Theses and Dissertations

Issuing Body

Mississippi State University


Catchot, Angus

Committee Member

Musser, Fred

Committee Member

Cook, Donald

Committee Member

Gore, Jeffrey

Date of Degree


Document Type

Graduate Thesis - Open Access


Entomology and Plant Pathology

Degree Name

Master of Science (M.S.)


College of Agriculture and Life Sciences


Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology


Experiments were conducted to determine the impact of twospotted spider mite, Tetranychus urticae Koch, on cotton injury and yield. Artificial infestations were initiated at the three leaf stage of cotton growth and removed after specified durations of infestation. Yields were reduced for durations of infestation 21 days or greater. In a second experiment, the interactions between twospotted spider mite, thrips, at-planting insecticides, and foliar insecticides were studied to determine their impact on cotton yields. Twospotted spider mites and thrips reduced cotton yield. In a third experiment, twospotted spider mites were released from a central point in 0.024 hectare blocks of cotton and injury was recorded at various distances from that point. Injury was clearly visible seven meters from the infestation point within 16-28 days after infestation. Twospotted spider mites caused significant yield losses in cotton in all of these experiments.