The Asian Long Horned Beetle
Introduction
The sustained existence of our environment and ecosystem is quickly being diminished and depleted by invasive species. Invasive species can be thought of as non-native, or alien species to a specific ecosystem that immediately causes economic or environmental harm or even harm to human upon introduction (7). This is concerning not only to our well being, but also on a macro-spectrum, our environment. In time where global warming and industrialization are already challenging the preservation of the biodiversity of ecosystems, invasive species are becoming an increasing threat to environments and ecosystems. A species that has recently threatened and destructed many states including Massachusetts, New York, and Ohio, is known as the Asian Long-Horned Beetle. The Asian Long-Horned Beetle attacks many species of trees, including “poplars, maples, elms, and mulberries” and has a primary impact on street trees (5). Although the beetle is no bigger than an inch, it definitely packs a punch, causing massive and widespread destruction, which costs several hundreds of dollars to be spent per infestation.
Background on the Asian Long-Horned Beetle The Asian Long-Horned Beetle is a native to Asia and was introduced to the United States in 1996 from “wood pallets and other wood packing material accompanying cargo shipments from Asia” (7). The Asian-Longhorned beetle is a tiny creature that is measured to be 1 to 1.5 inches in length and antennae that can be as long as four inches. They can be spotted by their shiny black exterior with white spots, as well as their white and black-banded antennae (2). Given its recent introduction, it didn’t take long for it to leave its impact on our environment. The first report of the effects of the Long-Horned Beetle came in August 1996 from Brooklyn, New York where they were discovered on many hardwood trees. Soon after in 1998 another report came from Chicago, Illinois. Reports would later report the spread of the Beetle in New Jersey, Massachusetts, and Ohio. The beetle feeds on an ultimately kills numerous amount of trees within the United States, and leaves many areas of the country and its ecosystems at risk for vast destruction.
The Life of an Asian Long-Horned Beetle
Given the amount of destruction that the Asian Long-Horned Beetle can cause, it is surprising to find out that the species lives for an extremely short period of time. The lifespan for a male is 50 days and 66 days for females. The reason the Asian Long-Horned Beetle can cause so much destruction in such a short time is because of its incredibly high reproductive rate. The life cycle of the Asian Long-Horned Beetle can be classified into four stages: egg, larvae, pupae, and adult (3). The first stage of the life of the Asian Long-Horned Beetle is the egg stage. North Dakota State University gives a report on this process: “in preparation for egg-laying, females chew oval grooves in the bark in which they lay one egg about 5-7 mm in length.” The report also states that on average a female will lay about 25-40 eggs, and the eggs will then hatch in one to two weeks (3). After the eggs are hatched, the next phase of the life cycle begins in which the young larvae will begin feeding by chewing their way trough the vascular tissue of the tree and moving into the wood (About). As the larvae grows larger they will begin to migrate deeper which creates tunnels in the trees when they feed, and the pupation will then physically happen within these tunnels the larvae create in the wood (3). There transition between pupae and adult happens in summer, and when finally adults, the beetle will exit the tree by “creating large exit holes about 10-15 mm in diameter” (3). Adulthood takes place between early summer and mid-fall. It is important to note that the majority of the life cycle and creation of new beetles takes place within the invaded trees and will even begin in aiding in the destruction process of the tree.
How the Vast Destruction Takes Place As previously stated, it is important to understand the creation and life cycle of the Asian Long-Horned Beetle, because it is what causes the vast infestation of our trees. In the following description of the process of infestation, it will become obvious how the life cycle is the equivalent to the destruction cycle of the given trees. In the first stage when the females prepare to lay their eggs they chew out “oviposition cavities” that are found in the trunk bark and branch junctions, or on the trunk itself (5). This has already begun to disrupt the structure and quality of the tree and its bark. In the next stage where the larvae looks to feed to grow, they will tunnel through the vascular tissue of the tree by chewing their way through to move through the wood (4). The vascular tissue of the tree is used to transport fluid and important nutrients from the tree’s crown and its roots internally. Therefore after this process, the beetles have already cut off this crucial system of the tree, causing disruption in future growth and life of the tree. When the newly matured, adult beetle looks to exit the tree it will chew and create large round holes in the tree about 10-15 mm in diameter, which will further deteriorate the tree’s physicality and existence (3). The large holes also will release sap flow, which will cause the tree to be prone to a second attack by other diseases and insects (5). In the final stage of the Asian Long-Horned Beetle’s life as an adult it for a lack of a better word, puts the icing of the tree’s cake by feeding on the bark of twigs and leaves of the tree, which will give final depletion of the tree. Given the short life span and short life cycle of the Asian Long-Horned Beetle it is no wonder why depletion of trees happen so quickly and sweep through specific areas of the country.
Ways to Notice Infestation Although ecological invasive species may not be as important to some as say maybe global warming, or economic crises might be, there has been a recent push by many organization to make it as important. A website created under the United States Department of Agriculture: Animal and Plant Health Inspection Service, gives you many facts and information about the beetle. One of the most important sections of the website is information about how you can tell an infestation is happening. Given that most of the life of the Asian Long-Horned Beetle is spent within the tree, it is much more useful to point out the infested tree then the actual beetle. The website outlines four ways to tell if the beetle has infested a tree: “dime-sized exit holes, shallow scars in bark, sawdust-like material around the tree, and dead branches” (1). The easiest and probably most important way to tell that a tree has been infested is by the dime-sized holes that the beetles create when they exit the tree as adults. The can be ¼ inch or greater and appear as perfectly round holes (1). Similarly you can notice on an infested tree multiple oval depressions that appear on the bark of the tree that are created as the adult female looks to create a space for her eggs (1). Finally, if you can notice any sawdust like material around the tree or can identify that the tree is particular dead or depleted looking, the tree has most likely been depleted. The website stresses numerously the importance of reporting these findings if you see a tree that looks this way, in order to eliminate the spread and hopefully eliminate the impending economic and ecological impacts.
Ecological, Environmental, and Economic Impacts Given all the previous information of just exactly how the Asian Long-Horned Beetle can quickly dismantle a tree, it now proves to be important to identify just how crucial this quick depletion is in our country today. In an article published in 2009 by American Entomologist, it reports:
“Based on a study of urban forests in nine large American cities, it was estimated that the beetle could destroy as much as 30% of the trees (1.2 billion trees) and 35% of their canopy cover; collectively valued at $669 billion. Additionally, it would impact property values, fall foliage tourism, forest products industry, maple syrup production, and aesthetics, as well as significantly reducing the environmental benefits provided by trees” (6).
Not only are the beetles taking down numerous trees in our environment, but also creating harmful effects for the rest of the ecosystem, by taking down all these trees. For example as it says in the previous quotation, by reducing the environmental benefits provided by trees, this means a reduction in clean air, clean water, shade, and most importantly a place to live for many forest bound species. To conclude, not only will the Beetle take out many trees and cause for much investment and trying to eliminate the infestation, but it also has drastic effects for the rest of the ecosystems survival as well as economic survival, for example lumber stores.
How Can It Be Stopped? Although it will take somewhat of a countrywide effort, the spread of the Asian Long-Horned Beetle can be stopped. It is no doubt that the Asian Long-Horned Beetle has many biological advantages that makes it hard to eliminate, like for example that it lives most of its early stages within the tree, which makes it impossible to stop the infestation at the beginning of development, as well as the numerous amount of host trees they have available. As the USDA website exclaims, if we all make an effort to report infested looking trees we can begin a movement to eliminate the spread just as it has been from states like Illinois.
Conclusion
Not only does invasive species pose as a threat to the environment in which the species are hosted, but it also has detrimental consequences to the surrounding ecosystems an economies. The Asian Long-Horned Beetle is a recent example of an invasive species that is able to do just that. In such a short life that is lived mostly within the tree it is hard to stop the infestation as it begins. Due to this, it has caused many ecological and economic hardships in our country, and it needs to be stopped. The Asian Long-Horned Beetle gives a good example of just how detrimental an invasive species can be and just how important it is for us as citizens of this country to do something to stop it.