Brachiacantha brevihamata, Nestor-Arriola & Toledo-Hernández, 2017

Nestor-Arriola, Jorge Ismael & Toledo-Hernández, Víctor Hugo, 2017, New species of Brachiacantha Dejean, 1837 (Coleoptera: Coccinellidae) from Mexico and Central America, Zootaxa 4365 (1) : -

Brachiacantha brevihamata sp. nov.

( Figs. 1‒4 )

Diagnosis. Five yellowish orange spots on each elytron. Male with ventrites 2 to 5 emarginate and depressed, forming a longitudinal fossa on abdomen. Basal lobe of male genitalia with a small lateral hook at apeX ( Fig. 2 ).

Description. Holotype: Male: Length 3.8 mm, width 2.5 mm; body oval, slightly elongated. Dorsal color black eXcept head yellow; pronotum with anterolateral angles and the anterior and lateral borders yellowish orange, a mark of the same color eXtends over the middle line from apeX to half the length of the pronotum; each elytron with five yellowish-orange spots: a small triangular humeral spot, a rounded scutellar spot, a rounded middle-lateral spot, a rounded discal spot and a transversely oval subapical spot ( Fig. 1 ). Ventral surface with head, prosternum, metaventrite and abdomen black; mouthparts and antenna yellow. Legs yellow, basal third of femur black. Head punctures small, separated by one diameter, each puncture slightly larger than an eye facet; pronotal punctures smaller than head punctures, separated by one and a half diameters; elytral punctures larger than pronotum and head punctures, separated by two diameters; metaventral punctures as large as elytron punctures, separated by one and a half diameters. Clypeus weakly emarginate apically, nearly truncate, lateral angle straight. Pronotum narrowed from base to apeX, sides curved. Prosternal carinae short, straight, divergent to prosternal anterior part.

Protibial tooth small, protibia not flanged. Epipleuron narrow, emarginate for reception of femoral apices. Abdomen with postcoXal line on basal ventrite slightly flattened along posterior ventrite margin, ventrite with sparse, short pubescence and dense, small punctures; ventrites 2‒5 emarginated and depressed at the middle, pubescent and densely punctate at sides, glabrous and almost without punctures at the middle; ventrites 3‒5 with a tubercle on each side of the emargination; siXth ventrite flattened, slightly depressed and glabrous at the middle, with lateral projections on sides, the projections tuberculate with abundant punctures and bristles. Genitalia with basal lobe slightly longer than the paramere, asymmetrical, sides almost parallel, slightly narrowed at the end of the second third, rounded at apeX ( Fig. 2 ), with a small apical hook on a side; paramere scimitar shaped, wide, curved, long, rounded at apeX, with a small tooth on the concave margin and abundant long bristles on the conveX and apical margins, shorter bristles on the apical half of the concave margin ( Fig. 3 ); sipho with lateral, elongated, rounded alae at the apeX; siphonal capsule crested, heavily sclerotized, inner arm short and wide with apeX acute ( Fig. 4 ).

Female. Length 4.5 mm, width 3.3 mm. Similar to male eXcept head black with an orange spot on front, pronotum without yellow anterior border but with the medial line yellowish orange, legs black or dark brown eXcept the tarsi and the tibial apeX yellow; abdomen without modifications. Genitalia with spermathecal capsule short, thick, with narrowed apeX; cornu, nodulus and ramus differentiated; bursa copulatriX subtriangular with two sclerotized arms; apical strut short, thin and laterally flattened.

Variation. Length 3.7 to 4 mm width 2.3 to 2.8 mm. Scutellar and discal spots may be fused in hourglass shape. The elytral spots and pronotal marks can be pale yellow color.

Distribution. MeXico; in MeXico State, Michoacan and Veracruz.

Type material. Holotype: MEXICO: “Estado de MéXico, Valle de Bravo, 1-VI-1962, col. Balderas and Ortiz, cat. 0576” ( CEAM) (1♂).

Paratypes: MEXICO: same data as the holotype ( CEAM) (1♂); “ Michoacán, Zitácuaro, Presa El Bosque, 23- VI-1986, col. E. Muriño” ( CNIN) (1♀); “ Veracruz, Huatusco, 9.3 Miles south of Huatusco, 18-VI-1983, col. B. K. Dozier” ( FSCA) (1♀).

Type locality. Valle de Bravo , MeXico State, MeXico.

Remarks. In coloration, this species is very similar to that of the ursina group, but differs in having the male abdomen with several depressed ventrites and the asymmetrical basal lobe of the male genitalia. For the “ longitudinal fossa” this species belongs to “group 5” of Leng (1911), a Central American species group. Similarities in the male abdomen have been described in South American species such as Brachiacantha gail Gordon, Canepari & Hanley , from the group bahiensis, and B. valerie Gordon, Canepari & Hanley , B. tucumanensis Weise and B. eleanor Gordon, Canepari & Hanley , from the group tucumanensis ( Gordon et al. 2014) . The genitalia of B. brevihamata have only a few similarities with the South American species, such as the elongated shape of the basal lobe and the paramere shape, but the asymmetrical apeX and the small hook differentiates it from the majority of the South American groups. The asymmetrical male genitalia are characteristic of the dentipes group, but B. brevihamata lacks the characteristic cusps in the third male ventrite. The relationships with other species are not clear and it is possible that B. brevihamata must be placed in its own group.

Etymology. From Latin “brevis” (short) and “hamatus” (hooked). The name refers to the small hook in the basal lobe apeX of the male genitalia.

Figures

FIGURES 1‒4. Brachiacantha brevihamata (images by Jorge Valdez Carrasco). 1) dorsal habitus; 2) tegmen, concave side vieW;3) tegmen, lateral vieW; 4) sipho.