Volatile interaction between undamaged plants affects tritrophic interactions through changed plant volatile emission

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

“…In general, effective repellent CPs directly influence aphid behavior through their VOCs. Nevertheless, in line with previous studies, our work showed that some plants can act by means of a second mechanism that requires the presence of the host plant. We demonstrated that C. annuum and T. patula volatiles alone did not exhibit a significant effect on M. persicae aphids, nevertheless the mixture of these two plants acts significantly on M. persicae olfactory behavior.…”

“…Odor blends from L. latifolia , O. basilicum , R. officinalis , and T. patula contain α‐terpineol, which was associated with M. persicae repellent effects . Our results confirmed that aphid responses to some individual compounds were not the same when these compounds were mixed with others . The repellent activity of some compounds could be modulated by other compounds which can either inhibit or mask their effects .…”

“…Differences between results were probably related to qualitative (presence/absence of specific VOCs) and quantitative variations among the chemical composition of volatiles perceived by aphids . Variations in volatile profiles of the same plant species can be related to genetic differences and to various biotic and abiotic factors linked to plant nutritional status, stress conditions, and phenological stages . In addition, aphid olfactory responses to headspace volatiles released from living plants can be different from those of essential oils .…”

“…The properties of plant VOCs against aphids, such us repellency, have been frequently discussed in previous studies . In contrast, as it is difficult to monitor whole‐system experiments, few studies were focused on their mode of action or on the underlying mechanisms …”

“…4,6,[17][18][19] In contrast, as it is difficult to monitor whole-system experiments, few studies were focused on their mode of action 8 or on the underlying mechanisms. 20 Nevertheless, in order to optimize the use of CP in pest management, we need not only the confirmation of the effectiveness of the plant VOCs tested but also a greater understanding of the mechanisms involved. 3 For this purpose, it is necessary to understand how CP acts and several hypotheses have been proposed for the mode of action of their volatiles towards aphids.…”