Leptometriella monteana Roig-Alsina

A. Roig-Alsina, 2008, A revision of the South American bee genus Leptometriella Roig-Alsina (Hymenoptera, Apidae, Emphorini), Zootaxa 1688, pp. 20-36 : 32-33

Leptometriella monteana Roig-Alsina , n. sp.

(Figs. 6, 11, 22–25)

Diagnosis. This species can be recognized by the bare, polished, nearly inpunctate basal band of the scutellum, the mostly glabrous metapostnotum, the moderately elevated vertex of the head, the short vestiture of the metasomal terga, and the T7 of the male with the two apical points forming a V-shaped notch medially. The male genitalia and terminal sterna associate L. monteana with L. minima and L. boliviana .

Description. Female holotype. Length 6.0 mm (paratypes 6.0– 7.2 mm); length of forewing 5.3 mm (paratypes 5.1–5.5 mm).

Head black, mandible with dark brown apex. Antenna with scape, pedicel, and first two flagellomeres black, rest of antenna dark brown. Thorax and propodeum black; tegula dark brown, black close to scutum. Metasoma black, with apices of sterna and pygidial plate brown. Legs blackish to dark brown with tibial spurs yellowish, and apex of tarsi reddish brown. Wings hyaline with veins and pterostigma brown. Vestiture mostly white to pale gray, but light brown to brown on apex of mid tibia, dorsum of hind tibia, all tarsi and most of metasomal sterna; prepygidial fimbria orange brown to brown medially and paler at sides, pygidial fimbria brown (dark vestiture more extended on metasomal terga and legs in specimens of southern distribution, see color variation below). Vestiture dense and long on most of head, but sparse on clypeus and labrum; hairs on clypeus 0.8–1.8 times MOD, between antennal sockets 1.2–2.0 times MOD. Hairs on scutum 1.5–1.8 times MOD; on mesopleuron 1.8–2.6 times MOD; metapostnotum with short hairs (0.2–0.3 times MOD) close to propodeal margin, remainder of metapostnotum glabrous. T1–4 with apical band of dense, appressed hairs, that on T1 sometimes interrupted medially. T2 basally to apical band with appressed hairs 0.5–0.8 times MOD, and intermixed erect hairs 0.5–1.0 times MOD; T3–T4 also with intermixed appressed and erect hairs. Punctures of moderate size, but sparse, on clypeus and labrum; on rest of body punctures small. Margins of scutum with punctures rather dense, but median part of posterior half of scutum polished, with punctures minute, sparse, separated by 3–6 times their diameter; dorsum of scutellum with transverse band with few or no punctures; upper part of metapostnotum glabrous, polished, with few wrinkles at sides close to metanotum; punctures of mesopleuron as sparse as those of center of scutum. Vertex of head moderately elevated behind ocelli, distance from median ocellus to vertex in frontal view as long as 1.15 ocellar diameters. Proportion of UID to LID 1:0.91; IAD to AOD 1:0.42. Proportion of scape, pedicel and first three flagellomeres 3.3:0.8:1:0.5:0.6; first flagellomere as long as 1.15 times its apical width. Mandible apically narrowly pointed; preapical tooth distinct, small. Metapostnotum nearly vertical, in same plane as metanotum. Gradulus of T6 with short gradular carina restricted to posterior part of tergum.

Male. Length 5.4–6.7 mm; length of forewing 5.0– 5.7 mm.

Color of cuticle and vestiture similar to that of female, but pale vestiture (white to pale gray) more extensive, light brown hairs restricted to hind tarsus. Distribution of vestiture and punctation similar to that of female, although denser. Hairs of scutum 1.6–2.4 times as long as flagellar diameter. T2–T6 with apical band of dense hairs; band on T1 less defined. Hairs of basal parts of terga erect (appressed hairs absent), those on T2 0.8–1.2 times as long as flagellar diameter. Hairs of S2–S5 rather short, 1.0–1.5 times as long as flagellar diameter, those on S3–5 shorter medially. S6 evenly covered with short hairs. Proportion of first three flagellomeres, 1:0.7:0.8; first flagellomere as long as 1.0–1.1 times its apical width. Mandible tapering apically. T7 with two apical points separated distally by a distance similar to their length, forming medially a Vshaped notch. S7, S8 and genital capsule as in figures 22–25.

Color variation. The color pattern of the vestiture of this species presents latitudinal variation. Specimens from the north (provinces of Catamarca to northern Mendoza) have pale hairs on most of the body, except a few areas with brown hairs: the males have brown hairs only on the tarsi, and the females have brown hairs on the apex of the mid tibia, the dorsum of the hind tibia, all the tarsi, the prepygidial fimbria medially, the pygidial fimbria, and most of the metasomal sterna. Specimens from Neuquén and Río Negro are darker, having brown hairs on T3–T4 (female) or on T3–T6 (male) basally to and contrasting with the pale apical bands. The females have brown hairs on entire T5–T6 including the prepygidial and pygidial fimbriae, and the mid and hind legs have brown hairs beyond the apex of the femora in both sexes. A female from southern Mendoza (La Tosca) is intermediate, with brown hairs basally to the pale bands on T3–T4, but with prepygidial fimbria with pale hairs laterally and legs colored as in northern specimens. I have not detected any morphological differences that may suggest that the southern specimens represent a different species.

Etymology. The name monteana , pertaining to the Monte, refers to the Monte biogeographic region ( Cabrera & Willink, 1973), where the species occurs.

Material studied. Holotype female, Argentina, La Rioja, Guandacol, 29-XI-1993, P. Hazeldine ( MACN). Paratypes: Argentina: Catamarca: 3 females, 1 male, Belén, 30-X-1972, on flowers of Verbesina encephaloides, L. Stange ( IFML); 1 female, 2 males, Andalgalá, 6-XI-1972 and 17-X-1973, all on flowers of Sphaeralcea, J.L. Neff ( CTMI); 1 female, El Rodeo, 20-28-I-1958, R. Golbach ( IFML). La Rioja: 3 males, Nonogasta, XI-1927, M. Gómez ( MACN); 1 female, Chilecito, 25-XI-1944, A. Ogloblin ( MLP); 2 females, 1 male, Famatina, 23-XI-1975, L. Stange ( IFML). San Juan: 2 males, Pampa de Vieja, 8 km NE San José de Jáchal, 1-XI-1991, J.G. Rozen, L. Peña & A. Ugarte ( AMNH). Mendoza: 1 male, Mendoza, P. Joergensen ( MACN); 1 male, San Rafael, base Volcán Diamante, 2-XII-1982, Del Vitto (IADIZA); 1 female, 1 male, Malargüe, La Tosca, 20-XI-1973, J.L. Neff ( CTMI). Neuquén: 1 female, Arroyito, ruta nac. 237, 6-10-XII- 1987, A. Willink ( IFML). Río Negro: 1 female, Luis Beltrán, XI-1987, M. Fritz ( MACN); 1 male, San Antonio Oeste, XII-1984, M. Fritz ( MACN).