Phylogeny of gall midges (Cecidomyiidae)

This chapter reviews recent insights into the phylogenetic arrangement of the Cecidomyiidae and some of its lower categories within the Diptera. Particular attention is devoted to the phylogenetic implications of feeding modes and host associations. The Cecidomyiidae belong to the Sciaroidea, together with its sister group, the recently erected New Zealand family Rangomaramidae. Traditionally, the Cecidomyiidae were subdivided into three subfamilies. The Cecidomyiinae are undoubtedly monophyletic, as are the Lestremiinae after exclusion of the Catotrichini, which was recently raised from tribe to subfamily. The Porricondylinae remain paraphyletic. Phylogenetic hypotheses for Cecidomyiidae, Lestreminae, and Lasiopteridi, as presented in various recent monographs, are summarized and analyzed. on Recent viewpoints on cecidomyiid feeding modes are discussed. Fungivory is postulated to be the original feeding mode in Cecidomyiidae. Gall induction and predation modes are therefore derived conditions. Gall-inducing habit occurs only in the Cecidomyiinae, but has been postulated to have evolved several times. The same is true for gall-midge induced ambrosia galls, in which the cecidomyiids need fungi to leaf mediate their nutrition. Because host ranges in many ambrosia gallers are significantly broader than such ranges in gallers without fungal mediation, ambrosia galling is considered as a separate trajectory in gall-midge evolution. Predating behavior is hypothesized to have evolved from fungivory directly, and once. Cecidomyiidae offer intriguing examples for cospeciation with associates: not only host plants, but also inquilines and parasitoids.