REVIEW OF HOLARCTIC TARSONEMID MITES (ACARINA: PROSTIGMATA) PARASITIZING EGGS OF IPINE BARK BEETLES

Abstract

A group of tarsonemid mites, which are egg parasites of ipine bark beetles, is reviewed on a Holarctic basis. The genus Iponemus (new name for Moseria Beer and Nucifora) is proposed and described for the group, and 24 species or subspecies, including 19 described as new, are described, keyed, and illustrated. A detailed species-group description follows the generic description, and includes several structures hitherto not reported for species of Tarsonemidae. The variation and usefulness of the few characters available for distinguishing forms of Iponemus is discussed, and the provisional treatment of some forms as species and others as subspecies is explained.These mites are among the most host-specific associates of scolytid beetles: 16 of the 18 species or subspecies of Iponemus associated with the nearctic, pine-feeding ipines are monospecific, and each of the other two is restricted to two closely related species of hosts. The mites and the beetles together are considered with regard to size correlations, the degree of host specificity, the mites as taxonomic indicators of their hosts, biogeography, life history, and the role of egg parasitism by the mites in the population regulation of their hosts.