Repellence of Myzus persicae (Sulzer): evidence of two modes of action of volatiles from selected living aromatic plants.

BACKGROUND Intercropping companion plants (CPs) with horticultural crops could be an eco‐friendly strategy to optimize pest management. In this research, volatile organic compounds (VOCs) emitted by some CPs were investigated for their repellent properties towards the green peach aphid (Myzus persicae Sulzer). The aim of this study was to understand the modes of action involved: direct effects on the aphid and/or indirect effects via the host plant (pepper, Capsicum annuum L.). RESULTS We identified two promising repellent CPs species: the volatile blend from basil (Ocimum basilicum, direct repellent effect) and the mixture of (or previously intercropped) C. annuum plants with Tagetes patula cv. Nana (indirect effect). This effect was cultivar‐dependent and linked to the volatile bouquet. For the 16 compounds present in the O. basilicum or T. patula bouquets tested individually, (E)‐β‐farnesene and eugenol reported good repellent properties against M. persicae. Other compounds were repellent at medium and/or at highest concentrations. Thus, the presence of repellent VOCs in a mixture does not mean that it had a repellent propriety. CONCLUSION We identified two promising repellent CPs species towards M. persicae, with a likely effect of one CPs' VOCs on the host plant repellency and highlighted the specific effectiveness of VOC blends

MINUTE PIRATE BUG (\u3ci\u3eORIUS INSIDIOSUS\u3c/i\u3e SAY) POPULATIONS ON TRANSGENIC AND NON-TRANSGENIC MAIZE USING DIFFERENT SAMPLING TECHNIQUES

Field experiments were conducted to evaluate the populations of minute pirate bug [Orius insidiosus (Say)] using visual, sticky cards and destructive sampling techniques in transgenic and non-transgenic maize in three locations in Nebraska (Mead, Clay Center. and Concord) United States of America. during 2007 and 2008 . All sampling methods revealed significant counts of O. insidiosus on CP4 EPSPS maize plus an insecticide application for control of first generation O. nubilalis at R2 (blister) sampling period. Similarly, visual observations of O. insidiosus on Cry1Ab x Cry3Bb1 x CP4 EPSPS maize yielded significantly higher mean adult counts at R2 (blister) sampling period tor both years while, sticky cards and destructive sampling methods gave significant counts during 2007 and 2008, respectively. During both sampling periods (R1 and R2), mean adult counts of O. insidiosus differ significantly among the three sites at Mead. Clay Center, and Concord. Nebraska. Results from this research show that Cry1Ab maize, Cry1Ab x CP4 EPSPS maize. Cry1Ab x Cry3Bb1 x CP4 EPSPS maize, and CP4 EPSPS maize had no significant effects on O. insidiosus population abundance compared to CP4 EPSPS maize treated with insecticides