Graduate Thesis Or Dissertation
 

Factors influencing pesticide resistance in Psylla pyricola Foerster and susceptibilty in its mirid predator, Deraeocoris brevis Knight

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/cc08hh93x

Descriptions

Attribute NameValues
Creator
Abstract
  • Factors influencing pesticide susceptibility and resistance were studied in Psylla pyricola Foerster, and its mirid predator, Deraeocoris brevis Knight in the Rogue River Valley, Oregon. Factors studied were at the biochemical, life history, and population ecology levels. Studies on detoxification enzymes showed that glutathione S-transferase and cytochrome P-450 monooxygenase activities were ca. 1.6-fold higher in susceptible R. brevis than in susceptible pear psylla, however, esterase activity was ca. 5-fold lower. Esterase activity was ca. 18-fold higher in resistant pear psylla than in susceptible D. brevis, however, glutathione S-transferase and cytochrome P-450 monooxygenase activities were similar. Esterases seem to be a major factor conferring insecticide resistance in P. Pvricola. Although the detoxification capacities of P. pyricola and D. brevis were quite similar, pear psylla has developed resistance to many insecticides in the Rogue River Valley, whereas D. brevis has remained susceptible. Biochemical factors may be important in determining the potential of resistance development, however, they are less important in determining the rate at which resistance develops. Computer simulation studies showed that life history and ecological factors are probably of greater importance in determining the rate at which resistance develops in P. pvricola and D. brevis. High fecundity and low immigration of susceptible individuals into selected populations appear to be major factors contributing to rapid resistance development in pear psylla compared with D. brevis. Implications of this study for pesticide resistance management of pear psylla are discussed.
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome) using Capture Perfect 3.0 on a Canon DR-9050C in PDF format. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR.
Replaces

Relationships

Parents:

This work has no parents.

In Collection:

Items