Reproduction

         Xylocopa virginica emerge from their nest after overwintering in March, but it is not until April and into May that they start to reproduce (Gerling and Hermann 1978). This organism will not come out from their nest until the temperature has warmed to at least 20°C for a week straight (Skandalis et al. 2011). As they begin to come out for the mating season, males tend to be seen a few days prior to females. This is advantageous for males because the first males that emerge will take on the role of resident male while those who come out later will become the satellite males (Prager and Richardson 2012). Establishing these different roles is important for the reproductive success of the male.

        While all males reproduce, or try to reproduce, X. virginica females take on the role of either a reproductive or non-reproductive female (Richards 2011). The reproductive females are considered the dominant female of the nest who forage for food and care for their young. The non-reproductive females do not have a role that benefits the nest. They get their food from the reproductive female and rarely, if ever, leave the nest (Peso and Richards 2010).

       Eastern Carpenter Bees are unique in the fact they have multiple mating strategies (Prager and Richardson 2012). The most common technique is the defense mating system. This occurs when a resident male X. virginica guards his territory outside of a nest waiting for a reproductive female to emerge (Barrows 1983). Once the female comes out of the nest, the male will immediately grab the female. Although this act of grabbing is often seen as aggressive towards females, this strategy is overall beneficial to both males and females. The male bees wait outside of the nest providing protection to the nest and the potential female mates (Gerling and Hermann 1978). The second mating strategy is similar to that of the first, however, instead of the resident male it is the satellite male that tries to mate with the female (Barrows 1983). When a resident male leaves his territory, a satellite male will take on the responsibility of guarding the nest while he is gone. During this time, if a female were to come out of her nest, the satellite male would take advantage of the opportunity and would try to mate with that female (Prager and Richardson 2012).

        Mating between this species also takes place in areas other than near the nest. Some male X. virginica will establish territories at food plants and will use these sites as mating grounds (Barrows 1983). Females are often robbing nectar at plants such as the Rabbiteye Blueberry Plant, Vaccinium ashei, therefore having territories away from the nest can be beneficial to male’s reproductive success (Sampson et al. 2004). Another similar strategy is called scramble-competition mating. In this technique there are no distinct territories created, instead, male Eastern Carpenter Bees will patrol around various flowers waiting for a female (Barrows 1983). The last mating strategy that has been seen in X. virginica takes place near landmarks that do not already have nests by them. These landmarks could include places such as buildings and boulders (Barthell et al. 2006). Although all of these strategies have been observed in the Eastern Carpenter Bee, most males will first try to gain a territory near a nest and if unable to do so, will later resort to the other strategies (Barrows 1983).

        Females begin to lay their eggs in the beginning of May. Due to the structure of their nest, the first eggs are laid at the end of the tunnel which is the furthest point away from the entrance (Gerling and Hermann 1978). When laying their eggs, females will place them on a pollen and nectar ball, which will serve as a source of nourishment to the developing offspring. Once this is completed, they use the wood they have chewed while making the tunnels to construct a wall that separates the offspring from the rest of the nest (North Carolina Museum of Natural Sciences 2013). This wall will later be broken by the hatched offspring when they are ready to freely move about the nest. To learn more about female nesting and the process of laying their eggs click here.

        Initially, offspring are born with cloudy white wings that will eventually become brown and then change to black like that of the adults. Once they have hatched, the new X. virginica gain the ability to fly within three to four days. However, it is not until three to four weeks that they will begin to leave the nest (Gerling and Hermann 1978).

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