Scolytus excavatus Wood, 2007

V. Petrov, Alexander & Y. Mandelshtam, Michail, 2010, New data on Neotropical Scolytus Geoffroy, 1762 with description of five new species from Peru (Coleoptera, Curculionidae, Scolytinae), ZooKeys 56, pp. 65-104 : 81-82

Scolytus excavatus Wood, 2007

Description is based on specimens collected in Peru and provided by Sarah Maria Smith.

Peru Madre de Dios, Los Amigos Biological Station, GPS: S12°34'9"; W70°6'0.40", 19-25.V.2008 Smith & Hulcr Colls.

Description.

Male: body length 5.5-6.4 mm, 1.8-2.0 times as long as wide; color red brown to black. Front concave eye to eye from epistoma to well above upper level to eyes, mandibles at base are strongly thickened and elevated, with blunt tubercles, with deep transverse furrows and rugositites, frontal margin above mandibles strongly incurved towards central portion of the front, center of front with small median carinate tubercle, front above this tubercle with the circular impression that occupies space up to upper level of eyes, bottom of the impression with the surface smooth, finely punctured. Sides of impression are covered with yellow erect bristles not forming dense brush, in the upper portion of front hair-like vestiture is sparse, in several specimens represented by singular hairs only; antennae brown, club elliptical with evenly rounded apex, covered by short golden hairs. Pronotum 0.8-0.95 times as long as wide, its base with the median projection towards scutellum, lateral sides of prontoum are evenly narrowed from base to apical margin, without subapical constriction; pronotal surface faintly shining, nearly dull, covered by minute punctures, diameter of punctures at the sides of pronotum slightly larger that diameter of punctures in its centre, apical margin of pronotum with sparse hairs.

Scutellum very small, triangular, immersed deeply into scutellar impression.

Elytra 0.8-1.0 times as long as wide; striae impressed, strial punctures of moderate size, not confluent. Interstriae about tree times as wide as striae, covered by small punctures with few scattered setiferous pores bearing one erect thick short bristle each. Posterior elytral margin with only sparse puncturation. Abdomen black, its surface dull, evenly punctured by punctures of moderate size, vestiture abundant, entire surfaces of abdominal sternites 2-4 covered by long yellow hairs, surface of the fifth sternite with sparse hair-like vestiture except on lateral sides of the fifth sternite base. Border between first and second sternites junction strongly projected backwards and also elevated, shape of the second sternite is cup-formed incurved, median part of second sternite anterior margin with the shark back fin-shaped denticle curved upwards; this denticle occupies the spase from base of sternite and up to center of the sternite. Fifth abdominal sternum is medially impressed, its posterior margin is elevated.

Legs black, tarsi reddish-brown; femora are covered by short recumbent hairs, outer margin of meso- and metatibia with long erect yellow hairs

Female: Body length: 4.8-5.3 mm, 1.7-2.0 times as long as wide. Front concave eye to eye from epistoma to well above upper level to eyes, each mandible at the base bear processes with apices directed upwards and towards the apex of the process of adjoining mandible (in older beetles these processes may be broken off); center of the front with deep longitudinal impression continuing upwards up to upper level of eyes, lateral sides of the impression are densely covered with pale hairs. Lateral margins of front are elevated, curved near eyes, following the upper level of eyes line. Frontal surface smooth, gently punctured, at lateral sides of front pale hairs are set denser. From the vertex two symmetrically set fringes (forelocks) of long dark grayish-black hairs are directed towards center of the front. Pronotum: 0.74-0.96 times as long as wide, essentially as in male. Elytra: 0.8-1.2 times as long as wide and similar to elytra of male. Abdomen is covered by short yellow hairs, second sternite with basal margin rounded, subvertical, middle of segment with a large cylindrical spine. Apex of this spine is thickened and covered by short hairs, fifth sternite concave, its apical margin acute.

Host.

Pterocarpus rohrii ( Fabaceae ).

Biology.

bigynous, each gallery is built by 2 - 4 females.

Notes.

Male is described here for the first time. S.L. Wood erroneously treated female holotype as a male. Studies of a long series of Scolytus excavatus ,collected bySarah M. Smith and Jiri Hulcr, allowed to remove this inaccuracy and to expand the description of the female of this unusual species.