title: Multiple Resistances Against Formulated Organophosphates, Pyrethroids, and Newer-Chemistry Insecticides in Populations of Helicoverpa armigera (Lepidoptera: Noctuidae) from Pakistan.
abstract: Field populations of Helicoverpa armigera Hübner from 15 localities across the Punjab, Pakistan, were assessed by the leaf dip method for resistance against formulated organophosphates, pyrethroids, and newer insecticide groups. Resistance levels in H. armigera have been incrementally increasing for organophosphate and pyrethroid insecticides after decades of use in Pakistan. Resistance ratios (RRs) documented for organophosphates were 24- to 116-fold for profenofos and 22- to 87-fold for chlorpyrifos. For pyrethroids, RRs were 3- to 69-fold for cypermethrin and 3- to 27-fold for deltamethrin. Resistance levels against newer chemistries were 2- to 24-fold for chlorfenapyr, 1- to 22-fold for spinosad, 1- to 20-fold for indoxacarb, 1- to 18-fold for abamectin, and 1- to 16-fold for emamectin benzoate. Resistant populations of H. armigera were mainly in the southern part of the Punjab, Pakistan. The most resistant populations were collected from Pakpattan, Multan, and Muzzafargarh. Of the nine insecticides tested, LC50 and LC90 values were lower for newer insecticide groups; resistance levels were moderate to very high against organophosphates, very low to high against pyrethroids, and very low to low against the newer-chemistry insecticides. These findings suggest that the newer-chemistry insecticides with different modes of action could be included in insecticide rotations or replace the older insecticides. Supplementing the use of synthetic insecticides with safer alternatives could help to successfully lower the farmer's reliance on insecticides and the incidence of resistance due to repeated use of insecticides against major insect pests.
authors.affiliation: Department of Entomology, University of Agriculture, Faisalabad, Pakistan.
authors.forename: Mirza Abdul
authors.initials: MA
authors.lastname: Qayyum
authors.affiliation: Department of Entomology, University of Agriculture, Faisalabad, Pakistan.
authors.forename: Waqas
authors.initials: W
authors.lastname: Wakil
authors.affiliation: Department of Entomology, University of Agriculture, Faisalabad, Pakistan.
authors.forename: Muhammad Jalal
authors.initials: MJ
authors.lastname: Arif
authors.affiliation: Department of Plant Pathology, University of Agriculture, Faisalabad, Pakistan.
authors.forename: Shahbaz Talib
authors.initials: ST
authors.lastname: Sahi
authors.affiliation: Plant Protection Division, Nuclear Institute of Agriculture and Biology, Faisalabad, Pakistan.
authors.forename: Noor Abid
authors.initials: NA
authors.lastname: Saeed
authors.affiliation: Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria 3010, Australia.
authors.forename: Derek Allan
authors.initials: DA
authors.lastname: Russell
mesh_terms: D000818:Animals; D007305:Insecticide Resistance; D007306:Insecticides; D009036:Moths; D010755:Organophosphates; D010154:Pakistan; D011722:Pyrethrins
chemical_list: D007306:Insecticides; D010755:Organophosphates; D011722:Pyrethrins
keywords: Helicoverpa armigera; insecticide resistance; newer-chemistry insecticide; organophosphate; pyrethroid