J. Exp. Zool. India Vol. 16, No. 2, pp. 583-590, 2013 ISSN 0972-0030

EXPERIMENTAL ANALYSIS OF CHITIN SYNTHESIS INHIBITORS AGAINST THE LARVAE OF EUPROTIS ICILIA STOLL : LONGEVITY AND WEIGHT LOSS

Menka Gupta and Ashish Kumar Gupta Department of Zoology, P. P. N(P G) College, Kanpur, Subhash College, Kanpur- 208 001, India. [email protected] (Accepted 7 July 2013)

ABSTRACT – Euprotis icilia Stoll a polyphagous pest, feeds upon castor, , cotton, , mango, and pea etc. Their caterpillars defoliate plants completely. Castor ( communis L.), a valuable oil seed crop destroyed by these pests throughout the India. For comparative evaluation, two growth regulators were used against the 3rd & 5th instar larvae under larval feeding treatment and residual film treatment. Insect growth regulators belong to benzoyl phenyl urea group, commonly reported as a chitin biosynthesis inhibitor was discovered by Van Daalen et al (1972). These compounds showed insecticidal character, they affect the moulting process, as the chemical interfered with cuticle deposition. Mulder Gijswijt (1973) synthesized the two new promising insecticides of benzoyl phenyl urea group which brought about the formation of defective cuticle by interfering with biosynthesis of chitin. Ishaaya et al (2002) reported that novaluron as a powerful toxicant for controlling lepidopteron larvae. Present investigation is based on comparative assesment of two important chitin synthesis inhibitor novaluron & buprofezin on 3rd & 5th larval stages of fraterna to find out efficacy of insect growth regulators against selected pest. Yanhua Wang et al (2008) reported buprofezin susceptibility survey, resistance selection and preliminary determination of the resistance mechanism in Nilaparvata lugens(Homoptera; Delphacidae). The effect of novaluron on prolongation of the life span of Euproctis icilia is less but buprofezin exhibited greater increase in larval longevity than novaluron. Key words : Euproctics icilia, Novaluron, Buprofezin, larval feeding treatment, residual film treatment.

INTRODUCTION film treatment method. The insect growth regulators used Agrochemical research has resulted in the discovery in the present investigation are novaluron & buprofezin, of novel chemicals that act on selective biochemical sites chitin synthesis inhibitor. Khan and Srivastava (1989) present in specific insect groups. These chemicals are studied the biological effect of insect growth inhibitor, insect growth regulators (IGRs) such as benzoyl phenyl diamino- furyl-S, triazine, used as larval residual and adult urea which inhibit chitin formation in (Ishaaya, feeding treatment, on the larval development and mortality 1990; Dhadialla et al, 1998; 2005; Palli and Retnakarn, at Euproctis icilia Stoll. (; Lymantrjdae) were 2001). These novel compounds are very potent against investigated. They observed that the compound was highly important lepidopteron pests such as Spodoptera littoralis, toxic to the larval instars, effective growth inhibitor and Pericallia ricini, Bemisia tabasi. Helicoverpa armigera, successful sterilant in adult stage of Euproctis icilia. It Utetheisa pulchella, Lobesia botrana, Cryptoblabes produced maximum 88.88 per cent and minimum 33.33 gnidiella (Ishaaya et al, 1986; Baum et al, 1992; Saxena, per cent net mortality at 12.0 and 0.0012 mg/cm2 level of 2000). The bioefficacy of fourth generation insecticides is residual deposit, respectively. Besides, different types of generally noticed during moulting as it affects the process deformities were exhibited at lower concentration. High of chitin deposition due to which the insect does not concentration produced complete lethal action. The complete the developmental process and dies. It also results deformity includes mostly larva - pupa intermediate and in failure to feed, due to displacement of mandibles and in adult, wings were mostly affected. Maximum 16.6 per labrum. These insecticides also produce delayed cent deformity was recorded at 0.0012 mg/cm2 level. The symptoms, in which the adults fail to come out from compound significantly increased the larval and pupa puparium and therefore cannot fly, feed and mate. The survival period and reduced the adult life span. present study is based on comparative evaluation of two MATERIALS AND METHODS insect growths regulators on longevity & weight loss on The insect samples used in the present investigation the larvae of Euproctis iclia by larval feeding & residue are Euproctis iclia. It is a polyphagous pest and mainly