Toxomerus idalius (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 : 36-38

Toxomerus idalius (Hull)

( Figs. 3, 50, 51, 52, 101, 102, 103)

Mesogramma idalia Hull, 1951a: 11 (descr.).

Mesogramma eurydice Hull, 1951a: 17 (descr.).

Mesograpta eurydice Fluke, 1956: 222 (cat.).

Mesograpta idalia Fluke, 1956: 223 (cat.).

Toxomerus idalius Gerdes, 1975: 13 ; Thompson et al., 1976: 51 (cat. & n. comb.).

Toxomerus eurydice Gerdes, 1975: 13 ; Thompson et al., 1976: 50 (cat. & n. comb.), syn. nov.

Male. Head: face 2/3 as long as eye width, yellow, shiny except sparsely white pollinose and pilose laterally ( Fig. 3); gena black; frontal triangle yellow, sometimes with a little brown macula next to lunule, white pilose; vertical triangle black, bronze pollinose, black pilose; occiput black, silver pollinose, with thick white pile, with a short row of brownish pile superiorly; antenna yellow, black pilose, arista brown.

Thorax: postpronotum yellow; proepisternum black, white pollinose; proepimeron yellow; scutum black except broadly yellow laterally, bronze pollinose except for bluish-white pollinose medial vitta, yellow pilose; scutellum usuaaly yellow, sometimes brownish with yellow margins, black pilose; anterior anepisternum black, long 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 on apical 1/3; metafemur yellow except for black annulus on apical 1/3, yellow and black pilose; pro- and mesotibiae yellow, yellow pilose; metatibia usually yellow, sometimes brownish on medial 1/3, black pilose; pro- and mesotarsi yellow, yellow pilose; metatarsus brown, black pilose. Wing: hyaline, extensively microtrichose, bare only: on basal 1/2 or less of cell C, basal 1/5 of cell R1, basal 2/3 or less of cell R and basal 3/4 or less of cell BM; alula broader than cell BM appically, microtrichose.

Abdomen: terga yellow and black pilose; 1 st tergum black except yellow anteriorly and laterally; 2 nd tergum black with medial yellow fascia; 3 rd to 4 th terga black with yellow fascia on anterior 1/2 with two medial black macula; 5 th tergum yellow with black macula medially. Male genitalia: surstylus with pointed apex, with scattered short setae; postanal process 3/4 as long as surstylus; aedeagus enlarged, proeminent dorsally and ventrally; superior lobe somewhat quadrangunlar with short dorsal extension, forked distad, with scattered hairs, longer along anteroventral margin, with small lobe medio-posteriorly with hairs ( Figs. 50–52).

Female. Similar to male except for the frons black, bronze pollinose, black pilose. Anterior anepisternum bare, sometimes with rare short piles.

Female genitalia: 9 th tergum with somewhat triangular black macula; epiproct somewhat elliptical; cercus slender; hypoproct somewhat triangular; 9 th sternum as in Fig. 102; three rounded spermatecae similar in size. ( Figs. 101–103).

Length. Body 7.0–8.0 mm, wing 5.5–6.5 mm.

Discussion. Gerdes (1975) indicated that the male genitalia of Toxomerus idalius and Toxomerus eurydice were identical and suggested that the names are synonyms. The examination of the male holotype of Mesogramma eurydice and male holotype and five male paratypes of Mesogramma idalia confirmed this synonymy.

Type material examined. Holotype. ECUADOR. Puyo : Oriente, Mesogramma idalia , male, 3–15/XII/ 1938, F. M. & H. Brown ( AMNH) . Paratypes. ECUADOR. San Francisco : Mesogramma idalia , 3 ♂, 1/X/ 1938, W. C. Macintyre ( CNC) . COLOMBIA. Cali : Mesogramma idalia , 2 ♂, 27/I/1935, Herbert F. Schwarz ( CNC) .

Other material examined. BRAZIL. Pernambuco: Caruaru , 3 ♂, IV/1972, VI/1972, M. Alvarenga ( MNRJ) . Bahia: Salvador , 2 ♂, 28/VIII/1951, D. Albuquerque ( MNRJ) . Rio de Janeiro: Friburgo , ♂, II/ 1932, M. L. ( MNRJ) . São Paulo: S. Bocaína, ♂, III/1954, Dalcy, R. Barros ( MNRJ) ; São Paulo, ♂, 2/XII/ 1965, R. Inoue ( CNC) ; Osasco , ♂, XII/1957, J. Lane ( CNC) ; Campos do Jordão , ♂, III/1945, J. Lane ( CNC) ; 2 ♂, III/1945, Wygodzinsky ( CNC) ; Cajurá , 2 ♂, X/1954, M. P. Barreto ( MZSP) . Santa Catarina: Nova

Teutônia, 13♂, 2 ♀, VI/1970, XI/1971, F. Plaumann ( USNM). Geographical record. Tropical and subtropical South America .