Centris (Hemisiella) merrillae Cockerell, 1919

(Figures 9–12, 29)

Centris merrillae Cockerell, 1919: 191.

Diagnosis. Both sexes with light yellowish gray pubescence on head and mesosoma; clypeal disc and labrum areolate. Female scopa orange brown; ventral surface of hind basitarsus with dark brown hairs. Male metasoma brown; T6 and T7 with orange pubescence; hind leg with dark brown to black hairs; femur mainly with whitish pubescence and posterior margin of tibia with light brown hairs.

This species seems somewhat similar to C. nebulosa new species (see below), differing from it by the coloration of the pubescence on head and mesosoma (light yellowish gray in C. merrillae; dark gray in C. nebulosa new species) and by the surface of the clypeal disc (areolate in C. merrillae; fine, dense, and relatively uniform punctation in C. nebulosa new species). The females also differ in the coloration of the scopa (orange brown in C. merrillae; grayish yellow in C. nebulosa new species).

Morphology. Female (Figs. 9, 10). Measurements: Approximate body length: 14.5; head width: 4.7; thorax width: 5.3; forewing length: 11.5; UID: 2.2; LID: 2.3; mandible length: 1.7; basal mandibular width: 0.9; labrum length: 0.6; labrum width: 1.4; F1 length: 1.0; F2 length: 0.3; F3 length: 0.4; scape length: 0.6; diameter of the median ocellus: 0.3; distance between the lateral ocellus and the eye: 0.5. Coloration: Head, mesosoma and legs dark brown to black. Mandible, labrum, lower paraocular area and base of fore and middle tibiae yellow. Clypeus yellow with upper margin dark brown and with triangular spot of same color on lower edge. Anterior surface of flagellum orange, from apex of F1 to apical half of F10. Tegula brown. Metasoma brown with apical bands of terga and sterna slightly translucent. Wing membrane light brown with veins brown. Sculpture: Clypeus and labrum areolate, both with coarse and dense punctation. Terga with fine and dense punctation, sparser and thicker from T4 or T5 until T6. Pubescence: Head with whitish pilosity on gena, yellow on occiput and interantennal area. Vertex with dark brown pubescence, extended to area between ocelli. Mesoscutum and mesoscutellum with light yellow pilosity, yellowish white on lateral surface of mesepisternum, femora of all legs, and tibiae of fore and middle legs. Tarsi mainly with orange pilosity, except fore leg with yellowish white pubescence. Scopa orange with some yellow hairs basally. Ventral surface of hind tibiae and basitarsus with dark brown hairs. Distal surface of T1–T4 with short brown hairs. Distal terga with yellow pilosity. Sterna with orange hairs. Structures: Mandible with three teeth (1st>3rd>2nd) with acute apex. Preapical tooth almost fused with rutellum. Trimal angle relatively acute. Acetabular carina reaching base of third tooth. Labrum semicircular. Clypeal disc relatively flat (lateral view), with poorly developed longitudinal carina, slightly evident in some specimens. Inner orbits of compound eyes relatively parallel. Vertex below upper interocular tangent. Fore elaiospathe with anterior secondary comb formed by three giant apically curved hairs. Pretarsal claws with a small preapical tooth, absent in hind leg.

Description. Male (Figs. 11, 12). Measurements: Approximate body length: 12.5; head width: 4.2; thorax width: 5.2; forewing length: 11.2; UID: 1.7; LID: 1.9; mandible length: 1.4; basal mandibular width: 0.7; labrum length: 0.7; labrum width: 1.2; F1 length: 0.9; F2 length: 0.2; F3 length: 0.3; scape length: 0.6; diameter of the median ocellus: 0.3; distance between the lateral ocellus and the eye: 0.3. Coloration: Integument dark brown to black. Mandible, labrum, lower paraocular area and base of fore and middle tibiae yellow. Clypeus yellow with dark brown spot on upper edge. Anterior surface of flagellum orange, from apex of F1 to basal half of F10. Tegula brown. Terga dark brown with apical bands slightly translucent. Distal segments orange. Sterna yellowish brown. Wing membrane light brown with brown veins. Sculpture: Clypeus and labrum areolate, with coarse and dense punctation, sparser on clypeal disc. T1–T3 with fine and dense punctuation, sparser on T4-T7. Pubescence: Head with whitish pilosity on gena, yellow on upper half of occiput, interantennal area, clypeus, and labrum. Vertex with dark brown pubescence. Mesoscutum and mesoscutellum with light yellow hairs, lighter on lateral side of mesepisternum and on femora of legs. Fore leg mainly with light yellow hairs. Middle leg mainly with dark brown pubescence, except dorsal surface of tibia with orange brown pubescence. Hind leg with dark brown to black hairs; femur mainly with whitish pubescence and posterior margin of tibia with light brown hairs. Dorsal surface of T1 with white yellowish, long and dense pilosity. T2–T4 with dark brown, short and dense pubescence. T5 with a mixture of orange and brown, long and plumose hairs. Sterna mainly with orange hairs. Structures: Mandible with three teeth (1st>3rd>2nd) with acute apex. Second tooth almost fused with rutellum. Trimal angle relatively straight. Acetabular carina reaching base of third tooth. Labrum semicircular. Clypeal disc flat (lateral view) with longitudinal, of variable length and poorly developed carina in some specimens. Inner orbits of compound eyes converging above. Vertex below upper ocular tangent. Hind femur well-developed. Hind basitarsus with spine-like projection on posterior surface.

Floral record. Oryza sativa L. (Poaceae) (new record).

Comment. Male specimens of this species were not found in Colombian collections. The male of C. merrillae described for the first time herein is from St. Augustine, Trinidad and Tobago. A female collected in the same locality was used for figures 9 and 10.

Type material. Holotype female (United States National Museum Smithsonian, USNM, examined).

Type locality. BRAZIL, Amazonas, Manaus.

Distribution (Fig. 29). COLOMBIA: AMAZONAS: Parque Nacional Amacayacu, Caño Mata-Mata. CHOCÓ: Río Sucio (Corregimiento Puente América-Cacarica). META: Villavicencio.

Material examined. COLOMBIA: AMAZONAS: 1 female: AM. P. N. N. Amacayacu III 27-90 A. Bonilla \ 5845\ LABUN 007032 (LABUN). 1 female: P. N. Amacayacu C. Matamatá 11:38h A. Villa 23.8.84 004\ 13872\ LABUN007149 (LABUN). CHOCÓ: 1 female: PK (I- 020161 10.VIII.1978 \ Choco - Rio Sucio Cacarica Col: H. E. E\ 0320\ Centris (Hemisiella) sp. Det: Moure, mayo/90\ 0 320 (ICN). META: 1 female: Colombia Meta Villavicencio, 467 m alt. N 4°09’ N 72°58’ W 9-Abr-2004 A. Martínez \ Jama al vuelo en hojas de Oryza sativa (Poaceae) - arroz\ Centris (UNAB). WITHOUT INFORMATION: 1 female: Sta Fe en flores Jul. 1982 A. Muñoz\ 196 (MEFLG). 1 female: Tolu (Cor) en Vuelo Mar. 1975 J. Cano (MEFLG).