Sarracenia carnivorous plants cannot serve as efficient biological control of the invasive hornet Vespa velutina nigrithorax in Europe

Vespa velutina nigrithorax, an invasive species, a direct result of increased trade and climate change, is spreading rapidly in Europe and endangering entomofauna in general and more alarmingly honeybee (Apis mellifera) populations, and therefore their pollination services. All traps used now, to try to control this species, seem to be not efficient enough and non-selective. However, in the current context of massive disappearance of insects in general, it is urgent to find means of protection for the entomofauna. While no selective trapping is still occurring, we performed a pilot study to test a carnivorous plant as a potential biocontrol tool to trap V. velutina. In our study, we analyzed the hornet-capturing ability of two Sarracenia hybrids (S. juthatip soper and S. evendine) on a 2-years period (2015 and 2016). Our results show that these plants trapped more dipterans than other taxa, and they do not attract many hornets. In such condition, both Sarracenia hybrids cannot therefore be used in a mass trapping system, because they are not selective, and too few hornets are trapped. To maximize captures of V. velutina while minimizing captures of non-target species, other systems need to be thus developed, as traps using hornet pheromone-based baiting

Sarracenia carnivorous plants cannot serve as efficient biological control of the invasive hornet Vespa velutina nigrithorax in Europe

International audienceCitation: Wycke M-A, Perrocheau R, Darrouzet E (2018) Sarracenia carnivorous plants cannot serve as efficient biological control of the invasive hornet Vespa velutina nigrithorax in Europe. Rethinking Ecology @: @-@. https://doi. Abstract Vespa velutina nigrithorax, an invasive species, a direct result of increased trade and climate change, is spreading rapidly in Europe and endangering entomofauna in general and more alarmingly honeybee (Apis mellifera) populations, and therefore their pollination services. All traps used now, to try to control this species, seem to be not efficient enough and non-selective. However, in the current context of massive disappearance of insects in general, it is urgent to find means of protection for the entomofauna. While no selective trapping is still occurring, we performed a pilot study to test a carnivorous plant as a potential biocontrol tool to trap V. velutina. In our study, we analyzed the hornet-capturing ability of two Sarracenia hybrids (S. juthatip soper and S. evendine) on a 2-years period (2015 and 2016). Our results show that these plants trapped more dipterans than other taxa, and they do not attract many hornets. In such condition, both Sarracenia hybrids cannot therefore be used in a mass trapping system, because they are not selective, and too few hornets are trapped. To maximize captures of V. velutina while minimizing captures of non-target species, other systems need to be thus developed, as traps using hornet pheromone-based baiting

Configural perception of a binary olfactory mixture in honey bees, as in humans, rodents and newborn rabbits

International audienceHow animals perceive and learn complex stimuli, such as mixtures of odorants, is a difficult problem, for which the definition of general rules across the animal kingdom remains elusive. Recent experiments conducted in human and rodent adults as well as newborn rabbits suggested that these species process particular odor mixtures in a similar, configural manner. Thus, the binary mixture of ethyl isobutyrate (EI) and ethyl maltol (EM) induces configural processing in humans, who perceive a mixture odor quality (pineapple) that is distinct from the quality of each component (strawberry and caramel). Similarly, rabbit neonates treat the mixture differently, at least in part, from its components. In the present study, we asked whether the properties of the EI.EM mixture extend to an influential invertebrate model, the honey bee Apis mellifera. We used appetitive conditioning of the proboscis extension response to evaluate how bees perceive the EI.EM mixture. In a first experiment, we measured perceptual similarity between this mixture and its components in a generalization protocol. In a second experiment, we measured the ability of bees to differentiate between the mixture and both of its components in a negative patterning protocol. In each experimental series, the performance of bees with this mixture was compared with that obtained with four other mixtures, chosen from previous work in humans, newborn rabbits and bees. Our results suggest that when having to differentiate mixture and components, bees treat the EI.EM in a robust configural manner, similarly to mammals, suggesting the existence of common perceptual rules across the animal kindgdom

Effects of early rearing environment on affiliative behaviours and neonatal physiology in sheep

International audienc

A Background of a Volatile Plant Compound Alters Neural and Behavioral Responses to the Sex Pheromone Blend in a Moth

International audienceRecognition of intra-specific olfactory signals within a complex environment of plant-related volatiles is crucial for reproduction in male moths. Sex pheromone information is detected by specific olfactory receptor neurons (Phe-ORNs), highly abundant on the male antenna. The information is then transmitted to the pheromone processing macroglomerular complex (MGC) within the primary olfactory center, the antennal lobe, where it is processed by local interneurons and projection neurons. Ultimately a behavioral response, orientation toward the pheromone source, is elicited. Volatile plant compounds (VPCs) are detected by other functional types of olfactory receptor neurons (ORNs) projecting in another area of the antennal lobe. However, Phe-ORNs also respond to some VPCs. Female-produced sex pheromones are emitted within a rich environment of VPCs, some of which have been shown to interfere with the detection and processing of sex pheromone information. As interference between the different odor sources might depend on the spatial and temporal features of the two types of stimuli, we investigated here behavioral and neuronal responses to a brief sex pheromone blend pulse in a VPC background as compared to a control background in the male noctuid moth Agrotis ipsilon. We observed male orientation behavior in a wind tunnel and recorded responses of Phe-ORNs and MGC neurons to a brief sex pheromone pulse within a background of individual VPCs. We also recorded the global input signal to the MGC using in vivo calcium imaging with the same stimulation protocol. We found that VPCs eliciting a response in Phe-ORNs and MGC neurons masked responses to the pheromone and decreased the contrast between background odor and the sex pheromone at both levels, whereas α-pinene did not interfere with first order processing. The calcium signal produced in response to a VPC background was tonic, lasting longer than the VPC stimulus duration, and masked entirely the pheromone response. One percent heptanal and linalool, in addition to the masking effect, caused a clear delay in responses of MGC neurons to the sex pheromone. Upwind flight toward the pheromone in a wind tunnel was also delayed but otherwise not altered by different doses of heptanal

Unexpected effects of sublethal doses of insecticide on the peripheral olfactory response and sexual behavior in a pest insect

International audiencePesticides have long been used as the main solution to limit agricultural pests, but their widespread use resulted in chronic or diffuse environmental pollutions, development of insect resistances, and biodiversity reduction. The effects of low residual doses of these chemical products on organisms that affect both targeted species (crop pests) but also beneficial insects became a major concern, particularly because low doses of pesticides can induce unexpected positive-also called hormetic-effects on insects, leading to surges in pest population growth at greater rate than what would have been observed without pesticide application. The present study aimed to examine the effects of sublethal doses of deltamethrin, one of the most used synthetic pyrethroids, known to present a residual activity and persistence in the environment, on the peripheral olfactory system and sexual behavior of a major pest insect, the cotton leafworm Spodoptera littoralis. We highlighted here a hormetic effect of sublethal dose of deltamethrin on the male responses to sex pheromone, without any modification of their response to host-plant odorants. We also identified several antennal actors potentially involved in this hormetic effect and in the antennal detoxification or antennal stress response of/to deltamethrin exposur