A review of termitophilous and other termite-associated scuttle flies worldwide (Diptera: Phoridae)

A review is provided of the morphological and behavioural observations known for the 190 recorded termitophilous and other termite-associated species of Phoridae (scuttle flies) known worldwide. A full list of these termite-associated phorids is provided, together with their recorded termite hosts, as an Appendix. The influence of batch size, egg size, developmental cycle, wing reduction and winglessness, egg-laying and morphological adaptations of a termite-associated lifestyle is discussed, based on differences observed among termite-associated phorids. A high number of termitophilous phorid species with batch sizes of four eggs or less are noted, probably reflecting the stable environment termitophilous phorids experience, and the high percentage of species with parasitoid or predatory larvae. Minimising the free-living larval stage by a reduction of the number of instars, by larval instar curtailment, or by endoparasitism is here hypothesised to be an advantageous life history strategy for many termite-associated phorids. Termite-associated phorids can be divided into four main types, according to their biology and morphology. The exploitive- and generalistic-types include both obligate and non-obligate termite associates that take advantage of the more vulnerable stages of the termites. The protective- and guest-types are obligate associates, spending full larval and pupal stages with their hosts. The guest-type is described as being socially integrated, communicating with the host and being involved in worker/nymph interactions.