Toxomerus steatogaster (Hull)

Borges, Zuleica M. & Couri, Marcia S., 2009, Revision of Toxomerus Macquart, 1855 (Diptera: Syrphidae) from Brazil with synonymic notes, identification key to the species and description of three new species 2179, Zootaxa 2179, pp. 1-72 : 54-55

Toxomerus steatogaster (Hull)

( Figs. 38, 71, 72, 73, 149, 150, 151)

Mesogramma steatogaster Hull, 1941a: 62 (descr.).

Mesogramma steatornis Hull, 1943b: 20 (descr.).

Mesograpta steatogaster Fluke, 1956: 230 (cat.).

Mesograpta steatornis Fluke, 1956: 230 (cat.).

Toxomerus steatogaster Thompson et al., 1976: 55 (cat. & n. comb.).

Toxomerus steatornis Thompson et al., 1976: 53 (cat. & n. comb.), syn. nov.

Male. Head: face 1/2 as long as eye width, yellow, shiny except sparsely white pollinose and pilose laterally; gena brown to black; frontal triangle shiny brown, black pilose; vertical triangle black, white pollinose, black pilose; occiput black, silver pollinose, with thick white pile, with a short row of brownish pile superiorly; antenna yellow, sometimes with brown basoflagellomere, black pilose, arista brown.

Thorax: postpronotum yellow; proepisternum black, bronze pollinose; proepimeron yellow; scutum black except broadly yellow laterally, bronze pollinose except for bluish-white pollinose medial vitta, yellow pilose; scutellum yellow, black pilose; anterior anepisternum black, sparsely yellow pilose; posterior anepisternum black on anterior 1/2, yellow pilose dorsally, posterior ½ yellow, yellow pilose; katepisternum black except dorsal 1/3 yellow, dull, yellow pilose; anterior and dorsomedial anepimeron yellow; posterior anepimeron black; plumula yellow, calypter yellowish with yellowish fringe except brown fringe on dorsal lobe; posterior mesothoracic pleuron (katepimeron, meron, katatergum, anatergum and postscutellum) black, anatergum yellow posterodorsally; methatoracic pleuron yellow; metasternum yellow; halter yellow. Legs: pro- and mesocoxae black on basal 2/3, yellow apically, yellow pilose; metacoxa yellow, yellow pilose; trochanters yellow, yellow pilose; pro- and mesofemora yellow, yellow pilose, mesofemur black pilose posteriorly; metafemur yellow except for black annulus on apical 1/3, yellow pilose on basal 2/3 and black pilose on apical 1/3; tibiae yellow, pro- and mesotibiae yellow pilose; metatibia black pilose; pro- and mesotarsi yellow, yellow pilose; metatarsus yellow, fourth and fifth tarsomeres brown, black pilose. Wing: hyaline, extensively bare, as follow: mostly of cells C, SC, R, BM, CuP, basal 2/3 of cell R1, basal 1/3 of cell R2+3 and anterior basal 1/2 of cell R4+5; alula broader than cell BM appically, microtrichose.

Abdomen: terga yellow and black pilose; 1 st tergum yellow except narrowly black posteriorly; 2 nd tergum yellow except narrowly black fascia posteriorly; 3 rd to 4 th terga yellow except narrowly black fascia posteriorly, sometimes interrupted medially and extended in two medial black macula; 5 th tergum yellow with black macula medially ( Fig. 38). Male genitalia: surstylus with pointed apex, with scattered short setae; postanal process 1/2 as long as surstylus; aedeagus enlarged, slightly proeminent dorsally; superior lobe somewhat rounded with very short dorsal extension, with hairs along anterior margin and medially ( Figs. 71–73).

Female. Similar to male except for the frons black, bronze pollinose, black pilose.

Female genitalia: 9 th tergum with a spur medially; epiproct somewhat semielliptical; cercus slender;

hypoproct somewhat oval; 9 th sternum as in Fig. 150; three elliptical spermatecae similar in size ( Figs. 149–151).

Length. Body 7.5 mm, wing 5.5–6.0 mm.

Discussion. The synonymies were based on the examination of the female holotype and two females cotypes of Mesogramma steatogaster and male holotype and female allotype of Mesogramma steatornis .

Type material examined. Holotype. BRAZIL Amazonas: Rio Branco , Mesogramma steatogaster , male, 28/VIII/24 ( CNC). Cotype. BRAZIL. Goiás: Rio das Allmas, ♀, V/1938, F. Lane ( MZSP). São Paulo: Tamoyo, ♀, III/1944, Barreto ( MZSP).

Other material examined. ECUADOR. Sucua: Rio Upano , ♂, 30/I/1939 ( AMNH) . BRAZIL. Amazonas: R. Itaborai, 2♀, V/1950, J. C. M. Carvalho ( MNRJ) ; Marabitanas , ♀, VII/1949, J. C. M. Carvalho ( MNRJ) ; Urupes , ♀, VI/1949, J. C. M. Carvalho ( MNRJ) ; Cauaburi , 3 ♀, 9/XII/1962, J. Bechyné ( MZSP) . Goiás: Corumbá , 2♂, ♀, II/1946, XI/1946, M. P. Barreto ( MZSP) . São Paulo: Mogi Guacu , 3 ♂ & ♀, 23–28/ X/1970, J. W. Boyes ( CNC) ; Avanhandava , ♂, II/1946, M. P. Barreto ( MZSP) . Paraná: Porto Cabral , ♀, 1–25/IV/1944, Carrera & E. Dante ( CNC) .

Geographical record. Ecuador and Brazil.