Minnesota hires wasp assassins to kill emerald ash borers

stingless wasp tetrastichus.jpg
This sick little bastard is now on the state's payroll.
​Emerald ash borers are real punk insects. They have no respect for Minnesota's trees, and at about an inch long as adults, they're pretty hard to round up by human hand.

As recently leaked documents show, the Minnesota Department of Agriculture has responded to the influx of emerald ash borers (EAB) by employing ruthless wasps, which have been given one assignment: Kill them. Kill them all.

Well, all right, the Ag Department publicly announced that they'd be doing it. Still, what they're not making much of, and what other media outlets won't tell you, is exactly how brutal the stingless wasps' campaign will be.

The wasps, three particularly emerald ash borer-hating species of which are in use, have already been sicked on EAB's in the metro area, after the super-pests were found in both Hennepin and Ramsey counties. Today, the wasps have been dumped into Winona County, the Star Tribune reports.

emerald ash borer.jpg
Do not wear clothing that would make you look like an emerald ash borer.

EAB larvae, as their name implies, bore into the wood of ash trees, and essentially starve them. Minnesota's got 975 million ash trees, and the EABs would kill every single one of them unless they're stopped.

Hence, the wasps. These particular species were bred in Michigan, but carry in their veins -- well, okay, vein -- Chinese ancestry that dates back through the ages.

So, how's it work? You might want to be sitting down.

Apparently, the wasps do to the EAB larvae what the EAB larvae do to the tree. As explained by Monika Chandler, the state Department of Agriculture's biocontrol expert, it goes like this:

Tetrastichus planipennisi adults find and insert their eggs into EAB larvae. Spathius agrili behaves similarly except that the wasp eggs and developing wasps are attached to the outside of the EAB larvae. The developing wasps feed on and eventually kill the EAB larvae. Egg parasitoid, Oobius agrili, adults insert their eggs into EAB eggs on ash bark.

Pretty sick, huh? But tough times call for desperate measures. The lesson here is, do not mess with Minnesota's ash trees.

In order to save those trees, Minnesota finds itself in league with wasps that literally lay their own eggs inside the eggs of the enemy. These things have neither stinger nor conscience.

How much are they being paid? Do we trust them? And when the emerald ash borers are all gone, what will stop them from turning on the humans who trained them?

Some day, Mark Dayton will have to answer these questions. Until then, try not to look like an emerald ash borer larva.

Sponsor Content


All-access pass to the top stories, events and offers around town.

  • Top Stories


All-access pass to top stories, events and offers around town.

Sign Up >

No Thanks!

Remind Me Later >