Understanding insect declines requires integrating life-history dynamics

While correlative studies show worrying insect declines in recent times, the nature of insect population dynamics and the paucity of long-term data makes the assessment of the status and trends of insect populations challenging and disconnected from conservation actions. The assessment of life-history dynamics, the joint responses of reproduction, survival, and other vital rates across the life cycle to environmental change, is increasingly seen as an important bridge joining underlying mechanisms to population outcomes under global change, which can substantially improve predictions of declines. However, life-history dynamics under global change have been assessed for a very biased sample of animals in the tree of life, namely mammals, birds, and, among invertebrates, species of economic or cultural significance. This hinders us from developing sound predictions and actionable conservation actions to mitigate declines for a wide range of species. Here, we review methods for assessing life-history dynamics effectively given heterogeneous data. We also argue that insects, and invertebrates more generally, have unique ecological and evolutionary niches and thus show unique life-history dynamics that are strongly linked to environmental cues. Hence, while we can learn a lot from life-history population dynamics developed for vertebrate species, this uniqueness calls for its own model development. We emphasize that such model development can advance the theory and conservation applications of life-history research more broadly.