Affiliation:
1. Centre for Ecology, Evolution and Environmental Changes (cE3c), Faculdade de Ciências, Universidade de Lisboa , Lisbon , Portugal
2. Population Ecology Lab, Adam Mickiewicz University , Poznań , Poland
Abstract
Abstract
Metal accumulation is used by some plants as a defence against herbivores. Yet, herbivores may adapt to these defences, becoming less susceptible. Moreover, ecosystems often contain plants that do and do not accumulate metals, but whether such heterogeneity affects herbivore adaptation remains understudied. Here, we performed experimental evolution to test whether the spider mite Tetranychus evansi adapts to plants with high cadmium concentrations, in homogeneous (plants with cadmium) or heterogeneous (plants with or without cadmium) environments. For that we used tomato plants, which accumulate cadmium, thus affecting the performance of these spider mites. We measured mite fecundity, hatching rate, and the number of adult offspring after 12 and 33 generations and habitat choice after 14 and 51 generations, detecting no trait change, which implies the absence of adaptation. We then tested whether this was due to a lack of genetic variation in the traits measured and, indeed, additive genetic variance was low. Interestingly, despite no signs of adaptation, we observed a decrease in fecundity and number of adult offspring produced on cadmium-free plants, in the populations evolving in environments with cadmium. Therefore, evolving in environments with cadmium reduces the growth rate of spider mite populations on non-accumulating plants. Possibly, other traits contributed to population persistence on plants with cadmium. This calls for more studies addressing herbivore adaptation to plant metal accumulation.
Funder
European Research Council
Fundação para Ciência e Tecnologia
Fundo Europeu de Desnevolvimento Regional
Publisher
Oxford University Press (OUP)
Subject
Ecology, Evolution, Behavior and Systematics
Reference66 articles.
1. Differential metal-specific tolerance and accumulation patterns among Thlaspi caerulescens populations originating from different soil types;Assunção,2003
2. Terrestrial higher plants which hyper-accumulate metallic elements—A review of their distribution, ecology and phytochemistry;Baker;Biorecovery,1989
3. Transient local adaptation and source-sink dynamics in experimental populations experiencing spatially heterogeneous environments;Bisschop;Proceedings of the Royal Society B: Biological Sciences,2019
4. Heritability and artificial selection on ambulatory dispersal distance in Tetranychus urticae;Bitume;PLoS One,2011
5. Nongenetic inheritance and its evolutionary implications;Bonduriansky,2009