We’ve had plenty of traffic here at the Myrmecos Blog as bewildered midwesterners look for answers about the swarm of tiny insects that has descended on our cities this week. As best as we can tell, here’s the scoop.
Q: What are the annoying little bugs that are swarming Central Illinois this week?
Q: What are they doing?
Summer has ended, and the aphids are leaving the soybean fields to look for buckthorn to lay their eggs on.
Q: Why are there so many of them?
We don’t really know. Part of the answer is that Illinois farmers grow a lot of soy, so there are plenty of resources to support a bumper crop of bugs. Also, soybean aphids are a new pest for our continent, arriving here from Asia less than 10 years ago. They might have escaped their native diseases, parasites, and enemies. It may also have taken them this much time to build up to the high numbers we’re seeing this year. The cooler, wetter weather earlier in the summer and lower numbers of ladybird beetle predators may also be a factor.
Q: Are soybean aphids dangerous?
No. These aphids do not bite or sting, nor do they transmit any human diseases. Their immediate negative effects are limited to their host plants.
Q: What can I do to get rid of them?
Unfortunately, there is little that can be done. Pesticides are a greater health risk than the insects themselves, and given the sheer number of aphids any strategy short of mass spraying across the entire county will not have much effect. We recommend waiting it out and spending more time indoors if the bugs bother you.
Insect repellents will not work either, as repellents target insects that are attracted to us. The aphids are merely incidental.
Q: Will they harm my garden?
Not unless you have buckthorn or soy. These aphids are picky when it comes to feeding on plants.
Q: When will they go away?
Their numbers should subside once cooler weather hits. We hope.