Scientists working on environmentally friendly ways to combat insect pests continually quest for biological control’s version of a better mousetrap: natural enemies of a harmful species that outperform those already employed against it. In the case of invasive pests, the hunt may take scientists far afield, even to remote corners of the globe. So it was that Dr. Jian J. Duan, an entomologist at the United States Department of Agriculture’s Agricultural Research Service in Delaware, trekked twice into the vast forests of Russia’s Primorsky Krai region, a magnificent wilderness of mixed hardwoods and conifers so wild that it is a last stronghold of the majestic Siberian) tiger.
The search for parasitized eggs drew Dr. Duan, accompanied by Russian forestry scientists, into the deep woods of interior Primorsky during 2009 and 2010. Finding wasp eggs was rather like a game of hide-and-seek because EAB deposits its eggs under loose bark or crevices in bark. Duan went from tree to tree, stripping away bark and looking for eggs. Not just any eggs, but eggs that had turned black, a tip that the wasp had visited them.