Species of Oxyporus are easily recognized by their characteristic labial palpi (Fig. 1.1.2) and prognathous mandibles, which normally cross (Fig. 1.1.1). Their unique habitus makes them difficult to confuse with any other subfamily.

Widely distributed in North America, species of Oxyporus are associated with fleshy fungi and are almost exclusively collected from them. Both adults and larvae tear pieces of the stem and cap with their mandibles, digesting the fungus pre-orally (Hanley and Goodrich 1994). Females construct egg chambers within the host fungus and remain there after oviposition (Hanley and Goodrich 1995). Both females and males have been observed to guard the egg chamber (Hanley and Goodrich 1995). To pupate, mature larvae drop off their host and bury themselves in the soil below (Hanley and Goodrich 1994). The common O. vittatus Gravenhorst (Fig. 9.9.1) utilizes a broad range of fungal host genera while O. quinquemaculatus LeConte (Fig. 9.9.2) exhibits a strong preference for fungi in the genus Pluteus Fries (Hanley and Goodrich 1995). Other species, such as O. major Gravenhorst (Fig. 9.9.3), are intermediate in the breadth of their host range (Hanley and Goodrich 1995). However, the larvae of all species seem to be found only from one or two host fungi (Hanley and Goodrich 1995). The males of some Oxyporus are dimorphic for mandible size, with the difference more pronounced in species with narrower host preferences (Hanley 2001). Hanley (2001) hypothesized that the two male types corresponded to differences in mate acquisition strategies.