SUNY ESF studying wasps as predators of emerald ash borer

May 13, 2016

Scientists are going to war against an invasive insect that’s decimating the ash tree population in central New York, by using one of its natural predators. While these tiny wasps may not stop the current infestation in its tracks, they may help deal with these kinds of things in the future.

SUNY ESF graduate student Mike Jones spends a lot of time scraping the bark off of dead ash trees. And occasionally, he’ll find a plump emerald ash borer larva.

These trees may hold the key to why some of the different kinds of parasitic wasps that eat the beetles don’t do well in colder climes, like central New York. So Jones is growing wasps to try and find the best fit for upstate New York, feeding them larva and watching them work.

“The female, when she stabs larva, she paralyzes it and then lays her eggs on the larva and then the eggs hatch and consume it alive,” said Jones.

As a biologic strategy to defeat the tree-killing bug since 2007, four species of predator wasps have been released in 22 out of 27 states infested by the EAB. They were released last summer in central New York, but some didn’t make it through winter. So Jones is studying which kind of species will do the best here. He admits the wasps won’t stop the invasion that’s ultimately going to kill all the ash trees in central New York that aren’t treated.

Jones and an ash tree that has already been killed by EAB.
Credit Ellen Abbott / WRVO News

"Where they become really important is after that initial age of emerald ash borer passing through and you have high ash mortality. There are going to be lingering ash that survive, and will become susceptible later to the emerald ash borer.”

And fine-tuning the attack wasps, which are a natural predator to the EAB in China, will also help scientists who have to deal with the next invasive species that comes to American shores.

"It’s not if the next invasion happens, it’s when. With as much trade as we do, we’re getting stuff all the time from other parts of the world. And every once in a while, one of them’s going to establish and do something like this.”