Insect responses to global change offer signposts for biodiversity and conservation

1. Insects have emerged as causes célèbres for widespread concern about human effects on global biodiversity. Here, we consider how insects provide opportunities both to understand the ecological effects of global change and to enhance environmental conservation. 2. Despite a limited time frame and geographic extent of quantitative evidence, recent studies of changes to the abundance, distribution, and diversity of insects indicate temporally heterogeneous trends which vary among taxa, regions, and biotopes. These results suggest a) that insect numbers are responding to multiple stressors in the wider context of the changes to fitness, abundance, distributions, and biotic interactions that result from habitat and climate change; and b) that habitat specialists with narrow geographic ranges may be particularly at risk. 3. Predictions of the effects of global change on insects based on macroecology and ecophysiology can be tested by combining approaches, including experiments and observations over gradients of latitude, elevation, and urbanization; as well as innovative quantitative analyses of data from standardised monitoring schemes and opportunistic data from historical collections and citizen science. Linking these complementary approaches helps to detect the mechanisms influencing insect responses to the interacting drivers of global change and to inform conservation. 4. The impetus and debate provoked by recent high profile reports of insect declines provide opportunities to promote insect conservation, but also to obtain comprehensive evidence for the effects of global change on biodiversity and thus develop and communicate measures to mitigate the threats to ecosystems from global change. Recent trends in insect abundance, distributions and diversity are consistent with widespread but heterogeneous responses to global change, particularly to the interacting effects of land‐use and climate change. Insights can be gained into the governing mechanisms by linking complementary approaches including experimentation, modelling and observational studies, such as those based on monitoring schemes, collections and citizen science. Monitoring the responses of insects to conservation interventions and over gradients of climate and land‐use can inform evidence‐based measures to mitigate the effects of global change on biodiversity.