ECONUTRISENS · The conquest of a new habitat: a study of nutritional and sensory adaptations in Drosophila suzukii larvae

The conquest of a new habitat: a study of nutritional and sensory adaptations in Drosophila suzukii larvae

Animals need to feed to get substances to use as sources of energy and material to function, maintain their bodies, grow, and reproduce. These substances are nutrients such as proteins, carbohydrates, and lipids. Different food sources contain these nutrients in different proportions, which means that, depending on the specific needs of an organism, some foods are nutritionally better. Animal have mechanisms to match their feeding choices to their needs. However, for some organisms, such as fruit-fly larvae, the choice is out of their control. During their life cycle, Drosophila fruit flies go through two feeding stages, the larva and adult, which have very different objectives and needs. Larvae feed to grow and accumulate resources fast. They are on the clock to be able to enter metamorphosis and turn into adult flies. They feed where they are born, and cannot waste time or energy searching for food. On the other hand, adult flies need nutrients to survive and reproduce. This means obtaining energy and material to find partners, fight, court, and couple, produce and lay eggs. By choosing where they lay the eggs, adults also choose what food the larvae will have to eat. There are many species of Drosophlla flies. They live in a wide variety of habitats and have adapted to a wide variety of food sources and egg-laying substrates. Adult D. melanogaster female flies prefer to feed and lay eggs on overripe fruits that are colonized by yeasts. These fruits are protein-rich, and a good feeding substrate for the larvae. In contrast, D. suzukii adult females prefer to lay eggs in ripening fruits that are still on the plants. They have a unique physical adaptation, an enlarged and serrated ovipositor, which allows them to pierce the skin of those fruits and insert the eggs inside. These fruits are tough, with high sugar and low protein content. D. melanogaster develops poorly with such food composition. Nonetheless, D. suzukii larvae develop without problem on this food. How have the nutritional needs, behavior, and physiology of D. suzukii larvae adapted to the egg-laying preference of the adults? With my project, I study these questions at different levels; the nutritional composition of host fruits, the larval behavior, and the larval physiology. How does the fruit change as larvae develop? How do larvae develop in it? Is there a relationship between larval behavior and their survival in this environment? This project touches on important issues for society. First, D. suzukii flies attack berries, cherries, and grapes and produce damage to fruits that are still on the plant reducing productivity. Basic knowledge of the development, behavior, and physiology of the species is necessary to protect crops. Second, from a purely basic biology sense, this project will explore how an adaptation to a new niche, such as being able to use hard fruits to lay eggs on, influences many aspects of a species' biology.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз