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Water stress affects Tomicus destruens host pine preference and performance during the shoot feeding phase
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Edité par CCSD ; Springer Nature (since 2011)/EDP Science (until 2010) -
International audience. The effect of water stress on host selection and performance during the shoot feeding phase, by the Mediterranean pine shoot beetle Tomicus destruens, was studied.* Young potted Pinus pinaster plants were subjected to two water supply regimes: (i) well watered; (ii) 4-5 months of moderate drought stress. Plant volatile organic compound (VOCs) emissions were collected by SPME and analysed by GC/MS. * In tests with paired plants, the number of holes and tunnels excavated by beetles in well watered pines was significantly larger than in stressed plants, whereas in no-choice tests no differences occurred.* Beetle survival was significantly higher on well watered, than on stressed pines (p = 0.006), while fat contents also increased (p = 0.09).* Plants could be assigned to treatments based on VOCs emissions, stressed pines emitting more myrcene and less β-pinene than well watered ones.* It is concluded that during the shoot feeding phase, T. destruens preferentially attacks non-stressed plants, in detriment of stressed ones, upon which a higher fitness is attained.* The role of pines VOCs emissions under moderate drought stress, in the host selection and colonization process by the pine shoot beetle, is discussed.