Ovicidal effect of insect growth regulators against eggs of trogoderma granarium (EVERTS) AND Tribolium castaneum (HERBST)

The herein reported studies were conducted to investigate the ovicidal effect of different insect growth regulators (IGRs), viz., lufenuron 50EC, flufenoxuron 10DC, pyriproxyfen 10.8EC, tebufenozide 20SC, methoxyfenozide 240SC, triflumuron 20SC, and buprofezin 25%WP against Trogoderma granarium (Everts) and Tribolium castaneum (Herbst). All these IGRs were applied to the glass vials at four concentrations viz., 2.5, 5, 7.5 and 10 ppm, additionally, an untreated control using four replicates through Completely Randomized Design (CRD). Results showed that highest ovicidal action was exerted by pyriproxyfen where only 32.83% hatching was recorded in T. castaneum eggs followed by lufenuron at 10ppm while methoxyfenozide was least effective. Similarly, in T. granarium, the hatching suppression was highest (38.83% hatching) due to pyriproxyfen treatment and was lowest in methoxyfenozide treatment. The growth rate was highly effected by pyriproxyfen and least effected by methoxyfenozide against both insects. From these results, it is concluded that the applications of IGRs have proved to be very effective against both species examined in the present study. Hence, these compounds particularly pyriproxyfen, an analog of the juvenile hormone (JH) followed by Chitin synthesis inhibitors (i.e., flufenoxuron, lufenuron and triflumeron) should be considered as potential components in managing immature stages of stored grains insect pests. (author)