Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School



For more than a century, scientists have recognized that insect diseases are often caused by microorganisms and have suggested that these microbes might be used for insect control. Chemical control methods are presently the most common and effective means of controlling insect pests. However, many controversies have arisen concerning the total environmental impact of chemical pesticides on non-target organisms. Numerous insect pathogens have been isolated and studied with the expectation of their use as an alternative means of insect control. Among the more prominant microbes under investigation are the insect viruses. Most insect viruses exhibit a very limited host range; therefore, it should be possible to use them for control of a target-insect population while leaving beneficial insects and other fauna unharmed. This type of specificity is not always shared by most chemical insecticides and other nonvirus pathogens. This study was initiated to gain a better understanding of the virus-host relationship as it occurs with a granulosis virus in the army cutworm, Euxoa auxiliaris (Grote). This insect pest is widely distributed from Mexico to Canada and has been reported in destructive numbers in all states west of the Mississippi River, except Louisiana. Winter wheat and alfalfa are the principal crops damaged by larval feeding with reports of corn, sugar beets, barley, oats, and sweet clover occasionally being infested. Information from this study will enable researchers to assess the effectiveness of this virus as an integral part of a pest management program for this insect pest. In addition, a description of the biogenesis of this virus within this host will contribute basic information in understanding the pathogen-host relationship at cellular and organismic levels.

Library of Congress Subject Headings

Insects -- Diseases


South Dakota State University Theses



Number of Pages



South Dakota State University