Phylogeny and ecology of mites associated with bark and ambrosia beetles

Abstract

Associations between bark- and ambrosia-beetles and mites include phoresy, parasitism, predation, commen- salism, and mutualism. One of the main associations is phoresy, which is mite "hitch-hiking" for dispersal through other organisms. I suggest that most symbiosis between the beetles and mites evolved from phoresy. Since the associations are reported to exist in Mesostigmata, Prostigmata, Astigmata and Oribatida without genetic relationships, I conclude that association with the beetles evolved independently and multiple times in the order Acari. Predacious mites do not show food specificity to the beetles but they feed on insect eggs and larvae including bark and ambrosia beetles, nematodes and other small organisms. Negative impacts by mite predation and parasitoidism are negligible given that those mites are phoretic on the host beetles. Mutualism is not direct but indirect between the beetles and mites, involving fungi, nematodes and other mites. Therefore, I hypothesize that associations between them developed due to the use of the same habitat.