Grallipeza mellea (Williston)

Marshall, S. A., 2013, Grallipeza Rondani (Diptera: Micropezidae: Taeniapterinae) of the Caribbean and North America, Zootaxa 3682 (1), pp. 45-84 : 65

Grallipeza mellea (Williston)

Figs. 32–37

Calobata mellea Williston, 1896:373 .

Grallipeza placida (Loew) , Hennig, 1934: 307. Grallipeza mellea, Steyskal, 1968 :48.7.

Description: Size: Approximately 8mm. Colour: Head, including frontal vitta and palpus, almost entirely orange with only ocellar triangle black ( Fig. 33 ); gena and central occiput all or partly silvery. Fore femur slightly darkened only on mesal surface or distal fifth, tarsomere one and tarsomere two off-white, tarsomere 3 brown distally, other tarsomeres brown. Hind femur uniformly pale. Katepisternal bristles golden, silvery area of katepisternum indistinct, restricted to posterodorsal third. Postpronotum prominent, with small dark setulae; one large and 1–2 small suprahumeral bristles. Wing with infuscated discal area quadrate distally, expanded at level of CuA1 and extending from base of CuA1 to apex of R2+3. Apex of wing lightly infuscated. Abdominal pleuron almost entirely pale, darkened along dorsal edge only.

Head: Arista conspicuously long-haired at least over basal ¾. Pedicel with long ventroapical bristles, one almost as long as first flagellomere. Supra-antennal shelf small but exposed between lower frons and scape. Lunule with black setulae, face pale setulose, ventral half membranous and microsetulose. Clypeus shining orange. Palpus orange, parallel-sided with short dark bristles on ventral half. Gena with dense silvery setulae. Frontal vitta almost parallel, orange with an indistinctly darkened anterior patch ( Fig. 33 ).

Thorax: Cervical sclerite slightly convex ventrally, microtrichose and without distinct pores, female with a differentiated densely microtrichose ventral patch. Postpronotum setulose and with several weak bristles along ventrolateral half. Fore femur with an anterior row of about 12 and a posteroventral row of about 10 stout bristles along length ( Fig. 34 ). Two distinct dorsocentral bristles; 1 distinct suprahumeral bristle at end of a row of small dorsocentral setulae; acrostichal setulae forming 2 distinct presutural rows, scattered postsuturally. Wing: Anal cell microsetulose except for a narrow longitudinal strip, wing membrane with central pigmented area distally rounded, extending from base of vein CuA1 to apex of R2+3 (or nearly so).

Male abdomen: Pleuron of segment 2 with an elongate-oval differentiated area (all specimens shriveled but this is presumably eversible as a dome in fresh material). Tergite one reddish, posterior preabdominal tergites dark, tergite 6 black and shining bare. Epandrium elongate and yellow, 2.3 times as long as high. Genital fork with arms strongly incurved with a distinct inner basal shoulder, almost entirely enclosing a circular area distally, basally deeply cleft such that only the distal half has teeth on the mesal surface; mesal surface of distal half with about 30 black teeth in two loose rows. Distiphallus elongate, sinuate, about twice as long as epandrium, ending in a small but dense bulb ( Fig. 37 ).

Female abdomen: Oviscape very long (almost as long as balance of abdomen; Fig. 32 ), apex orange, otherwise shining dark brown. Abdominal tergite 1 pale, tergites 2–5 dull brown; tergite 6 and oviscape dark and shining. Common spermathecal duct of uniform width, about twice as wide as single spermathecal duct; paired spermathecae cup-shaped, striate on main part and with a convoluted and tuberculate base ( Fig. 36 ). Single spermatheca T-shaped with 2 equal narrow lobes.

Type material: (lectotype female BMNH). St. Vincent. Leeward side St. Vincent, HH Smith, W. Indies 1907- 66. Non-type material examined: St. Vincent. Kingstown Botanical Garden, 25–27.iii.1989, W. Mathis (2 Ƥ 1 3, USNM); Montreal, 26.iii.1989, A. Freidberg (3 Ƥ, USNM); Cumberland, 28.iii.1989, W. Mathis (1 Ƥ, USNM); Mangaroo, 28.iii.1989, A. Freidberg (1 3, USNM).

Comments: As pointed out by Steyskal (1967), Hennig (1934) was in error to synonymize this species with the Cuban species Grallipeza placida , from which it differs in having golden katepisternal bristles, a diffuse discal spot on the wing, a mostly reddish fore femur with distinct ventral bristles, and an entirely pale abdominal pleuron. More importantly, the spermathecae and associated ducts are entirely different in these two species, with G. m e l l e a more closely resembling G. spinuliger and G. placidoides from Dominica and St. Lucia. Grallipeza mellea is most similar to G. grenada , from which it differs in having two pairs of dorsocentral bristles.

Figures

FIGURES 32 – 37. Grallipeza mellea. 32, female right lateral; 33, male head dorsal; 34, male to show ventrally bristled fore femur; 35, male left lateral; 36, spermathecae and ducts; 37 male terminalia left lateral.