Scolytus thoracicus Chapuis, 1869

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 : 90-92

Scolytus thoracicus Chapuis, 1869

Material examined.

Peru: Loreto province, 20 km NNE from Iquitos, Momon river, Gen Gen vill., 8.02.2007 A.Petrov

Diagnosis.

Species differs from its relatives by male frontal characters and by stepped median spine on sternite 2 in both sexes.

Description.

Male: body length 3.0-4.3 mm, 1.9 times as long as wide; colour dark brown or black. Front flattened on dorsal half, strongly, transversely impressed in lower third, impression surface is roughly punctured, median line at impressed portion of front is slightly elevated. Center of front with transverse carina, strongly, dorsoventrally compressed, center of carina strongly thickened and overhanging frontal impression; area above carina smooth and dull, gently shagreen and punctured by sparse minute punctures, devoid of hairs. Lateral parts of front slightly elevated, covered by dense brushes of long brown hairs, hair apices directed towards centre of front. Antennal funiculus and scapus reddish brown. Club grayish brown, of elongate form, 2.1 times as long as wide, abundantly covered by short golden hairs. Pronotum 1.0 times as long as wide, lateral sides almost straight and parallel on basal half, arcuately converging toward broadly rounded anterior margin; surface smooth, shining, punctures minute on disk, much lager on lateral margins of the apical area. Pronotum has an acute lateral margin dividing it from prosternite. Lateral sides of prothorax (propleura) are densely and evenly punctured by punctures that is larger compared to punctures at lateral sides of pronotum, towards apical margin with gentle pale hairs of moderate length.

Scutellum of moderate size, triangular, densely punctured by minute punctures, slightly deepened into scutellar impression.

Elytra 1.0 times as long as wide, 1.0 times as long as pronotum; rows of punctures weakly, narrowly impressed, punctures small, punctures in striae not confluent; interstriae smooth, shining, three times as wide as strial punctures, punctures very small. At the posterior elytral portion among minute punctures of interstriae are larger setiferous pores each bearing one short erect hair. Lateral sides of elytra with a row of yellow hairs of moderate length. Short elytral declivity with obscure puncturation. Abdomen black, its surface dull, evenly punctured by deep punctures of moderate size; second sternite vertical, armed by a median, laterally compressed spine, occupying sternite portion from its base to centre. Apex of tubercle with asymmetrically bifurcated apex, two-stepped. Lateral margins of second sternite with elevated blunt tubercles. Abdominal sternites and spine are covered by erect yellow hairs; longer hairs are located on border between first and second sternites, on lateral sides of sternites and on apex of fifth sternite. Legs dark grayish brown, femora covered with long brown hairs.

Female: similar to male except front convex, without tubercle; punctures fine, surface coarse aciculate; vestiture of fine, uniformly distributed hairs, extending upper level of eyes; spine in second sternite two-stepped as in male but much smaller.

Notes.

The species is recorded for Peru for the first time. The male studied did not differ from male of Scolytus thoracicus from Brazil.