Lappodiamesa deploegi, Published, 2007

Published, First, 2007, Chironomid midges from early Eocene amber of France (Diptera: Chironomidae), Zootaxa 1404, pp. 1-66 : 57-59

Lappodiamesa deploegi n. sp.

( Figs. 56, 57)

Etymology: This species is named for Gaël De Ploëg, who discovered the Oise amber and its fauna.

Diagnosis: Frontal tubercule absent; head without inner vertical and orbital setae; antenna with normal plume; apex of palp segment 3 without projection; antepronotum with only ventral antepronotals; MCu present, R present but not forked, MCu distal to FCu but proximal to RM; tarsomere 4 cylindrical; fore leg without pseudospurs.

2+3

Description: Head deformed, 0.33 mm long; ocelli absent; antenna 0.85 mm long, much longer than head, distinctly hairy, with 13 flagellomeres covered with long setae (shortest 0.05 mm long, longest 0.41 mm long), 12 th flagellomere 0.47 mm long, 13 th with distinctly apical nipple and long subapical seta, pedicel broad and short, rounded, with few setae; eye bare but deformed, with moderate apically expanded dorsomedial extension, with 2 rows of ommatidia at minimum width; mouthparts lacking functional mandibles; 5 palpomeres with numerous setae and all cylindricals; numerous postocular setae, numerous outer vertical setae, frontal and inner vertical setae not visible, probably absent. Thorax 0.94 mm long, 0.56 mm wide, 0.74 mm high; postnotum bare; surface of scutellum with few long setae; scutal tubercle absent; numerous prealar setae and 1 supraalar setae; numerous anterior acrostichals present; numerous dorsocentrals; preepisternal setae absent. Wing macropterous, 1.34 mm long, 0.44 mm wide, hyaline, with macrotrichia; anal vein An 2 absent; radius with 3 branches R 1, R 2+3, and R 4+5; R 2+3 well separated from R 1 and nearly to R 4+5, R not divided into R 2 and R 3; costa ending just beyond insertion of last branch of radius; only M 1+2 and M present; cross­vein MCu present, distal to FCu (0.025 mm long) but proximal to RM, anal lobe moderately developed, squama with few setae. Halter 0.21 mm long. Fore femur 0.55 mm long, tibia 0.57 mm long, tarsus 1.12 mm long; mid femur 0.67 mm long, tibia 0.65 mm long, tarsus 1.12 mm long, hind femur 0.52 mm long, tibia 0.7 mm long, tarsus 1.3 mm long; 2 long spurs on mid and hind tibiae; tarsomere 4 of all legs cylindrical, not cordiform; hind tibial comb of 1 row; pulvilli absent; pseudospurs present on tarsomeres 1­3 on mid legs. Abdomen 1.44 mm long, 0.36 mm wide; gonostylus 0.1 mm long, 0.008 mm wide, narrow and elongate; gonocoxite 0.15 mm long, 0.06 mm wide at base, numerous long setae on outer surface of gonocoxites; anal point not visible.

2+3

3+4

FIGURE 57. Lappodiamesa deploegi n. sp., holotype PA 1161, drawing of male genitalia; a, dorsal view; b, ventral view (scale bar = 0.2 mm).

Discussion: Lappodiamesa deploegi n. sp. is in the Diamesinae based on the above features (see discussion on Pagastia ). Cretodiamesa differs from L. deploegi by having the male antenna with six flagellomeres, five of them being very short and the last one very long. The Protanypodini , Boreoheptagyiini , Harrisonini, and Lobodiamesini are excluded for the same reasons as above. Brundin (1966) divided the Heptagyiini into five recent genera, all of which differ from L. deploegi : Heptagyia Philippi, 1865 , and Paraheptagyia Brundin, 1966 , have the fourth tarsomeres longish and cordiform; Araucania Brundin, 1966, and Limaya Brundin, 1966 , differ from L. deploegi in the relative position of RM, MCu, and FCu and their fourth tarsomeres cordiform; Maoridiamesa Pagast, 1947 , differs from L. deploegi by having hairy eyes. The only remaining tribe is the Diamesini , in which L. deploegi also falls in the key to Holarctic genera of Oliver (1989). Within this tribe, L. deploegi would fall near the recent genus Lappodiamesa Serra­Tosio, 1968 , because of the following characters: thorax without setae on anepisternum, epimeron II, or preepisternum; rows of dorsocentrals not converging on prescutellar area; frontal tubercule absent; antenna with normal plume; antepronotum with only ventral antepronotals; fourth tarsomere cylindrical; head without inner verticals, apex of palpal segment 3 without projection; head without orbital setae; and fore leg without pseudospurs. Endo (2004) indicated that at least some recent species of Lappodiamesa have no pseudospurs on the fore leg.

Material: Holotype PA 1161, (male).