Читать книгу Honey Bee Medicine for the Veterinary Practitioner - Группа авторов - Страница 76

An age‐related division of labor among worker honey bees is well known, where younger bees perform the inside tasks (first two to three weeks of life), while older bees complete the outside jobs (last one to three weeks of life) (Winston 1987). However, because bees are sensitive to social changes within their colony, this division of labor is not firm and behavioral maturation of work activities may change, directly regulated by worker to worker interactions (Leoncini et al. 2004). For example, when a colony begins to lack older foraging bees, some bees commence foraging as young as five days of age, two weeks earlier than usual. Similarly, when a colony has an overabundance of older bees, younger bees delay their maturation to foraging (Leoncini et al. 2004).

The transition of a honey bee during aging from a life without flying and only inside hive tasks to one of outside defense and foraging, imparts unique functional demands and energy requirements (Elekonich and Roberts 2005). Vitellogenin, a storage protein produced in the fat body of insects and secreted into the hemolymph, plays a central role in such social organization of the honey bee colony, influencing social behavior, stress resilience, immunity, and longevity (Amdam et al. 2012). Besides guiding behavior and lifespan, vitellogenin also affects brood food production and worker specialization for pollen versus nectar collection (Nelson et al. 2007). Similarly, juvenile hormone acts to regulate the rate of behavioral development in honey bees, and guides many of the necessary conversions from a bee fostering brood to one collecting and processing nectar (Sullivan et al. 2000; Elekonich and Roberts 2005). Vitellogenin together with juvenile hormone are inversely correlated to the onset of foraging behavior in worker honey bees; younger nurse bees have low levels of juvenile hormone that increase with age and high vitellogenin, while older foraging bees exhibit the opposite relationship (Johnson 2010; Corona et al. 2007; Sullivan et al. 2000; Robinson 1987).

Other mechanisms are also involved in the behavioral transition of worker honey bees, including the queen and brood pheromones, which inhibit and accelerate worker maturation toward foraging, respectively (Doke et al. 2015; Bortolotti and Costa 2014). In addition, older foraging bees release a pheromone, ethyl oleate, that affects the behavioral maturation of young bees as outlined above, slowing down the transition of nurse bees into foragers (Leoncini et al. 2004). Complex models of division of labor in insect societies are proposed that integrate social, environmental, and nutritional factors, as well as both primer and releasing pheromonal mechanisms; the queen and brood pheromones, as well as vitellogenin and juvenile hormone are considered important parts of the story (Doke et al. 2015; Johnson 2010).