mm in length. Paired and forked horny projections are often found on the ninth 
abdominal segment. Keys to the species occurring in Delaware are available (232). 
Both adults and larvae of many species feed on decaying fruit, fermenting sap 
under bark, and sap exudations from freshly cut logs, stumps, or wounds on living 
trees. Bark-infesting species often kill patches of cambium (fig. 107) that heal over 
to form pocket defects causing lumber degrade losses in valuable species like oak. 
A number of species apparently can penetrate the bark of oak where there are no 
previous injuries. Numerous studies have shown that nitidulid beetles are vectors of 
oak wilt fungus, Ceratocystis fagacearum (Bretz) Hunt. 
F-519925, 519926 
Figure 107.—Evidence of nitidulid attacks on oak: A, 
scars overgrown after attacks; B, pockets in the wood 
beneath scars shown on A. 
244 
