Saproxylic Diptera Chapter 5
Diptera rivals Coleoptera as perhaps the most abundant and diverse order of saproxylic insects, with saproxylic habits known from at least 75 (48%) of the 157 ﬂy families recognized globally. Some ﬂy families are mostly if not entirely saproxylic including Aulacigastridae, Axymyiidae, Canthyloscelidae, Clusiidae, Pachyneuridae, Pantophthalmidae, Periscelididae, Xylomyidae, and Xylophagidae. Saproxylic ﬂies are common inhabitants of virtually all moist to wet microhabitats including sap ﬂows, under bark, in rotting wood, tree hollows, and fungal fruiting bodies. Most species are saprophagous or fungivorous although many predatory species exist as well, including some of the most important natural enemies of bark beetles. Although very poorly studied compared to beetles, it is clear that many saproxylic ﬂy species are declining due to forest loss or degradation, and some taxa (e.g., mycetophilids) are good indicators of forest continuity. The dependence of ﬂies on wet or
even saturated substrates suggests they need special consideration when developing conservation strategies. Studies addressing their sensitivity to various management interventions are urgently needed.