The cluster digging behavior of larvae confers trophic benefits to fitness in insects

• Published in: Insect science 2024-06, Vol.31 (3), p.870-884
• Main Authors: Wu, Yujie, Wang, Qiang, Yang, Weikang, Zhang, Sheng, Mao, Chuan‐Xi, He, Nana, Zhou, Shaojie, Zhou, Chuanming, Liu, Wei
• Format: Article
• Language: English
• Subjects: Breeding success; cluster digging; Clusters; determinant; development; Digging behavior; Drosophila; fecundity; Fitness; Food; Food quality; Food resources; Food sources; Foraging behavior; Fruit flies; Insects; Larvae; Larval development; mathematical model; Mathematical models; Population density; Reproduction; Reproductive fitness; Species diversity; Spiracles
• ISSN: 1672-9609; 1744-7917; 1744-7917
• DOI: 10.1111/1744-7917.13307

Collective behaviors efficiently impart benefits to a diversity of species ranging from bacteria to humans. Fly larvae tend to cluster and form coordinated digging groups under crowded conditions, yet understanding the rules governing this behavior is in its infancy. We primarily took advantage of the Drosophila model to investigate cooperative foraging behavior. Here, we report that Drosophila‐related species and the black soldier fly have evolved a conserved strategy of cluster digging in food foraging. Subsequently, we investigated relative factors, including larval stage, population density, and food stiffness and quality, that affect the cluster digging behavior. Remarkably, oxygen supply through the posterior breathing spiracles is necessary for the organization of digging clusters. More importantly, we theoretically devise a mathematical model to accurately calculate how the cluster digging behavior expands food resources by diving depth, cross‐section area, and food volume. We found that cluster digging behavior approximately increases 2.2 fold depth, 1.7‐fold cross‐section area, and 1.9 fold volume than control groups, respectively. Amplification of food sources significantly facilitates survival, larval development, and reproductive success of Drosophila challenged with competition for limited food resources, thereby conferring trophic benefits to fitness in insects. Overall, our findings highlight that the cluster digging behavior is a pivotal behavior for their adaptation to food scarcity, advancing a better understanding of how this cooperative behavior confers fitness benefits in the animal kingdom. Schematic diagram showing that larvae of many insect species engage in cluster digging in the favorite or unfavorite substrates. This collective behavior promotes survival, larval development, and reproductive success, which confers trophic benefits to fitness in insects in nature.