Mesorhaga mexicana, Bickel, Daniel J., 2007

Bickel, Daniel J., 2007, The Mesoamerican Mesorhaga (Diptera: Dolichopodidae), with a taxonomic conspectus of the New World fauna, Zootaxa 1411, pp. 47-67 : 63-64

Mesorhaga mexicana n. sp. ( Fig. 3 f)

Type material. Holotype ɗ, Mexico: MORELOS, Cuernavaca, 15.viii.1954, R.R. Driesbach ( CAS).

Description. Male: body length: 3.4 mm; wing: 3.0 x 1.4 mm.

Head: 2–3 strong postvertical setae present, in line with the postoculars; strong proclinate vertical present on lateral frons; vertex, frons, face, and clypeus metallic blue-green, covered with silvery pruinosity; clypeus narrowed distally and adjacent to margins of eyes; palp and proboscis brown; scape and pedicel black (first flagellomere missing); ventral postcranium with abundant white setae.

Thorax: metallic green with bronze reflections; setae black; pleura with some grey pruinosity; ac as 4 offset pairs of setae; lateral scutellar setae about quarter length of medians.

Legs: coxae, trochanters and femora, and leg III dark brown; tibiae and basitarsi I and II yellow, with their distal tarsomere brown; CI and CII with whitish anterior hairs, CIII with white lateral seta; femora with av and pv rows of white ventral setae. I: 3.6; 3.6; 2.0/ 0.7/ 0.5/ 0.3/ 0.3. II: 4.4; 4.6; 3.0/ 1.2/ 0.8/ 0.5/ 0.3. III: 5.0; 5.7; 2.2/ 1.9/ 1.0/ 0.7/ 0.5; TIII with short dorsal setae.

Wing: unusually broad, almost half as wide as long; M with gentle curve at 1/2 between m-cu crossvein and wing apex; CuAx ratio: 0.8; lower calypter pale yellow, with black rim and fan of black setae; halter stalk brown, club black.

Abdomen: metallic blue-green with bronze reflections, covered with short, dark setae dorsally and pale setae ventrally; with dark, bronze-brown bands present on tergal overlap of segments 2–6; tergum 1 with posterolateral row of long black setae; hypopygium ( Fig. 3 f) dark brown; hypandrium expanded apically to form hood; phallus elongate and narrow; epandrial lobe ovate, with setae at 1/2 and ¾, with strong basal seta; surstylus rather short, with setae as figured; cercus thick basally, curved and greatly expanded apically, clavate, with groups of elongate subapical setae as figured.

Female: unknown.

Remarks. Mesorhaga mexicana is known only from the type locality in Morelos, Mexico. The wing on this species is wider than usual, the width being almost half the wing length, while in most Mesorhaga species, the wing width is about one third of the wing length.

Mesorhaga minatitlan n. sp. ( Fig 4 a)

Type material. Holotype ɗ, Mexico: VERACRUZ: Minatitlan , 26.viii–1.ix.1961, R. &. K. Driesbach ( CAS).

Description. Male: body length: 3.5 mm; wing: 3.7 x 1.3 mm.

Head: 2–3 strong postvertical setae present, in line with the postoculars; proclinate vertical seta on lateral frons; vertex, frons, face, and clypeus metallic blue-green, covered with silvery pruinosity; clypeus narrowed distally and adjacent to margins of eyes; palp and proboscis dark brown-yellowish; antenna black; 1st flagellomere subrectangular; arista dorsal, about as long as head height; ventral postcranium with abundant black setae.

Thorax: metallic green with bronze reflections; setae black; pleura with some grey pruinosity; ac present as single, irregular row of 5 setae, anteriormost paired, with single row of 3 posterior setae; lateral scutellar setae about 1/4 length of medians.

Legs: all coxae and trochanters brown; FI yellow, FII and FIII brown; tibiae and basal tarsomeres yellow, distal tarsomeres brown; CI and CII with black anterior hairs, CIII with black lateral seta;.I: 3.6; 3.6; 1.9/ 0.8/ 0.5/ 0.4/ 0.4; It5 slightly wider than t5 on legs II and III. II: 4.2; 4.8; 3.0/ 1.2/ 0.8/ 0.5/ 0.4. III: 5.0; 6.0; 2.3/ 1.8/ 1.2/ 0.6/ 0.4; TIII with some short, dorsal setae.

Wing: hyaline; M with distinct curve at 1/2 between m-cu crossvein and wing apex; CuAx ratio: 0.9; lower calypter brown, with black rim and fan of black setae; halter black.

Abdomen: metallic blue-green with bronze reflections and covered with short dark setae dorsally and pale setae ventrally; dark bronze-brown bands present on tergal overlap of segments 2–6; tergum 1 with posterolateral row of long black setae (MSSC); hypopygium ( Fig.4 a) dark brown; phallus and hypandrium elongate and narrow; epandrial lobes ovate, with setae near apex, and strong seta near base; surstylus with 3 arms and setae as figured; cercus curved and distally expanded, with group of strong distal setae.

Female: unknown.

Remarks. Mesorhaga minatitlan is known only from the type locality in lowland Veracruz, Mexico. It is close to the Costa Rican M. villanuevi in hypopygial structure and venation.

Figures

FIGURE 3. Mesorhaga isthmia n. sp. a hypopygium, left lateral. b. male postabdomen with phallus extended, left lateral; c. male tarsus I, posterior view. d. male wing, dorsal. M. baadsvicki n. sp.: e. hypopygium, left lateral. M. mexicana n. sp.: f. hypopygium, left lateral.

FIGURE 4. Mesorhaga minatitlan n. sp.: a. hypopygium, left lateral. M. nayaritensis n. sp.: b. hypopygium, left lateral. M. caudata Van Duzee: c. male postabdomen, left lateral; d. male postabdomen, dorsal.