Nano Essential Oils against cotton leaf worm, Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae) Abdel-Raheem M. A.* *Pests & Plant Protection, Department, Agricultural and Biological Research Division, National Research Centre, 33 rd ElBohouth St. – Dokki, Giza -Egypt. Abstract : Background: Spodoptera littoralis is a highly destructive insect pest. Use of insecticides to control larvae has led to several problems and hazards such as development of resistance and residual effects. Purpose: Evaluate the impact of the essential oils (bulk and Nano phase) of Purslane; Mustard and Castor oil were tested for their impacts against larvae of Spodoptera littoralis. Methods: The tested essential oils were obtained by steam distillation of dried plants and Encapsulation of Nano particles is a method over which a chemical is slowly but efficiently released to the specific host for insect pests control. Results: The most impact oil was Purslane oil (bulk and Nano) then Mustard and the least one was Castor. The high concentration % mortality of larvae was 70.0, 40.2 & 15. 5 % and 90.4, 80.8 & 62.2 % in Purslane, Mustard and Castor (bulk and Nano phase), respectively. The number of laid eggs decreased with increasing tested oils concentrations. Conclusion: Purslane essential oil showed good effect against the S. littoralis larvae followed by Mustard and Castor as Bulk and as Nano. Keywords: Nano, Bulk, Purslane oil, Mustard oil, Castor oil, Spodoptera littoralis. Introduction S. litura is found in Asia, Australia and the Pacific Islands, [1-5]. Possibility of utilizing nanotechnology for the development of bio-pesticides is exploring by Scientists, [6, 7] . Nano particles have large surface areas, they can adsorb and bond other compounds easily, circulate more easily in insect/lepidopteran systems, [8-10]. Alpha-pinene is a bicyclic terpene found in many essential oils including those from pine, piper, rosemary, and lavender, and possesses various biological activities such as repellent and antifeedant activities against the tobacco cutworm, Spodoptera litura, [11- 14]. Citrus hystrix DC essential oil contains linalool and the oil was good antifeedant activity to S. litura, [15& 16], also, antifeedant activity against gypsy moth, Lymantria dispar L. larvae, [17 & 18] . The nano formulations able to protect the botanicals from degradation enhance their bioavailability, [8, 19] . Nano emulsions improved the stability of the water insoluble pesticide, b-cypermethrin , [12]. Garlic extract- Abdel-Raheem M. A./International Journal of ChemTech Research, 2019,12(5): 123-128. DOI= http://dx.doi.org/10.20902/IJCTR.2019.120514 International Journal of ChemTech Research CODEN (USA): IJCRGG, ISSN: 0974-4290, ISSN(Online):2455-9555 Vol.12 No.05, pp 123-128, 2019