Bark and Ambrosia Beetles of the World

I have seen the holotype, allotype, and all paratypes of this species and find that the sexual dimorphism discussed by Wood (2007) to be very slight (Atkinson 2017).

This species belongs in the genus Monarthrum, not Amphicranus. The pattern of sexual dimorphism in both the antennal club and the declivity clearly places it in the first genus. The protibia of both males and females is slender with only a small number of tubercles on the posterior face (larger in males). (Atkinson 2017). Additional species that probably belong with this species include `fulgidus Wood, sexdenticulum Wood, and araguensis Wood.

This species probably belongs in the genus Monarthrum, not Amphicranus. This species is known only from males, but these resemble those of eggersianus Wood and fulgidus Wood in which the pattern of sexual dimorphism in both the antennal club and the declivity clearly places them in the first genus. Additional species that probably belong with this species include `sexdenticulum Wood,. (Atkinson 2017).

Apparently the male holotype of micidus Wood is simply a specimen of A. filiformis Blandford on the small side of the size range. Reported as A. filiformis by Noguera & Atkinson (1994:465)