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

http://lib.byu.edu/about/copyright/

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

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