Biological and ecological investigation of aquatic fireflies

Aquatic fireflies (Coleoptera: Lampyridae: Luciolinae: Aquatica and Luciola) are a group of important ornamental and resource insects. They are also environmental indicator species in water bodies, and are valuable for balance preservation of grass-water ecosystems. Understanding aquatic firefly biological and ecological characteristics is a key prerequisite for the scientific protection and utilization of these insects. Based on worldwide aquatic firefly research, this study summarized existing findings about biological and ecological characteristics of these aquatic insects, focusing on their life history, phenotypic and behavioral aquatic adaptations, flashing and predation behaviour, and the influence of key environmental factors on their survival. The results show that aquatic fireflies produce one generation annually, and the whole life cycle is completed in one year. They primarily inhabit calm and high-quality water bodies, including streams with slow or static water flow, ditches and lakes. Aquatic fireflies are adapted to water environments phenotypically (e.g., breathing gills) and behaviorally (e.g., swimming). Aquatic fireflies primarily prey on small freshwater snails and perform courtship by producing flashes of light. Water deterioration and light pollution are key factors leading to sharply decreasing population sizes of a wide range of aquatic firefly species. This study concluded that further research on predation, artificial feeding, and ecological adaptation of aquatic fireflies should be conducted in future to reveal the evolutionary mechanisms of their population dynamics and ecological adaptability, which will provide a theoretical basis for the protection and utilization of aquatic fireflies and other important environmental indicator insects.