Ecology and Sustainabilty

Title:

            The chosen topic for the paper is based on an invasive species. The research question for this paper is: Does predation by native woodpecker species increase mortality and therefore regulate populations of the invasive Emerald Ash Borer in hard wood forests of South-eastern Michigan, USA?

Literature Review:

According to Koenig and Liebhold (2017), it has been stated that the emerald ash borers result in the massive destruction of the ash trees on account of parasitic manifestation. However, the researchers critically performed a study to access that whether or not the emerald ash borer species (EAB) have an effect on the primary predators locate within the concerned geographical area. The findings of the study revealed that the woodpeckers who are the primary predators of the bird can help in the prevention of the manifestation of infection within the ash trees and at the same time control the population of the EAB. At the same time, the scientists also deduced that the EAB served as a source of nutrition and helped in the increase of the bird population especially during the winter months. This findings were based upon the data retrieved from the American Breeding Bird Survey Data.

Another study conducted by the researchers Therese et al. (2018) state that woodpeckers have been identified as the biological predators that extensively feed on the emerald ash borer. The researchers predicted that the mortality rate of the emerald ash borer is extensively being affected by the wood peckers. In order to regulate the mortality rate, the researchers conducted a cohort study. Four parasitic wasps from Asia were introduced that parasitized the larvae of the emerald ash borers. It characteristically revealed that there was a major reduction in the foraging activity of the woodpecker. The findings crucially state that the woodpeckers do not prefer parasitized larvae primarily because of lower nutrition value.

             However, Flower et al. (2014), used an interventional, observational and destructive tree harvesting approach to determine the effect of bark-foraging bird predation on ash trees. Further it was compared with the rate of non-ash trees. The study included the deciduous forest belt in Ohio and then the results indicated that emerald ash borer had a great impact on the forest, bark forage birds and majorly affected the ash trees compared to the non-ash trees (Flower et al., 2014). Further, due to this effect, the number of healthy canopies also decreased. This was witnessed by the presence of more than 46 ash tree sampling which determined that due to the predation of the bark-foraging birds, the number of tree level emerald ash borer decreased which was speculated to grow up to 85% in normal condition. Therefore, the researchers were able to determine that due to the presence of native bark-foraging birds, the amount of emerald ash borer decreased and increased the number to a great extent (Flower et al., 2014).

On the other hand, another research article by Jennings et al. (2013) indicated the aspect that there is evidence to support the fact that emerald ash borer or Agrilus planipennis, is a beetle responsible for the destruction of ash trees, in North America. Therefore, a study was conducted to detect the pattern of the primary bird predator, woodpecker and then decides the strategy using which the manifestation of the beetle infestation can be prevented in parts of North America (Jennings et al., 2013). For this purpose, the researchers included the ash trees of New York and then determined that most of the trees were affected by the presence of this specific beetle however the predation of woodpecker also affected the population of beetle drastically. However, the trees which were ash borer free were also inclusive of a large number of larvae which pointed out that for the complete destruction of this beetle, the larvae must be destructed. Hence, this factor was highlighted by the researchers Jennings et al. (2013) in their research article.

 Jennings et al. (2016), aimed to evaluate the significant difference in the control of the beetle population on exposure to woodpeckers. The authors compared and evaluated the findings of the research based upon the ash trees in New York and Maryland. The findings stated that the trees that were not exposed to the woodpeckers had greater population manifestation of the beetles compared to the trees that were foraged by the woodpeckers. At the same time the researchers established that the woodpeckers alone are not responsible for controlling the population of the beetles but have a major role in the process of biological control.

Conclusion:

            Hence, to conclude it can be said that the introduction of a biological invasive species such as Picoldes pubescens can help in the biological control of the emerald ash borer intensively. Further, on the basis of the research studies it can be said that to reduce the rate of infection caused by the beetles the larval growth needs to inhibited. It can also be said that the beetles subsequently help in enhancing the population rate of the predators specially during the winter season.

References:

Flower, C. E., Long, L. C., Knight, K. S., Rebbeck, J., Brown, J. S., Gonzalez-Meler, M. A., & Whelan, C. J. (2014). Native bark-foraging birds preferentially forage in infected ash (Fraxinus spp.) and prove effective predators of the invasive emerald ash borer (Agrilus planipennis Fairmaire). Forest Ecology and Management, 313, 300-306.

Jennings, D. E., Duan, J. J., Bauer, L. S., Schmude, J. M., Wetherington, M. T., & Shrewsbury, P. M. (2016). Temporal dynamics of woodpecker predation on emerald ash borer (Agrilus planipennis) in the northeastern USA. Agricultural and Forest Entomology, 18(2), 174-181.

Jennings, D. E., Gould, J. R., Vandenberg, J. D., Duan, J. J., & Shrewsbury, P. M. (2013). Quantifying the impact of woodpecker predation on population dynamics of the emerald ash borer (Agrilus planipennis). PloS one, 8(12), e83491.

Koenig, W. D., & Liebhold, A. M. (2017). A decade of emerald ash borer effects on regional woodpecker and nuthatch populations. Biological Invasions, 19(7), 2029-2037.

Murphy, T. C., Gould, J. R., Van Driesche, R. G., & Elkinton, J. S. (2018). Interactions between woodpecker attack and parasitism by introduced parasitoids of the emerald ash borer. Biological Control, 122, 109-117.