-segmented maxillary palps present, palp segment lengths in a row: about 0.1, 0.2, 0.2, 0.12, 0.3 mm (female: Fig. 2A ; male: Fig. 4B inset); 5 th segment flexible, not annulated. Labial palps three-segmented, terminal segment longest.

Thorax: Mesoscutum ( Fig. 3C ) distinct, sclerotized, running longitudinally, with dark marginal ridges on both sides. Two bands with setiferous punctures along dorsal side of mesoscutum not completely visible, but as far as visible, some setae appear in row, visible along right band ( Fig. 3C Inset).

Tibial spurs: 2/4/4, metatibia, each with a pair of apical and preapical spurs ( Fig. 1B )

Wings: The forewings about 4.5 mm long in males and 5.0 mm long in females. Sexual dimorphism is more pronounced in the venation ( Fig. 2B, 2C ): forks III present in females, males without them. In both sexes Sc and R 1 straight running parallel to the wing margin. R 2 + R 3 forming fork I present and R 4+5 simple, discoidal cells absent. Crossvein r-m incompletely indicated. In male M two-branched in M 1+2 and M 3+4; in female M threebranched, M 1 + M 2 forming fork III and M 3+4 simple. Cu 1 two-branched in Cu 1a and Cu 1b forming fork V. Crossvein m-cu closing the long thyridial cell. In male venation Cu 2 and A 1+2+3 running parallel and reaching the wing margin together at arculus. Crossvein between Cu 1b and Cu 2 reaching arculus. In female Cu 2 and A 1+2+3 running parallel but reaching the wing margin at different distance. In both sexes simplified hind wing venation, forks I, II, III, IV absent, exclusively fork V present ( Fig. 2D ), crossveins absent.

Genitalia: Access and visibility of the male and female genital structures are difficult in amber. In the female, a pair of dorsal setose lobes visible ( Fig. 3B inset, 4A inset); details of the gonopod plate not visible. In ventral view, the male genitalia equipped with a pair of inferior appendages ( Fig. 3A ), each consisting of a dark, rod-shaped coxopodite and an apically attached harpago that is shorter and lighter in color than the coxopodite and tapers and curves slightly toward the genital midline. As far as visible, a rod-shaped appendage nearly as long as the coxopodite tentatively interpreted as a meso-dorsal appendage of tergum 10.

Figures

FIGURE 1. Palleptocerus grimaldii sp. nov., mating. A, A mating pair, male holotype (right), female paratype 1 (left), ZFMK- TRI000831, in ventral view; scale bar = 2 mm. B, Male paratype, ZFMK-TRI000833, metatibia, each with a pair of apical and preapical spurs (arrows), circle = branching spurs; scale bar = 0.5 mm.

FIGURE 2. Palleptocerus grimaldii sp. nov., characters. A, Maxillary palp of female paratype 1, ZFMK-TRI000831; scale bar = 0.1 mm. B, Wing venations, venations of male forewing, female forewing and hind wing; scale bar = 1 mm.

FIGURE 3. Palleptocerus grimaldii sp. nov., genitalia. A, Male holotype, ZFMK-TRI000831, adult in dorsal view; scale bar = 1 mm. A Inset, Male genitalia with a pair of inferior appendages (inf ap); scale bar = 0.3 mm. B, Female paratype 1, ZFMK- TRI000831, adult in dorsal view; scale bar = 1 mm. B Inset, Female genitalia with a pair of lobes (dolo); scale bar = 0.2 mm. C, Mesoscutum sclerotized, running longitudinally, with dark marginal ridges on both sides; scale bar = 0.1 mm. C Inset, a row of setae, inside along of the marginal ridge of mesoscutum, scale bar = 0.05 mm

FIGURE 4. Palleptocerus grimaldii sp. nov., paratypes. A, Female paratype 2, ZFMK-TRI000832, adult in ventral view; scale bar = 1 mm. A Inset, Female genitalia with a pair of dorsal setose lobes (dolo); scale bar = 0.3 mm. B, Male paratype, ZFMK- TRI000833, adult in ventral view; scale bar = 1 mm. B Inset, Male genitalia with five-segmented maxillary palps (mx); scale bar = 0.3 mm.