Substrate-borne vibrations produced during the interaction with natural enemies alter aphids probing behavior

The “ecology of fear”, i.e., physiological and behavioral alterations displayed by pests in response to predation risk, has recently been proposed as a sustainable alternative to chemicals for pest control. However, the development of such a strategy requires a detailed understanding of the signals and cues underlying the pest-antagonist interaction and eliciting the prey behavioral alteration. Here, we characterized the substrate-borne vibrations produced during the interaction between the green peach aphid Myzus persicae and its antagonists, the parasitoid wasp Aphidius colemani and the ladybug Adalia bipunctata. Thereafter, coupling the electrical penetration graph (EPG) with a stimulus controller, we evaluated whether the playback of the vibrations, alone and in combination with the alarm pheromone, impacted aphid probing behavior and interaction with the host plant. Aphids responded to vibrations exhibiting longer non-probing, shorter intracellular probes, i.e. the behavior through which the insect evaluates host plant quality, delay in accessing the phloem vessels and decrease of the frequency of phloem salivation events. In contrast, on plants treated with the alarm pheromone, insects displayed longer intracellular probes. We hypothesize that the alarm pheromone, signaling a distant threat, might induce a careful evaluation of the host plant in order to decide the magnitude of the reaction. On the other hand, vibrations might indicate a closely approaching threat pushing the aphid to rush the host evaluation process and the whole feeding process. The possible repercussion of the behavioral alterations observed on the dynamics of aphid-borne plant virus transmission is also discusse

Intruding into a conversation: how behavioral manipulation could support management of Xylella fastidiosa and its insect vectors

Behavioral manipulation (BM) is a multimodal control approach based on the interference with the stimuli mediating insect perception and interaction with the surroundings. BM could represent a win–win strategy for the management of vector-borne plant pathogens as the bacterium Xylella fastidiosa, since it could reduce the number of vectors alighting on host plants and, consequently, the chances for transmission to occur. In this review, we summarized current knowledge and highlighted gaps in information on (i) how insect vectors of X. fastidiosa in general, and more specifcally the meadow spittlebug Philaenus spumarius, locate and accept the host plant; and (ii) how behavioral manipulation techniques could be applied to disrupt the vector–host plant interaction. Finally, we discussed how diverse BM strategies could be combined with other integrated pest management tools to protect olive groves from inoculation with the fastidious bacterium

Exploring the role of vibrational cues in a parasitoid-host interaction

The green peach aphid, Myzus persicae Sulzer (Aphididae, Hemiptera), is a major agricultural pest worldwide, and an efficient vector of several plant viruses, whose control still majorly relies on pesticides. However, the need to reduce pesticide use, given their side effects on non-target organisms and human health, and their inefficacy for containing the spread of aphid-borne viruses, call for research on alternative tools for pest control, such as biological control. Aphidius colemani Viereck (Braconidae, Hymenoptera) is a parasitoid that is commonly used as a biological control agent of M. persicae, but little is known about the behavioral interaction with its host. The potentiality of Biotremology for pest control has already been highlighted by several studies. However, the role of substrate-borne vibrations in inter- and intra-specific communication in some insect taxa, including aphids and parasitoids, has never been addressed, and further studies may pave the way for the sustainable control of species currently representing major threats for food safety and security. Therefore, the aim of this study is to characterize the role of substrate-borne vibrations in: i) the inter-specific communication between M. persicae and its parasitoid A. colemani; ii) the intra-specific communication between an “attacked” aphid and its conspecifics. Thereafter, the impact of previously recorded vibrational cues or signals on the aphid feeding behavior will be assessed using the Electrical Penetration Graph (EPG) technique, with a particular focus on the patterns conducive to viruses’ acquisition and inoculation. Two are the major outcomes expected from the present study: i) insights into the role of substrate-borne vibrations in aphids intra-specific communication and parasitoid foraging behavior; ii) a proof of concept of the applicability of semiophysicals as an alternative to pesticides for aphids and aphid-borne viruses control

Substrate-borne vibrations produced during the interaction with natural enemies alter aphids probing behavior

The "ecology of fear", i.e., physiological and behavioral alterations displayed by pests in response to predation risk, has recently been proposed as a sustainable alternative to chemicals for pest control. However, the development of such a strategy requires a detailed understanding of the signals and cues underlying the pest-antagonist interaction and eliciting the prey behavioral alteration. Here, we characterized the substrate-borne vibrations produced during the interaction between the green peach aphid Myzus persicae and its antagonists, the parasitoid wasp Aphidius colemani and the ladybug Adalia bipunctata. Thereafter, coupling the electrical penetration graph (EPG) with a stimulus controller, we evaluated whether the playback of the vibrations, alone and in combination with the alarm pheromone, impacted aphid probing behavior and interaction with the host plant. Aphids responded to vibrations exhibiting longer non-probing, shorter intracellular probes, i.e. the behavior through which the insect evaluates host plant quality, delay in accessing the phloem vessels and decrease of the frequency of phloem salivation events. In contrast, on plants treated with the alarm pheromone, insects displayed longer intracellular probes. We hypothesize that the alarm pheromone, signaling a distant threat, might induce a careful evaluation of the host plant in order to decide the magnitude of the reaction. On the other hand, vibrations might indicate a closely approaching threat pushing the aphid to rush the host evaluation process and the whole feeding process. The possible repercussion of the behavioral alterations observed on the dynamics of aphid-borne plant virus transmission is also discussed