Insights into Brochosome Distribution, Synthesis, and Novel Rapid-Release Mechanism in Maiestas dorsalis (Hemiptera: Cicadellidae)

SIMPLE SUMMARY: Leafhoppers, a large hemipteran family, have a unique behavior of covering themselves with brochosomes. Brochosomes are believed to act as a protective coating for leafhoppers, serving to enhance hydrophobicity and provide protection against predators and parasites. In this study, we investigated the distribution, synthesis, and release mechanisms of brochosomes in the rice pest, Maiestas dorsalis. We found uniform brochosome coverage on different body parts and observed the step-by-step process of brochosome synthesis in the Malpighian tubules. Additionally, we identified a rapid and efficient mechanism for the release of brochosomes. Our study provides valuable insights into the synthesis and release mechanisms of brochosomes, enhancing our understanding of leafhopper biology. ABSTRACT: The leafhopper family Cicadellidae, comprising over 22,000 species, exhibits a unique behavior of anointing their bodies with excretions containing brochosomes. Brochosomes are synthesized in the distal segment of the Malpighian tubules and serve various functions, including hydrophobic protection and defense against pathogens and predators. In this study, we investigated the distribution, synthesis, and release mechanisms of brochosomes in the rice pest leafhopper Maiestas dorsalis. Using SEM and TEM, we observed brochosomes’ consistent coverage on the integument throughout the insect’s life cycle. Moreover, we identified four distinct developmental stages of brochosome synthesis within the distal segment of the Malpighian tubules, originating from the Golgi region. Most importantly, our research revealed a novel and highly efficient release mechanism involving the fusion of brochosome-containing vesicles, leading to a rapid and substantial release of brochosomes into the tubule lumen after molting. These findings shed light on the intricate processes of brochosome synthesis and release in leafhoppers, offering valuable insights into their functional significance and ecological role in these fascinating insects.