Scolytus proximus 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 : 88-90

Scolytus proximus Chapuis, 1869 Figs 2223

Material examined.

Peru: Loreto province, 20 km NE from Iquitos, Momon river, Gen Gen vill., 120 m a.s.l., 5-7.02.2007 A.Petrov (48♂♂, 24♀♀); 70 km SW from Iquitos to Nauta, 26-29.02.2008 A.Petrov (41♂♂, 37♀♀); 58 km SW from Iquitos to Nauta, Itaya river, 120 m a.s.l., 5-8.V.2009 A.Petrov (4♂♂, 2♀♀).

Diagnosis.

Species differ from other species in genus by frontal vestiture in male and in female, by elytral puncturation and by form of second abdominal sternite spine that is alike in form to a shark dorsal fin.

Description.

Male: body length 2.8-3.5 mm, 1.8-1.9 times as long as wide; colour dark brown black, surface shining. Front flattened on dorsal half, weakly transversely impressed in lower third, lateral areas on lower third somewhat aciculate-granulate, median line on impressed area is slightly elevated. Centre of front with callous-like tubercle slightly rising above impression; above tubercle frontal surface coarsely aciculate. Lateral sides of front slightly elevated, covered with dense brushes of long brown hairs, hair apices curved towards centre of front. Centre of frontal area covered by recumbent hairs of moderate size. Antennal funiculus and scapus reddish brown. Club ellipsoid, grayish brown, densely covered with short golden hairs. Pronotum black, 0.8-0.88 times as long as wide, attains maximum width at the middle of its length; surface smooth, shining, puncturation very small and sparse on disk, more dense and of moderate size on apical margin and of large size at lateral sides of pronotum; surface with few unconspicuous hairs, nearly glabrous. Pronotum separated from prosternite (propleura) by well-developed acute lateral margin, lateral portions of prothorax (propleura) densely punctured by large punctures, surface with recumbent hairs.

Scutellum triangular, deeply set into scutellar impression.

Elytra 0.8-0.94 times as long as wide, 0.9-1.0 times as long as pronotum. First and second rows of punctures impressed from base to declivity, others not impressed or feebly impressed in base and evidently impressed from a middle to apical part of elytra. Punctures in striae of moderate size, sometimes size of punctures become larger from base towards posterior part of elytra. Interstriae three times as wide as striae, smooth, shining, weakly impressed in anterior part of elytra, punctured by small punctures, among which larger setiferous pores can be found in posterior elytral portion. Declivity short; first, third, fifth and seventh interstriae with pale sparse, erect, scale-like hairs forming rows from elytral center and up to apical elytral portion with strongly confused (obscure) puncturation; all other interstriae have only 1-2 short bristles nearby margin of declivity. Abdomen dark brown, surface faintly shining, nearly dull, punctured by small punctures, covered with short pale bristles, under bristles abdominal surface with plumose setae. Erect bristles on second sternite three times as long as on fifth sternite. Second sternite is vertical, with large laterally compressed spine; form of the spine is similar to a shark dorsal fin with its apex curved upwards towards third sternite; size and form of spine is strongly variable between specimens. Legs reddish brown, covered by short yellow hairs.

Female: similar to male except front has shorter hairs evenly covering frontal surface from middle to lateral margins, hairs in centre of front pale, on upper portion of front above upper level of eyes of front a dark fringe consisting of two bundles of dark-grayish brown bristle-like hairs running downwards; hair apices in fringe directed towards front centre.

Notes.

Unfortunately, the authors were unable to study the type series of Scolytus proximus and for material determination we used only the original description (Chapuis, 1869) and specimens from the collection of K. Schedl.

Biology.

Scolytus proximus infests trunks and large branches of the fallen trees. Parental tunnels are biramous and transverse; the larval mines are longitudinal. Length of transverse tunnels is 20-35 mm.