Nesiergus Simon 1903

Guadanucci, José Paulo L. & Gallon, Richard C., 2008, A revision of the spider genera Chaetopelma Ausserer 1871 and Nesiergus Simon 1903 (Araneae, Theraphosidae, Ischnocolinae), Zootaxa 1753, pp. 34-48 : 43

Nesiergus Simon 1903

Nesiergus Simon 1903: 927 ; Benoit 1978: 410; Smith 1990: 132.

Type species: Nesiergus insulanus Simon 1903 , by original designation.

Diagnosis: Males differ from those of Chaetopelma by their tibial apophysis branches being strongly fused basally, with the retrolateral branch being short and wide, rather than being longer than wide. Females differ from those of Chaetopelma by their short spermathecae receptacula, which are nearly as wide apically as basally.

Description: Chelicerae without rastellum. Carapace oval, longer than wide; sparsely pilose. Cephalic region slightly raised. Eye tubercle weakly raised, small. Eye group rectangular, anterior eye row procurved, posterior row recurved. Fovea transverse. Maxilla with produced anterior lobe, conical; 60–100 cuspules on inner angle; lyra and serrula absent. Labium nearly as long as wide, with 30–50 cuspules restricted to centre of labium. Labiosternal junction moderately deep; sigilla oval, distinct and located near junction. Sternum oval with three pairs of small, rounded sternal sigilla; posterior sternal sigilla one or less than one diameter from sternal margin. Palps and legs slender, sparsely pilose. Male tibial apophysis comprising two branches strongly fused at base; prolateral branch short and rounded, with adjacent spine; retrolateral branch slightly longer, bearing line of short apical spines. Male metatarsus I straight, bends externally to retrolateral branch of tibial apophysis. Scopulae on ventral surface of metatarsi very dense on anterior legs, less dense on posterior legs. Scopulae on tarsi I–II entire, III–IV divided by band of thick setae. Scopula on retrolateral femur IV absent. Stridulatory setae absent. Superior tarsal claws of both sexes without teeth, inferior tarsal claws absent, claw tufts well developed. Tarsi with clavate trichobothria in two parallel dorsal rows along segment, separated by longitudinal line of long, thin setae; filiform and clavate trichobothria are interspersed. Filiform trichobothria on metatarsi (single row) and tibiae (two rows); clavate trichobothria in compact group on cymbium. Tarsi without spines. Cymbium longer than wide, bilobed. Palpal bulb with long, thin embolus. Spermathecae comprising two long receptacles without lobes. Abdomen coloration uniformly brown, abdominal markings absent. Urticating hairs absent. Two pairs of spinnerets; posterior median spinnerets very short; posterior lateral spinnerets elongated, all three segments of similar length and bearing spigots, apical article digitiform or triangular (as in N. insulanus ).

Species included: N. gardineri ( Hirst 1911) n. comb.; N. halophilus Benoit 1978 ; N. insulanus Simon 1903 .