Abstract
European Gypsy moths are regarded as the greatest insect pests in the United States as they have been reported to cause severe damages both to the environment and the economic features. These insects are believed to have emerged from Massachusetts after they were accidentally released by a professor who was doing research on silk production. They later spread across the United States through two different ways. One, they spread across short distances naturally where the caterpillar stage climbs to the top of a tree and spin a silk thread which allows them to be blown by wind a process called ballooning. The second way involves the queen laying her eggs on household equipment such as vehicles which enables them to be driven away too far off destinations. These insects have been known to cause much damage to the environment and also economically as the caterpillar stage feeds on various trees and shrubs thus leaving them to die or prone to other infections.
Various environmental and economic problems are associated with the European Gypsy Moth. As a result of this, studies have been undertaken on finding the best ways, in particular the Bacillus Thuringiesis, of controlling the effects and the spread of the insect. Bacillus Thuringiensis has been found to be the best control of European Gypsy Moth, although there are other alternative.
European Gypsy Moths damages and kill trees and shrubs where they eat the entire leaves and the needles. The metamorphism stages develop from the egg, larva, pupae and then the adult. These insects occurred after a professor who was carrying out research on silk accidentally released them. This contributed to the spread of the insects to the Northeast into parts of Virginia, Ohio and Michigan. The spread occurs through a natural process where the caterpillars climb to the top of a tree and shed a s silk thread which allows them to be blown off by the wind to various locations. This behavior is known as ballooning. Over the past few years, these insects have moved over long distances on outdoor household equipment such as vehicles, firewood and other possessions as the female moths lay most of their eggs on such kind of equipment (Spruce et al, 403).
These insects feed on many kinds of trees and shrubs where they defoliate the trees and leave them for dead or prone to other infections and pests. The female moths lay large numbers of eggs which range from 500 to 1000 eggs in every turn. They cover the eggs with their wings and bodies in order to provide some additional protection during the cold seasons. After this process, the eggs develop into larva where the instar larvae feed on the top branches by chewing small holes in them (Resh and Ring 275). The second and third instars feed from the outer parts of the leaves towards the center. This process occurs when the population is very high as they compete for food. When the population is low, the younger larvae prefer feeding during the day while the older larvae feed at night.
The European Gypsy Moth spread considerably at slower rates due to the fact that the female moths cannot fly and thus makes it harder for the species to get to areas where they can flourish. Nevertheless, these insects manage to take over areas of the Northeast due to the fact that the female eggs lay masses of eggs and the caterpillars that hatch are capable of eating over 300 species of trees and shrubs. Research has shown that during the defoliation process, the insects feeding process sounds like moderate rainfall (Resh and Ring 280). This can defoliate an entire forest. The effects caused by these insects are largely felt on the environmental and economic aspects. The effects depend on the species of trees, the amount of damage done, the health of the tree and available soil moisture. There are several effects that affect the environmental and economic aspects.
Wild animal feed from the trees and others live with them or under them. Defoliation brings about severe effects as all the animals will be left with no food or dwelling places as most of the forests are damaged and the organisms lack plants, food, shelter and shades. In addition to this, these pests have affected the ecological cycle in that they damage forests which help in absorbing some of the carbon dioxide produced by humans and animals. This affects the environment as rainfall formation is altered and thus drought as well as respiratory diseases that occur due to pollution of air (Spruce et al., 433).
Similarly, the gypsy moths have brought significant effects to the economic view as they affect the timber production process. Most of the timber used comes from healthy and strong trees that have grown properly. These insects have affected the growth of trees and thus causing negative effects on the production of timber that is used to make furniture as well as other resources. They have also affected the tourism industry as the wild animals have had to migrate to other places where they can get food and shelter. Tourists who travel to reserves and game parks have reduced in numbers as there are no animals to watch. The tourism industry is a big contributor to the country’s economy but the insects have affected this source of revenue. Recreation facilities have also been largely affected as people lack places to relax under shades or play around since the trees around these areas have all dried up or died thus causing them to be un-conducive.
The government as well as research companies have invested so much money in trying to curb the infestation of these insects and the disease that arise in effect to the damages they cause. Millions of dollars have been spent in trying to control the spread of these insects which also affects the economy. The drought effect that arises due to defoliation has made the government to spend or lose much money in providing for areas heavy struck by the disaster. For instance, the urban Forestry in the United States has allocated about $ 300,000 for tree maintenance this year and to initiate the European Gypsy Control program (Whitmire, 235).
The process of controlling the gypsy moth has resulted in the use of Bacillus Thuringiensis Kurstaki. This is a naturally occurring bacteria found in the soil that is used as a pesticide to control gypsy moth. The first incidental activity of this bacterium was discovered in 1911 and it has been in use ever since. It is a spore forming bacterium that produces crystal protein which are poisonous to many species of insects/ it can be found almost everywhere in the world as it is distributed in the soil. It is largely used in agriculture mostly in organic farming and in urban aerial spraying programs. It works in such a way that it has to be eaten in order to cause mortality after which the toxin dissolves in the high pH insect gut and become active. The toxin then attacks the gut cells of the insect rupturing holes the lining.
The spores of the bacteria spill out of and germinate in the insect thus causing death within a couple of days. The toxin prevents the insects from eating the treated parts of the plant. The main advantage about this bacterium is that they do not cause disease outbreaks on their own. They are also not harmful to the environment as when sprayed on the plants and diluted 99% of it is water. They also contain ingredients that make it stick to plant leaves thus offering protection to the leaf. Another advantage is that they have residues of food crops and act as preservatives that have been approved by researchers for use on food (Sansinenea, 376).
The disadvantage of this bacterium is that it brings about allergic reactions such as skin rashes, irritation of the eyes, nose and throat. Respiratory diseases are also part of the disadvantages brought about by use or exposure to Bacillus Thuringiensis especially to person's illnesses such as leukemia, AIDS or other immune system deficiency. Therefore, the Bacillus Thurindiensis bacterium is not a proper control of gypsy moth because it has effects on the health of human beings through the allergies and respiratory diseases.
An alternative method of controlling gypsy moths is mass trapping. It involves setting up pheromone traps in the forest in areas that are infested. This will prevent the male moths form mating with the female ones as the female moth is on the ground. This method will reduce the population of these moths by monitoring and comparing the number of male moths caught each year and the number or proportion of unfertilized egg masses found in the treatment area. The main advantages of this process are that it does not involve any spraying and trapping results even if fertile egg masses, they will not increase the population (Resh and Ring 395). The method provides highly accurate delimitation of moth populations resulting in a reduction in potential treatment areas. The disadvantages include: the process has not been proven to eradicate all the moths. It is also limited in that all male moths must be captured before they reach a female for the method to be successful (Resh and Ring 400).
In conclusion, European gypsy moths have brought about huge impacts on the environmental and economical spectrum and critical steps should be taken to curb the situation. Various methods should be strategized to prevent the spread and control the levels of damages caused by these insects.
Works Cited
Resh, Vincent H, and Ring T. Cardé. Encyclopedia of Insects. Amsterdam: Elsevier/Academic Press, 2009. Print.
Sansinenea, Estibaliz. Bacillus Thuringiensis Biotechnology. Dordrecht: Springer, 2012. Print.
Spruce, Joseph P.; Sader, Steven; Ryan, Robert E.; Smoot, James; Kuper, Philip; Ross, Kenton; Prados, Donald; Russell, Jeffrey; Gasser, Gerald; McKellip, Rodney; Hargrove, William. "Assessment of MODIS NDVI time series data products for detecting forest defoliation by gypsy moth outbreaks." Remote Sensing of Environment 115.2 (2011): 427-437. Web.
Whitmire, Stefanie L.; Tobin, Patrick C. "Persistence of invading gypsy moth populations in the United States." Oecologia 147.2 (2006): 230-237. Web.
