Abstract
Insecticide resistance inHelicoverpa armigerais an enduring threat to the economic production of cotton in Australia. In the past, relatively small quantities of organophosphates, principally methyl parathion and profenofos, were used to controlH. armigeraon the late season cotton. While resistance to profenofos was detectable from time to time by bioassay, organophosphate resistance did not give control problems in the field. More recently, however, increasing resistance ofH. armigerato alternative control chemicals such as endosulfan, pyrethroids, and carbamates has resulted in an expanded use of the organophosphates (methyl parathion, profenofos, and chlorpyrifos) on cotton and other crops and, as a consequence, there is an emerging and serious field-resistance problem in Australia. This situation has been compounded by the discovery of cross-resistance between profenofos and methyl parathion inH. armigera.Selection of field-collectedH. armigeraby profenofos resulted in a high level of resistance to both profenofos (92-fold) and methyl parathion (52-fold).H. armigeraremain susceptible to chlorpyrifos. Out studies have identified an insensitive acetylcholinesterase (AChE) as the resistance mechanism causing resistance to methyl parathion and which presumably causes cross-resistance between the methyl parathion and profenofos in AustralianH. armigera.AChE from the profenofos-resistantH. armigerawas approximately 8 times less sensitive to inhibition by methyl paraoxon, compared to the AChE from susceptibleH. armigera.It is not yet clear how this is associated with insensitive AChE responsible for methomyl and thiodicarb resistance, recently reported in this species.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.