Stipomorpha wheeleri ( Mann , 1928)

Reemer, Menno, 2013, Taxonomic exploration of Neotropical Microdontinae (Diptera: Syrphidae) mimicking stingless bees, Zootaxa 3697 (1), pp. 1-88 : 73-74

Stipomorpha wheeleri ( Mann, 1928)

Figs 220–224 , 250 .

Microdon wheeleri Mann, 1928 .

Studied type specimens. Two specimens labelled as types (red labels) in USNM-collection: 1 male & 1 female; both with same labels: label 1: "no. 147"; label 2: "Red Tank, C.Z. 2.27.23, W.M. Wheeler". The female has an additional label stating: " Microdon wheeleri Mann type ". Mann (1928) stated that he designated a ‘ type and allotype’. As his description is based primarily on the female, which also carries a lable stating ‘type’, this is regarded as the holotype. There are also two specimens (same locality and date) labelled as paratypes on blue labels, as well as four empty puparia, from which the specimens were reared.

Redescription (based on holotype)

Adult female. Body size: 8 mm.

Head. Face occupying slighty more than 1/3 of head width in frontal view; shining pale yellow; yellow pilose on lateral 1/4, bare medially. Gena yellow. Oral margins not produced laterally, not notched anteriorly. Frons and vertex yellow; yellow pilose; ocellar triangle black, elevated; frontal ocellus split in two. Occiput yellow; yellow pilose. Eye bare. Antennal fossa about as wide as high. Antenna pale brown; antennal ratio 3.5:1:3; basoflagellomere parallel-sided with rounded apex, with sensory pit at 3/4 from base; arista slender, about 2/3 of length of basoflagellomere.

Thorax. Scutum shining dark brown, except yellow along margins; yellow pilose, except for a medially interrupted fascia of black pile posterior to transverse suture. Postpronotum and postalar callus yellow; yellow pilose. Scutellum yellow; yellow pilose. Anepisternum more or less flat, pilose anteriorly and posteriorly, widely bare in between; brown anteriorly, yellow posteriorly. Anterior anepimeron yellow pilose dorsally, bare ventrally. Posterior and dorsomedial anepimeron yellow; bare. Katepisternum and katepimeron yellow; bare. Meron, katatergum and anatergum brown; bare. Katatergum long microtrichose, anatergum short microtrichose. Calypter blackish, halter yellow.

Wing: hyaline, tinged with yellow; microtrichose except bare on basal 1/10 of cell r1, on most of cell br except microtrichose along vena spuria , on posterobasal 2/3 of cell bm, on basal 1/3 of cell cup.

Legs: Yellow; yellow pilose, except dorsal surface of hind tibia and basal three tarsomeres of hind tarsus black pilose. Coxae and trochanters yellow; yellow pilose.

Abdomen. Yellow; yellow pilose. Second tergite wider than thorax, widest point at 2/3 from base; third and fourth tergites strongly narrowing. Tergites 3 and 4 fused, with abrupt lateral transition (view from dorsal). Sternite 1 bare, other sternites sparsely yellow pilose.

Male (based on paratype). As female, except for following differences.

Head. Face occupying about 1/3 of head width in frontal view. Frons dark brown; yellow pilose. Vertex dark brown, black pilose. Occiput brown; black pilose dorsally, yellow pilose ventrally. Basoflagellomere with sensory pit at 2/3 from base; arista slender, about 2/3 of length of basoflagellomere.

Thorax. Scutum entirely blackish brown; entirely black pilose. Postpronotum, postalar callus and scutellum black pilose. Pilosity of pleurae as in female, but black instead of yellow.

Legs: Brown, more extensively black pilose.

Abdomen. Brown and black pilose on tergites 1, 2 and basal half of 3, then gradually getting yellow and yellow pilose. Genitalia as in fig. 250 (drawn from paratype).

Notes. The male paratype is much darker in colouration than the female holotype. Mann (1928) writes that Wheeler, who reared the specimens from their pupae, told him that all specimens were yellow at the time of emergence and darkened gradually. So, possibly the female is yellow because it is teneral.

Figures

FIGURES 212 – 221. 212 – 215. Stipomorpha tenuicauda female (holotype). 212. habitus dorsal; 213. habitus lateral; 214. head frontal; 215. head dorsal. 216 – 219. Stipomorpha trigoniformis male (holotype). 216. habitus dorsal; 217. habitus lateral; 218. head frontal; 219. wing. 220 – 221. Stipomorpha wheeleri male (paratype). 220. habitus dorsal; 221. habitus lateral.

FIGURES 222 – 232. 222 – 224. Stipomorpha wheeleri. 222. male (paratype), head frontal. 223. female (holotype), habitus dorsal; 224. female (holotype); habitus lateral. 225 – 227. Stipomorpha zophera male (holotype). 225. habitus dorsal; 226. habitus lateral; 227. head frontal. 228 – 229. Stipomorpha, tergites 1 & 2 dorsal. 228. S. mendax; 229. S. mixta. 230 – 232. Stipomorpha, male genitalia lateral. 230. S. apicula (holotype); 231. S. elcopala (holotype); 232. S. fallax (holotype).

FIGURES 246 – 251. Stipomorpha, male genitalia latera. 246. S. simillima (holotype); 247. S. spuria (holotype); 248. S. tenuicauda (Bolivia, coll. RMNH); 249. S. trigoniformis (holotype); 250. S. wheeleri (paratype); 251. S. zophera (holotype).