Myrmecophily among mesostigmatid mites

Abstract Ant nests are biodiversity hot spots, concentrating resources from a wide area that can be exploited by other organisms, known as myrmecophiles. The mite order Mesostigmata includes a wide range of lineages that have become myrmecophiles with many species reliant on ant nests for at least part of their development. The nature of the associations is quite variable, including predators of smaller arthropods in the nest (close to the ancestral lifestyle of these mites), scavengers, kleptoparasites, parasites, and parasitoids. A few mite species show extreme modifications of morphological and/or developmental patterns, others show almost none. Some host specificity is common but one-on-one host specialization is rare or poorly tested. Phoresy on the ants is common, but the target ant caste varies with the goal of phoresy. In general, the diversity of mesostigmatid mites in the nest of a given ant species is affected by habitat conditions along with a range of life history characteristics of the ants, including factors such as body size, colony size, colony founding mode, social parasitism, and nest density. Unfortunately, the life history of the majority of mites associated with ants is still unknown.