Pieza agnastis (Hall) Hall, 2002

Evenhuis, Neal L., 2002, Pieza, a new genus of microbombyliids from the New World (Diptera: Mythicomyiidae), Zootaxa 36, pp. 1-28 : 5-6

Pieza agnastis (Hall) , comb. nov.

Mythicomyia agnastis Hall, 1976:77 . Painter, Painter & Hall, 1978: 11. Evenhuis, 1983: 462.

Male and female. Length: 0.80­1.37 mm. Head. Black; eyes dichoptic, separated at vertex by 1.5 distance between lateral ocelli; front dark brown to black, depressed medially; face black; antennae black, scape minute; pedicel slightly wider than long, first flagellomere ovoid­conical, rounded apically, length about 1.7 greatest width; second flagellomere about three­fourths length of first flagellomere, with subapical style; occiput dull black, gray pollinose ventrolaterally, becoming brownish ventrally; proboscis black, labrum pointed, stiff, length equal to height of oral margin; labium length slightly longer than head height.

Thorax. Mesonotum and scutellum dark brown to black, with scattered dark hairs; humeral callus, thin notopleural line, and postalar callus yellow; interhumeral and posthumeral marks absent; pleura black, wing base and upper edge of katepisternum vaguely yellowish; coxae and basal four­fifths of femora dark brown, remainder of legs yellow; halter stem orange to brownish yellow, knob yellow to orange, some specimens with brown dorsally on knob.

Wing ( Fig. 3 ). Hyaline; veins brown; costa ends at one­third distance from end of vein R4+5 to M1; vein Sc incomplete, ending at level just beyond midpoint between origin of Rs and end of R2+3; Rs evanescent at connection with R1; R2+3 origin about three­fourths distance from origin of Rs to r­m crossvein, arising almost perpendicular to Rs, ending in R1 just before level of r­m crossvein; r­m crossvein at basal one­third of cell dm; R4+5 slightly curved toward wing margin; cell dm shorter than cell cua1, narrowed apically at base of cell m1; vein at base of cell m1 and r­m crossvein short, subequal in length; M1 curved toward wing margin; M2 only slightly curved, if at all, toward wing margin; base of vein A1 vestigial, remainder of vein present only as fold; fringe of hairs along posterior margin of wing fairly dense, longest on anal lobe, becoming gradually shorter toward end of costal vein.

Abdomen. Dorsum dark brown; yellow fasciae restricted to narrow transverse bands on posterior margins of most tergites, especially distinct on tergites III­VI; venter marked as on dorsum, vestiture pale.

Genitalia. Not dissected.

Types. Holotype female from CHILE: Santiago Province: El Canelo, 9.i.1967, M.E. Irwin. Holotype in MEUC. A long series of paratypes in the J.C. Hall Collection at UCR plus material in CAS, collected at the same places and dates as recorded in Hall (1976), but pinned and labeled subsequent to that paper, were examined during this study. Holotype examined previous to its deposition in MEUC.

Detailed information on this type locality and other localities in Chile that were visited during the University of California­Universidad de Chile Arthropod Expedition to Chile and parts of Argentina can be found in Irwin and Schlinger (1986).

Distribution. Known only from Maule and Santiago Provinces in Chile.

Figures

FIGURES 3 ­ 4. Wings of Mythicomyiinae. 3. Pieza agnastis (Hall). 4. Mythenteles propleuralis (Melander).