Thesis (Ph.D.)--University of Nebraska-Lincoln, 2008. / Title from title screen (site viewed Jan. 13, 2009). PDF text: vii, 132 p. : ill. (some col.) ; 4.76 Mb. UMI publication number: AAT 3315331. Includes bibliographical references. Also available in microfilm and microfiche formats.

Thesis (M.S.)--University of Wisconsin--Madison. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 51-60).

Thesis (Ph. D.)--University of Wisconsin, 1965. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliography.

Thesis (M.S.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on October 31, 2007). Includes bibliographical references.

Title from PDF of title page (University of Missouri--Columbia, viewed on Feb. 24, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Dissertation advisor: Dr. Georgia Davis. Vita Includes bibliographical references.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 86-87). Also available via the Internet.

No description available.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1975. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 80-84).

Historically, the organophosphate insecticide chlorpyrifos was used to protect peanuts (Arachis hypogaea L.) from soil-dwelling insect pests. In 2022, its registration was canceled by the Environmental Protection Agency (EPA) for all food crops. The southern corn rootworm, Diabrotica undecimpunctata howardi Barber (Coleoptera: Chrysomelidae) (SCR), was the major pest of developing peanut previously managed by chlorpyrifos and there are no known alternative insecticides for its control. The SCR larvae can cause economic damage by feeding on developing pods and pegs. Field condition is an important factor in SCR survival as the larvae rely on soil moisture to survive, and larvae cannot feed on fully developed pods. The dependency of SCR on soil moisture and host availability allows for cultural modifications (e.g., planting date, judicious irrigation practices, selecting fields based on soil characteristics) to reduce losses to this pest. Alternatively, or in addition to these strategies, identifying varieties with resistance to SCR can provide growers with non-chemical methods to mitigate losses. Therefore, this project was developed to identify sources of resistance in commercial cultivars and advanced breeding lines of Virginia type peanuts to SCR and examine whether early digging can reduce SCR injury. Implementing an effective integrated pest management (IPM) plan relies on a clear understanding of the pest life cycle in relation to the susceptible stage of the crop. We also evaluated SCR phenology in relation to peanut development. Replicated field trials were used to screen cultivars and investigate the effect, if any, of early digging in reducing pod injury. We monitored SCR adult populations over time using sticky traps. Our research will help manage a problematic pest in this region with limited, or no, reliance on insecticides. / Master of Science in Life Sciences / In 2022, the Environmental Protection Agency effectively banned the use of chlorpyrifos insecticide for food crops by revoking all food tolerances that had previously been set. In Virginia peanut, farmers were left with no alternatives to control subterranean insects that feed on the marketable portion of the crop, the pod. Virginia peanuts are grown in eight counties along the southern border of Virginia (Peanut Facts - Virginia-Carolina Peanut Promotions (aboutpeanuts.com)) and in 22 eastern North Carolina counties. My project focuses on the pod injuring of the southern corn rootworm (SCR), which were historically controlled by chlorpyrifos. Chlorpyrifos was applied at pegging as a granular product to protect peanut through the late-summer portion of the growing season. Larvae of SCR require moisture, usually in the form of moisture held in soil, to stay alive, and heavier soils and irrigated fields in our region are at higher risk for SCR. Injury is not seen until peanuts are dug for harvest. Host plant resistance would be a desirable non-chemical control alternative. In the following experiments, we evaluated cultivars and advanced breeding lines for SCR resistance, and adult populations were tracked to determine if infestation timing has changed since last documented in the growing season. Our goal is to provide peanut farmers with sustainable methods to manage a problematic below ground pest.

Studies of the life history and habits of Diabrotica longicornis (Say), a new pest of corn in Quebec, were undertaken in the field and in the laboratory. Seasonal activity and habits were established by monitoring life stages in the field during the years 1979, 1980 and 1981. The threshold temperature for development of NCR eggs was estimated at 9.7(DEGREES)C. The mean thermal constant for first hatching in the laboratory was 326 degree days above 9.7(DEGREES)C. Eclosion occurred in the field when average soil temperature conditions at the 5 - 10 cm depth reached 331 - 334 degree days. / Pupation occurred in the soil from late June to early July. Adults emerged from mid-July to August, and oviposition occurred during the same period. Oviposition preferences of NCR beetles were studied in relation to local soil types, soil moisture, and soil surface conditions, both in the laboratory and in the field under free choice conditions. In both cases, a clear preference was shown for moist, cracked, clay soil. / The behaviour of adults held under controlled environmental conditions (12L:12D diel light cycle, 23 (+OR-) 2(DEGREES)C temperature, 60 - 80 per cent RH) was investigated, and emergence, locomotor activity and sexual behaviour were recorded. The duration of larval stages reared in the laboratory on natural diets were compared with those for field-collected larvae. Natural enemies and mortality factors for the species were investigated in the field. A simple method for rearing NCR in the laboratory was developed.