Polygraphus trenchi Stebbing, 1905

Buhroo, Abdul Ahad, 2024, A taxonomic monograph of subfamily Scolytinae (Coleoptera: Curculionidae) in the Western Himalaya, Zootaxa 5533 (1), pp. 1-82 : 51-52

40. Polygraphus trenchi Stebbing, 1905

( Figure 51 )

This species is diagnosed by the following morphological characters: ♀ frons plano-concave, surface shiny; two prominent, reddish-golden brushes of long hairs around the upper and lateral margins of frons, curled inwards and downwards without intersecting medially to about halfway and then continue in two thin strands, a few separate hairs covering the inner surface of eyes also meet the thin strands; antennal club ovate with pointed apex; pronotum 1.38× wider than long; lateral sides somewhat rounded on the basal half, narrowly constricted towards anterior third; a median conspicuous longitudinal raised line on pronotum, surface shining with minute punctures each with a fine hair, lateral margins set with moderate scales; scutellum depressed; elytra 1.43× as long as its width, twice as long as pronotum; basal margin crenulate, lateral sides somewhat parallel on basal two third, converging posteriorly into a rounded apex; striae narrow, marked with small round punctures on basal half of disc becoming much smaller posteriorly, striae 1 more impressed upto declivity; interstriae nearly four times wider than striae with close, fine granulations becoming larger and wider apart in apical fourth, interstrial surface with dense short scale-like setae; declivity convex with rows of minute interstrial granules; body moderately shining, dark brown; body length: 3.08–3.15 mm, 2.44× as long as wide.

Males are smaller than females; frons has few sparse yellow hairs and two small, median tubercles, placed transversely; body length: 2.90–2.97 mm.

Remarks: The position and configuration of frontal brushes in females serve as a diagnostic feature in the identification of this species.

Material examined: New records: India: 2 ♂ ′s, 2 ♀ ′s. Jammu , Kishtwar, Kundhal Padder (33° 18.820′ N, 076° 04.492′ E, 7000 ft.), A.A. Buhroo, 09.09.2017 ( KUIC). Jammu, Kishtwar, Kijaye Padder (33° 16.144′ N, 076° 07.680 E, 6145 ft.), A.A. Buhroo, 09.09.2017 ( KUIC) .

Distribution: India: Jammu (new record), Punjab, Pakistan

Hosts: Pinus gerardiana ( Pinaceae )

Phylogenetic assessment:

The phylogenetic treatment of the Himalayan Polygraphus along with other closely related species was carried out using the COX-1 genes to examine the monophyly and sister groups of each species ( Fig. 52 ). The NJ tree showed that P. trenchi populations are monophyletic with P. proximus Blandford, 1894 populations distributed in Russia and that they differ from them by 14.73–14.89%, while P. pini populations formed a separate monophyletic cluster with well-supported bootstrap values and that their intraspecific nucleotide difference was between 0.5–1.92%. The research also revealed that P. trenchi and P. major differed by 14.07%, whilst P. major and P. pini were 15.37% dissimilar.

Figures

FIGURE 51. Polygraphus trenchi. Male: dorsal view A, lateral view B; female: dorsal view C, lateral view D.

FIGURE 52. A phylogenetic tree obtained from the NJ for the COX-1 genes of Himalayan Polygraphus (in blue) and related species. Numbers at the branches represent bootstrap values.