Toxicity and Repellency Effects of, Achillea Millefolium and Lavandula Angustifolia and Mentha Piperita Plants Extracts on Bracon Hebetor Adult Insect

Bracon hebetor say bee is one of the most important biological control factors that can be effective in controlling larvae of lepidoptera pests such as Helicoverpa armigera hubner at acceptable economic level. The present review was aimed at studying probable adverse effects of Achillea millefolium, Lavandula angustifolia, and Mentha piperita plants extracts on adult insect of the B. hebetor bee. The bee was grown on last instar larvae of Ephestia kueheniella Zell. All bioassay experiments were carried out at temperature of 26±1 °C and relative humidity of 60±5, and under photoperiod conditions of 16 hours of lightness and 8 hours of darkness. Findings of the study indicated that spearmint plant had the highest lethal effect on adult insect of B. hebetor bee in fumigant and contact toxicities and other plants, respectively, Achillea millefolium, Lavandula angustifolia, and Mentha piperita had the least lethal effect on adult insect of B. hebetor bee in fumigant and contact toxicities. The estimated LC50 value for spearmint plant at 48 hours was 6 microliters/ml in fumigant toxicity and 3.2 microliter/ml in contact toxicity. Repellency effect of spearmint, Achillea millefolium, Lavandula angustifolia, and Mentha piperita plants extracts was studied on adult insect using tube -Y olfactory-meter device. Cotton wool soaked with the extract was placed at one end of the device and the other end was closed with web and the insects were released in the main branch. Each iteration of the experiment was conducted on 20 insects. Results of analysis of variance (ANOVA) of the data related to repellency effect of the studied extracts indicated that being a stronger repellant compared to other two extracts, spearmint extract with lower concentration can repel adult insects of B. hebetor bee.