Hypselosyrphus helvus, Reemer, Menno, 2013

Reemer, Menno, 2013, Taxonomic exploration of Neotropical Microdontinae (Diptera: Syrphidae) mimicking stingless bees, Zootaxa 3697 (1), pp. 1-88 : 28

Hypselosyrphus helvus spec. nov.

Figs 70–73 .

Studied type specimens. HOLOTYPE. BRAZIL. Female. Label 1: " Brasil: Roraima / Rio Uraricoera / Ilha de Maraca"; label 2: " 19-24-vii-1987 / J.A. Rafael / L.S. Aquino"; label 3: "Armadilha de / malaise"; label 4 (yellow): "INPA / Rafael 1989". Coll. INPA (when studied the specimen was on loan in the USNM-collection).

Redescription (based on holotype)

Adult female Body size: 10 mm.

Head. Face occupying 1/4 of head width in frontal view; yellow; entirely yellow pilose. Gena hardly developed. Oral cavity directly bordering eye margins; with lateral margins not produced. Frons yellow, except black around lunula; yellow pilose, except black pilose around lunula. Vertex convexly produced, shining blackish brown; yellow pilose; ocellar triangle not elevated compared to rest of vertex. Occiput very narrow; black on dorsal half, yellow on ventral half; entirely yellow pilose. Eye entirely with short, white pile, a little longer than ommati diameter. Antennal fossa a little higher than wide. Antenna yellowish; antennal ratio approximately as 4:1:3.

Thorax. Entirely yellow and yellow pilose. Scutellum semicircular; with posterior margin apicomedially very faintly slightly sulcate; pale. Anepisternum convex, without sulcus; anterior part pilose, posterior part bare. Anepimeron entirely pilose. Katepisternum pilose dorsally; bare ventrally. Katatergum long yellow microtrichose. Anatergum short microtrichose. Other pleurae bare. Calypter and halter yellow.

Wing: hyaline; with veins yellow and anterior half tinged with yellow. Microtrichose, except bare on 1st costal cell, basal 1/10 of 2nd costal cell, basal 1/2 of cell br, posterobasal 1/3 of cell bm, anterobasal 1/6 of cell cup, basomedian 1/4 of alula.

Legs: Yellow; yellow pilose; hind tibia strongly widened and with pile as long as width of tibia.

Abdomen. Widest point at posterior 1/3 of tergite 2. Tergites and sternites (including sternite 1) entirely yellow and yellow pilose.

Male. unknown.

Etymology. The Latin adjective helvus (bay, yellow) was chosen because of the entirely yellow thorax and abdomen of this species.

Diagnosis. This is the only Hypselosyrphus -species with entirely yellow thorax and abdomen and with hyaline wings.

Distribution. Only known from Brazil (Roraima).

Figures

FIGURES 63 – 71. 63 – 66. Hypselosyrphus amazonicus female (holotype). 63. habitus dorsal; 64. habitus lateral; 65. scutellum; 66. wing. 67. Hypselosyrphus anax male (holotype), habitus dorsal. Photo: American Museum of Natural History. 68 – 69. Hypselosyrphus corbiculipes female (holotype). 68. habitus dorsal; 69. habitus lateral. 70 – 71. Hypselosyrphus helvus female (holotype). 70. habitus dorsal; 71. habitus lateral.

FIGURES 72 – 75. 72 – 73. Hypselosyrphus helvus female (holotype). 72. head frontal; 73. head lateral. 74 – 75. Hypselosyrphus marshalli (photographs by S. A. Marshall). 74. female (holotype), habitus; 75. male, habitus.