南美番茄蛾,Phthorimaeaabsoruta(Meyrick),是印度番茄的主要害虫之一。自2014年报告以来,化学防治一直是应对这种害虫的主要手段,在露天和保护性种植。尽管定期喷洒杀虫剂,据报道,2019-2020年期间,南印度主要番茄种植区爆发了许多疫情。进行了一项研究,以调查杀虫剂抗性对生物学的影响,生化酶,和各种绝对假单胞菌田间种群中的基因表达。,班加罗尔,Kolar,马杜赖,塞勒姆,和Anantapur对常用的杀虫剂如氟本二酰胺,cyantraniliprole,还有Indoxacarb.在不同位置的P.absoruta种群中记录到增加的杀虫剂抗性比率(RR)水平。与易感人群相比,耐药人群中细胞色素P450单加氧酶(CYP/MFO)和酯酶水平显着增加。通过分子研究,我们确定了四个新的CYP基因。,CYP248f(氟苯二酰胺),CYP272c,CYP724c(cyantraniliprole),和CYP648i(吲哚沙卡威)。这些基因的表达水平随着从G1到G20(代)的抗性增加而显着增加,表明已鉴定的基因参与了绝对疟原虫的杀虫剂抗性发展。此外,抗性种群的繁殖力下降,增加幼虫发育期,和成人长寿,造成更多的作物损害。因此,本研究中产生的信息有助于了解绝对疟原虫对杀虫剂抗性的发展,并建议农民和研究人员通过采用杀虫剂抗性管理作为综合虫害管理下的策略来明智地使用杀虫剂。
The South American tomato moth, Phthorimaea absoluta (Meyrick), is one of the key pests of tomato in India. Since its report in 2014, chemical control has been the main means of tackling this pest, both in the open field and protected cultivation. Despite regular insecticidal sprays, many outbreaks were reported from major tomato-growing regions of South India during 2019-2020. A study was conducted to investigate the effect of insecticide resistance on biology, biochemical enzymes, and gene expression in various P. absoluta field populations viz., Bangalore, Kolar, Madurai, Salem, and Anantapur to commonly used insecticides such as flubendiamide, cyantraniliprole, and indoxacarb. Increased levels of insecticide resistance ratios (RR) were recorded in P. absoluta populations of different locations. A significant increase in cytochrome P450 monooxygenase (CYP/MFO) and esterase levels was noticed in the resistant population compared to susceptible one. Through molecular studies, we identified four new CYP genes viz., CYP248f (flubendiamide), CYP272c, CYP724c (cyantraniliprole), and CYP648i (indoxacarb). The expression levels of these genes significantly increased as the folds of resistance increased from G1 to G20 (generation), indicating involvement of the identified genes in insecticide resistance development in P. absoluta. In addition, the resistant populations showed decreased fecundity, increased larval development period, and adult longevity, resulting in more crop damage. The information generated in the present study thus helps in understanding the development of insecticide resistance by P. absoluta and suggests the farmers and researchers to use insecticides wisely by adopting insecticide resistance management as a strategy under integrated pest management.