Ambrosiodmus Hopkins, 1915

Smith, Sarah M., Beaver, Roger A. & Cognato, Anthony I., 2020, A monograph of the Xyleborini (Coleoptera, Curculionidae, Scolytinae) of the Indochinese Peninsula (except Malaysia) and China, ZooKeys 983, pp. 1-442 : 1

Ambrosiodmus Hopkins, 1915

Ambrosiodmus Hopkins, 1915a: 55.

Phloeotrogus Motschulsky, 1863: 512. Wood 1969: 113.

Brownia Nunberg, 1963: 37. Synonymy: Wood 1980: 96.

Type species.

Xyleborus tachygraphus Zimmerman, 1868; original designation.

Diagnosis.

2.5-4.8 mm, 1.7-2.8 × as long as wide, body usually stout and darkly colored. Ambrosiodmus is distinguished by the pronotum short and rounded, types 1 or 2 in dorsal view; pronotal disc entirely asperate; pronotum anterior margin without a carina or serrations; elytral disc convex; declivity rounded and steep at apex; antennal club flattened, type 4; scutellum flat, flush with elytra; mycangial tufts absent; and procoxae contiguous.

Similar genera.

Ambrosiophilus , Beaverium , Immanus .

Distribution.

Temperate and tropical regions of the world.

Gallery system.

This consists of a radial entrance tunnel leading to branched tunnels. These usually lie predominantly in one horizontal plane but may extend into three dimensions. They lack enlarged brood chambers. Many gallery systems are often started in a small area of the tree. Unlike many xyleborines, the galleries of different individuals often interconnect so that beetles can move between galleries ( Beeson 1961; Kasson et al. 2016).

Remarks.

Recent studies suggest that all Ambrosiodmus and Ambrosiophilus species (see below) are associated with a single species of polypore basidiomycete ambrosia fungus ( Flavodon ambrosius ) ( Kasson et al. 2016; Li et al. 2017). This fungus has greater ability to break down lignocellulose than most ambrosia fungi. This enables the beetles to colonize wood at a more advanced state of decay than most ambrosia beetles, and to persist in the same tree over several generations ( Kasson et al. 2016; Li et al. 2017).