Cold storage of Halotydeus destructor (Acari: Penthaleidae) for use in experiments.

Abstract

Survival of medium sized nymphal stages of redlegged earth mite Halotydeus destructor (Tucker) (mainly tritonymphs and deutonymphs) stored under low temperature (1.5 degrees C) in sealed plastic boxes remained more than 50% after 12 days of storage, with some mites surviving for up to eight weeks. Adding fresh subclover leaves into the storage box increased the survival rate of mites from 12% to 28%, 19 days after the storage started. Mites stored for two weeks at low temperatures showed feeding activity in a screening experiment similar to mites collected directly from the field. This indicated that cold storage of redlegged earth mite can be used to build up mite numbers for large screening experiments, or to extend the period of availability of mites collected from the field. However, their reproductive ability was greatly reduced after three weeks at low temperature. Thus, care should be taken when using mites for experiments measuring reproduction. The implications of low temperatures for reducing field populations of mites in midwinter are also discussed.