Brachiacantha erythrura Mulsant, 1850

Nestor-Arriola, Jorge Ismael & Toledo-Hernández, Víctor Hugo, 2019, Contribution to the knowledge of the dentipes group of the genus Brachiacantha (Coleoptera: Coccinellidae), Zootaxa 4701 (6), pp. 537-552 : 545-548

Brachiacantha erythrura Mulsant

( Figs. 2a, b , 3 a–d)

Brachyacantha erythrura Mulsant 1850:530 . Crotch 1874:211. Gorham 1894:187. Leng 1911:302.

Type material: Not examined. Material examined: COSTA RICA: “Barva, C. H. Ballow, 5271, V-23 ‘37” ( USNMNH) (1♂); “octubre” ( USNMNH) (2♀, 2♂); “ Turrialba , 17-VIII-1944, E. J. Hambleton, common bean” ( USNMNH) (2♂) ; “ San Isidro Coronado , 15-IX-1923, Neoria, det. J. B. Chapin 1991” ( MUCR) (1♂) . EL SALVADOR: “La Ceiba, Vera Willboru” ( USNMNH) (1♀) . SONSONATE: “ 19-VIII-1905, Fred Knab” ( USNMNH) (1♀) . GUATEMALA: ESCUINTLA: “ 08-IX-1908, Fred Knab” ( USNMNH) (1♀) . RETALHUELEU: “ 16-V-1945, E. J. Hambleton” ( USNMNH) (1♀) . MEXICO: NUEVO LEON: “ Monte Morelos, 23-V-1952, M. Cazier, W. Gertsch and R. Schrammet, det. Dieke 1954” ( USNMNH) (1♂) ; TAMAULIPAS: “ Llera, km. 77 Llera-Zaragoza , 19-IX-2008, col. E. Ruiz C., cítricos y hierba, det. A. Marín B. quadrillum ” ( RLF) (1♂) ; “ Victoria , 14-VI-2008, col. A. Ruiz Cansino, s/hierbas” ( UAT) (1♀) . VERACRUZ: “ 7 mi N. Hotel Playa Azul, Laguna de Catemaco , 1000-1500 ft., J. V. Weems Jr., det. R. Gor- don 1971” ( FSCA) (2♀) . NICARAGUA: CHINANDEGA: “1954, Baker” ( USNMNH) (1♂) ; “ Baker ” ( USNMNH) (1♀) . MANAGUA: “ Baker ” ( USNMNH) (2♀, 1♂) ; “ Baker, ChpnSlide , 40-1” ( USNMNH) (1♀) ; “ 21-X-1957, Sequeria , det. Chapin ” ( USNMNH) (1♀) .

Diagnosis: Elytra black without spots, but with the apical border yellow, orange or red. Cusps on the third male ventrite small. Basal lobe of male genitalia without apical hook.

Redescription: Male: Length 3.8 to 3.9 mm, width 2.8 to 2.9 mm; body oval. Dorsal color black except head yellow, orange or red; pronotum with anterolateral angles and anterior border orange or red; each elytron with a yellowish, orange or red mark on the apical border ( Fig. 2b ). Ventral surface with head, prosternum, mesoventrite and metaventrite black; abdomen reddish brown; mouthparts, antenna and legs orange or yellow. Head punctures small, separated by two diameters or more, each puncture as big as an eye facet; pronotal punctures larger than head punctures, separated by two diameters; elytral punctures equal in size to pronotal punctures, separated by two diameters; metaventral punctures equal in size to elytral punctures, separated by one diameter. Clypeus not emarginate apically, almost truncated, lateral angle slightly concave. Pronotum narrowed from base to apex, sides curved. Prosternal carinae as long as half length of prosternum, slightly curved, convergent to prosternal anterior part, almost fusing in a triangular shape. Protibial tooth large, protibia not flanged. Epipleuron narrow, emarginate for reception of femoral apices. Abdomen with postcoxal line on basal ventrite complete, flattened along posterior ventrite margin; basal ventrite with sparse, short pubescence and dense, small punctures; ventrites 2–5 with short pubescence and densely punctate; ventrite 3 with a small cusp on each side of midline ( Fig. 2a ); ventrites 4, 5 and 6 flattened, slightly depressed and emarginated in the middle. Genitalia with basal lobe slightly shorter than the paramere, asymmetrical, sides almost parallel, slightly narrowed at the second third, apex oblique, without apical hook ( Fig. 3a ); paramere scimitar shaped, curved, long, rounded at apex, with abundant long bristles on the convex and apical margins ( Figs. 3a, b ); sipho with short, rounded alae at the apex ( Figs. 3c, d ); siphonal capsule crested, heavily sclerotized, inner arm short and wide with apex round ( Fig. 3c ).

Female: Similar to male but pronotum almost black with only the anterolateral angles orange or yellow. Variation: The only variation registered is the sexual dimorphism.

Hosts: This species has been collected on Phaseolus vulgaris L.

Distribution: Mexico and Central America ( Fig. 4 ).

Discussion: Brachiacantha erythrura was originally described by Mulsant (1850) but was considered a variation of B. dentipes (Fabricius) by Gorham (1894). Leng (1911) considered B. erythrura to be a valid species and placed it in his group 2; Gordon (1985) later used the groups 1 and 2 of Leng to define the dentipes group, but he did not include B. erythrura . The coloration is similar to that of some specimens of B. quadrillum , but the ventral cusps are larger in B. quadrillum and the male genitalia lack an apical hook in B. erythrura .

Figures

FIGURE 2. Brachiacantha erythrura, male. a) Abdomen. b) Dorsal habitus.

FIGURE 3. Brachiacantha erythrura, male genitalia. a) Tegmen, concave side. b) Tegmen, lateral view. c) Siphonal apex. d) Sipho.

FIGURE 4. Collection sites of Brachiacantha erythrura.