Megachile (Pseudocentron) variplantis Vachal, 1909

Durante, Silvana, Torretta, Juan Pablo & Colombo, Maria Guadalupe, 2014, Descriptions of unknown sexes, new geographical records, and host associations for two South American species of Megachile (Hymenoptera: Megachilidae), Zootaxa 3814 (1), pp. 133-138 : 135-136

Megachile (Pseudocentron) variplantis Vachal, 1909

( Figs. 5–8 )

Megachile variplantis Vachal, J. (1909) : 9.

Megachile (Pseudocentron) variplantis ; Raw, 2002: 31; Moure et al., 2007: 988; Moure et al., 2012.

Description. Female. (Three individuals) Total length 11.50 mm. Head, maximum width 4.75 mm, maximum length 3.50 mm; forewing length 9.30 m. Integument. Black ( Fig. 5 ) except: brown on flagellum, tibial spurs 2 and 3; dark reddish brown on apex of distitarsus; ferruginous on tibial spur 1 and claws (dark brown apically). Wings pale brown-hyaline; veins and stigma brown. Vestiture. Black and pale yellowish ( Fig. 5–7 ); head black, paraocular areas, pronotal lobe, scutum, scutellum, axillae, metanotum and T1 with abundant pale yellowish pubescence; dark brown on lower surface of gena, lower surface of mesosoma, coxae, trochanters and femora and tomentum on hind tibia; dark ferruginous on inner surfaces of tarsi; T1–T6 covered with black hairs ( Fig. 8 ); T1–T2 with distal yellowish white pubescence; scopa ferruginous on S2–S5, S1 and basal surface of S2 covered with black scopal hairs; S6 with central area bare, subapical row of short black hairs, and basally dark ferruginous hairs. Punctation. Integument generally coriaceous, densely punctate; clypeus and supraclypeal area more densely punctate, separated by 0.1–0.2 times a puncture diameter with central line shining and impunctate. Mandible coriaceous, scarcely punctate. Scutum, scutellum and axilla with punctures, separated by 0.1–0.2 times a puncture diameter. T2–T5 only coriaceous, T6 micro-sculptured, distal margin shining and impunctate. Structure. Inner margin of eyes subparallel ( Fig. 7 ); paraocular carina present. Proportional lengths of scape, pedicel and first three flagellomeres 1.00:0.22:0.36:0.24:0.26; distal flagellomere broader than long (0.40:0.24). Inter-antennal distance longer than antenna-clypeal distance (0.84:0.46), longer than antennocular distance (0.84:0.72), and shorter than antennal insertion to median ocellus (0.84:0.92). Clypeus and supraclypeal area nearly flat; apical margin of clypeus as in fig 13; mandible with four teeth, with complete cutting edge in third interspace and incomplete cutting edge in second interspace (Fig. 15). Median ocellus located below supraorbital line; interocellar distance subequal to ocellocular distance (0.72:0.80) and longer than ocelloccipital distance (0.72:0.52). Gena subequal to eye (1.00- 1.00), in lateral view. Scutellum rounded, not protuberant in profile. Metasoma, cordate. T6 straight in profile, dorsally rounded.

Type material studied. Mendoza. 1 male holotype, H. Rolle col. ( MNHP).

Other material studied. (Three females and nineteen males) ARGENTINA. Buenos Aires. 1 male, Canal San Fernando, 28-X-1945 ( MLP); 1 male, Tandil, 17-XI-1951, Fritz leg. ( MLP); 1 male, locality data unknown, 27-III- 1904, Bretes leg. ( MACN). Catamarca. 1 male, La Viña, 9-XI-1942, A. Ogloblin leg. ( MLP); 2 males, Valle Viejo, 17-V-1936 ( MLP). Córdoba. 1 male, Río Tercero, 1-XII-1941 ( MLP). La Pampa. 1 male, Victorica, 4-XI-1945, Daguerre leg. ( MLP). Mendoza. 1 male, Mendoza, Reed leg. ( MLP). Misiones. 1 male, Loreto, A. Ogloblin leg. ( MLP). Neuquén. 1 male, Neuquén, 22-I-1945, Lloyd leg. ( MLP). Río Negro. 2 males, Choele Choel, 23-XI-1946 ( MLP); 1 male, El Bolsón, 15-III-1945 Lloyd col. ( MLP); 1 male, Río Colorado, III-1958 ( MLP). San Juan. 1 male, Villa Colón, 23-XI-1941 ( MLP). Santa Cruz. 1 female and 2 males, L. Argentino, El Calafate, 25-I-2005, D. Medan leg. (on Matricaria inodora , Asteraceae ) ( FAUBA); 1 female and 1 male, L. Argentino, El Calafate, 27-I- 2005, D. Medan leg. (on Senecio filaginoides , Asteraceae ) ( FAUBA); 1 female, Río Chico, L. Pueyrredón, camping El Tío, 26-I-2010, D. Medan leg. (on Melilotus albus , Fabaceae ) ( MLP). Tucumán. 1 male, Tucumán, Reed leg. ( MLP).

Distribution. ARGENTINA. Mendoza, Entre Ríos and Salta ( Raw, 2007; Ascher & Pickering, 2011,). New records: Buenos Aires, Catamarca, Córdoba, La Pampa, Misiones, Neuquén, Río Negro, San Juan, Santa Cruz and Tucumán.

Bionomical observations. Males and females were captured on flowers of Matricaria inodora and Senecio filaginoides (both Asteraceae ). The two sexes are similar in the color of wing, veins and stigma, body pubescence, and sculpturing of scutum, scutellum and axilla.

In the key to species of Megachile of Mitchell (1930), the females of M. variplantis run to couplet 8, agreeing with the characteristics indicated for the female of M. timida . The key can be amended as follows:

8. Dorsum of thorax entirely covered with rather dense fulvous pubescence......................................... 8’ - Dorsum of thorax with conspicuous black pubescence........................................ M. velhoensis Mitchell 8’. Antenna, tegula, veins, wings and legs ferruginous; scopa white and black.......................... M. timida Mitchell - Antenna, tegula, veins, wings and legs black or brown; scopa ferruginous and black................. M. variplantis Va c h a l

Remarks. M. (P.) variplantis is easily separated from other species by the ferruginous scopa (in M. (P.) poeyi Guérin [= M. velhoensis Mitchell ] and M. (P.) timida it is white), by the dark ferruginous tomentum on hind tibia and the absence of tergal bands (in M. (P.) gomphrenae Holmberg and M. (P.) gomphrenoides Vachal is pale yellowish and dark brown tomentum respectively and T2-5 with complete white yellowish apical bands). Moreover, M. variplantis is the only species of Megachile (Pseudocentron) collected in this location with such an austral distribution ( Raw, 2007; Moure et al. 2012; this work).

Figures

FIGURES 5 – 8. Megachile (Pseudocentron) variplantis Vachal. Female. 5, habitus, lateral view. 6, head and mesosoma, lateral view. 7, head, frontal view. 8, metasoma, dorsal view.