Aesthetic & Economic Impacts

Aesthetic and Economic Impacts of the Gypsy Moth in Residential Areas

The gypsy moth has been the major introduced pest to eastern North American forests and urban areas since the early 1900's. Despite its increasing abundance and range extension, most people know very little about the gypsy moth, its biology, and it's impacts. It is not surprising, then, that most people are not prepared for the impact of the gypsy moth during severe outbreaks.

What, then, are the "impacts" of a gypsy moth infestation? Most scientists recognize two categories by which insect impacts are assessed: aesthetic and economic. Aesthetic impacts involve human perceptions and the "relationship" that people have with their property and its visual appeal. Economic impacts include those factors that can be measured monetarily (e.g., tree loss, cost of prevention, cost of control).

Aesthetic Impacts

Defoliation (leaf loss) due to gypsy moth caterpillar feeding occurs during late spring to mid-summer - the time of year when most people spend a significant amount of time out-of-doors. Homeowners who have spent the year grooming their trees and landscape begin to watch the fruits of their work disappear in literally a matter of days. Large numbers of caterpillars begin to strip the trees of leaves while caterpillar feces seems to rain down from the sky. When a tree becomes defoliated gypsy moth caterpillars begin to wander in search of fresh foliage. The landscape begins to lose its beauty (i.e., an aesthetic impact), caterpillars become a major nuisance, and people feel helpless because, at this point, it is virtually impossible to solve the problem.

A defoliated forest in northern Virginia.

For most people, gypsy moth caterpillars are a nuisance. For others they can become an ordeal. Even temporary health problems can arise due to allergic reactions to the hairs covering gypsy moth caterpillars and egg masses. These allergies last only as long as gypsy moths are abundant. However, some people suffer severe anxiety and in some cases psychosomatic disorders called illusory and delusory parasitosis.

Gypsy moth caterpillars that have died due to starvation.

Aesthetic impacts associated with gypsy moth infestations can be difficult to quantify however, a New Jersey study showed that residents forfeited almost 200 days of recreational use of their property during an outbreak. Perhaps those who suffered most were those who devoted countless hours beautifying their landscapes.

Economic Impacts

Unlike aesthetic impacts, economic impacts are more tangible and directly relate to property value. Several studies show that trees in residential areas increase property values from between five to fifteen percent (Dwyer et al., 1992). The presence of defoliated, dying, or dead trees therefore, can decrease the salability of the property and its value. There is at least one example of a Virginia land owner who was unable to sell property because it was infested and subsequently defoliated. In addition, trees that are defoliated may die and have to be removed. Tree removal will cost homeowners either the time required to remove the dead tree(s) themselves or money to hire tree and stump removal experts. This can run into hundreds of dollars.

Another economic impact of the gypsy moth is the cost associated with prevention and control. Costs are incurred with determining whether a population should be treated and then, of course, there are the actual costs of control (e.g., insecticide application). Depending on the size of a piece of property and the number of trees control costs can run into the hundreds of dollars. A survey conducted in New Jersey (Kegg 1976) showed that homeowners who chose commercial control programs spent almost four times as much as those homeowners who participated in cooperative public control programs. Similar results were reported by Moeller et al. (1977) where they found that commercial control programs cost homeowners more than twice that of homeowners who participated in cooperative gypsy moth management programs. Cooperative programs can be based with states, counties, or cities or even be composed of groups of independent homeowners who want to save money. It is advisable to call or visit your local Cooperative Extension office to obtain gypsy moth control advice before contacting a private pest control operator. Your locality may have already established an organized gypsy moth management program.

References Cited

Dwyer, J. F., E. G. McPherson, H. W. Schroeder, and R. A. Rowntree. 1992. Assessing the benefits and costs of the urban forests. Journal of Arboriculture. 18: 227-234.

Kegg, 1976. In C. C. Doane and M. L. McManus (eds.), The gypsy moth: research toward integrated pest management. USDA Forest Service Tech. Bull. #1584.

Moeller, 1977. In C. C. Doane and M. L. McManus (eds.), The gypsy moth: research toward integrated pest management. USDA Forest Service Tech. Bull. #1584.