author(s)
Valsala KK, Gokuldas M

abstract
Experiments were conducted to study the repellent and oviposition deterrent effects of different concentrations (0.5, 2, 4 and 6%) of leaf extract of Clerodendrum infortunatum on the pulse beetle, Callosobruchus chinensis. All the tested concentrations showed significant difference in repellent and oviposition deterrence against C. chinensis, when compared to the control sample. Here a dose dependent effect was observed. Repellency increases with concentration and decreases with exposure time. Among the different concentrations tested, 6% extracts showed highest repellent effect. Dose dependent effects were observed in the case of oviposition deterrence and adult emergence of insects while treating with the extracts. Maximum oviposition deterrence was exhibited in insect present in 6% concentration of extract treated sample. Minimum number of insects (mean, 0.5) emerged from the samples treated with the higher concentration (6%). Percentage of reproduction control exhibited by the extract was 97.1. It is thus inferred that C. infortunatum extract at 6% concentration exhibited the highest per cent repellency and oviposition deterrency index against the pulse beetle, C.chinensis.