Abstract
The overwintering habitats and winter mortality rates of predaceous mites (Phytoseiidae: Typhlodromus) were investigated during three successive winters, 1965-66, 1966-67, and 1967-68. Three species were predominant in derelict apple orchards, Typhlodromus mcgregori Chant on twigs and spurs and rough bark of scaffold limbs and trunk, Typhlodromus occidentalis Nesbitt on rough bark of scaffold limbs and trunk, and Amblyseius cucumeris Oudemans in ground cover. Other species (Typhlodromus columbiensis Chant, Typhlodromus caudiglans Schuster, Amblyseius fallacis (Garman), Amblyseius ovatus (Garman), Amblyseius floridanus (Muma), and Amblyseius rosellus Chant) were collected only incidentally. Substantial numbers of T. mcgregori and T. occidentalis were found to fall with yellowed falling leaves during the autumn leaf drop; however, a majority of the mites stayed on the trees, overwintering on twigs and spurs (T. mcgregori) and bark (T. occidentalis). Typhlodromus mcgregori was found overwintering primarily under old corky abscission layers of leaf petioles and fruit stalks on the 1-5 year old section of twigs and spurs. No significant winter mortality of T. mcgregori was found during the five month period from December to April. The importance of overwintering sites and winter mortality rates to biological and integrated control programs is discussed.
Degree
MS
College and Department
Life Sciences; Plant and Wildlife Sciences
Rights
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BYU ScholarsArchive Citation
Leetham, John Wayne, "Overwintering sites and winter mortality rates of certain predaceous mites in Central Utah orchards (phytoseiidae: typhlodromus)" (1968). Theses and Dissertations. 7809.
https://scholarsarchive.byu.edu/etd/7809
Date Submitted
1968-08-01
Document Type
Thesis
Handle
http://hdl.lib.byu.edu/1877/Letd228
Keywords
Mites; Apples, Diseases and pests; Phytoseiidae
Language
English