Grallipeza baracoa (Cresson)

Marshall, S. A., 2013, Grallipeza Rondani (Diptera: Micropezidae: Taeniapterinae) of the Caribbean and North America, Zootaxa 3682 (1), pp. 45-84 : 55-57

Grallipeza baracoa (Cresson)

Figs. 13–14

Systellapha baracoa Cresson, 1926:265

Rainieria baracoa, Cresson, 1930:318

Grallipeza baracoa, Hennig, 1934:308 ; Steyskal, 1967:82; 1968:48.7 Grallipeza nebulosa (Loew) , Cresson, 1938:356; Steyskal, 1965:635

Description: Size: Approximately 7 mm. Colour: Head, including frontal vitta and palpus, almost entirely orange with only ocellar triangle black; frontal vitta paler anteriorly and paler than orbital plate; clypeus darker than face, palpus pale, parallel-sided with short dark bristles on ventral half. Legs yellow with most of fore femur and all of fore tibia black, fore tarsomeres 1–3 white, fore tarsomeres 4–5 dark. Mid and hind femora orange with a distinct distal black ring and with a diffuse longitudinal black mark on anterior surface ( Fig. 13 ). Tarsomere one of hind leg white, contrasting with dark tarsomeres 2–5. Thorax almost entirely orange except for silvered or browned patches on katepisternum, posterior half of anepisternum and propleuron. Katepisternum with a double row of golden bristles. Abdominal pleuron of female almost entirely white, with a small yellow patch on ventral half of segments 3–4 ( Fig. 13 ). Male with a distinct, round, black microsetulose membranous dome on pleuron of segment 2.

Head: Arista bare on distal half, basal half with short hairs only slightly longer than width of basal aristomere. Pedicel with long ventroapical bristles, one almost as long as first flagellomere. Frontal vitta depressed below level of orbital plates and slightly expanded anteriorly and tapered behind ocelli.

Thorax: Cervical sclerite not clearly visible on examined material, but female with ventral surface modified and apparently with pits or pores. Postpronotum bare. Fore femur with only small ventral setulae. Two distinct dorsocentral bristles, suprahumeral bristles forming a prominent row of 5–6 bristles grading into a continuous row of small dorsocentral setulae. Acrostichal setulae forming regular rows presuturally, scattered postsuturally. Wing: Anal cell short and bare in basal half, membrane otherwise setulose. Membrane without distinct pigmentation. Costal vein yellow, other veins brown.

Male abdomen: Genital fork with long, dense apical-ventral setae, mesal face on basal half with 3 widely spaced teeth, distal half with three teeth crowded near apex. Junction between arms of fork forming a U-shape in contrast to the V-shape of the closely related G. nebulosa (but only one damaged genitalic mount examined for G.

baracoa ). Distiphallus relatively narrow basally, ending in a strikingly swollen distal bulb with a tongue-like distal extension shorter than the bulb ( Fig. 14 ).

Female abdomen: Oviscape relatively short, about ½ as long as preabdomen and double length of tergite 6. No dissection available.

Type material: Holotype (male, USNM): Cuba, Baracoa , Sept. 1901, A. Busck. Paratypes (2 Ƥ), same as holotype. Other material examined: (female photographs only; see comments, and one male, BIOECO): Cuba, Baracoa , el Yunque, N 20°20.419', W 74°33.040' S.A. Marshall (photographs) and G. Garcés (specimen, in alcohol).

Distribution: The type specimens are from “ Baracoa ” and recent collections/photographs are all from El Yunque (“the anvil”), an isolated mountain close to Baracoa . This contrasts with the only Cuban congener, G. placida , which has been frequently photographed or collected in areas surrounding Barcoa as well as elsewhere in Cuba. Cresson (1930) mentions a specimen of G. b a r a c o a from Cayamas, Cuba but the identity of this specimen needs to be confirmed. A female specimen from San Vincente, Cuba (J.C. Bradley, 14.vii.1940) in the Cornell University insect collection keys to G. baracoa and is probably this species.

Comments: Grallipeza baracoa is easily distinguishable from the only recognized sympatric species, G. placida , by its banded mid and hind femora, white first hind tarsomere, almost bare arista, prominent suprahumeral bristles and its relatively clear wing membrane. Although no female specimens were available for dissection, there is no doubt about the validity of this species. The live fly shown in the photograph was not collected.

Grallipeza baracoa resembles the continental North American G. nebulosa in colour, chaeototaxy and antennal characters but differs in the colour of the fore tarsi. Unfortunately, it was not possible to compare the female genitalia to the very distinctive structures of the latter species. The only available male genitalic mount for G. baracoa has a broken genital fork, but it is more U-shaped than the relatively V-shaped fork of the closely related G. n e b u l o s a. More significantly, the distiphallus bulb of G. baracoa suggests a close relationship to G. nebulosa . Both of these species have a similar, strikingly robust bulb that extends distally as a flat bib. This “bib” is shorter than the bulb in G. baracoa ( Fig. 14 ), longer in G. n e b u l o s a ( Fig. 40 ), but this structure is clearly homologous in these species, and unlike congeners other than G. placida . Cresson described this species as a Systellapha in 1926, moved it to the genus Rainieria in 1930, then (1938) decided it was a synonym of Grallipeza nebulosa . Steyskal (1965) followed this synonymy but later (1967) recognized that G. nebulosa and G. baracoa were separate species.

Figures

FIGURES 13 – 14. Grallipeza baracoa. 13, live female, Baracoa, Cuba; 14, male epandrium and associated structures.

FIGURES 38 – 44. Grallipeza nebulosa. 38, live male Florida; 39, live female Florida; 40, female right lateral; 41, female head and thorax dorsal; 42, male terminalia ventral; 43, spermathecae and ducts; 44, male terminalia left lateral.