Insect Growth Regulatory Action of Certain Leaf Fractions of Cleistanthus Collinus (Roxb.) Benth (Family: Euphorbiaceae) Against Spodoptera Litura Fab. (Noctuidae: Lepidoptera)

Hexapoda 15(2): 125 - 127, 2008 ISSN 0973-8592

INSECT GROWTH REGULATORY ACTION OF CERTAIN LEAF FRACTIONS OF Cleistanthus collinus (Roxb.) Benth (Family: Euphorbiaceae) AGAINST Spodoptera litura fab.

(Noctuidae: Lepidoptera)

T. Selvamuthukumaran* and S. Arivudainambi

Department of Entomology, Faculty of Agriculture, Annamalai University, Annamalainagar – 608 002

* Corresponding author: entoselva@gmail.com

ABSTRACT: Eleven fractions of leaf extract of Cleistanthus collinus (Roxb.) Benth (Family: Euphorbiaceae) extracted using acetone and fractionated through TLC technique, when bio assayed at 1 per cent concentration against 3rd instar larvae of Spodoptera litura Fab. in the preliminary screening, fractions VII, VIII and IX were found to possess various degrees of anti insect properties. Further, the selected fractions viz., VII, VIII and IX were assayed at lower concentrations such as 0.1, 0.3 and 0.5 ppm against 3rd, 4th and 5th instar larvae of Spodoptera litura Fab., and fraction VII was found possessing significant insect growth regulatory action. It exerted 86.67, 73.33 and 60.00 per cent malformation against third, fourth and fifth instar larvae respectively at 0.5 ppm.

KEY WORDS: Cleistanthus collinus, Insect growth regulatory action, Spodoptera litura.

INTRODUCTION

Many botanicals interfere directly with growth and development of insects. Azadirachtin treatment resulted in various forms of malformations as like larval pupal intermediates, wing deformities and wingless adults when applied topically to S.litura larvae and pupae (Koul, 1985). Formation of pupal – adult intermediates was reported in topical application of Aristolochia elegans (Lit and Rejesus, 1990), Acorus calamus (Behera and Satapathy, 1997) and Vitex negundo (Sukumaran et al., 1987) on early fifth instar S. litura larva.

However, the large scale utilization of botanicals has limitation because of huge biomass requirement. This...