Taxonomy

Amasa Lea, 1894: 322.

Synonyms

Pseudoxyleborus Eggers, 1930: 206. Wood, 1984: 223.

Anaxyleborus Wood, 1980: 90. Wood, 1983: 647.

Diagnosis

2.5−5.0 mm long, 2.11−3.4 times as long as wide. Amasa is distinguished by the elytral declivity truncate, margined with a circumdeclivital ring; antennal club flat, types 4 or 5 (typically type 4), club sutures sinuate, two sutures visible on posterior face; protibia typically slender, inflated and granulate on posterior face (rarely distinctly triangular or unarmed on posterior face), anterior margin of the pronotum with a row of serrations; scutellum flat, flush with elytral surface; declivital face with three striae; procoxae contiguous or narrowly separated; and mycangial tufts absent.

Amasa is easily confused with other species possessing truncate declivities in other genera listed below and can be most readily distinguished by the declivital face with only 3 striae.

May be confused with

Xylosandrus, Cyclorhipidion, Pseudowebbia, Truncaudum, and Webbia

Distribution

Distributed throughout Asia and Australasia, also occurring in Africa. One species has been introduced to Brazil, Chile, and Uruguay (Flechtmann and Cognato 2011, Gómez et al. 2017, Kirkendall 2018).

Gallery system

This usually comprises a short radial tunnel leading to a single, large, flat brood chamber, extending in the longitudinal plane.

Remarks

Previous morphological studies of Amasa have suggested that species are very morphologically variable (Hulcr and Cognato 2013). As a result many species were considered conspecific and part of a morphological continuum. Molecular data generated as part of this study has demonstrated that Amasa species are actually morphologically conserved even across broad ranges (Smith et al. 2020a). Amasa species outside of our coverage area are thus in need of revision, and potentially much of the diversity is awaiting discovery.