Xyleborinus saxesenii ( Ratzeburg, 1837 )

Buhroo, Abdul Ahad, 2024, A taxonomic monograph of subfamily Scolytinae (Coleoptera: Curculionidae) in the Western Himalaya, Zootaxa 5533 (1), pp. 1-82 : 69-70

55. Xyleborinus saxesenii ( Ratzeburg, 1837)

( Figure 69 )

= Bostrichus saxesenii Ratzeburg, 1837

= dohrnii Wollaston, 1854 ( Tomicus )

= decolor Boieldieu, 1859 ( Tomicus )

= aesculi Ferrari, 1867 ( Xyleborus )

= sobrinus Eichhoff, 1876 ( Xyleborus )

= subdepressus Rey, 1883 ( Xyleborus )

= frigidus Blackburn, 1885 ( Xyleborus )

= arbuti Hopkins, 1915 ( Xyleborus )

= floridensis Hopkins, 1915 ( Xyleborus )

= pecanis Hopkins, 1915 ( Xyleborus )

= quercus Hopkins, 1915 ( Xyleborus )

= subspinosus Eggers, 1930 ( Xyleborus )

= tsugae Swaine, 1934

= librocedri Swaine, 1934

= pseudogracilis Schedl, 1937 ( Xyleborus )

= retrusus Schedl, 1940 ( Xyleborus )

= peregrines Eggers, 1944 ( Xyleborus )

= pseudoangustatus Schedl, 1948 ( Xyleborus ) = paraguayensis Schedl, 1949 ( Xyleborus )

= opimulus Schedl, 1976 ( Xyleborus )

= cinctipennis Schedl, 1980 ( Xyleborus )

This species is diagnosed by the following morphological characters: ♀ frons broadly convex, surface shining, reticulate with rather coarse, shallow punctures; a distinct median line from epistoma up to upper level of eyes, epistomal margin with a few short hairs; anterior margin of compound eyes emarginate; antennal funicle with five segments; club slightly longer than wide, obliquely truncate, with segment 1 corneous encircling anterior face, segment 2 narrow, concave, corneous on anterior face only; sutures absent on posterior face; pronotum longer in lateral view (type 8), sides almost straight and parallel on more than basal half, broadly rounded in front (type 8 in dorsal aspect); anterior margin armed by ten or more low serrations; summit slightly in front of middle of pronotum length, anterior slope coarsely, closely asperate; posterior areas finely reticulate, punctures minute, rather numerous; vestiture hair-like, sparse, mostly on margins; elytra 1.58× as long as wide, 1.26× as long as pronotum; disc occupying basal one third of elytral length; striae not impressed, punctures small, somewhat larger on discal portion of striae 2, 3 and 4; interstriae more than twice as wide as striae, smooth, shining with rather minute punctures, some near declivity replaced by small tubercles; declivity steep, convex, weakly impressed; surface smooth, usually granulate; striae 1–3 clearly indicated with small punctures in rows; interstriae 1 feebly elevated, armed by a row of seven to eight small, pointed tubercles, 2 somewhat flat, unarmed except for three to four minute tubercles at declivital summit, 3 armed by a row of about eight small, pointed tubercles more stronger towards apex; apex of interstriae 4 confluent with elevated apex marked by few pointed tubercles; vestiture of short, fine strial hair, and long, erect, rather coarse interstrial setae, some setae on declivity more than twice as long as distance between rows; color dark reddish brown; body length: 2.10–2.24 mm, 2.90× as long as wide.

Male similar to female except eyes smaller; pronotum 1.1× as long as wide, summit indefinite, anterior slope more gradual, asperities minute, restricted to a much smaller area, anterior margin unarmed; declivity longer and not as steep as in female; strial and interstrial punctures poorly formed, declivital tubercles reduced in size and number.

Material examined: New record: India: 4 ♀ ′s. Kashmir , Srinagar, Hazratbal (University Campus), (34° 07′51.10 ′′ N, 074° 50′ 01.09′′ E, 5220 ft.), A.A. Buhroo, 20.08.2017 ( KUIC) .

Distribution: India: Assam, Kashmir, Uttarakhand, West Bengal. Asia, Europe, North and South America, Australia, Africa.

Hosts: Aesculus indica ( Sapindaceae ) and Salix alba ( Salicaceae ) (new host records). Fraxinus excelsior ( Oleaceae ), Juglans regia ( Juglandaceae ), Prunus armeniaca , P. cornuta ( Rosaceae ), Symplocos theaefolia ( Symplocaceae )

Genus Xyleborus Eichhoff, 1864

Xyleborus species are diagnosed by the following morphological characters: body length: 1.9–3.9 mm; scutellum flat, flush with elytra, mycangial tufts absent; lateral margin of pronotum obliquely costate; pronotum from dorsal view rounded frontally (types 2, 7); elytral disc longer than declivity; elytral disc strial and interstrial punctures seriate; pronotal disc alutaceous; posterior face of the protibiae flat, unarmed; antennal club typically obliquely truncate with segment 1 nearly covering the entire posterior face (type 2); antennal funicle five-segmented; anterior pronotal margin unarmed; procoxae contiguous; host: deciduous trees.

Figures

FIGURE 69. Xyleborinus saxesenii. Female: dorsal view A, lateral view B, frons C, elytral declivity D.