Horistonotus angustifrons sp. nov.

(Figs. 1–16, 113–116, 157)

Holotype (male): [Brazil]. Canindé do S[ão] F[rancis]co (SE), (Faz[enda] Brejo), 22.IV.2000, am.1, Iannuzzi, L. col. (Malaise); Projeto Xingó Biodiversidade Área 5 (MZSP).

Paratypes. Canindé do S. Fco. (SE), (Faz. Brejo), 15.IV.2000, am.1, Iannuzzi, L. col.(Malaise); Projeto Xingó Biodiversidade Área 5 (3 exs) (UFPE, MZSP); idem, 22.IV.2000, idem (1 ex.) (MZSP); idem Área 6 (1 ex.) (UFPE); idem, (Faz. Poço Verde), 18.III.2000, am.1, idem Área 1 (2 exs) (UFPE, MZSP).

Holotype (male). Body length: 5.2 mm.

Integument shiny, light reddish-brown with antennae and legs slightly lighter. Pubescence long, fine, moderately dense and yellowish not masking integument.

Frons convex, very narrow, longer than wide, emarginate laterally; anterior margin narrower than eye width at same level; anterior margin prominent and rounded, raised forming narrow ridge; punctation weak, moderately coarse and moderately dense. Antenna (Figs. 1, 113) long, reaching more than three antennomeres beyond hind angles of pronotum in male; subserrate; antennomeres III–X elongate, narrow, slightly wider near apex.

Pronotum (Fig. 2) slightly longer than wide (length including hind angles); punctation weak, moderately coarse and moderately dense, denser near fore angles (Fig. 116); hind angles wide, backwardly directed, carinate lateroexternally; carina joined with lateral carina; moderately convex, somewhat parallel-sided; convexity decreasing to basal direction; lateral margins carinate almost until apex; posterior margin prominent, emarginate and flat at middle. Hypomeron (Fig. 3) with punctation moderately coarse and dense. Pronotosternal suture (Fig. 3) slightly curved, not forming anterior channel. Prosternum with punctation well marked, coarse and sparse; prosternal spine short, a little longer than procoxae. Metacoxal plate (Fig. 6) wide at internal half, gradually narrowed at lateral half. Tibia (Fig. 5) with two microspined tibial spurs; tarsal claws (Figs. 8, 114) with wide triangular tooth near base. Last ventrite of male (Fig. 9) transverse, triangular with rounded apex; in high magnification, marginate (Fig.10). Scutellum (Figs. 4, 115) longer than wide, pentagonal with lateral margins concave. Elytra slightly wider than pronotal base; apices narrowed and conjointly rounded; each stria marked by one row of very coarse punctures; interstices narrow and convex.

Paratypes. Body length: 4.4–5.7 mm.

Integument coloration (Fig. 157) variable, reddish-brown, brownish-yellow, brownish-orange or sometimes brownish; antennae and legs sometimes yellowish. Hind wing (Fig. 7) 2.13 times longer than wide; wedge cell absent; apex with one opened W-like sclerotization.

Male. Tergite VIII (Fig. 12) wider than long, cordiform with setae of varied sizes near margin of distal half. Sternite VIII (Fig. 11) membranous, transverse, band-like, strongly notched anteromedially forming two well developed triangular setose lobes. Sternite IX (Fig. 13) elongate, elliptical with apex prominent and rounded; setae moderately long on distal fourth. Tergite IX (Fig. 14) transverse, band-like, strongly notched at middle; short setae laterally near apex; tergite X elongate, longer than IX, inserted apically at middle of IX; short setae at apex. Aedeagus (Figs. 15–16): basal piece narrow, longer than wide, narrower than parameres. Parameres separated, more than twice median lobe length (excluding basal struts); narrowed laterally at extremities and on inner side at distal fifth; apical region strongly narrowed with one dorsal and one ventral seta and rounded apex. Median lobe short (excluding basal struts), gradually narrowed from base to distal fourth; distal fourth sub-elliptical; apex pedunculate.

Etymology.The specific epithet is a derivative of the Latin word angustus (=narrow) + frons, referring to the shape of frons.

Remarks. H. angustifrons is easily recognized, especially by frons very narrow and antennae subserrate and very thin. Additionally, the tooth of tarsal claws is very wide and apex of parameres pedunculate. The coloration varies from light reddish-brown to reddish-brown and other brownish tonalities like brownish-yellow or brownishorange.

Distribution. Brazil: Sergipe.