Pest control - Gypsy moth hunt on Crown Hill
Tue, 06/13/2006
Gypsy moths are back on the radar in Ballard. The Washington State Department of Agriculture (WSDA) is laying almost 1000 traps, predominantly in a 60-acre area of Crown Hill during the month of June. The effort is in response to finding an unusually high number of the moths last year.
"We caught 8 moths in the Crown Hill area ... that's a lot of months," said James Marra, the managing entomologist for the state Department of Agriculture. Marra said the number of moths captured suggests a high likelihood - as much as 75 percent, that a reproducing population could exist, running the risk of permanent settlement by the pest.
Despite a widespread belief that the Gypsy is a common moth, they do not have an established population in Washington State and are not native to North America. Over the last century, the insects have become entrenched in 19 states in the eastern US. The moths defoliate plants, primarily deciduous trees and shrubs, but with very heavy populations where other food is scarce, will also target evergreen trees.
The US Department of Agriculture claims that the moth has been the subject of more intense eradication efforts that any other forest insect and the WSDA lays some 25,000 traps across the state every year as part of its effort to find introductions of the moth. Where the moth is found, the department attempts to eradicate it, often with the use of pesticides. Last year, the Madison Valley in Seattle and a neighborhood in Bellevue were both sprayed for gypsy moths.
Marra said that the traps being laid in Crown Hill, which will be checked around late September, will serve the dual use of providing more information about the moth's population, as well as reducing it.
The traps, tent-shaped boxes not much larger than a pint glass, contain a pheromone, which serves to confuse the male gypsy moth's reproductive instincts.
"The down side is this method is kind of iffy, sometimes it works, sometimes it doesn't.
Mass trapping isn't something we rely on if we have a reproducing population but in this instance we 're willing to try it."
Marra said the state has yet to find physical evidence of the moths breeding, a process often requiring entomologists to physically inspect an area on foot.
If a breeding population is discovered, WSDA will attempt to eradicate the moths, possibly with a strain of BTK, a bacterial agent with a related strain found in most domestically produced corn. The agent poisons the moth, and has proven consistently effective, though there have been concerns, both in the United States and abroad, that the lack of long term studies of BTK can't definitively ensure the product is harmless to humans.
The traps currently being distributed are within a four square mile area between Aurora Avenue North, 24th Avenue NW, NW 98th Street and NW 54th Street.
WSDA representatives distributing the traps in people's yards are required to notify the owner, either in person or by leaving "door hanger" notices.
According to the WSDA, gypsy moth introductions often occur when people living in a moth-infested state relocate to Washington, bringing egg masses, attached to outdoor furniture and vehicles.
Marra said that Washington State gets more introductions than all other western states combined - in part because the temperate forest climate of the state, and partly because unlike states with similar climates, for instance, California, Washington has no border inspection program.
The European gypsy moth is the primary concern of the state agriculture department. Another strain, the Asian gypsy moth, was first found in the United States on an ocean-going ship at the port of Tacoma. Though Asian gypsy moths have yet to gain a foothold in the United States, they are considered a serious threat to Washington State because of their taste for evergreen trees and because unlike the European gypsy moth, the female Asian gypsy moth can fly allowing populations to spread more quickly.