Trypoxylon Latreille 1796

Sandhouse (1940) is the most reliable source for identification of North American species for Richards (1934) does not include all of our species. The revisions cited below include the species of both Trypoxylon and Trypargilum which are considered herein to be separate genera. ~Most species of Trypoxylon nest in pre-existing cavities such as hollow stems or twigs, abandoned beetle borings in dead wood or structural timber, or, rarely, in soil. The Species Group Fabricator is unusual in that some species build free mud cells whereas others nest in pre-existing cavities in wood or soil. The preferred prey of the North American species are small spiders, usually immatures, belonging to several families of snare-builders, but errant spiders are used occasionally; as few as 4 and as many as 20 spiders may be stored in a single cell. Trypoxylon males do not participate in some of the nesting activities as do those belonging to Trypargilum; there is one report of a male usually being present in the nest of an extralimital species of the Fabricator Group, but this needs confirmation. The cocoons of our North American species are delicate silken structures except in johnsoni which constructs a brittle cocoon incorporating sand from the cell partition.