International Journal of Agricultural Science Research Vol. 2(6), pp. 206-213, June 2013 Available online at http://academeresearchjournals.org/journal/ijasr ISSN 2327-3321 ©2013 Academe Research Journals Full Length Research Paper Effect of plant chemicals on oviposition deterrent and ovicidal activities against female moth, Spodoptera litura (Fab.) (Lepidoptera: Noctuidae) A. Jeyasankar 1 *, K. Elumalai 2 , N. Raja 3 and S. Ignacimuthu 4 1 Department of Zoology, Arignar Anna Government Arts College, Musuri - 621 211, Tamilnadu, India. 2 Unit of Entomotoxicity, Department of Advanced Zoology and Biotechnology, Govt. Arts College Nandanam, Chennai - 600 035, Tamil Nadu, India. 3 Department of Biology, Faculty of Natural and Computational Sciences, Post Box 196, University of Gondar, Ethiopia. 4 Entomology Research Insitutue, Loyola College, Chennai-600 034, Tamilnadu, India. Accepted 21 May, 2013 Oviposition deterrent and ovicidal activity of crude extracts, fractions and compounds A and B from the leaves of Syzigium lineare Wall., were tested against armyworm Spodoptera litura Fab. The concentration tested for crude extract was 0.625, 1.25, 2.50 and 5.0%; fractions of 0.025, 0.05, 0.075 and 0.1%; and compounds A and B of 25, 50, 75 and 100 ppm, respectively. Among the crude extracts tested, the maximum oviposition deterrent and ovicidal activity were observed in ethyl acetate extract at 5% concentration. In fractionation, maximum oviposition deterrent was found in fraction 6 and ovicidal activity was the highest in fraction 3. Both activities were statistically significant by LSD “(p<0.05) compared” to positive and negative control. Compounds A and B were tested for oviposition deterrent and ovicidal activities of S. litura. Highest oviposition deterrent was noticed in compound A and significant ovicidal activity was found in compound B compared to the control. Based on IR, 1 H and 13 C NMR data, compound A was 7-hydroxy-undec-1en-3-one and compound B was 3-(3-hydroxy-hexyl)- tetrahydro-pyran-4-one. The oviposition deterrent and ovicidal activity of S. lineare reported against S. litura was the first of its kind and it can be useful for the development of novel botanical pesticides in future after field confirmation. Key words: Oviposition deterrent, ovicidal, Syzigium lineare, Spodoptera litura, plant extracts. INTRODUCTION Spodoptera litura Fab. (Lepidoptera: Noctuidae) is commonly called army worm which is an economically important pest of cosmopolitan distribution, and it causes extensive damage to more than 180 crops (Isman et al., 2007). The damage caused by the pests is mainly by defoliation and the estimated damage potential in tobacco nurseries is to an extent of 80 to 100% and 72 to 98% in soybean (Chari and Ramaprasad, 1987; Singh, 2000). Due to growing awareness about the negative impact of chemical pesticides, it becomes imperative to develop alternative strategies. One of the safer alternative methods is using locally available plant resource in a sustainable way. The plant extracts with oviposition deterrent and ovicidal activity are really a valuable weapon to protect the crops before the plants were damaged by the pests. Statistically significant feeding deterrent activity was observed in ethyl acetate extract of Hydrophila auriculata at 5% concentration against S. litura (Basker et al., 2011). In a cage study, crude oil emulsion of neem seed extract reduced egg laying properties of S. litura on treated cabbage plant (Naumann and Isman, 1995). Raja et al. (2004) reported oviposition deterrent activities of hexane extract of Aegle *Corresponding author. E-mail: sankar.alagarmalai@gmail.com. Tel: +91 9894214939.