Herbivore life histories are altered by drought stress in their hosts plants

Abstract Drought associated with climate change can stress plants, altering their interactions with phytophagous arthropods. Dryness not only impacts cultivated plants but also their parasites, which in some cases are favoured by drought. Herbivorous arthropods feeding on drought-stressed plants typically produce bigger offspring and develop faster. However, how much responses to abiotic factors differ among populations of a species remains poorly documented. 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. Thus, climate in the area of origin influences mite response to drought.. Data are available in csv files DevelopmentTime.csv: number of adults per plant by date Fecundity3Day.csv: number of eggs, daughters and sons per plant for 3 day old females Fecundity9Day.csv: number of eggs, daughters and sons per plant for 9 day old females ClimateData.csv Worldclim variables (+ GAI) value for each population tested Common_garden_mite.R: R script of data analysis (2021-10-20)