Cretapelopia salomea, Veltz & Azar & Nel, 2007

Veltz, Isabelle, Azar, Dany & Nel, André, 2007, New chironomid flies in Early Cretaceous Lebanese amber (Diptera: Chironomidae), African Invertebrates 48 (1), pp. 169-191 : 175-177

Cretapelopia salomea sp. n.

Figs 4–6

Etymology: After Salomé, daughter of one of the authors (I.V.).

Description: Head 0.82 mm long, 0.55 mm wide. Ocelli absent. Antenna 1.2 mm long, much longer than head, distinctly hairy, 14 flagellomeres; flagellomeres 1–13 covered with long setae (shortest 0.04 mm long, longest 0.5 mm long), scape broad and short, rounded, pedicel very short, flagellomere 13 very long (0.1 mm), flagellomere 14 evenly tapering from base to apical nipple, 0.17 mm long, 9 times as long as broad at base. Eye bare, deformed but with an apically-expanded dorso-medial extension, with 7 rows of ommatidia at minimum width. Clypeus 0.13 long with few dorsal setae. Mouthparts lacking functional mandible, labium 0.39 mm long; palpomeres with numerous setae, all approximately the same length.A row of short postocular setae; frontal, inner vertical and outer vertical setae not visible.

Thorax 1.14 mm long, 0.64 mm wide, 0.84 mm high; postnotum with numerous long setae and very distinct longitudinal median groove; numerous prealar and supraalar setae; series of about 10 anterior acrostichals; series of few poorly aligned dorsocentrals; postanepisternal setae present.

Wing macropterous, 2.32 mm long, 0.65 mm wide, hyaline, and covered with macrotrichia. Radius with only 3 branches R 1, R 2+3, and R 4+5; R 2+3 well separated from R 1 and R 4+5, R 2+3 apically forked into R 2 and R 3; R 2 0.06 mm long, ending in R 1, R 3 0.16 mm long, ending in costa. Costa produced beyond insertion of last radial branch by 0.04 mm, distinctly shorter than cross-vein RM. Only M

1+2

and M

3+4

present; cross-vein MCu present; cubital fork proximal to cross-vein MCu; cross-vein RM 0.03 mm slightly distal of MCu. Anal vein An 2 absent. Halter 0.36 mm long.

Fore femur length 0.82 mm, tibia 1.1 mm, tarsus 1.8 mm; mid femur 1.14 mm, tibia 1.08 mm, tarsus 1.34 mm; hind femur 1.04 mm, tibia 1.08 mm, tarsus 1.26 mm. Tibial spur formula 1–2–2; all spurs 0.08 mm long, with lateral comb-like teeth, (similar to those of extant genus Derotanypus ). Fourth tarsomeres of all legs cylindrical, not cordiform; claw of middle legs simple as in fore and hind legs, not pectinate; no apical brush on tarsomere 3 of middle leg.

Abdomen 2.26 mm long, 0.8 mm wide. Gonostylus strongly curved at base (base width 0.06 mm), with numerous long, strong setae, and distally very long (0.16 mm), straight, nearly as long as gonocoxite and tapering at apex; gonocoxite rounded, (0.2 mm long, 0.15 mm wide), with numerous long setae. Anal point sharp and long, 0.1 mm wide at base, 0.02 mm high. Inferior volsella apparently rounded, covered with setae.

Holotype:Specimen 309, male. LEBANON: Mont Lebanon district [Mouhafazit Jabal Loubnan]: Hammana / Mdeyrij, Caza Baabda; Early Cretaceous (D. Azar coll.).

Paratype: Specimen 295, male, same data as holotype.

Discussion: Cretapelopia gen. n. appears to fall into the tribe Pentaneurini (Tanypodinae) for the same reasons as Libanopelopia (see above). However, it differs from the latter genus in having very reduced R 2, with veins R 1 and R 2+3 very closely parallel, thus being in accordance with the wing venation of the Pentaneurini .

In the Tanypodinae keys ( Murray & Fittkau 1989; Saether et al. 2000) this new genus keys to couplets 6 and 24 respectively. It will not key further since the costal extension is short while postnotals are present. Disregarding the postnotals, the genus keys to couplets 24 and to Pentaneura Philippi, 1865 respectively because of the following characters: vein MCu placed beyond FCu, costa not produced; inferior volsella apparently present and rounded in shape; gonostylus broad and strongly curved at base, but distally long, straight and tapering apically; anal point broader than long; scutal tubercle absent; tibia of middle leg bearing two spurs of equal length; tibial spur formula 1–2–2. The tibial spurs of Cretapelopia are very different from those of Pentaneura (see Murray & Fittkau 1989). In couplet 24, genera without a scutal tubercle, Rheopelopia Fittkau, 1962 , Thienemannimyia Fittkau, 1962 , Meropelopia Roback, 1971 , and Arctopelopia Fittkau, 1962 , lack postnotals or anepisternals. In these genera, the costa ends approximately opposite to the apex of M 1+2, but R 3 ends almost halfway between R 1 and R 4+5. Among the Tanypodinae , only some Anatopyniini and Macropelopiini have postnotals or anepisternals; present in Cretapelopia . However, judging from the distribution of the thoracic chaetotaxy in the Orthocladiinae , both basal and advanced genera may have these setae and, at least among the orthoclads, this character appears to be of low phylogenetic value.

Figures

Figs 4–6. Cretapelopia salomea gen. et sp. n., holotype 309: (4) details of general habitus, scale bar = 1 mm; (5) wing, scale bar = 0.5 mm; (6) male genitalia, scale bar = 0.2 mm.