Osirinus tarsalis, Melo & Zanella, 2003

Melo, Gabriel A. R. & Zanella, Fernando C. V., 2003, The species of the parasitic bee genus Osirinus (Hymenoptera, Apidae), Journal of Natural History 37 (24), pp. 2919-2929 : 2927-2928

Osirinus tarsalis , new species

Comments

At a first glance, this species suggests an Osiris because of its strongly punctured clypeus, upturned lamella along anterior margin of pronotum and relatively bulging dorsolateral lobes of pronotal collar. However, presence of only one subapical tooth in the mandibles, its wide frons, the rounded contour of area between vertex and occiput, lack of subapical teeth on female mid tibia and lack of depressions or rugosity on metapostnotum clearly exclude it from Osiris . Within Osirinus , this species seems to be more closely related to O. parvicollis and O. rutilans .

The paratypes agree quite well with the holotype, except for their slightly slender hind tibia (respectively, 4.3 × and 4.4 × longer than wide) and slender hind basitarsus of paratype from ‘Chapada’ (about 4 × longer than maximum width). The paratype from ‘Chapada’ was dissected and it could be observed that its labrum possesses five small preapical denticles.

Description

Holotype. Body length: 6.2 mm; maximum head width: 1.9 mm; forewing length: 6.0 mm. Colour: predominantly reddish yellow, except for dark reddish brown claws and apical third of mandibles and for reddish brown distal half of flagella. Wing veins brown, pterostigma brownish yellow, membrane hyaline, except for light brownish infuscate apical portion. Pubescence: mostly pale yellow, except for reddish yellow setae on legs and metasoma and brown setae covering wing membrane and veins. Dense and finely plumose on labrum, frons (except on supraclypeal area and above antennal sockets), gena, mesoscutum, scutellum, metanotum and upper half of mesepisternum laterally. Clypeus without decumbent, plumose setae. Conspicuously dense on posterior half of vertex. Disc of mesoscutum uniformly covered with short, dense and finely plumose, erect setae. Longest setae on scutellum about 1.3 × the length of 2nd flagellomere. Simple setae on hind tibia slender, not bristle-like; plumose setae with very short branches, not very distinct from simple setae. Integumental surface: predominantly very smooth and shiny; setigerous punctures very fine, except for a few strong punctures on clypeus and for those on lateral surface of mesepisternum. Metapostnotum completely smooth, without a basal depression. Structure (measurements in mm): head about 1.2 × wider than long (1.92:1.54); inner orbits weakly concave on its upper portion and slightly converging below (upper to lower interorbital distance, 1.14:1.03); eye 2 × as long as its maximum width (1.23:0.61); mandible about 2.6 × longer than its outer basal width (0.84:0.32); clypeus 2.4 × wider than long (1.0:0.42), its disk relatively flat, in lateral view less protuberant than supraclipeal area. First flagellomere about 0.5 × as long as 2nd (0.13:0.27). Labial palpus five-segmented, apical segment minute. Apical portion of foretibial spur (apical to velum) longer than half the length of basal portion (0.19:0.25); hind tibia, in posterior view, about 4.0 × longer than wide (1.52:0.38); hind basitarsus, in lateral view, distinctly fusiform, about 3.7 × longer than its maximum width (1.1:0.3). Forewing M and Cu diverging distinctly distal to cu-a; proportion of lengths of submarginal cells on posterior margin 1.5:1:1.4 (0.61:0.40:0.55). Medial portion of anterior margin of pronotum upturned and forming a distinct, backward-directed lamella. Dorsolateral lobes of pronotal collar distinctly bulging, almost connected to one another medially. Mesoscutum about 1.1 × wider than long (1.27:1.14). Pygidial plate triangular, acuminate apically, translucent lateral and apical margins well developed and slightly upturned.

Type material

Peru : Holotype female ( DZUP), ‘AVISPAS-Cuzco, PERU 20-IX-62, LUIS E. PENA’. Paratypes: Brazil , Mato Grosso : one female ( MACN), ‘ Chapada’ and ‘ Col. E. GIACOMELLI’; Peru : one female ( AMNH), ‘ Tingo Maria, Huan., Peru, Oct. 23 1946, Alt. 2200 ft. ’ and ‘ J. C. Pallister, Coll. Donor Frank Johnson’ .

Etymology

This species is named for the widened basitarsi of its hind legs, from the Greek tarsos, ankle plus the Latin suffix - alis, pertaining to.