Taxonomy

Ambrosiodmus Hopkins, 1915a: 55.

Synonyms

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

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

Diagnosis

2.5−4.8 mm long, 1.7−2.8 times as long as wide, body usually stout and darkly colored. Ambrosiodmus can be distinguished by the pronotum short, rounded; pronotal disc entirely asperatepronotum anterior margin without a carina or serrationselytral disc convexelytral declivity rounded and steep at apexscutellum flat, flush with elytramycangial tufts absent; and procoxae contiguous.

May be confused with

Ambrosiophilus, Beaverium, and 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 the species in Ambrosiodmus and Ambrosiophilus Hulcr and Cognato 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).