Theses and Dissertations at Montana State University (MSU)
Permanent URI for this collectionhttps://scholarworks.montana.edu/handle/1/733
Browse
2 results
Search Results
Item Evaluating host plant preference and pheromone attract and kill as strategies to manage pea leaf weevil Sitona lineatus (L.) (Coleoptera: Curculionidae) in Montana(Montana State University - Bozeman, College of Agriculture, 2022) Kiju, Pragya; Chairperson, Graduate Committee: Michael A. Ivie and Kevin Wanner (co-chair); This is a manuscript style paper that includes co-authored chapters.Pea leaf weevil (Sitona lineatus) is the most common insect pest of field peas grown in Montana. Montana is the number one producer of field pea in the US. Currently, Montana producers spray insecticides at least once or twice during the spring growing season to avoid leaf damage inflicted by pea leaf weevil adults and larvae. Complete reliance on insecticides may, however, raise the risk of pea leaf weevil populations developing genetic resistance. Therefore, this project focuses on development of alternative pulse insect pest management strategies such as pheromone-based attract and kill and host plant preference. For the attract and kill strategy 6 different treatments compared combinations of aggregate pheromone (4-methyal-3,5- heptanedione) alone in two different forms; septa and pellet, pheromone with granular insecticide (Deltamethrin). To determine the effect of host variety on adult feeding preference, 10 field pea, 2 faba bean, 2 lentil and 2 chickpea varieties were assessed for feeding damage. Crescent shaped notches were counted on 10 individual plants per replicate plot. The average number of larvae within the nitrogen fixing root nodules of each variety was also recorded on 5 randomly selected individual plants per plot. Faba bean was the most preferred host while lentil and chickpea suffered almost no feeding damage. 'Delta' and 'Lifter' field pea varieties appeared to be preferred over 'DS Admiral' and 'AC Agassiz' varieties. Given the significant level of feeding on all pea and faba bean cultivars further evaluation of low-cost pheromone traps are essential to establishing an IPM control approach.Item Overcoming the challenges of tamarix management with Diorhabda carinulata through the identification and application of semiochemicals(Montana State University - Bozeman, College of Agriculture, 2018) Gaffke, Alexander Michael; Chairperson, Graduate Committee: David K. Weaver; Sharlene E. Sing, Tom L. Dudley, Daniel W. Bean, Justin A. Russak, Agenor Mafra-Neto, Paul A. Grieco, Robert K. D. Peterson and David K. Weaver were co-authors of the article, 'Semiochemicals to enhance herbivory by Diorhabda carinulata aggregations in saltcedar (Tamarix spp.) infestations' in the journal 'Pest management science' which is contained within this thesis.; Sharlene E. Sing, Tom L. Dudley, Daniel W. Bean, Justin A. Russak, Agenor Mafra-Neto, Robert K. D. Peterson and David K. Weaver were co-authors of the article, 'Field demonstration of a semiochemical treatment that enhances Diorhabda carinulata biological control of Tamarix spp.' submitted to the journal 'BioControl' which is contained within this thesis.; Sharlene E. Sing, Tom L. Dudley, Daniel W. Bean, Justin A. Russak, Agenor Mafra-Neto, Robert K. D. Peterson and David K. Weaver were co-authors of the article, 'Allee effects and aggregation pheromones: new releases of Diorhabda carinulata remain longer in the presence of pheromone formulations' submitted to the journal 'Biological Invasion' which is contained within this thesis.; Sharlene E. Sing, Jocelyn Millar, Tom L. Dudley, Daniel W. Bean, Robert K. D. Peterson and David K. Weaver were co-authors of the article, 'Behavioral responses of Diorhabda carinulata adults to repellent compounds isolated and identified in volatiles collected from conspecific larvae' submitted to the journal 'Journal of chemical ecology' which is contained within this thesis.The northern tamarisk beetle, Diorhabda carinulata (Desbrochers), is an approved and established classical biological control agent for saltcedars (Tamarix spp.). Adequate control of Tamarix has not yet been achieved in certain areas where D. carinulata has been released. Retaining beetle populations on sites where it has been released is problematic, and accurately monitoring D. carinulata populations to determine successful establishment is difficult. Negative, indirect impacts have also resulted from the agent's establishment outside targeted treatment areas in the southwestern United States. Manipulation of D. carinulata spatial distribution with semiochemicals could potentially resolve or ameliorate these and other operational issues. Lures utilizing a specialized wax based matrix for the controlled release of semiochemicals were impregnated with a previously identified pheromone and/or behaviorally active host plant volatiles known to stimulate aggregation in D. carinulata. Emission of these compounds from the matrix was characterized using a push-pull volatile collection system, and quantified using gas chromatography-mass spectrometry. Observed release rates confirm that semiochemicals lures formulated with this matrix are a viable option for facilitating aggregation of D. carinulata under field conditions. The results of field-based assays indicate saltcedars treated with this semiochemical delivery system attracted and retained higher densities of D. carinulata than Tamarix that received a control (semiochemical free) lure. Higher densities of both adult and larval D. carinulata were recorded on treated plants. Semiochemically treated Tamarix plants also exhibited more damage, resulting in a greater decrease in canopy volume than control trees. The attraction and retention of D. carinulata to these species-specific semiochemicals on treated Tamarix plants also arrested the dispersal of newly released individuals, resulting in greater population growth. Repellent semiochemicals were also investigated for their potential to manipulate spatial distributions of D. carinulata in the field and behavioral assays conducted with reproductive adults demonstrated the ability of larval produced compounds to repel conspecific adults. These results indicate that semiochemical-impregnated media could be useful for detecting, retaining, and directing populations of D. carinulata. The use of semiochemicals could be used to potentiate low density populations, increase monitoring efficacy, retain adults on release sites, and repel D. carinulata from sensitive habitat.