Megachile (Zonomegachile) gigas Schrottky

Gonzalez, Victor H., Griswold, Terry & Engel, Michael S., 2018, South American Leaf-Cutter Bees (Genus Megachile) Of The Subgenera Rhyssomegachile And Zonomegachile, With Two New Subgenera (Hymenoptera: Megachilidae), Bulletin of the American Museum of Natural History 2018 (425), pp. 1-73 : 1-73

Megachile (Zonomegachile) gigas Schrottky

Figures 5G, H , 21 , 23

Megachile gigas Schrottky, 1908: 235 (neotype ♂ [here designated], examined, ANSP 4133). Silveira et al., 2002: 215 (placement in Zonomegachile Mitchell ).

Megachile sanctipauli Schrottky, 1913: 205 (neotype ♂ [here designated], examined, ANSP 4133). Silveira et al., 2002: 214 (placement in Pseudocentron Mitchell ).

Megachile aequalis Mitchell, 1930: 246 (holotype ♂, examined, ANSP 4133: Mato Grosso, Chapada dos Guimarães). Mitchell, 1943: 666 (placement in Chrysosarus Mitchell ). Moure, 1948: 332 (placement in Acentron Mitchell ).

DIAGNOSIS: Both sexes of this species are easily recognized by T1–T4 with dense, appressed, apical yellow fasciae, legs orange, and wings yellow. The hypostomal tooth is strong in the male (fig. 5G), distinctive in frontal view as in M. kalina , n. sp. However, the latter species lacks the distinctive coloration of the wings and legs and the yellow fasciae on the terga.

DESCRIPTION: Male: total body length 14.6 mm; forewing length 10.0 mm; head width 5.1 mm. Head 1.3× wider than long; inner orbits of compound eyes straight or nearly so; intertorular distance 1.5x times torulorbital distance; interocellar distance 2.2× OD, 0.9× ocellocular distance; ocelloccipital distance 3.6× OD, 1.5× ocellocular distance; scape 3.1× longer than broad, pedicel shorter than F1, about as long as broad, F1 1.3× longer than broad, shorter than F2, remaining flagellomeres longer than broad. Clypeus emarginate medially on distal margin; hypostomal area with strong, anteriorly projected tooth, distinct in frontal view. Procoxa with apical spine long, about 1.5× OD; protibia with posterior margin rounded, not carinate; probasitarsus parallel-sided, 2.3× longer than broad; mesobasitarsus 1.9× longer than broad; metabasitarsus 3.0× longer than broad. Preapical carina of T6 with semicircular emargination, 2.9× broader than deep, tooth lateral to emargination blunt, orthogonal.

Head and mesosoma black, except: mandible dark reddish brown; scape and pedicel dark brown, flagellum light reddish brown; legs light reddish brown to orange with pro- and mesotarsi yellowish. Terga dark brown; sterna brownish. Wings, tegula, pterostigma, and veins yellowish.

Pubescence light reddish brown except: clypeus (erect setae), discs of T1–T3, and posterior margin of metabasitarsus with dark brown setae; inferior margin of hypostomal tooth apically and apex of procoxal spine with tuft of short, dense, stiff light reddish-brown setae; clypeus (appressed setae), supraclypeal area, gena, hypostomal area, and sterna with whitish setae; sides of T3 and T4 with dark brown setae; discs of T5 and T6 with erect, long (1.5–2.0× OD) dark brown to black setae. Protarsi with dense fringe of long setae along their posterior margin, 1.3× longer than width of basitarsus; mesotarsi with sparser, longer fringe of setae than on protarsi, at least 3.5× longer than width of basitarsus (fig. 23D). Distal margins of T1–T4, discs of T3 and T4 basally, and nearly entire disc of T5 with dense, appressed, yellow fascia obscuring integument. S1–S4 with apical fasciae longer than on terga.

Face and vertex with coarse, nearly contiguous punctures; clypeus with punctures shallower and larger than on vertex; supraclypeal area with minute, fine punctures; gena with shallower, larger punctures than on vertex, punctures becoming smaller, coarser inferiorly. Mesoscutum coarsely and densely (≤0.5× PW) punctate, punctures slightly larger than on vertex, integument among punctures imbricate; mesoscutellum and axilla shinier, with sparser punctures than on mesoscutum; mesepisternum with punctures larger, sparser than on mesoscutum, becoming smaller, denser dorsally; metepisternum and lateral and posterior surfaces of propodeum strongly imbricate, punctures on metepisternum and lateral surface of propodeum slightly smaller and sparser than those on mesepisternum dorsally, becoming smaller, shallower, and widely separated (≥1.0× PW) on posterior surface of propodeum; propodeal triangle microalveolate; metanotum weakly imbricate with smaller, shallower punctures than on mesoscutellum, separated by at most a puncture width; legs weakly imbricate to smooth and shiny with coarse punctures on outer surfaces of tibiae. Terga weakly imbricatelineolate, weakly shiny, minutely and uniformly punctate, punctures separated by at least two puncture widths on basal terga, denser on T4 and T5; T6 with coarse, nearly contiguous punctures, much larger than on preceding terga; sterna strongly imbricate, with coarser, sparser punctures than on terga.

HOLOTYPE ( M. aequalis ): ♂, Chapada/Nov./ Megachile aequalis Mitchell , Type 4133 ( ANSP).

NEOTYPE ( M. gigas , here designated): ♂, Chapada/Nov./ Megachile aequalis Mitchell , Type 4133 ( ANSP). Schrottky (1908) described this species from a female specimen from São Paulo, Brazil, and the type now lost ( Rasmussen et al., 2009). It has been widely recognized that M. gigas , M. sanctipauli Schrottky (whose type is also lost, see below), and M. aequalis Mitchell are synonyms (e.g., Moure et al., 2007). Accordingly, we here designate as neotype the holotype of M. aequalis (the only surviving type specimen for the three species-group names involved) thereby rendering these names as objective synonyms and stabilizing their nomenclatural application.

NEOTYPE ( M. sanctipauli , here designated): ♂, Chapada/Nov./ Megachile aequalis Mitchell , Type 4133 (ANSP). Schrottky (1913) described this species from a male specimen from São Paulo, Brazil, and the type now lost ( Rasmussen et al., 2009). As noted above, it has been widely recognized that M. sanctipauli , M. gigas , and M. aequalis are synonyms (e.g., Moure et al., 2007). Accordingly, we here designate as neotype the holotype of M. aequalis thereby rendering these names as objective synonyms and stabilizing their nomenclatural application.

PARATYPES (n = 2♂♂): 2♂♂, same data as holotype (ANSP).

COMMENTS: The whereabouts of the female type of M. gigas Schrottky as well as the male type of M. sanctipauli Schrottky are unknown. They are probably lost as for many other species described by Curt Schrottky ( Rasmussen et al., 2009). The description presented here is therefore based on the male holotype and two male paratypes of M. aequalis Mitchell deposited in ANSP. We were not able to examine females of this species and thus, female characters mentioned in the diagnosis and keys were taken from the original description ( Schrottky, 1908).

Figures

FIGURE 5. Some morphological features used in the phylogenetic analysis.A, B. Pubescence of apex of female sixth sternum. C, D. Pubescence of male clypeus. E–G. Modifications of the male mandible and hypostomal area. H. Modifications of male protarsus.I. Pubescence of posterosuperior surface of male metafemur.A. Megachile (Creightonella) cognata Smith (Uganda, Tororo, SEMC 1177151).B, E, G. M. (Acentron) albitarsis Cresson (♀, Costa Rica, San José, SEMC 1177780; ♂, Costa Rica, Guanacaste, SEMC 1177784). C. M. (Chalepochile) ardua Mitchell (male holotype). D. M. (Aporiochile) tricosa Cockerell (male holotype). F, H. M. (Zonomegachile) gigas Schrottky (Brazil, Mato Grosso, ANSP 4133). I. M. (Chalepochile) tacanensis Moure (Argentina, Tucumán, SEMC 1184302).

FIGURE 21. Collection localities for species of Megachile (Zonomegachile).

FIGURE 23. Male holotype of Megachile aequalis Mitchell, a junior subjective synonym of M. (Zonomegachile) gigas Schrottky. A. Facial view. B. Lateral habitus. C. Dorsal habitus. D. Outer surface of mesotarsus. E. Dorsal view of T5 and T6.