A few months ago, I wrote a post about how some fairyfly wasps had managed to shrink to lilliputian sizes by shedding nuclei. Although this wasp (Gonatocerus ater) is much larger (though still miniscule), it too had a trick up its antenna. It made its way across the country in less than a year.
Credit: Jason Mottern, UC Riverside Department of Entomology.
In August, 2010, the first North American specimen of this species was discovered by Serguei Triapitsyn (principal museum scientist from the University of California, Riverside) in upstate New York. By August, 2011, it was found in Irvine, California. Three thousand miles is pretty far to travel in one year when you’re only a millimeter long. That’s almost 5 billion body lengths. If the tiny insects had journeyed under their own power, they’d have had to move millions of body lengths each day, the equivalent of a six-foot man traveling well over ten thousand miles a day. Of course, it’s much more likely that G. ater hitched a ride to the west coast, just as it originally must have done from Europe.
The good news is that G. ater isn’t likely to be an ecological threat, and may even be a boon. Like all fairywasps, G. ater makes its living by laying its eggs inside the eggs of larger insects. I’m sure I don’t need to tell you what happens to the hosts. In this case, the victim of choice is most likely a leafhopper (Rhytidodus decimaquartus), a pest that feeds on Lombardy poplar trees. In fact, the researchers suggest that G. ater was transported within leafhopper eggs that were themselves attached to sticks.