LE3 .A278 2022

2022

Easy, Russell

Acadia University

Bachelor of Science

Honours

Biology

Biology

The oblique banded leafroller (Choristoneura rosaceana) is a species of tortricid moth whose larval stage is an agricultural pest to orchards of fruit trees within the Rosaceae family. Due to its identification as an agricultural pest, OBLR was chosen as the model organism to study the effects of heatwave exposure on larval survival, weight gain and pesticide efficiency. OBLR larvae received either control or pesticide treatments at differing time points and were reared in normal and simulated heatwave conditions. These larvae were sampled at different time points, where mass and mortality were measured. Molecular studies were performed to optimize primers for genes of interest involved in insect detoxification and immune pathways for use in future gene analysis studies. Primers for GST, GBP and GAPDH were chosen based on previous success in studies on Choristoneura species and run in qPCR assays to assess their specificity and compatibility with the OBLR genome. qPCR standard curves were also created for these primers. Larvae exposed to the heatwave gained more mass than those that remained in the control conditions. In addition, mortality rates decreased and mass increased as the pesticide was applied at later time points relative to heatwave exposure, indicating a potential relationship between heatwave exposure, the timing of pesticide application and pesticide efficiency. Overall, many gaps in knowledge still exist regarding how environmental changes relating to temperature and the length and frequency of heatwaves will impact pesticide efficiency, especially in OBLR. Due to the potential impacts on current pest mitigation strategies and thus on agricultural success, further research in this field is of importance as climatic conditions continue to change as predicted.

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https://scholar.acadiau.ca/islandora/object/theses:3773