Climate Change in the Underworld: Impacts for Soil‐Dwelling Invertebrates

Hibbard

Holzkämper

et al. 2018

Ecology and Evolution

Climate change is predicted to increase the risk of drought in many temperate agroecosystems. While the impact of drought on aboveground plant‐herbivore‐natural enemy interactions has been studied, little is known about its effects on belowground tritrophic interactions and root defense chemistry. We investigated the effects of low soil moisture on the interaction between maize, the western corn rootworm (WCR, Diabrotica virgifera), and soil‐borne natural enemies of WCR. In a manipulative field experiment, reduced soil moisture and WCR attack reduced plant performance and increased benzoxazinoid levels. The negative effects of WCR on cob dry weight and silk emergence were strongest at low moisture levels. Inoculation with entomopathogenic nematodes (EPNs, Heterorhabditis bacteriophora) was ineffective in controlling WCR, and the EPNs died rapidly in the warm and dry soil. However, ants of the species Solenopsis molesta invaded the experiment, were more abundant in WCR‐infested pots and predated WCR independently of soil moisture. Ant presence increased root and shoot biomass and was associated with attenuated moisture‐dependent effects of WCR on maize cob weight. Our study suggests that apart from directly reducing plant performance, drought can also increase the negative effects of root herbivores such as WCR. It furthermore identifies S. molesta as a natural enemy of WCR that can protect maize plants from the negative impact of herbivory under drought stress. Robust herbivore natural enemies may play an important role in buffering the impact of climate change on plant‐herbivore interactions.

mentioning

confidence: 99%

Influence of drought on plant performance through changes in belowground tritrophic interactions

Hibbard

Holzkämper

et al. 2018

Ecology and Evolution

“…The increased infection rate by nematodes was sufficient to compensate for their lower survival in term of progeny number. While climate change may not directly impair EPN ability to control herbivore pest population, changes in host abundance, phenology and quality can drastically modulate their efficacy (Guyer et al, 2018;Hiltpold et al, 2016Hiltpold et al, , 2020Půza & Mrácek, 2005). Interestingly, the increase in spider predation rate F I G U R E 3 Effects of single and combined climatic variables on entomopathogenic nematode fitness and parasitism efficacy.…”

Section: Discussionmentioning

confidence: 99%

“…Compared to single climate parameters, much less is known about the direct effects of combined and interactive impact of multiple parameters on natural enemies of herbivores (Hiltpold et al, 2016;Jactel et al, 2019;Kreyling & Beier, 2013;Robinson et al, 2012). A meta-analysis on the impact of multiple global change drivers on the survival of animals from all trophic levels revealed that combined climatic stressors led to nonadditive effects, comprising synergistic and antagonist interactions, in the majority (65%) of the examined studies (Darling & Côté, 2008).…”

mentioning

confidence: 99%

Natural enemies of herbivores maintain their biological control potential under short‐term exposure to future CO₂, temperature, and precipitation patterns

Doan

Pfander

et al. 2021

Ecology and Evolution

“…The increased infection rate by nematodes was sufficient to compensate for their lower survival in term of progeny number. While climate change may not directly impair EPN ability to control herbivore pest population, changes in host abundance, phenology and quality can drastically modulate their efficacy (Půza & Mrácek 2005;Hiltpold et al 2016;Hiltpold et al 2020;Guyer et al 2018). Interestingly, the increase in spider predation rate was prey species-specific.…”

Section: Discussionmentioning

confidence: 99%

“…Compared to single climate parameters, much less is known about the direct effects of combined and interactive impact of multiple parameters on natural enemies of herbivores (Robinson et al 2012;Kreyling & Beier 2013;Jactel et al 2019;Hiltpold et al 2016). A meta-analysis on the impact of multiple global change drivers on the survival of animals from all trophic levels revealed that combined climatic stressors led to non-additive effects, comprising synergistic and antagonist interactions, in the majority (65%) of the examined studies (Darling & Côté 2008).…”

Section: Introductionmentioning

confidence: 99%

NATURAL ENEMIES OF HERBIVORES MAINTAIN THEIR BIOLOGICAL CONTROL POTENTIAL UNDER FUTURE CO₂, TEMPERATURE AND PRECIPITATION PATTERNS

Doan

Pfander

et al. 2020

Preprint

Climate change will profoundly alter the physiology and ecology of plants, insect herbivores and their natural enemies, resulting in strong effects on multitrophic interactions. Yet, manipulative studies that investigate the direct combined impacts of changes in CO2, temperature, and precipitation on this group of organisms remain rare. Here, we assessed how three day exposure to elevated CO2, increased temperature, and decreased precipitation affect the performance and predation success on species from four major groups of natural enemies of insect herbivores: an entomopathogenic nematode, a wolf spider, a ladybug and a parasitoid wasp. Future climatic conditions (RCP 8.5), entailing a 28% decrease in precipitation, a 3.4°C raise in temperature and a 400 ppm increase in CO2 levels, slightly reduced the survival of entomopathogenic nematodes, but had no effect on the survival of other species. Predation success was not negatively affected in any of the tested species, but was even increased for wolf spiders and entomopathogenic nematodes. Factorial manipulation of climate variables revealed a positive effect of reduced soil moisture on nematode infectivity, but not of increased temperature or elevated CO2. These results suggest that natural enemies of herbivores are well adapted to short term changes in climatic conditions and may not suffer from direct negative effects of future climates. These findings provide mechanistic insights that will inform future efforts to disentangle the complex interplay of biotic and abiotic factors that drive climate-dependent changes in multitrophic interaction networks.