159 Journal of Biological Control, 31(3):159-167, 2017, DOI: 10.18311/jbc/2017/16333 Research Article T. VENKATESAN 1* , S. HELEN MAHIBA 2 , S. K. JALALI 1 , S. L. RAMYA 1 and M. PRATIBHA 1 1 ICAR-National Bureau of Agricultural Insect Resources, P.B. No. 2491, H.A. Farm Post, Hebbal, Banaglore - 560024, Karnataka, India 2 Regional Seri cultural Research Station Central Silk Board, Veeranam Road, Allikuttai Post, Vaikkalapattarai, Salem - 636003, Tamil Nadu, India * Corresponding author E-mail: tvenkat12@gmail.com Detection of insecticide resistance and mechanisms of resistance in field populations of Chrysoperla zastrowi sillemi (Neuroptera: Chrysopidae) collected from different geographical locations in India (Article chronicle: Received: 22-06-2017; Revised: 21-09-2017; Accepted: 30-09-2017) ABSTRACT: The toxic effect of commonly used insecticides in cotton fields was studied on 9 populations of Chrysoperla zastrowi sil- lemi (Esben-Petersen), an important predator of sucking pests collected in India. The dose mortality bioassay against 3-days old larvae was determined using three insecticides viz., endosulfan, fenvalerate and acephate by topical bioassay method. Mechanism of resistance to the above mentioned insecticides were determined without and with three metabolic inhibitors (synergists), viz., piperonyl butoxide (PBO), S,S,S-tributyl-phosphorotrithioate (DEF) and diethyl maleate (DEM). Among the populations, resistant ratios (RR) of CZS-8 was significantly higher i.e. 50.36., 66.11 and 277.51-fold for endosulfan, fenvalerate and acephate, respectively compared to susceptible popu- lation (CZS-10). The CZS-8 was selected for synergism study it showed higher LC 50 values and resistance ratio for all three insecticides. It showed 8.97-fold, 18.49-fold and 6.38-fold increase in synergism ratio for endosulfan indicating the resistance was strongly synergised by PBO, DEF and DEM. Similarly for fenvalerate, CZS-8 showed 8.69-fold and 3.63-fold significant increase in synergism ratio by DEF and DEM, respectively and for acephate, CZS-8 showed 54.82-fold, 150.87-fold and 113.52-fold significant increase in synergism ratio indicating that the resistance could be due to cytochrome p-450, esterase and glutathione s- transferase activity. The study indicated that the field population of C. z. sillemi developed resistance to different groups of insecticides. Among different geographical populations, CZS-8 collected from Sriganganagar, was recorded as most resistant. KEY WORDS: Chrysoperla zastrowi sillemi, cytochrome p450, esterase, glutathione –S- transferase insecticide resistance, INTRODUCTION The Common green lacewing, Chrysoperla zastrowi sillemi (Esben-Petersen) (Neuroptera: Chrysopidae), is an important biological control agent of sucking pests in dif- ferent agroecosystems (Symondron et al., 2002; Venkatesan et al., 2008; Henry et al., 2010). It has long been considered as a promising candidate for pest management programs worldwide due to its wide prey range and geographical dis- tribution, voracious larval feeding capacity and commer- cial availability (Medina et al., 2003; Pathan et al., 2010; Sayyed et al., 2010). Parasitoids and predators are highly susceptible to insecticides than their host insects [Croft and Brown, 1975), which make them difficult to establish in in- secticide sprayed field. Parasitoids and predators are known to develop resistance to insecticides in nature like their prey insects either by direct exposure or by consumption of prey insects treated with insecticides (Wu et al., 2004; Wu and Miyata, 2005). However, resistance development is due to a combination of biological and ecological factors operating in the field (Venkatesan et al., 2009; Pathan et al., 2010). Compatibility of insecticide with biocontrol agents is im- portant as their application against the insect pests directly and indirectly determines the effectiveness of bioagents. In nature, populations of predators and insect pests always mutually co-exist often in a density-dependant association. Any adaptation of the insect pests with insecticide sprays is likely to be followed by the predator also to sustain them- selves in a given habitat. In India, several chemical insecticides are used in- discriminately to control insect pests especially on cotton against sucking pests, which has led to resistance in many insect pests (Reddy and Rao, 1989; Kranthi et al., 2001). In a study conducted from 2007 to 2009, monocrotophos