Infracommunity dynamics of chiggers (Trombiculidae) parasitic on a rodent.

We studied the structure of chigger mite (Trombiculidae) communities parasitic on a South African rodent, Rhabdomys pumilio. We aimed to determine whether: (a) different chigger species differ in preferences for certain body areas of a host and (b) chigger assemblages among body areas of the same host individual, are structured and if so, whether the structure of these assemblages is aggregative or segregative. Rhabdomys pumilio is parasitized by seven chigger species belonging to six genera. The three most abundant species (Leptotrombidium sp. nr. muridium, Schoutedenichia sp. and Neoschoengastia sp. A) displayed a non-random distribution across the host body, with the two most abundant species (L. sp. nr. muridium and Schoutedenichia sp.) significantly associated with the tail area. In addition, whenever non-randomness of chigger co-occurrence in the same body area was recorded, it indicated positive but not negative co-occurrences of different species. This might be due to similarity of chigger species in resource needs and strategies to avoid host defence efforts.