Female, pinned. Original label: “COSTA RICA, PUNTARENAS, Península de Osa, Rancho Quemado, 200 m, Sep. 1992, col. A. Marín, L-S 292500_511000” (MNCR).

Costa Rica • 1♀; Puntarenas, same data than the holotype; 10 Sep.-10 Oct. 1993 (MNCR). 1♀; same data as holotype; Dec. 1992; F. A. Quesada leg.; (MNCR). 2♀; Puntarenas, P. N. Corcovado, send. Rio Claro; 1991; L-S 508300_270500 (MNCR). 1♀; Puntarenas, P. N. Corcovado, Est. Sirena; 0–100 m; Mar.-June 1991; L-S 270500_508300 (MNCR). 1♀; same data, 17 June-4 Sep. 1991; malaise trap; (MNCR).

Dorsal color black; pronotum anterior angles pale yellow; each elytron with three pale yellow spots, one near the scutellar shield and two near the apex, no humeral or mid-lateral spots. Sponda large and conspicuous.

Holotype. Female. Length 2.3 mm, width 1.7 mm; body oval, convex. Dorsal color black except head pale yellow; pronotum with lateral angles pale yellow; elytron with three pale yellow oval spots: scutellar shield spot small, small discal spot in the apical half of elytra, sub-apical spot large and oval (Fig. 69). Ventral surface with head, prosternum, metaventrite and abdomen dark brown; legs, mouthparts and antennae yellow. Head punctures small, separated by their diameter, each puncture as large as an eye facet; pronotal punctures larger than head punctures, separated by their diameter; elytral punctures as large as those on pronotum, separated by their diameter; metaventral punctures larger than elytral punctures, separated by their diameter to two diameters. Clypeus slightly emarginated. Carinae on prosternal process straight, larger than half prosternum, convergent, joined near the anterior margin of prosternum but not touching it. Protibia not flanged, basal tooth small, sponda obvious (Fig. 70). Basal abdominal ventrite without setal tuft. Abdomen with postcoxal line on basal abdominal ventrite curved, only touching the posterior ventrite margin, ventrite with sparse, long pubescence and small, dense punctures. Ventrites II-VI pubescent throughout, punctures fine, dense. Genitalia not examined.

Male. Unknown.

Length 2.1–2.6mm. Width 1.5–1.8 mm.

The species name is a popular name for the inhabitants of Costa Rica.

COSTA RICA, Puntarenas: Península de Osa, Rancho Quemado, 8°40'54.88"N, 83°33'33.81"W.

Costa Rica.

Although having three spots on each elytron is common in several Brachiacantha species, the particular pattern of B. tica, with one spot in the basal half of the elytron and two in the apical half, is not shared with any other species of the genus.