Dryocoetes quadrisulcatus Strohmeyer, 1908c

Buhroo, Abdul Ahad, 2024, A taxonomic monograph of subfamily Scolytinae (Coleoptera: Curculionidae) in the Western Himalaya, Zootaxa 5533 (1), pp. 1-82 : 27-28

19. Dryocoetes quadrisulcatus Strohmeyer, 1908c

( Figure 24 )

This species is diagnosed by the following morphological characters: ♂ frons subconvex, coarsely granulate-punctate, surface with few long sparse hairs; minute granules denser on flattened area above epistoma and on lateral sides; epistomal margin with fringe of dense, long yellow hairs; vertex shiny, smooth, irregularly punctured; eyes elongate, anteriorly emarginate; antennal club sub-circular, slightly longer than wide, obliquely truncate with two recurved sutures on anterior face, and one suture on apical posterior face, basal corneous portion occupies about half the total length; pronotum slightly longer than wide (1.08×); evenly convex; basally truncate, sides sub-straight up to middle, narrowed and curved towards rounded apex; pronotal surface mostly granulate, coarser antero-laterally; somewhat irregular punctures around impunctate median line towards pronotal base; sparse, long yellow hairs on anterior and lateral portions; scutellum elongate, tongue-shaped, smooth, shiny-black; elytral base as wide as pronotum, 1.55× longer than pronotum and 1.67× as long as wide; basal margin truncate, sides parallel, posteriorly somewhat broadly rounded; elytra strongly striate punctate, strial punctures large, closely placed and especially deeply impressed on first two striae; interstriae as wide as striae, punctures much smaller, as numerous as on striae; declivity somewhat steep, striae 1 strongly and 2 less strongly sulcate and both dilated away from sutural line towards apex; sutural interstriae slightly elevated, with minute setose granules on declivital interstriae; elytral interstriae with long yellow hair-like setae, somewhat longer on lateral sides and on declivity; body dark brown; body length: 2.24–2.61 mm, 2.80× as long as wide.

Female body length: 2.25 mm. The strongly deepened, striae 1 on the disc and declivity is more evident in males of this species, though it is also developed in the females.

Remarks: This species is distinct from the rest of the Indian species due to its grooved (sulcate) striae 1 and 2 on its declivity.

Material examined: New records: India: 4 ♂ ′s, 4 ♀ ′s. Kashmir, Thajwas Sonamarg (34° 18.222′ N, 075° 16.388′ E, 9865 ft.), A.A. Buhroo, 12.07.2012 ( KUIC). Kashmir, Bandipora, Tragbal Gurez (34° 29.647′ N, 074° 38.1652′ E, 9432 ft.), A.A. Buhroo, 18.08.2018 ( KUIC) .

Distribution: India: Kashmir, Uttarakhand

Hosts: Abies pindrow ( Pinaceae )

Phylogenetic assessment:

The phylogenetic analysis based on COX-1 gene comparison was carried out between the Himalayan Dryocoetes species and other closely related species of the genus ( Fig. 25 ). The NJ tree analysis revealed that Dryocoetes quadrisulcatus and D. himalayensis formed different clades and were monophyletic with a nucleotide difference of 11.52%. Along with North American Dryocoetes affaber ( Mannerheim, 1852) , Himalayan D. indicus likewise belonged to a distinct monophyletic group, although it differed from it by a nucleotide difference of 8.38–9.01%. The European populations of Dryocoetes also formed distinct clades. The nucleotide divergence between Dryocoetes quadrisulcatus and D. indicus was 16%.

Genus Taphrorychus Eichoff, 1878b

Taphrorychus species are diagnosed by the following morphological characters: body length: 1.5–2.7 mm; funicle with five segments; club flat, round with three slightly procurved sutures; pronotum as long as wide, anteriorly constricted, with rows of fine granules; elytra with striae; ♂ elytral declivity flat; female declivity rounded; ♂ frons granulate with sparse filliform setae; ♀ frons with crown of dense, short, filliform setae; body black to brown; antennae and legs light brown; hosts: deciduous trees and conifers.

Key to the Himalayan species of Taphrorychus Eichoff, 1878b

1 Elytral disc very distinctly striate-punctate, the strial punctures of moderate size and closely placed; interstriae much wider, in places finely transversely wrinkled and each with median row of widely spaced rather large punctures as those on the main striae.................................................................................. T. betulae Schedl

- Elytral disc with indistinctly marked striate and interstriae, striae 1 and 2, well-marked and impressed; punctures on both striae and interstriae of equal size and depth, declivital interstriae marked by long erect hairs and few minute granules.............................................................................................. T. hewetti (Stebbing)

Figures

FIGURE 24. Dryocoetes quadrisulcatus. Male: dorsal view A, latero-declivital view B; female: dorso-lateral view C.

FIGURE 25. A phylogenetic tree obtained from the NJ for the COX-1 genes of D. indicus, D. quadrisulcatus (in blue) and related species. Numbers at the branches represent bootstrap values.