Melaloncha palpalis Borgmeier, 1934

Brown, Brian V., 2006, Revision of the untreated taxa of Melaloncha s. s. bee-killing flies (Diptera: Phoridae), Zootaxa 1280 (1), pp. 1-68 : 60-62

Melaloncha palpalis Borgmeier

Figs. 49 , 57

Melaloncha palpalis Borgmeier, 1934, p. 172 , figs. 10, 12, plate 3 fig. 5 (♀; Suiza de Turrialba, Costa Rica).

Melaloncha cuspidata Borgmeier, 1934, p. 174 , plate 3 fig. 7 (♀; Yungas de Coroico , Bolivia); 1959, p. 171 (in key); 1971b, p. 131 (♀; Nova Teutônia, Brazil). NEW SYNONYMY.

Holotypes. Melaloncha palpalis , ♀, COSTA RICA: Suiza de Turrialba , 28.v.1921 [ LACM ENT 121863 ] (examined; Hungarian Natural History Museum, Budapest) .

Melaloncha cuspidata , ♀, BOLIVIA: La Paz: Yungas von Coroico, 30.x.1906, 1600 m [ LACM ENT 115326 ] (examined; Dresden Museum, Germany) .

Recognition. The two described species M. palpalis and M. cuspidata are extremely similar. Originally, Borgmeier (1934) separated the two by the following characters: scutum with dark posterolateral spots and palpus whitish ( M. palpalis ) versus scutum without spots and palpus reddish ( M. cuspidata ). Later (1959, 1971b), realizing these traits were unreliable, he keyed them with the following: palpi slender; foretarsomere 1 longer than tarsomeres 2+3 combined; second costal segment longer than first ( M. cuspidata ) versus palpi thick; foretarsomere 1 longer, as long as 2–4 combined; second costal segment shorter than first ( M. palpalis ). I measured all the available specimens to obtain further data on these characters ( Table 1), and found that there is little support for them. Although the ratio of foretarsal segments could support recognition of the two species, this is weak evidence relative to differences among other Melaloncha species. The palpus in both species appear similar in structure, and costal sector 1 of M. cuspidata was not always shorter than sector 2; in most instances it was longer. Furthermore, the structural similarities in the ovipositor are such that it seems likely they are a single species. Further specimens are needed from different localities to fully resolve this question, but for now I consider the two to be synonyms.

Specimens of this species are extremely similar to some specimens of M. striatula (see discussion under M. striatula , below).

Description. Female (male unknown). Body length 2.2–3.1 mm. Frons yellow, bare of setulae; ocellar triangle black. Mean frontal width 0.45 head width, range 0.40–0.50. Ocular and genal setae yellow to black; in some specimens dorsal ocular setae black, other setae yellow. Flagellomere 1 and segments 1–2 of arista yellow; aristomere 3 black. Palpus yellow, slightly inflated; palpal setulae yellow. Scutum yellow to yellowish brown, with posterolateral dark spot. Scutellum yellowish­brown, with anterolateral round black spot. Pleuron yellow except basalare black. Legs yellow, except foretarsomeres in some specimens darker and in some specimens (newly collected material from Bolivia) apical foretarsomere dark brown. Combined length of foretarsomeres approximately equal to length to slightly longer than foretibia. Foretarsal claws recurved, with large basal lobe. Mean costal length 0.50 wing length, range 0.49–0.53. Halter yellow. Abdominal tergites yellow with black posterior strip. Venter of abdomen yellow. Ovipositor black, yellow at base; elongate, straight, slightly laterally flattened, laterally cleft along apical one­quarter; with sparse, short setae.

Variation. Four specimens from Cumbre Alto Beni are smaller than the rest and have shorter ovipositors. I have set these aside and labeled them as possibly belonging to another species, but in other respects they resemble typical M. palpalis .

Host. Females were attracted to a mixed aggregation of bees at Cumbre Alto Beni, including Apis mellifera , Partamona epiphytophila , and Plebeia spp.

Geographical distribution. Costa Rica south to Bolivia and Brazil.

Other material examined. BOLIVIA: La Paz: 40 km N Caranavi, Cumbre Alto Beni, 15.83°S, 67.56°W, 2♀, 13.iv.2003, 2♀, 18.iv.2003, B. Brown, S. Marcotte, E. Zumbado, 3♀, 17.iv.2004, 3♀, 21.iv.2004, E. Zumbado, honey­sprayed undergrowth, 1600 m ( CBFC, LACM) . BRAZIL: Santa Catarina: Nova Teutônia , 27.18°S, 52.38°W, 1♀, iii.1967, 1♀, vii.1971, F. Plaumann, 300–500 m ( MZSP) ; Sao Paulo: Coqueiros , 1♀, 1960, E. Rabello ( MZSP) . COSTA RICA: Alajuela: Alberge de Heliconia , 10.71°N, 85.04°W, 1♀, 20.vi.2000, D. M. Wood, Gressitt Malaise trap ( LACM) . VENEZUELA: Lara: Parque Nacional Yacambu , 6–8.iv.1981, A. S. Menke, L. Hollenbert ( USNM) .

Figures

FIGURES 43–53. Melaloncha spp., female, ovipositor, left lateral (except Figs. 52 and 53, bottom). Figs. 45 and 52 showing intersegmental membrane and sclerite of intersegment 7–8.

FIGURES 56–61. Melaloncha spp., female, scanning electron micrographs. 56–57. Foretarsal claws. 56. M. digitalis, 57. M. palpalis. 58–60. Venter of forefemur. 58. M. lacerna, 59. M. laselvae, 60. M. zurquiensis. 61. Intersegment 7–8, M. gradata.