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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.
(Accepted 7 July 2013)
ABSTRACT – Euprotis icilia Stoll a polyphagous pest, feeds upon castor, pomegranate, cotton, rose, mango, pigeon
pea and pea etc. Their caterpillars defoliate plants completely. Castor (Ricinus communis L.), a valuable oil seed
crop destroyed by these pests throughout the India. For comparative evaluation, two insect 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 Euproctis 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.
J. Exp. Zool. India Vol. 16, No. 2, pp. 583-590, 2013 ISSN 0972-0030
INTRODUCTION
Agrochemical research has resulted in the discovery
of novel chemicals that act on selective biochemical sites
present in specific insect groups. These chemicals are
insect growth regulators (IGRs) such as benzoyl phenyl
urea which inhibit chitin formation in insects (Ishaaya,
1990; Dhadialla et al, 1998; 2005; Palli and Retnakarn,
2001). These novel compounds are very potent against
important lepidopteron pests such as Spodoptera littoralis,
Pericallia ricini, Bemisia tabasi. Helicoverpa armigera,
Utetheisa pulchella, Lobesia botrana, Cryptoblabes
gnidiella (Ishaaya et al, 1986; Baum et al, 1992; Saxena,
2000). The bioefficacy of fourth generation insecticides is
generally noticed during moulting as it affects the process
of chitin deposition due to which the insect does not
complete the developmental process and dies. It also results
in failure to feed, due to displacement of mandibles and
labrum. These insecticides also produce delayed
symptoms, in which the adults fail to come out from
puparium and therefore cannot fly, feed and mate. The
present study is based on comparative evaluation of two
insect growths regulators on longevity & weight loss on
the larvae of Euproctis iclia by larval feeding & residue
film treatment method. The insect growth regulators used
in the present investigation are novaluron & buprofezin,
chitin synthesis inhibitor. Khan and Srivastava (1989)
studied the biological effect of insect growth inhibitor,
diamino- furyl-S, triazine, used as larval residual and adult
feeding treatment, on the larval development and mortality
at Euproctis icilia Stoll. (Lepidoptera; Lymantrjdae) were
investigated. They observed that the compound was highly
toxic to the larval instars, effective growth inhibitor and
successful sterilant in adult stage of Euproctis icilia. It
produced maximum 88.88 per cent and minimum 33.33
per cent net mortality at 12.0 and 0.0012 mg/cm2 level of
residual deposit, respectively. Besides, different types of
deformities were exhibited at lower concentration. High
concentration produced complete lethal action. The
deformity includes mostly larva - pupa intermediate and
in adult, wings were mostly affected. Maximum 16.6 per
cent deformity was recorded at 0.0012 mg/cm2 level. The
compound significantly increased the larval and pupa
survival period and reduced the adult life span.
MATERIALS AND METHODS
The insect samples used in the present investigation
are Euproctis iclia. It is a polyphagous pest and mainly