Warming increased feeding of a root-chewing insect at the soil surface and enhanced its damage on a grass

Publication date: Available online 10 September 2018Source: Soil Biology and BiochemistryAuthor(s): Tomonori Tsunoda, Kobayashi Makoto, Jun-Ichirou Suzuki, Nobuhiro KanekoAbstractAir and soil warming influences both plants and root herbivorous insects, but how warming alters their interactions is largely unknown. Because both the intensity of herbivory and plant susceptibility to the herbivory depend on temperature, it is difficult to predict the effects of insect herbivory on plant growth under warming. To analyse changes in belowground plant-insect interaction due to warming, we conducted a pot experiment using one grass species, Lolium perrene, and one beetle grub Anomala cuprea. Temperature (17 °C or 20.3 °C), presence or absence of a grub, and presence or absence of organic matter (OM) on the surface of the potted soil were manipulated. OM at the soil surface is an important resource for grubs, and contains neutral lipid fatty acids (NLFA) that can serve as a bacterial marker. NLFAs can be used as a tracer to determine whether grubs had fed upon OM, so we evaluated the consumption and vertical movement of a grub in response to warming. In the absence of grubs, plant biomass increased with warming, but was not affected by the OM treatment. In the presence of grubs, plant biomass was significantly decreased. Moreover, the interaction term between the temperature and grub treatments was significant, demonstrating that grub damage was more severe under warmer condition...
Source: Soil Biology and Biochemistry - Category: Biology Source Type: research