Multi‐factor climate change effects on insect herbivore performance

Abstract

The impact of climate change on herbivorous insects can have far-reaching consequences for ecosystem processes. However, experiments investigating the combined effects of multiple climate change drivers on herbivorous insects are scarce. We independently manipulated three climate change drivers (CO2, warming, drought) in a Danish heathland ecosystem. The experiment was established in 2005 as a full factorial split-plot with 6 blocks × 2 levels of CO2 × 2 levels of warming × 2 levels of drought = 48 plots. In 2008, we exposed 432 larvae (n = 9 per plot) of the heather beetle (Lochmaea suturalis Thomson), an important herbivore on heather, to ambient versus elevated drought, temperature, and CO2 (plus all combinations) for 5 weeks. Larval weight and survival were highest under ambient conditions and decreased significantly with the number of climate change drivers. Weight was lowest under the drought treatment, and there was a three-way interaction between time, CO2, and drought. Survival was lowest when drought, warming, and elevated CO2 were combined. Effects of climate change drivers depended on other co-acting factors and were mediated by changes in plant secondary compounds, nitrogen, and water content. Overall, drought was the most important factor for this insect herbivore. Our study shows that weight and survival of insect herbivores may decline under future climate. The complexity of insect herbivore responses increases with the number of combined climate change drivers.

The value of targeted reforestations for local insect diversity: a case study from the Ecuadorian Andes

“…Such climatic extremes are known to negatively affect insect survival and reproductive success either directly or through changes in host plant quality (e.g. Huberty and Denno 2004;Kishimoto-Yamada and Itioka 2008;Scherber et al 2013). Conversely, individual species may show a sudden proliferation following a drought (Kishimoto-Yamada et al 2009;van Bael et al 2004).…”

Changes in the background losses of woody plant foliage to insects during the past 60 years: are the predictions fulfilled?

“…It may also be a result of the complex and imperfectly understood interactions among environmental and biotic factors, and/or reflect the individualistic responses of herbivore species and their host plants to abiotic drivers of the global climate change [3,4,6,8,14,22].…”

Co2 Effects on Larval Development and Genetics of Mealworm Beetle, Tenebrio Molitor L. (Coleoptera: Tenebrionidae) in Two Different Co2 Systems

“…A forest habitat with a large number of plant species that use CO 2 in photosynthesis will reduce the CO 2 levels in FACE system and automatically decrease the exposure of CO 2 by T. molitor larvae. A FACE system built in a field area, as described by Scherber et al (2013), might be more suitable for use in conducting research on the impact of CO 2 on insects. Less absorption of CO 2 by plants will increase the chances that the larvae will be exposed to higher concentrations of CO 2 .…”