Synergistic olfactory processing for social plasticity in desert locusts

Abstract

1Desert locust plagues threaten the food security of millions. Central to their formation is crowding-induced social plasticity from solitarious to gregarious phenotypes. We investigated the impact of population density changes on locusts foraging choices and their neurobiology by examining how relevant food and social odors are coded in the antennal lobe. Our analysis shows that gregarious locusts are highly attentive to social cues during foraging, with olfaction playing an essential role. Using calcium imaging, we show that corresponding odors are encoded by projection neurons, revealing a stable combinatorial response map. Transient dynamics in the glomeruli converge into temporally evolving response motifs in the somata that differ between gregarious and solitarious insects. The dynamics of response motifs facilitate a crowding-dependent synergy between olfactory processing of food-related and social odors. Our study demonstrates the effectiveness of calcium imaging for locust olfaction, suggesting a crowding-induced adaptation to enhance food detection in swarms. 2 TeaserIn dense swarms, desert locusts optimize foraging efficiency by exhibiting an enhanced olfactory response to food odors.