Please note! This essay has been submitted by a student.
The invasive Emerald Ash Borer (Agrilus planipennis) is a phloem feeding beetle, which has devasted ash trees (Fraxinus spp. ) throughout North American. The Emerald Ash Borer (EAB) was discovered in southeastern Michigan and was soon after discovered in Ontario, Canada (Haack et al. 2002). The feeding behaviours of EAB block the flow of phloem within the effected ash tree, causing mortality within as little as 2 years. Much of the current scientific literature deals with the basic information and impact of EAB on North American forest, however, there is a lack research on suppressing EAB populations. A study done by Flower et al. (2012) looks into the impacts of EAB on the carbon cycling within different forests across the United States. The authors found a loss of ash biometric net primary productivity (~145 g C m-2 year-1).
However, this was partly compensated by non-Ash species (~36 g C m-2 year-1) (Flower et al. 2012). Another Study done by Cappaert et al. (2005) in southeast Michigan looked at the impact of woodpecker predation on EAB. Of the 24 total sampled plots, it was found that the mean woodpecker predation rate was 44%. Few applications and further research opportunities were provided for this study (Cappaert et al. 2005). Both of these studies, neglect to provide suggested actions to prevent or suppress the EAB invasion. A research paper released in 2002 by Haack et al. was the first paper released after the discovery of EAB in North America. The paper contains a great deal of information on the species as well as attempting to inform the public about the signs and symptoms of EAB infestation. The paper suggests contacting the proper authorities if EAB are found (Haack et al. 2002).
A study by Flower et al. (2014) looked at the use of bird predation on EAB larvae, as a way to suppress EAB populations in the Great Lakes region. The study found that bark-foragers were able to reduce EAB populations by up to 85%. The authors suggest the use of bark-foragers to regulate population abundance (Flower et al. 2014). Both papers provide simple ways to suppress populations, however, further research into suppression and control techniques are required. The paper by Haack et al. (2002) documents the introduction of EAB in North America. A number of plots in southeast Michigan were surveyed.
The discovery of EAB, induced the quarantine of Ash tree in a number of areas. The authors ask that if EAB are found, contact the proper authorities (Haack et al. 2002). Similarly, a study done Tluczek et al. (2011) provides potential applications for regulating EAB populations. The study looks into what attracts EAB to trees in Michigan. It was found that EAB were attracted to stressed ash trees, which were either girdled or produced methyl jasmonate. Approximately 30% of control ash trees were infected by EAB, however, EAB were found on 80% of girdled ash trees. Their survey from 2007 found that the larval density of the control group to be approximately 40 (larvae per m2), while the larval density of the girdled group was approximately 177 (larvae per m2) (Tluczek et al. 2011).
Further research into EAB dispersal and attraction could potentially help containment efforts. The study Flower et al. (2014) looks at the use of bird predation on EAB larvae, as a way to suppress EAB populations in the Great Lakes region. The study provides some insight into effects of species interactions on the overall health of the ecosystem. The authors found that predation was dependent on EAB density. Trees with small EAB densities (11. 5±3. 4 beetles per m2) had a smaller number of bark-forager holes (2. 6±0. 7), while trees with large EAB densities (116. 8±33. 5beetles per m2) had a larger number of bark-forager holes (52. 3±15. 1) (Flower et al. 2014).
Similarly, the study done by Cappaert et al. (2005) also focus on species interactions between EAB and woodpeckers. However, the study found a correlation between EAB density and predation in the selected sites (Cappaert et al. 2005). It is evident more research is required before concluding whether or not bark-foragers could be used as an effective biocontrol to help suppress EAB populations. A considerable amount of knowledge about EAB has been gained since their discovery in 2002. However, containment and suppression efforts of EAB in North America require a great deal of additional research, funding and cooperation. An important factor in helping to suppress EAB populations is improving methods of detection, along with an improved understanding of EAB population dynamics and dispersal patterns.