Diuncus corpulentus ( Eggers, 1930 )

Buhroo, Abdul Ahad, 2024, A taxonomic monograph of subfamily Scolytinae (Coleoptera: Curculionidae) in the Western Himalaya, Zootaxa 5533 (1), pp. 1-82 : 68-69

54. Diuncus corpulentus ( Eggers, 1930)

( Figure 68)

= Xyleborus corpulentus Eggers, 1930

This species is diagnosed by the following morphological characters: ♀ frons plano-convex, surface finely reticulate with distinct shallow sparse punctures, vestiture of very sparse fine hairs distinct on lateral areas near eyes, longer and relatively denser on epistomal margin; antennal club obliquely truncate (type 1), segment 1 corneous and dominant on both sides; pronotum from lateral view rounded (type 5), dorsal view rounded (type 1); postero-lateral angles broadly rounded; sides bulging out and converging anteriorly terminating into an angular projection, anterior margin armed with six asperities, larger pair at middle; summit distinct almost at middle; anterior declivous portion armed with distinct triangular asperities in concentric rows, gradually increasing in size anteriorly; posterior half shiny, finely reticulate and punctate, vestiture of sparse hairs anteriorly and postero-laterally; scutellum triangular flushed with elytra; elytra 1.58× as long as pronotum,1.27× as long as wide; basal margin substraight; lateral sides sub-parallel up to basal two-thirds, converging posteriorly into an angular apex; postero-lateral margins of elytra strongly carinate and confluent with interstria 7; striae marked by close fine punctures; interstriae 4–5× as wide as striae, surface flat with irregular punctures and inconspicuous hairs; declivity commencing from slightly above the middle, interstriae 2 armed by three denticles at commencement of declivity; declivital interstriae 3, 5, and 6 with a uniseriate row of denticles along its length; vestiture of minute, confused, recumbent interstrial hairs and a few long hairs along lateral sides; elytra and pronotum dark colored, basal half of pronotum yellowish-brown; body length: 2.62 mm, 2.15× as long as wide.

Male is very similar to female except small in size; eyes feebly emarginate; anterior pronotal margin weakly produced but unarmed; hairs inconspicuous.

Material examined: Holotype ♀ in FRI Dehradun ( Xyleborus corpulentus Eggers, 1930 ). Type locality: Upper Dihing Reserve, Lakhimpur, Assam, India

New record: India: 1 ♀. Himachal Pradesh, Palampur, Tanda (32° 06.141′ N, 076° 32.036′ E, 4008 ft.), A.A. Buhroo, 25.09.2018 ( KUIC) .

Distribution: India: Himachal Pradesh (Tanda Palampur) (new record), Assam, Andaman Islands, West Bengal. Nepal, China: Xizang

Hosts: Grevillea robusta ( Proteaceae ) (new host record). Acrocarpus fraxinifollius ( Fabaceae ), Artocarpus chama ( Moraceae ), Cryptocarya wightiana ( Lauraceae ), Sterculia villosa ( Malvaceae ), Vatica lanceifolia ( Dipterocarpaceae ).

Genus Xyleborinus Reitter, 1913

Xyleborinus species are diagnosed by the following combination of characters: body length: 1.4–3.5 mm (male dwarf, deformed and flightless); anterior margin of the compound eyes emarginated; antennal funicle five-segmented; the antennal club is obliquely truncate with segment 1 corneous and dominant on both sides of the club (type 1); pronotum longer than wide (type 8); anterior slope of pronotum convex, anterior margin armed by weak to moderate serrations; scutellum depressed, conical, not fitting in the scutellar notch, the cavity around the scutellum bears distinctive short tuft of hairs;elytra striate, punctures in rows; declivity usually armed by tubercles or spines; procoxae contiguous; host: deciduous trees.