Bittacus coheri Bicha

Bicha, Wesley J., 2011, A review of the Hangingflies (Mecoptera: Bittacidae) of South Asia with the description of a new species of Bittacus from Nepal, Zootaxa 3032, pp. 60-64 : 60-61

Bittacus coheri Bicha , sp. n.

Figs. 1–4

Diagnosis. This new species is unique among all described Bittacidae by presence of a dorsal bifurcated flap-like structure between the male epiandrial lobes of tergum 9. Additionally, the wing subcostal crossvein is midway between the level of the first fork of the radial sector and the Cu2 terminus. The 1A extends two-thirds the distance from the origin of the radial sector to the first fork of the radial sector.

Type material examined. Holotype male and 1 paratype male, Nepal, Amlekhganj (in the Eastern Terai), 520m at light, 6 August 1957; allotype female, same locality, 21 July 1957. Holotype and allotype deposited in California Academy of Science ( CAS), San Francisco, California, and 1 male paratype in the FSCA, Gainesville, Florida. All three specimens pinned, intact, but heavily mold-encrusted. Holotype male terminalia cleared in KOH and stored in glycerin in microvial attached to pin.

Description. Eyes dark brown; vertex and occiput yellowish brown, area between bases of ocelli dark brown; rostrum dark brown; maxillary and labial palps brown. Antennal scape and pedicel dark brown; flagellum brown basally grading to black apically, thicker basally, tapering apically; flagellum filiform; combined length approximately 7 mm.

Dorsum of thorax light orange-brown; pleural surfaces lighter orange-brown; pronotal setae inconspicuous. Mesonotum with two anterior and one posterior raised hemispherical areas. Metanotum with one anterior and one posterior hemispherical raised areas. Legs orange-brown, with fine, short, yellowish brown, apically directed hairs and a lesser number of longer, black, apically directed setae; hind femora thicker basally, tapering apically; ends of tibiae bearing two long, thick, brown spurs; hind leg tarsomere ventral surfaces with numerous dark brown to black setae.

Wings ( Fig. 1 ) narrow, without pigmented bands or spots; tinged with yellowish brown, slightly darker at apical margins. Basal anterior and posterior wing margins with 3–6 stout, black setae; entire margins with fine, short, yellow-brown setae; veins and crossveins with fine, pale setae. Thyridium at fork of media conspicuous. Pterostigma faint or absent. Apical margin of wings evenly curved. Sc vein joins costal margin distal to fork of media, but basal to terminus of Cu1 and Cu2 veins; anal crossvein at level of fork of media; two pterostigmal crossveins; Sc crossvein at a level midway between first fork of radial sector and terminus of Cu2 vein, nearly reaching Sc vein terminus; cell R2 elongate, bordered posteriorly by three complete cells. Vein 1A extending two-thirds of the distance from origin of radial sector to first fork of radial sector.

Abdomen of male generally light brown. Lobes of tergum 9 (epiandrium) ( Figs. 2, 3 ) narrow basally, gradually broadening distally, with rounded apices, bearing numerous small, black, basally directed setae on dorso-mesal surfaces. Epiandrial lobes widely divergent, separated dorsally by a small bifurcated flap-like structure, bearing 3–5 dark apical protuberances. Basistyles dark brown; dististyles large, dark brown, without lobes. Proctiger dark, inconspicuous. Aedeagus ( Fig. 4 ) filament-like, short, uncoiled, curved dorsally, darkened and thickened basally, tapering to slender, colorless tip; aedeagal lateral lobes large, extending dorso-caudally, pilose. Cerci long, slender, pilose.

Abdomen of female generally light brown. Segments 6–9 swollen.

Measurements. Body length of male approximately 16 mm; female length approximately 17 mm. Forewing length 17.0–21.0 mm.

Etymology. This species is named in honor of the collector, Ed Coher.

Taxonomic remarks. This insect may be the same species as the undescribed female Nepalese hangingfly discussed by Rust and Byers (1976) from Simra, Nepal, deposited in the Canada Department of Agriculture. This specimen has the Sc crossvein distal to the fork of the radial sector and a 1A vein extending almost to the level of the fork of the radial sector.

The affinity of Bittacus latipennis Gerstaecker, 1885 is uncertain at this time, because the male has not yet been described. However, B. latipennis can be readily differentiated from B. coheri and other south Asian hangingflies by its broad wings ( Esben-Petersen 1921, Fig. 131).The male of B. insularis Esben-Petersen, 1915 is also unknown at this time. Its female differs from B. coheri by having the 1A vein terminus opposite the origin of the radial sector, rather than extending two-thirds the distance to the first fork of radial sector. Bittacus coheri differs from all described south Asian and African Bittacus for which males are known, but is similar to many oriental Bittacus spp., such as B. monastyrskiyi Bicha, 2007 , in possessing conspicuous aedeagal lateral lobes ( Bicha 2007, Fig. 2 ). In the case of B. coheri , these lobes seem to resemble the hypovalves of panorpids. The function of these lobes is unknown, nor are their association with the aedeagus certain. The presence of a bifurcated flap-like structure extending dorsally between the male epiandrial lobes of tergum 9 is unique to B. coheri , is diagnostic for the species, and may justify creation of a new genus. However, the wing veination is not remarkably different from other species currently assigned to Bittacus . Orobittacus Villegas and Byers, 1981 possesses a median extension of tergum 9; although this extension is very different in form from that of B. coheri , it possibly suggests some distant relationship. The biology of B. coheri is unknown, but was recorded as being taken at light.

Figures

FIGURE 1. Bittacus coheri n. sp. Holotype, left forewing. Scale bar: 1 mm.

FIGURES 2 – 4. Bittacus coheri n. sp., holotype male terminalia. 2. Dorsal aspect. 3. Lateral aspect. 4. Ventrocaudal aspect. Abbreviations: a = aedeagus, b = bifurcated flap, c = cercus, d = dististyle, e = epiandrial lobe, l = aedeagal lateral lobes, p = proctiger. Scale bars: 0.5 mm.