Woody tissues are produced by each of the approximately 44,000 species of trees, shrubs, and woody vines found worldwide (Hickin, 1975). Most woody tissues are tougher, drier, and nutritionally poorer than leaf tissue when considered as a sustrate for insect growth and development (Slansky and Scriber, 195). Nevertheless, many insects have evolved to live and feed in woody environments; some species inhabit the relatively soft and nutritionally rich inner bark (phloem), whereas others are found in the harder more nutrient-deficient sapwood and heartwood. Other species are xylomycetophagous, feeding primarily on symbiolic fungi that grow within their galleries. Certain wood feeder inhabit living trees, some occur in recently dead trees or decaying logs, and others live within structural timbers and furniture.