Form and Function

        The structures of the Eastern Carpenter Bee help it accomplish many different functions. This organism has an exoskeleton which acts to support Xylocopa virginica and provides a site for muscle attachment. The muscle attachment sites on the exoskeleton aid X. virginica with flight, which allows them to gather nectar that will feed members of the nest. It also allows for jointed legs which permits easy movement throughout the nest (Encyclopedia of Life 2013). To check out another interesting organism with an exoskeleton click here. This link with take you to the Predaceous Diving Beetle, also known as the Dytiscus dauricus. Next, interestingly enough, the presence of a stinger is a trait that is only found in females (Missouri Department of Conservation 2013). Another structure is the mandible which allows X. virginica to burrow through the wood and make their nest (Encyclopedia of Life 2013). Lastly, the proboscis helps them steal nectar from flowers or fruits, most commonly from Rabbiteye Blueberry Plant (Sampson et al. 2004, Adler and Irwin 2006). Click here to get more information regarding the structures of the Eastern Carpenter Bee.

        X. virginica has adapted the ability to recognize their nestmates. This adaptation is truly remarkable as they can recall their nestmates in as little as 24 hours (Peso and Richards 2010). The ability to recognize nestmates is advantageous to both males and females.

        The dominant females benefit from this recognition because it allows for only a few females in the nest. In this species, only the dominant female is in charge of reproduction and cares for the young. This makes non-reproductive females in the nest unproductive, serving no purpose to benefit other members of the nest. The dominant females will only allow their sisters to overwinter in the nest with them (Peso and Richards 2010). The process of overwintering means that the males and females stay in that nest over the winter and return to that same nest the following year (Gerling and Hermann 1978). For this reason, the dominant female must be able to recognize her sisters the next year to exclude any non-sisters from living in the nest and using all the resources. (Peso and Richards 2010).

       Due to the fact that males are in charge of protecting the nest, nestmate recognition is also very beneficial to them. It is important to be able to distinguish nestmates and non-nestmates. This allows for males to focus their energy on fending off male non-nestmates who are competing for the dominant female (Peso and Richards 2010).

        Within the nest, aggression between males is present, however, quickly diminishes once the roles of each male bee has been set. Two types of males have been found to occupy a nest, including resident males and satellite males. The resident male is found above the nest and is considered to be the dominant male (Prager and Richardson 2012). Dominant males are characterized as having larger bodies and head sizes. These features may help make these males more attractive when the dominant female considers a mate in the process of sexual selection (Barthell et al. 2006). In contrast, satellite males are positioned around the sides of the nest (Prager and Richardson 2012). These males have smaller bodies which may hinder them during sexual selection (Barthell et al. 2006). After these roles are established, both the satellite and resident males maintain their status and rarely change from these roles (Prager and Richardson 2012). By stabilizing roles, fighting between the nestmate males will occur less often. This will increase the fitness of both the satellite and resident males, as they can now use their energy towards attacking male non-nestmates. This occurrence is known as the dear enemy effect (Barrows 1983, Peso and Richards 2010).

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