Zika virus (ZIKV) is an arbovirus that has dramatically spread in South America and the Caribbean regions since 2015. The majority of vector incrimination studies available for ZIKV showed that Aedes aegypti mosquitoes are important vectors for this virus. However, several reports suggest that Culex quinquefasciatus mosquitoes may be implicated in ZIKV transmission in certain urban settings. In the present study, we evaluated the vector competence for ZIKV of Cx. quinquefasciatus and Ae. aegypti mosquitoes from Guadeloupe using African, American and Asian strains. The results demonstrated that Cx. quinquefasciatus is refractory to ZIKV infection whatever the strain tested at 7, 14 or 21 days post-infection (dpi), while ZIKV transmission was recorded in Ae. aegypti for all the three strains. The African ZIKV strain was better transmitted by Ae. aegypti (∼ 50% mean transmission efficiency) and with a shorter incubation period (7 dpi) when compared to the Asian and American strains (<14% transmission efficiency; incubation period of 14–21 dpi). Taken together, these results suggest that only Ae. aegypti mosquitoes are involved in urban ZIKV transmission in Guadeloupe and highlight a higher infectiousness of the African ZIKV strain in this mosquito species when compared to the Asian and American ones.

Insects are highly dependent on odor cues released into the environment to locate conspecifics or food sources. This mechanism is particularly important for insect predators that rely on kairomones released by their prey to detect them. In the context of climate change and, more specifically, modifications in the gas composition of the atmosphere, chemical communication-mediating interactions between phytophagous insect pests, their host plants, and their natural enemies is likely to be impacted. Several reports have indicated that modifications to plants caused by elevated carbon dioxide and ozone concentrations might indirectly affect insect herbivores, with community-level modifications to this group potentially having an indirect influence on higher trophic levels. The vulnerability of agricultural insect pests toward their natural enemies under elevated greenhouse gases concentrations has been frequently reported, but conflicting results have been obtained. This literature review shows that the higher levels of carbon dioxide, as predicted for the coming century, do not enhance the abundance or efficiency of natural enemies to locate hosts or prey in most published studies. Increased ozone levels lead to modifications in herbivore-induced volatile organic compounds (VOCs) released by damaged plants, which may impact the attractiveness of these herbivores to the third trophic level. Furthermore, other oxidative gases (such as SO 2 and NO 2 ) tend to reduce the abundance of natural enemies. The impact of changes in atmospheric gas emissions on plant-insect and insect-insect chemical communication has been under-documented, despite the significance of these mechanisms in tritrophic interactions. We conclude by suggesting some further prospects on this topic of research yet to be investigated.RÉ SUMÉ Chez les insectes, les comportements de recherche de nourriture ou de partenaires reposent sur leur capacité à percevoir des signaux chimiques présents dans l'environnement : c'est le cas chez les insectes parasitoïdes et prédateurs qui utilisent les kairomones émises par leurs hô tes/proies pour les localiser. Dans un contexte de changements climatiques, et plus précisément de modifications des concentrations atmosphériques en gaz à effet de serre, la communication chimique entre insectes phytophages, plantes hô tes et ennemis naturels pourrait être impactée. En effet, plusieurs études ont démontré que des modifications chez les plantes dues à l'augmentation des concentrations en dioxyde de carbone et ozone pouvaient impacter indirectement les insectes phytophages, ainsi que les niveaux trophiques supérieurs. Plusieurs études se sont intéressées à l'effet des changements gazeux sur la vulnérabilité des insectes phytophages vis-à-vis de leurs ennemis naturels. Leurs résultats sont dans l'ensemble variables. Cette synthèse bibliographique indique que l'augmentation de la concentration en CO 2 n'augmente généralement pas l'efficacité ou l'abondance des ennemis naturels. L'augmentation d'O 3 va induire des mo...

Understanding how climate change will affect species interactions is a challenge for all branches of ecology. We have only limited understanding of how increasing temperature and atmospheric CO 2 and O 3 levels will affect pheromonemediated communication among insects. Based on the existing literature, we suggest that the entire process of pheromonal communication, from production to behavioural response, is likely to be impacted by increases in temperature and modifications to atmospheric CO 2 and O 3 levels. We argue that insect species relying on long-range chemical signals will be most impacted, because these signals will likely suffer from longer exposure to oxidative gases during dispersal. We provide future directions for research programmes investigating the consequences of climate change on insect pheromonal communication. IntroductionSince the 19 th century, the atmospheric concentration of greenhouse gases, particularly carbon dioxide (CO 2 ), have drastically increased causing changes to environmental parameters at a global scale, including temperature [1]. Recent studies now highlight the impact of such modifications on the whole dynamics of life [2]. Through cascade effects, entire ecosystems are being disturbed, impacting the population dynamics of inhabiting species and altering the ways that they interact with one another. This phenomenon has been well documented for insect-plant interactions mediated by plant secondary metabolites [3,4 ]. [12]. Although these insects can perceive a wide range of pheromone components, the activation of neurons in their macroglomerular complexes, and the elicitation of relevant behavioural responses, is combinatorial: it will happen only when the right combination and ratio of components is perceived at the same time [6].Developmental temperature has a strong influence on adult life history, morphology, and physiology. Furthermore, in some species, pheromone production and availability is dependent on larval, pupation, and/or adult developmental conditions [8,13,14], hence the effect of abiotic parameters on all the insect life stages is important. In the male beewolf, Philanthus triangulum, an increase of 5 8C in the larval rearing temperature led adult males to produce more pheromonal secretions [13]. Moreover, warmer rearing conditions led to higher relative amounts of compounds with high molecular weight. As a consequence, a shift in temperature could weaken intraspecific relationships of these insect species by reducing the efficiency (i.e. specificity, activity, timing of production, etc.) of their chemical communication.Increasing atmospheric CO 2 concentrations [1] could also affect the biosynthesis of insect pheromones. Changes in CO 2 concentrations affect plant biochemistry, including the synthesis of secondary metabolites [4 ]. Since some phytophagous insect species produce their pheromone components based on precursors taken from their host plant, we hypothesise that phytophagous insects could be among the most vulnerable to changes in atmospheric ...