Journal of Applied and Natural Science 10 (4): 1271-1275 (2018) ISSN : 0974-9411 (Print), 2231-5209 (Online) journals.ansfoundation.org Bio-rational insecticides toxicity against Liriomyza trifolii (Burgess) damaging Cantaloupes, Cucumis melo var. cantalupensis D. Srinivasa Reddy* Horticulture Research Station, DRYSRHU, Ananthrajupeta – 516105 (Andhra Pradesh), India C. Madhumati Horticulture Research Station, DRYSRHU, Ananthrajupeta – 516105 (Andhra Pradesh), India R. Nagaraj Horticulture Research Station, DRYSRHU, Ananthrajupeta – 516105 (Andhra Pradesh), India *Corresponding author. E-mail: dsr2020@gmail.com Abstract Field experiments were conducted for two seasons (2015-16 and 2016-17) to evaluate bio-rational insecticides against leaf miner (Liriomyza trifolii) damaging cantaloupes and it was found that among various insecticides viz. spinosad 45SC@0.32ml/l, abamectin 1.9EC @0.3ml/l, fipronil 5SC@2ml/l, fipronil 80WG@0.15g/l, cyantraniliprole 10OD@ 1.8ml/l, triazophos 40EC@2ml/l, diafenthiuron 50WP@1g/l, novaluron 10EC@1ml/l, neem soap@7.5g/l, pongamia soap@7.5g/l, azadirachtin 1%EC @5ml/l, abamectin (1.03 -2.33 mined leaves/10ft row) and spinosad (1.18-3.33 mined leaves/10ft row) in both the seasons prove to be highly effective in minimising the damage. All the treatments had significant effect on the yield as compared to control but among treatments they were non -significant in first season which was not the case in second season where highest yield was noted in spinosad (11.43t/acre) followed by azadirachtin(9.79t/acre) and abamectin (9.67t/acre). Though there was variation in yield within these treatments but they were statistically on par with each other. Similarly the treatments were on par with each other with respect to number of fruits per vine, fruit weight, TSS and number of seeds set per fruit. The overall findings indicate that the molecules viz., abamectin and spinosad can be recommended to control leaf miner in cantaloupes to achieve an appreciable yield. Keywords: Abamectin, Cantaloupes, Liriomyza trifolii, Spinosad Article Info DOI:10.31018/jans.v10i4.1898 Received: September 18, 2018 Revised: November 21, 2018 Accepted: November 27, 2018 How to Cite Reddy, D.S. et al. (2018). Bio-Rational insecticides toxicity against Liriomyza trifolii (Burgess) damaging Cantaloupes, Cucumis melo var. cantalupensis. Journal of Applied and Natural Science, 10(4): 1271-1275 INTRODUCTION Cucurbits are one of the most widely grown vege- table crops during kharif and summer season in all parts of the country and due to development and introduction of new hybrids of melons and cantaloupes, the cultivation of these crops in An- dhra Pradesh is expanding and farmers are reap- ing benefits in short duration. The introduction of new mechanization practices in horticulture viz., drip irrigation, mulching and fertigation were being adopted on larger scale by the growers due to encouragement and financial support by the pub- lic sector departments by providing subsidies, so that even small and marginal farmers are also able to earn the profit by cultivating these very short duration (55-60 days) and high profitable crops. At the same time, the pest scenario has been changing and the insect pests which were restricted to certain group of cucurbits also started damaging the melons and cantaloupes and among them, a regular and severe damage insect pest attacking these crops is serpentine leafminer. Serpentine leafminer, Liriomyza trifolii (Burgess) is a polyphagous insect and attacks a wide range of vegetables and ornamentals all over the world (Parrella, 1987, Seal et al. 2002). Both larvae and adults damage the host plants. The larvae feed on leaf mesophyll and reduce chlorophyll content. The adults also damage the leaves by puncturing them for feeding and oviposition (Parrella et al., 1985). Biological control of the leaf miners has had limited success so far and at present, chemi- cal control is the main tactic in managing these pests (Fathipour et al., 2006). Liriomyza has a potential to develop a resistance to insecticides and this potential affects effective control of leafminers (Parrella, 1987). The strong capability of L. trifolii to develop resistance to insecticides also made a displacement of other species on several crops possible (Schuster and Everett, This work is licensed under Attribution-Non Commercial 4.0 International (CC BY-NC 4.0). © 2018: Author (s). Publishing rights @ ANSF.