Resistance to pyrethroid insecticides in the tobacco budworm (Lepidoptera: Noctuidae) /
| Main Author: | |
|---|---|
| Other Authors: | , , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1988.
|
| Subjects: | |
| Online Access: | ProQuest, Abstract Link to OAKTrust copy |
| Abstract: | The objectives of the present study were to evaluate the resistance spectra of different pyrethroid-resistant tobacco-budworm strains, to determine alternate insecticides for controlling these insects, to evaluate synergism of insecticides by chlordimeform, and to identify the mechanisms of resistance and possible biological deficiencies associated with resistance to pyrethroid insecticides in the tobacco budworm. Insecticide bioassays with neonate tobacco-budworm larvae using the glass-vial technique revealed that the resistance spectra were approximately the same for all pyrethroid-resistant strains. However, resistance levels varied for each insecticide against each resistant strain. Chlordimeform synergized all insecticides tested, but synergism was variable for different insecticides and different strains. Extensive bioassays with a pyrethroid-resistant strain (ICI) showed that the main mechanism of resistance expressed in neonate larvae is target-site (kdr) resistance, since the resistance extended to all the pyrethroids tested. No cross resistance was observed in pyrethroid-resistant neonate larvae to the organophosphates monocrotophos, methyl parathion, profenofos, sulprofos, and acephate, the oxime carbamates methomyl and thiodicarb (only one resistant strain, Uvalde, was probably resistant to this insecticide), and the cyclodiene endosulfan. Bioassays with Stoneville (susceptible) and ICI (resistant) third instars showed resistance to methyl parathion, but no resistance to another phosphorothionate chlorpyrifos, the S-alkyl phosphorothiolates profenofos, sulprofos, and acephate, the carbamates methomyl and thiodicarb, and endosulfan. Chordimeform synergized most insecticides against both tobacco budworm strains. The high level of resistance to cypermethrin at this stage, the resistance to methyl parathion, and the high level of cypermethrin synergism by piperonyl butoxide are evidence for the presence of metabolic resistance in the ICI strain in addition to target site resistance. Based on the synergism data, increased mixed-function oxidase activity seems to be the main factor responsible for resistance in third instars... |
|---|---|
| Item Description: | Typescript (photocopy). Vita. "Major subject: Entomology." |
| Physical Description: | xii, 136 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references (leaves 110-128). |