What is "asemum moestum"

Pruner \Prun"er\, n.

1. One who prunes, or removes, what is superfluous.

2. (Zo["o]l.) Any one of several species of beetles whose larv[ae] gnaw the branches of trees so as to cause them to fall, especially the American oak pruner ( Asemum m[oe]stum), whose larva eats the pith of oak branches, and when mature gnaws a circular furrow on the inside nearly to the bark. When the branches fall each contains a pupa.