Xyleborus

European shot borer Xyleborus dispar in plum tree, from here.

Belongs within: Scolytinae.

Xyleborus is a cosmopolitan genus of xylomycetophagous (i.e. feeding on fungi growing on wood) bark beetles. Members of this genus are consanguineously polygynous, with haploid flightless males (Wood 1986).

Characters (from Wood 1986): Females with body length 1.7 to 5.9 mm, mostly more than 2.0 times as long as wide; segment I of antennal club corneous, its distal margin very acutely elevated into a continuous costa (forming a complete circle) extending from anterior face to apex; basal segment of labial palpus enlarged, conspicuously wider than segment 2 or 3; lateral margins of pronotum rounded; scutellum visible, moderately large, its surface flush with adjacent surface of elytra; procoxae contiguous, intercoxal piece longitudinally emarginate (a few individuals in javanus group subcontiguous but only feebly emarginate), its posterior element inflated, occasionally dentate; protibia with posterior face almost flat, smooth.

<==Xyleborus Eichhoff 1864 (see below for synonymy) W86
    |--*X. monographus [=Bostrichus monographus] W86
    |--X. bidentatus [=Phloeotrogus bidentatus; incl. *Boroxylon stephegynis] W86
    |--X. cryptographus [=Bostrichus cryptographus; *Heteroborips cryptographus] W86
    |--X. dispar [=X. (Apate) dispar, *Anisandrus dispar] W86
    |--X. kalshoveni [=*Notoxyleborus kalshoveni] W86
    |--X. meuseli [=*Xyleborips meuseli] W86
    |--X. prelaetus [incl. *Cyclorhipidion pelliculosum] W86
    |--X. pubescens W86
    |--X. spathipennis W86
    |--X. subcostatus [incl. *Progenius fleutiauxi] W86
    `--X. volvulus [=Bostrichus volvulus; incl. Xyleborus guanajuatensis, *Anaeretus guanajuatensis] W86

Xyleborus Eichhoff 1864 [incl. Anaeretus Dugès 1887, Anisandrus Ferrari 1867, Boroxylon Hopkins 1915, Cyclorhipidion Hagedorn 1912, Heteroborips Reitter 1913, Notoxyleborus Schedl 1934, Progenius Blandford 1896, Xyleborips Reitter 1913] W86

*Type species of generic name indicated

REFERENCES

[W86] Wood, S. L. 1986. A reclassification of the genera of Scolytidae (Coleoptera). Great Basin Naturalist Memoirs 10: 1-126.