Insect attractant and oviposition enhancing activity of hexadecanoic acid ester derivatives for monitoring and trapping Caryedon serratus

Abstract

This paper describes behavioural changes elicited in Caryedon serratus by some synthesized hexadecanoic acid ester derivatives, which can be effectively used for monitoring pest populations thereby reducing the risk of pests becoming established in stores. Six hexadecanoic acid ester derivatives were synthesized. Choice and no-choice experiments with different concentrations (0.1, 0.5 and 1.0 mg l−1) of derivatives against C. serratus revealed significant (p < 0.001) oviposition activity for five Hexadecanoic acid ester derivatives. In contrast, 1.0 mg l−1 benzoyl hexadecanoate reduced oviposition (4.7 ± 0.6) significantly (p < 0.001) as compared with control. In Y-tube olfactometer bioassays performed under laboratory conditions, synthesized derivatives elicited significant (p < 0.001) attractiveness (70–98%) in female C. serratus. Additionally, trap experiments performed in mini-stores also support highly significant (p < 0.001) attractiveness of 3-methylphenyl hexadecanoate (0.1 mg per 10 ml) and 4-bromophenyl hexadecanoate (1.0 mg per 10 ml). Conversely, benzoyl hexadecanoate significantly attracted male C. serratus. This study established the dose specific application of hexadecanoic ester derivatives in traps for effective management of this groundnut pest. The specificity of synthesized ester derivatives in attracting both sexes differently also indicates their probable resemblance to pheromone components of C. serratus.