Climate of origin influences how a herbivorous mite responds to drought-stressed host plants

Drought associated with climate change can stress plants, altering their interactions with phytophagous arthropods. Drought not only impacts cultivated plants but also their parasites, which in some cases are favored by drought. Herbivorous arthropods feeding on drought-stressed plants typically produce bigger offspring and develop faster. However, it is unclear how much responses to drought stress differ among populations of herbivore species. Here, we evaluate variability among populations of a major agricultural pest, the two spotted spider mite, Tetranychus urticae, in response to drought stress. We compare key life history parameters of twelve populations that originate from climates ranging from wet and cool Atlantic locations to medium to dry hot Mediterranean locations. We evaluated how plant drought stress affects four life history traits: development time, fecundity, sex-ratio and emigration rate in an experiment comparing well-watered and drought-stressed bean plants. Mites feeding on drought-stressed plants developed faster and attempted to leave leaves less often, and young females were more fecund. The mites from wet temperate climates exhibited greater plasticity between the two water regimes than mites originating from dryer and hot climates, suggesting that the climate in the area of origin influences mite response to drought

Predation interactions among henhouse-dwelling arthropods, with a focus on the poultry red mite Dermanyssus gallinae Running title: Predation interactions involving Dermanyssus gallinae in poultry farms

International audienc

Impact de la gestion de la biodiversité dans les vignobles sur les communautés d’acariens prédateurs Phytoseiidae

Dossiers Thématiques Agropolis "Vigne et Vin"National audienc

An experimental design to estimate the impact of water stressed plants on Tetranychus urticae life history parameters

International audienc

Impact de la gestion des vignes sur les acariens Phytoseiidae. Quels sont les effets de mesures augmentant la biodiversité dans les parcelles(agroforesterie, enherbement), à leurs abords (haies) ou à l’échelle du paysage ?

Impact de la gestion des vignes sur les acariens Phytoseiidae. Quels sont les effets de mesures augmentant la biodiversité dans les parcelles(agroforesterie, enherbement), à leurs abords (haies) ou à l’échelle du paysage

Phytoseiid mites of Martinique, with redescription of four species and new records (Acari: Mesostigmata)

International audienceAuthors report results of a study performed between May 2011 and September 2013 on cover plants tested for future uses in citrus orchards in Martinique. A total of twenty-two species were found among which eight are very common in the West Indies. A catalogue of four new records for Martinique and three new records for the French West Indies is provided, with some information on their biology when available, and biogeography. Some considerations for six additional species, two rarely recorded in the West Indies and four already recorded and very common but with some new data and discussions, are also provided. Among these 13 species, four are re-described

Evaluating the link between predation and pest control services in the mite world

International audience1. Pest regulation by natural enemies has a strong potential to reduce the use of synthetic pesticides in agroecosystems. However, the effective role of predation as an ecosystem service remains largely speculative, especially with minute organisms such as mites. 2. Predatory mites are natural enemies for ectoparasites in livestock farms. We tested for an ecosystem level control of the poultry pest Dermanyssus gallinae by other mites naturally present in manure in poultry farms and investigated differences among farming practices (conventional, free-range, and organic). 3. We used a multiscale approach involving (a) in vitro behavioral predation experiments , (b) arthropod inventories in henhouses with airborne DNA, and (c) a statistical model of covariations in mite abundances comparing farming practices. 4. Behavioral experiments revealed that three mites are prone to feed on D. gallinae. Accordingly, we observed covariations between the pest and these three taxa only, in airborne DNA at the henhouse level, and in mites sampled from manure. In most situations, covariations in abundances were high in magnitude and their sign was positive. 5. Predation on a pest happens naturally in livestock farms due to predatory mites. However, the complex dynamics of mite trophic network prevents the emergence of a consistent assemblage-level signal of predation. Based on these results, we suggest perspectives for mite-based pest control and warn against any possible disruption of ignored services through the application of veterinary drugs or pesticides. K E Y W O R D S animal farming, assemblage dynamics, biological control, ecosystem services, predation, trophic interaction