Pialea corbiculata Schlinger

Schlinger, Evert I., Gillung, Jessica P. & Borkent, Christopher J., 2013, New spider flies from the Neotropical Region (Diptera, Acroceridae) with a key to New World genera, ZooKeys 270, pp. 59-93 : 80-82

Pialea corbiculata Schlinger sp. n. Figs 20-24

Material examined.

Holotype male: Top label: "VENEZUELA / Mérida, 3500 m. / Páramo Mucubaji / nr. Laguna Negra". Second label: "29.iv-3.v.81 / Malaise trap / L. Masner / 8115". Third label: bright green "ACROCERIDAE/ E.I. Schlinger/ Specimen #/ 004215". Bottom label: red "HOLOTYPE ♂/ Pialea corbiculata/ Schlinger new species/ Det. E.I. Schlinger 2012" (CAS).

Diagnosis.

Antennae inserted in the middle of the head (male); post pedicel as long as the head height; head, thorax and scutellum black; legs and abdomen black with yellow markings; hind leg with tibia and first tarsomere swollen (Figs 20, 22), twice as wide as the second tarsomere; additional r-m crossvein (2r-m) present.

Description.

Male holotype with medium body size (Fig. 20, male body length: 7.3 mm) and wing longer than body (male wing: 8.6 mm). Head. Eyes black and densely covered with dark brown, long (equal to scape length) pile (Fig. 21), occiput and ocellar tubercle dark brown and densely covered with long dark brown pile, ocelli light brown, frons dark brown, scape and pedicel dark brown, pedicel with yellow setae, flagellum light brown, lacking apical setae. Male flagellum petal like, length ~2 × length of scape and pedicel combined. Face dark brown with brown pile, clypeus dark brown, with light brown pile and shorter than scape, mouthparts dark brown and strongly reduced. Thorax. Dark brown and densely covered with long brown pile (Fig. 22). Coxae dark brown, femora yellow with apex of ventral surface brown, tibia yellow with apex brown, tarsi brown, hind leg longer than fore- and mid-leg and with tibia and first tarsomere swollen (twice as wide as mid-leg). Lower calypter brown and densely covered long brown pile, halter brown. Wing. Transparent light brown with brown wing veins; M1 and M2 present. Abdomen. Densely covered with light brown pile (Fig. 22). Tergite I and VI brown, tergites II-V yellow with anterior margin and medial line brown; sternites I and VI brown sternite II–V yellow.

Comments.

Pialea corbiculata sp. n. is closely related to Pialea lutescens Westwood, 1876 and Pialea antiqua Schlinger, 1956, based on the presence of wing vein M1. It dif fers from those two species by the swollen tibia and first tarsomere of the hind leg and the presence of an additional r-m crossvein (2r-m), which are unique features within Pialea .

Etymology.

The species epithet, corbiculata, is in reference to the swollen hind tibia and tarsi which resemble the pollen collecting corbicula of many bees.