The kairomonal effect of hexane extract of the larvae of Ostrinia nubilalis and Sesamia cretica on Bracon breuicornis adults was evaluated through olfactometer tests. The parasitoid males showed no definite response to any kairomone. Females were attracted to the kairomone of S. cretica more than to that of 0. nubilalis. Highly significant effect of the sex pheromone of 0. nubilalis on the females of B. breuicornis was recorded. Kairomones (hexane extracts of larvae) varied in their effect on the released B. brevicornis parasitoids. The kairomone of S. cretica increased the parasitisation from 7.74 to 17.05%, while the kairomones of 0. nubilalis and of Spodoptera littoralis were not significantly effective. Spraying molasses solution (10%) on the corn stalks before releasing B. brevicornis parasitoids increased the rate of parasitism from 7.74 to 28.21%. The concentration of 5% gave insignificant increase in the parasitisation rate.

No abstract