The current agreement calls for scientists to set similar traps in forests around Chinese ports. The traps could confirm large populations, providing the evidence U.S. officials need to back up arguments for cargo inspections.
Past studies have shown that gypsy moths are attracted to light; they swarm from infested forests to the bright lights of nearby port cities and docked ships. Once an infested ship docks in the U.S., its infested containers can also disperse quickly.
This summer, the U.S. is seeing massive gypsy moth outbreaks in Pennsylvania and northern New Jersey. But nowhere is the gypsy moth's attraction to light more apparent than in far eastern Russia, which is in the second year of its worst outbreak since the early 1990s, says Steven Munson, the U.S. Forest Service’s team leader for the overseas monitoring program. He notes that larval caterpillars have been chewing through the vast forests around two major shipping ports—Vostochnyy and Nakhodka—near the Chinese and North Korean borders. U.S. scientists headed there last week to help check traps and search for egg masses, he says.
A naturally occurring virus helps structure gypsy moth infestations into cycles: An outbreak may last three years before the virus sends a population into dormancy for more than 10 years, Munson says. By mid-August, when the female Russian moths typically emerge from pupae and start laying eggs, researchers should know whether to step up ship inspections there or whether the virus is causing a new die-off.
*Note (7/14/08): Patrick Tobin's title has been modified since the original posting.