Scolytus stepheni Mandelstam and Petrov, 2010a

Buhroo, Abdul Ahad, 2024, A taxonomic monograph of subfamily Scolytinae (Coleoptera: Curculionidae) in the Western Himalaya, Zootaxa 5533 (1), pp. 1-82 : 56

44. Scolytus stepheni Mandelstam and Petrov, 2010a

( Figure 56)

This species is diagnosed by the following characters: ♂ frons flat, longitudinally aciculate, its surface with fine pale hair-like setae; lateral parts of frons near eyes covered by denser and longer hair-like setae; vertex deeply punctured; pronotum reddish-brown, wider than long; lateral sides parallel for most of their length, gently rounded towards apex; apical pronotum with a weakly developed constriction; pronotal surface shiny with small punctures, larger on anterior portion; scutellum triangular with weak scutellar impression; elytra reddish-brown, rather shining, as wide as pronotal base and 1.12× as long as its width, 1.5× as long as pronotum; elytral base slightly elevated; striae slightly impressed, strial punctures round, closely placed; interstriae flat with smaller punctures and less closely placed than striae; sub apical elytral constriction distinct; prior to apex, elytra with faint impression with irregularly set punctures; pale sparse erect hair-like setae near elytral apex; 5 th abdominal ventrite laterally thickened on posterior margin with two strong adjacent conical projections, each with a bundle of golden hair-like setae; body length: 4.6 mm, 2.40× as long as wide.

The female similar to male except larger in size; the frons is more convex, uniformly punctured, and evenly covered with short and less dense hairs; the 5 th abdominal ventrite has weakly developed callous-like elevations with short hair-like setae not forming bundles.

Material examined: Non-type specimens in FRI Dehradun. Locality: Pahalgam, 7000 ft, Lidar valley, Kashmir, C.F.C. Beeson, 07.06.1928

Distribution: India: Kashmir

Hosts: Ulmus wallichiana ( Ulmaceae )

Phylogenetic assessment:

A phylogenetic analysis of Scolytus nitidus , S. kashmirensis , S. rugulosus ( Müller, 1818) , S. amygdali Guérin-Méneville, 1847 and other closely related species was performed using the COX-1 genes to determine the monophyly and sister groups of each species ( Fig. 57 ). According to the NJ tree, S. nitidus and S. amygdali formed sister clades with well-supported bootstrap values, and the interspecific nucleotide difference between the two clades was greater than 10%. The two species came together to create a distinct monophyletic group. The tree also showed that S. kashmirensis and S. obelus Wood, 1962 formed distinct clades. Together, Scolytus regulosus and S. intricatus ( Ratzeburg, 1837) formed a monophyletic cluster.

Figures

FIGURE 57. A phylogenetic tree obtained from the NJ for the COX-1genes of Himalayan Scolytus (in blue) and related species. Numbers at the branches represent bootstrap values.