Pieza deresistans, Evenhuis, Neal L., 2002

Evenhuis, Neal L., 2002, Pieza, a new genus of microbombyliids from the New World (Diptera: Mythicomyiidae), Zootaxa 36, pp. 1-28 : 9-10

Pieza deresistans , sp. nov.

Female. Length: 0.81­1.05 mm. Head. Eyes dichoptic; ocelli form­ ing a narrow triangle on black ocellar tubercle; lateral ocellus 1.5 its diameter from inner eye margin; frons slightly longer than wide, depressed medially, yellow from level of median ocellus to anten­ nae, with medial brown spot; antenna black, scape minute; pedicel slightly wider than long; first flagellomere short, ovoid, broadest at or slightly beyond middle, slightly longer than wide; length of se­ cond flagellomere equal to width of first flagellomere; face brown; proboscis black, projecting beyond oral margin for 1.5 head height; occiput ( Fig. 10 ) yellow with brown centrally, in some spe­ cimens, thin strip of brown color extending dorsolaterally so as to form a shape similar to the top half of an “X”.

Thorax. Mesonotum dark brown with yellow vittae; humeral callus, interhumeral tri­ angular mark, lateral margin, postalar callus, narrow admedian vitta, and prescutellar area yellow; dark brown color of mesonotum almost reaching base of scutellum laterally; dor­ sum of mesonotum with scattered black hairs; scutellum yellow with scattered dark hairs; pleura black, anepisternum with upper portion yellow; medial longitudinal yellow stripe present; coxae and legs yellow; halter with stem and knob yellow to whitish.

Wing. Hyaline; veins brown; costa ending at midpoint between end of veins R4+5 and M1; vein R2+3 arising at nearly 90°; discal cell narrowed apically; vein at base of cell m1 slightly shorter than r­m crossvein.

Abdomen. Dorsum brownish; tergites IV­VII with yellowish white fasciae on posterior margin of each segment, yellow color broader on each succeeding posterior segment; tergites I and II darker brown than succeeding tergites; dorsum with scattered yellowish hairs; venter yellow.

Genitalia ( Fig. 14 ). Vaginal furca V­shaped, with lateral processes long, thin; spermathecal reservoir linear­ovate, with slight constriction basally, sclerotized on apical three­fourths; apical spermathecal duct membranous, tapering from reservoir to sperm pump, length about twice that of reservoir; sperm pump membranous, gradually flared from base to apex, length subequal to apical; spermathecal duct; apical duct joins apical valve inside flared apex of sperm pump; common duct short.

Male. Unknown.

Types. Holotype female from VENEZUELA: Aragua: 2 km N. Ocumare de la Costa, 31.iii—2.iv.1981, A.S. Menke & L. Hollenberg in USNM. Paratypes: 2 females, topotypic, collected with the types; 1 female, Zulia: 15 km. N. Carrasquero, 29.v.1976, A.S. Menke & D. Vincent. Two paratypes in USNM. One paratype in BPBM.

Remarks. This is the most yellow species of Pieza known. Some specimens appear orange, but this is probably due to a hypercyanic condition after capture.

Etymology. The specific epithet derives from the Latin “ de ” = away from, down + “ resistens ” = firm, tough; referring to the relative fragility of the only known four female specimens.

Distribution. Known only from the 2 localities in northern Venezuela.

Figures

FIGURE 10. P i e z a deresistans, sp. nov., occiput, poste­ rior view.

FIGURES 14 ­ 16. Pieza female genitalia. 14. P. deresistans, sp. nov. 15. P. flavitibia, sp. nov. 16. P. minuta (Greene).