Influência de pistas químicas de aranhas sobre a ação de herbívoros

Abstract

Predators can alter the behavior of herbivorous prey, which can indirectly benefit the plants consumed by these prey. Prey can detect predators through chemical cues left in the environment and respond to predation risk by modifying behavioral traits. Here, we evaluate whether chemical cues from jumping spiders can affect herbivore-plant interactions. Specifically, we examine whether the presence of these cues leads to: (i) reduced movement of herbivorous insects, (ii) reduced reproductive investment of these insects, and (iii) reduced leaf consumption. To achieve this, we conducted experiments assessing the movement of green aphids (Myzus persicae) in Petri dishes with and without chemical cues from spiders (Cotinusa aff. gemmea). We also evaluated the reproductive investment of aphids in these dishes by assessing reproductive time and the number of offspring produced. Finally, we quantified herbivory on bean leaves with and without spider chemical cues. We observed that aphids remained immobile for longer periods and increased their reproductive time in the presence of chemical cues. However, the chemical cues did not affect the number of offspring produced by the aphids. Lastly, we observed a reduction in herbivory by chewing insects on leaves with spider chemical cues. We conclude that aphids can detect chemical cues from jumping spiders and interpret this signal as a predation risk. The detection of these chemical cues leads to reduced movement of these herbivores and results in reduced leaf consumption on plants with spider chemical cues. Thus, we suggest that chemical cues from jumping spiders are important components in structuring plant-herbivore interactions, which can promote positive effects on plant communities.