Pieza minuta (Greene) Greene, 2002

Evenhuis, Neal L., 2002, Pieza, a new genus of microbombyliids from the New World (Diptera: Mythicomyiidae), Zootaxa 36, pp. 1-28 : 14-17

Pieza minuta (Greene) , comb. nov.

Mythicomyia minutum Greene, 1924: 62 .

Mythicomyia minuta Greene. Melander, 1928: 376 (emendation of minutum ); 1961: 225. Painter & Painter, 1965: 418. Cole & Schlinger, 1969: 238. Hull, 1973: 269. Evenhuis, 1983: 480. Hall & Evenhuis, 1986: 580.

Mythicomyia eremica Melander, 1961: 204 . Hull, 1973: 269. Evenhuis, 1983: 471. Syn. nov.

Mythicomyia (Mythenteles) eremica Melander. Hall & Evenhuis, 1986: 334 .

Male. Length: 0.78­1.36 mm. Head. Eyes dichoptic; ocelli forming a narrow triangle; lateral ocellus less than its diameter from eye margin; frons yellow, 2 as long as wide with brown spot in medial depression; antenna black, scape and pedicel minute, subequal in length, first flagellomere ovoid, length slightly less than 2 width; second flagellomere slightly longer than width of first flagellomere; proboscis black, projecting beyond oral margin for distance slightly less than head height; occiput black with minute white hairs on lower half.

Wing. Hyaline; veins brown; costa ending at midpoint between vein R4+5 and M1; cell dm narrowed apically; apical crossvein subequal in length to r­m crossvein.

Abdomen. Dorsum blackish brown on tergites I­III; tergite IV blackish brown on basal two­thirds, apical one­third yellowish white; tergites V­VII yellowish white; dorsum with scattered microscopic yellowish hairs; venter yellow.

Genitalia ( Fig. 12 ). In lateral view with gonocoxite small, thin, gonostyli not evident, in dorsal view subrhomboid with small medial notch; gonocoxal apodemes long, paddle shaped, truncate apically; aedeagal apodeme as in Fig. 10 , with large heart­shaped lateral vanes; lateral rami small, thin; aedeagus small, bottle shaped in ventral view; epandrium large, subspherical with pointed pseudo­surstyli; cercus hook­shaped with bifid end, slightly exserted.

Thorax. Mesonotum dull black; humeral callus, large interhumeral mark, broad lateral margin (diamond­shaped in front of transverse suture, deeply and broadly notched), and postalar callus yellow; dorsum with microscopic whitish hairs; scutellum flavotestaceous,darker brown medially, without hair; pleura black, upper portion including median longitudinal stripe yellow; coxae and basal two­thirds of femora black; apical one­third of femora, tibiae, and basitarsi yellow; rest of tarsi black; halter with stem brown, knob creamy white.

Female as in male except as follows: genitalia ( Fig. 16 ) with vaginal furca V­shaped, lateral processes paired, think, inner pair smaller, thicker than outer curved pair; spermathecal reservoir linear­ovate with long basal portion; apical spermathecal duct long, thin, tapering to sperm pump, length ca. 4 sperm pump; sperm pump membranous, fused basally to common duct; apical valve flared, with blunt apex; basal valve not evident; common duct with accompanying sclerotized basal plate.

Types. Holotype female of minuta ( USNM No. 26540) from UNITED STATES: New Mexico: Las Cruces, 14.vi.1917, J.M. Aldrich. The holotype was examined during this study. It is in fair condition and mounted on a 90°­angled minuten, which is coiled around a larger pin with the label data.

Holotype female of eremica (in USNM) from UNITED STATES: California: Riverside County: Palm Springs, 23.iv.1944, A.L. Melander. The holotype was examined during this study. It is in deplorable condition. Both wings are broken off and missing, but enough of the base of the left wing remains to confirm that the base of the medial vein between the 2 basal cells is present and that vein A1 is evanescent; the left hind leg and right fore femur are present, otherwise the remainder of the legs are missing; the head has the eyes collapsed and the abdomen is twisted and collapsed due to air drying; and the anterior portion of the mesonotum between the interhumeral marks is greasy.

Remarks. Reexamination of type specimens of Melander’s Mythicomyia in the USNM during this study revealed that minuta possesses characters of Pieza and not Mythicomyia . Further examination in comparison with material already at hand showed that eremica and minuta are conspecific, thus the new synonymy above.

The emendation from minutum to minuta was actually first done by Melander (1928) and not Melander (1961) as recorded in Hall and Evenhuis (1986).

Specimens of this species have been collected from 22 April to 29 July with the majority of specimens having been captured during June and July. There is 1 specimen (Aguas Calientes Indian Reservation, Riverside County, California [deposited in CAS]), which was collected 20 February, but otherwise agrees in all morphological characters with the other specimens of this species.

Distribution. Hall and Evenhuis (1986) recorded eremica from California and Sonora and minuta was only known from the type specimen from California. Additional material has been identified in this study, which extends the distribution to the following localities in the southwestern United States and northern Mexico: UNITED STATES: Arizona: Huachuca Mts. New Mexico: Doña Ana County. MEXICO: Baja California Sur: San Isidro Canyon.

Figures

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

FIGURES 12 ­ 13. Pieza male genitalia. 12. P. m i n u t a (Greene); a. lateral view; b. epiphallic complex, dorsal view; c. gonocoxites, ventral view. 13. P. ostenta (Melander); a. lateral view; b. epiphallic complex, dorsal view; c. gonocoxites, dorsal view.

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