Modeling and analysis of locust hoppers dynamics under olfactory receptor 35 deficiency

Locust plagues pose a persistent threat to agriculture, while insecticide-based control remains largely limited to the nymph stage and raises ecological and human health concerns. These limitations motivate the development of non-insecticidal strategies targeting swarm formation. Recent experiments have shown that 4-vinylanisole (4VA) and the olfactory receptor 35 (OR35) that detects it play key roles in individual aggregation behavior; however, the collective-level consequences of OR35 deficiency remain poorly understood. Here, we develop a mathematical model that incorporates 4VA-mediated attraction and heterogeneity arising from OR35-deficient individuals to systematically analyze their effects on collective dynamics of hopper groups. Using numerical simulations, we examine how changes in the proportion of OR35-deficient individuals shape collective behavior. Our results show that OR35 deficiency impairs gregarisation when visual interactions are limited and 4VA attraction operates within its effective range. These findings provide a collective-level interpretation of pheromone-sensing heterogeneity and suggest non-insecticidal strategies for locust swarm management. • Suppressing hopper group formation can reduce severe damage to crops. • Hopper group behavior is affected by individuals with reduced pheromone sensing. • Collective behavior of mixed hopper groups is systematically modeled and analyzed. • These individuals weaken gregarisation when visual interactions are limited. • This finding suggests non-insecticidal approaches to hopper group regulation.