Release and Evaluation of a Laboratory-Selected, Pyrethroid-Resistant Strain of the Predaceous Mite Metaseiulus occidentalis (Acari: Phytoseiidae) in Southern Oregon Pear Orchards and a Washington Apple orchard

$28.00 plus tax (Refund Policy)

Buy Article:


A laboratory-selected strain of the spider mite predator Metaseiulus occidentalis (Nesbitt) was released into two southern Oregon pear orchards and a Washington apple orchard in June 1980. The permethrin and organophosphorus insecticide (OP)-resistant predators became established in all three orchards, overwintered, and survived repeated permethrin applications during 1980 and 1981. By summer 1981, the predators had spread into adjacent trees in release areas in both states. Foliage damage was substantially reduced compared with trees lacking the permethrin-OP-resistant predators in Oregon in 1981. in Washington in 1980, spider mite populations were significantly lower and M. occidentalis populations significantly higher on release trees than on control trees. In 1981, the frequency and rates of permethrin applications caused high mortality of the resistant M. occidentalis and high spider mite densities developed on all sampled trees. Permethrin resistance levels remained high in the orchard populations after two field seasons, despite the polygenic nature of this resistance. Future releases should be considered, especially where releases can be made into each tree and selective acaricides can be used to manage spider mite-predator densities until a more stable relationship occurs.

Document Type: Research Article

Publication date: April 1, 1983

More about this publication?
  • Journal of Economic Entomology is published bimonthly in February, April, June, August, October, and December. The journal publishes articles on the economic significance of insects and is divided into the following sections: apiculture & social insects; arthropods in relation to plant disease; forum; insecticide resistance and resistance management; ecotoxicology; biological and microbial control; ecology and behavior; sampling and biostatistics; household and structural insects; medical entomology; molecular entomology; veterinary entomology; forest entomology; horticultural entomology; field and forage crops, and small grains; stored-product; commodity treatment and quarantine entomology; and plant resistance. In addition to research papers, Journal of Economic Entomology publishes Letters to the Editor, interpretive articles in a Forum section, Short Communications, Rapid Communications, and Book Reviews.
  • Editorial Board
  • Submit a Paper
  • Subscribe to this Title
  • Information for Advertisers
  • Visit this journal's homepage
  • ingentaconnect is not responsible for the content or availability of external websites
Related content



Share Content

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more