Agriculture Commons^™

Rapid Evolution In Agroecosystems: Transposable Elements And Epigenetics In The Colorado Potato Beetle, Kristian Brevik

Graduate College Dissertations and Theses

Within agricultural ecosystems, humans and insects enter into complex relationships. Humans consider many of these insects to be pests, and exert significant pressures upon them, such as efforts to kill them using insecticides. One of the ways insects respond to these efforts is by rapidly evolving resistance to insecticides - but how they do this is not fully understood. DNA methylation, an epigenetic mechanism, and transposable elements, which are mobile genetic elements within genomes, may each play a role in shaping the way insects rapidly evolve in response to exposure to insecticides. Understanding the role of transposable elements and DNA …

Repelling Contarinia Nasturtii (Diptera: Cecidomyiidae), A Brassica Specialist, Using Non-Host Essential Oils, Chase Stratton

Graduate College Dissertations and Theses

Swede midge, Contarinia nasturtii Kieffer (Diptera: Cecidomyiidae), is an invasive pest causing marketable losses on Brassica crops in the Northeastern United States and throughout southern Canada. Heading brassicas, like cauliflower and broccoli, are particularly susceptible because larvae feed concealed inside meristematic tissues of the plant, where head formation occurs. Our work details the development of a sustainable, affordable pest management tactic for swede midge – plant derived repellents.

First, it was necessary to establish both a damage and marketability threshold for swede midge, so we developed a technique to manipulate larval density of swede midge on cauliflower, We asked: (1) …

Evaluation Of Candidate Pheromone Blends For Mating Disruption Of The Invasive Swede Midge (Contarinia Nasturtii), Elisabeth Ann Hodgdon

Graduate College Dissertations and Theses

Swede midge (Contarinia nasturtii, Diptera: Cecidomyiidae) is a small invasive fly that is currently threatening Brassica vegetable and oilseed production in the Northeastern U.S. and Canada. Larvae feed on plant meristems, resulting in deformed leaves, stems, and heads. Extremely low damage thresholds for heading Brassica vegetables, multiple overlapping generations, and lack of effective organic insecticide options present serious challenges for managing this pest. Pheromone mating disruption (PMD), which involves confusing male insects with unnaturally large doses of sex pheromones, is particularly promising for swede midge management because it prevents mating and subsequent oviposition. One major challenge to PMD for swede …

Enhancing The Efficacy And Thermotolerance Of Selected Beauveria Bassiana Isolates For Management Of Sunn Pest, Eurygaster Integriceps, Using Electrofusion Techniques, Agrin Davari

Graduate College Dissertations and Theses

Sunn Pest, Eurygaster integriceps Puton (Heteroptera: Scutelleridae), is a major pest of wheat and barley in West and Central Asia and East Europe. The insect causes a significant reduction in yield and quality of grains. Entomopathogenic fungi, especially Beauveria bassiana are among the most dominant microbial agents that have been used against Sunn Pest. However, there are concerns related to their efficacy and thermotolerance particularly in countries with high temperature regimes.

Nine B. bassiana isolates were tested against Sunn Pest to estimate their virulence and speed of infection under laboratory conditions. The isolates were also exposed to 25, 36, 38 …

Swede Midge, Contarinia Nasturtii (Diptera: Cecidomyiidae), Response To Brassica Oleracea In Simulated Intercropping Systems, Gemelle Laureen Brion

Graduate College Dissertations and Theses

Monoculture agriculture has developed as a result of the Western agricultural growth model, which emphasizes reduced on-farm labor and maximum yield. As a result soil health, which is reliant on a diversity of soil-dwelling organisms, is compromised, pest problems are intensified, and biodiversity is lost when vast land areas are devoted to simplified vegetation schemes. There has been a tremendous rise in interest in alternative cropping schemes. The traditional practice of intercropping has received renewed interest as the emphasis on agricultural growth shifts from a purely development-based model to one of conservation and enhanced biodiversity.

Although intercropping has shown promising …