Nestmate to non-nestmate interactions and male to female interactions have been observed when looking at Xylocopa virginica.

        While looking at nestmates and non-nestmates a difference is observed between the way males and females are treated when entering an unfamiliar area. When male non-nestmates enter an area, the surrounding male members of the nest will attack this individual. As noted on the Form and Function page, the two types of males that defend the nest include satellite males and resident males. Each type of male has a distinct role including the resident males guarding above the nest and the satellite males guarding around the sides of the nest (Prager and Richardson 2012). It is advantageous for the males to recognize other male nestmates quickly so they can put their energy towards attacking unwanted visitors, an idea known as the dear enemy effect (Barrows 1983, Peso and Richards 2010). To gain access and attention from females, males defend the territories close to the nest (Barthell et al. 2006). Males will act with aggression in different ways with the most prominant being pushing and biting. Pushing is a behavior in which one bee applies contact to the head and does not release pressure until the other bee is moved far enough away from the nest. The next example of aggressive behavior is biting. Both pushing and biting are traits that occur sooner and more often in non-nestmate male interactions. Aggressive behaviors are mainly seen in males as their job is to defend the nest (Peso and Richards 2010).

        As stated above, X. virginica is very territorial and have been known to attack anything that may come in close contact with the nest they are protecting. They will lunge at insects of other species that have no interest in competing for the females and even Dandelion Pappi as possible threats to the nest (Barrows 1983). Click here to learn more about Dandelion Pappi or Taraxacum officinale and see why it is hard to believe that X. virginica views this plant as competition.

        The only instance in which aggression was not displayed between non-nestmates and nestmates was when a non-nestmate female entered an area with males. Males show a decrease in aggression and increase in tolerance when a female approaches, which is very different when males approach an unfamiliar nest. This decrease in aggression is due to the fact that males see non-nestmate female as a potential mating partner (Peso and Richards 2010). Males produce pheromones while hovering and defending the nest that help attract these potential mates (Barthell et al. 2006). They want to attract new females to avoid deadly inbreeding as many inhabitants of the nest are related to one another. This may lead to competition in the nest between the females as the dominant female only likes to have a small number of workers in the nest that consume the resources and make no positive contributions to the nest (Peso and Richards 2010).

        The idea that the Eastern Carpenter Bee has been labeled as a nectar robber is not an accurate description of the job they do. The term "nectar thieves" puts X. virginica in a negative light, when in actuality it benefits not only the plant they rob from, in this case being the Rabbiteye Blueberry Plant, Vaccinium ashei, but also Honey Bees, Apis mellifera (Sampson et al. 2004).

        X. virginica have been known to sometimes take nectar properly through the petals, but have been seen more commonly “stealing the nectar”. They form slits in the base of the petals with their mouths to obtain the nectar (Adler and Irwin 2006). The Eastern Carpenter Bee steals nectar around March to early April. This interaction benefits the A. mellifera as these organisms have very short tongues, and therefore cannot reach the nectar glands without the help of the Eastern Carpenter Bee first robbing the plant (Peso and Richards 2010). It was noted that 4%-50% of flowers robbed by the Eastern Carpenter Bees drew 65%-100% of Honey Bees to that plant (Sampson et al. 2004). This unique adaptation of robbing nectar was only observed in the X. virginica (Adler and Irwin 2006). To see the Honey Bee, A. mellifera for yourself, click the link here.

        This interaction not only helps species with shorter tongues like the A. mellifera gather nectar, but it is also very beneficial to the plant. After the nectar is robbed, the Rabbiteye Blueberry Plant, V. ashei, has an increase in the amount of pollen grains on the plant by about forty grains of pollen. This increase in pollen is about twenty times higher than if the plants had not been robbed by X. virginica. Increasing the amount of pollen heightens their chances of being collected by pollinators to help with cross fertilization. Cross pollination levels help with pollination, fruit set, and seed production. Overall, we can see that the interaction between X. virginica, A. mellifera, and V. ashei act as mutualistic relationships with each group benefitting in different ways (Sampson et al. 2004).
        Plants have many forms of reproduction aside from nectar that must be taken into account including the use of pollen grains. Larger bodied X. virginica are able to carry the greatest amount of pollen on their bodies after a floral visit compared to Bombus bimaculatus, Apis mellifera, Osmia lignaria, and Habropoda laboriosa. While X. virginica can carry the most pollen, this is not advantageous to the plant as they have the lowest pollen transfer despite their large size. This could result in a lower fitness for the plants that X. virginica are attracted to as this pollen is not being spread to other plants (Adler and Irwin 2006).

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