Toxomerus laenas
Creators: name: Borges, Zuleica M.
name: Couri, Marcia S.
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Syrphidae
Toxomerus
Toxomerus laenas

description: Toxomerus laenas (Walker)   
(Figs. 30, 56, 57, 58, 110, 111, 112)  
 Syrphus barbulus Walker, 1852: 238 (descr.); Kertész, 1910: 107 (cat.).   
 Syrphus laenas Walker, 1852: 241 (descr.); Kertész, 1910: 117 (cat.).   
 Mesogramma nitidiventris Curran, 1930: 9 (descr.); 1934: 398 (key).   
 Mesogramma vitrea Hull, 1941b: 45 (descr.).   
 Mesogramma barbula Hull, 1943a: 10 (n. comb.).   
 Mesogramma laenas Hull, 1943a: 10 (n. comb); 1943b: 16, 40 (key and ill.).   
 Mesograpta barbula Fluke, 1956: 218 (cat.).   
 Mesograpta laena Fluke, 1956: 224 (cat.).   
 Mesograpta nitidiventris Fluke, 1956: 226 (cat.).   
 Mesograpta vitrea Fluke, 1956: 233 (cat.).   
 Toxomerus barbulus Thompson et al., 1976: 48 (cat. & n.comb.), syn. nov.   
 Toxomerus laenus Thompson et al., 1976: 51 (cat. & n. comb.).   
 Toxomerus nitidiventris Thompson et al., 1976: 53 (cat. & n.comb.), syn. nov.   
 Toxomerus vitreus Thompson et al., 1976: 56 (cat.& n. comb.), syn. nov.   
 Male. Head: face 1/3 as long as eye width, yellow, sometimes with black medial vitta, shiny except sparsely white pollinose and pilose laterally; gena black; frontal triangle yellow, 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 to brownish, black pilose, arista brown.   
Thorax: postpronotum brownish to black; proepisternum black, white pollinose; proepimeron black; scutum black, bronze pollinose except for two lateral and one medial bluish-white pollinose vitta, white pilose; scutellum black, white pilose; anterior anepisternum black, long yellow pilose; posterior anepisternum black anterior 2/3, yellow pilose dorsally, and yellow posterior 1/3, yellow pilose; katepisternum black except dorsal 1/3 yellow, dull, yellow pilose; 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; methatoracic pleuron black; metasternum black; halter yellow. Legs: coxae black, yellow pilose; trochanters yellow to brownish, yellowish pilose; femora black, yellow on basal and apical extremities, yellow and black pilose; tibiae brown, yellow and black pilose; protibia sometimes yellow with black annulus on medial 1/3; tarsi brown, brown pilose; mesotarsus black pilose ventrally. Wing: hyaline to brownish, 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 as broad as cell BM appically, microtrichose.  
 Abdomen: terga yellow and black pilose; 1 st tergum all black; 2 nd tergum all black; 3 rd to 5 th terga all black or 3 rd tergum black and 4 th and 5 th terga orange (Fig. 30). Male genitalia: surstylus almost as long as epandrium, with scattered short setae; postanal process little distinct; aedeagus slender dorsally; superior lobe somewhat triangular with setae medio-ventrally and scattered hairs (Figs. 56–58).   
 Female. Similar to male except for the frons black, white pollinose, yellow pilose. Anterior anepisternum bare.   
 Female genitalia: 9 th tergum with not distinct black macula; cercus slender; hypoproct somewhat oval; 9 th sternum as Fig. 111; three rounded spermatecae similar in size (Figs. 110–112).   
Length. Body 6.0–7.0 mm, wing 5.0–5.5 mm.  
 Discussion. The synonymies were based on the examination of the male holotype of Mesogramma nitidiventris, male holotype of Mesogramma vitrea, male holotype of Syrphus laenas and female syntype of Syrphus barbulus. The postpronotum black is an external character that helps to identify this species. Toxomerus barbulus and Toxomerus laenas were described at the same paper (Walker 1852). T. laenas was choosed as senior synonym, based on the reason the description belongs a male specimen.   
 Type material examined. Holotype. BRAZIL. Syrphus laenas, male (BMNH).   
 Other material examined. PARAGUAY. Villarrica: 2 ♂, VIII/1937, F. Schade (USNM); ♀, IX/1937, F. Schade (USNM). BRAZIL. Goiás: Formosa, 2 ♀, 25/IV/1972, L. Knutson (USNM). Brasília: National Park, 2 ♀, 23/IV/1972, L. Knutson (USNM); Distrito Federal, ♂ & ♀, 24/IV/1972, L. Knutson (USNM); ♂ & ♀, 4–5/X/1974, L. Knutson (USNM). Minas Gerais: Viçosa, ♂, 13/X – 1/XI/1985, T. J. Henry & S. P. Fiuza F. (USNM); Lagoa Santa, 2 ♂, 18/I/1977, L. Knutson (USNM). São Paulo: Cantaneira, ♂, VII-45, J. Lane (MZSP); Boracea, ♀, VI-1947, Rabello (MZSP), ♀, IX-1947, J. Lane; Severínia, ♂, XII-1940, A. G. Silva; Salesópolis, 5 ♂ & 2 ♀, 14–19/X/1970, J. W. Boyes & J. H. Guimarães (CNC); Campininha, 3 ♂ & ♀, 23–28/ X/1970, J. W. Boyes (CNC). Rio Claro, ♀, 14/I/1977, L. Knutson (USNM); Piracicaba, ♂, 11/I/1977, L. Knutson (USNM); Bocaina, 3 ♂, V/1951, III/1954, Dalcy & R. Barros (MNRJ); Cajurá, ♂, X/1954, M. P. Barreto (MZSP). Paraná: Curitiba, ♂ & ♀, J. W. Boyes (CNC). Foz do Iguaçu, ♀, 19/VII/1961, N. L. H. Krauss (USNM). Santa Catarina: Nova Teutônia, 4♂, 2 ♀, 23/III/1960, I/1970, F. Plaumann (CNC); ♂, V/ 1970, F. Plaumann (USNM); 13 ♂ & 3 ♀, V/1970, F. Plaumann (MZSP).   
 Geographical record. South America, southern Brazil and Paraguay.
description: Published as part of 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, pp. 1-72 in Zootaxa 2179 on pages 39-40