eprintid: 4961 rev_number: 12 eprint_status: archive userid: 30 dir: disk0/00/00/49/61 datestamp: 2011-12-15 05:00:58 lastmod: 2011-12-15 05:00:58 status_changed: 2011-12-15 05:00:58 type: article metadata_visibility: show contact_email: Library-ICRISAT@CGIAR.ORG creators_name: Kranthi, K R creators_name: Jadhav, D R creators_name: Wanjari, R R creators_name: Kranthi, S creators_name: Russell, D. icrisatcreators_name: Jadhav, D R affiliation: ICRISAT(Patancheru) affiliation: NRI(Kent) affiliation: CICR(Nagpur) country: India country: UK title: Pyrethroid Resistance and Mechanisms of Resistance in Field Strains of Helicoverpa armigera (Lepidoptera: Noctuidae) ispublished: pub subjects: s2.16 subjects: s2.4 subjects: s2.7 full_text_status: restricted keywords: Helicoverpa armigera, pyrethroid resistance, India, cytochrome p450, esterases, nerve insensitivity abstract: Pyrethroid resistance was found in 54 field strains of Helicoverpa armigera collected between 1995 and 1999 from 23 districts in seven states of India. LD50 values of the field strains ranged from 0.06 to 72.2 μg/larva with slopes of 0.5–3.1. Resistance was highest in regions where pyrethroid use was frequent (four to eight applications per season). Resistance to deltamethrin was exceptionally high with resistance ratios of 13,570 and 27,160 in two strains collected during February 1998 in central India. Resistance to cypermethrin, fenvalerate and cyhalothrin also was high with resistance ratios of >1,000 in four strains collected from central and southern India. Resistance ratios were below 100 in >50% of the strains tested. Pyrethroid resistance was high in strains collected from the districts in Andhra Pradesh where a majority of the cotton farmer suicide cases in India were reported. Resistance to pyrethroids appeared to have increased over 1995–1998 in most of the areas surveyed. Studies carried out through estimation of detoxification enzyme activity and synergists indicated that enhanced cytochrome p450 and esterase activities were probably important mechanisms for pyrethroid resistance in field strains. Pyrethroid nerve insensitivity also was found to be a major mechanism in some parts of the country where the use of pyrethroids was high. The information presented illustrates the importance of proper insect management programs to avoid the consequences associated with improper insecticide use. date: 2001 date_type: published publication: Journal of Economic Entomology volume: 94 number: 1 publisher: Entomological Society of America pagerange: 253-263 refereed: TRUE issn: 0022-0493 official_url: http://dx.doi.org/10.1603/0022-0493-94.1.253 related_url_url: http://scholar.google.co.in/scholar?hl=en&q=allintitle%3A+%22Pyrethroid+Resistance+and+Mechanisms+of+Resistance+in+Field+Strains+of+Helicoverpa+armigera+(Lepidoptera%3A+Noctuidae)%22&btnG=Search&as_sdt=0%2C5&as_ylo=&as_vis=0 related_url_type: author funders: Natural Resources Institute funders: Department for International Development projects: Adaptive Research Intitiative projects: NRI/ICRISAT/ICAR Project citation: Kranthi, K R and Jadhav, D R and Wanjari, R R and Kranthi, S and Russell, D. (2001) Pyrethroid Resistance and Mechanisms of Resistance in Field Strains of Helicoverpa armigera (Lepidoptera: Noctuidae). Journal of Economic Entomology, 94 (1). pp. 253-263. ISSN 0022-0493 document_url: http://oar.icrisat.org/4961/1/pyrethroid%20Resistance%20and%20Mechanisms%20.pdf