Laboratory Selection for Beet Armyworm (Lepidoptera: Noctuidae) Resistance to Methoxyfenozide
Abstract
Beet armyworms, Spodoptera exigua (Hübner), were artificially selected in the laboratory for resistance to the insect growth regulator, methoxyfenozide. A field collected beet armyworm colony was separated into three cohorts that were independently selected with three concentrations (0.033 ppm, 0.064 ppm, and 0.125 ppm) of methoxyfenozide incorporated into a meridic diet. These concentrations corresponded closely with the LC10 (0.033 ppm), LC50 (0.072 ppm), and LC90 (0.161 ppm), respectively, for the original colony. After seven generations of continuous exposure to methoxyfenozide, resistance in the colony selected at the low concentration did not increase significantly. In contrast, LC50 values increased 9.7- and 9.4-fold for the colonies selected at the moderate and high concentrations, respectively, over that of the original colony. Crosses between resistant and susceptible individuals indicated that the resistance was heritable. At 4 d after exposure, mortality of offspring from the reciprocal crosses was intermediate between mortality for the offspring from the parental crosses. When rated at 10 d, mortality of offspring from the reciprocal crosses was not different significantly from offspring from the cross between susceptible parents. These data will be important for developing a management program for beet armyworm resistance to methoxyfenozide.View this article in BioOne
Downloads
Published
Issue
Section
License
Copyright for any article published in Florida Entomologist is held by the author(s) of the article. Florida Entomologist is an open access journal. Florida Entomologist follows terms of the Creative Commons, Attribution Non-Commercial License (cc by-nc). By submitting and publishing articles in Florida Entomologist, authors grant the FOJ and Florida Entomologist's host institutions permission to make the article available through Internet posting and electronic dissemination, and to otherwise archive the information contained both electronically and in a hard printed version. When used, information and images obtained from articles must be referenced and cited appropriately. Articles may be reproduced for personal, educational, or archival purposes, or any non-commercial use. Permission should be sought from the author(s) for multiple, non-commercial reproduction. Written permission from the author(s) is required for any commercial reproduction.
