They came from far away.  They are armed with shields, and suits of armor.  They are in our homes, and eating our food.  They number in the millions.  And they stink.

For years they were largely ignored, until apple farmers began noticing damage to their crops.  Then, in the summer of 2010, they were suddenly everywhere, eating everything.  Some farmers in Maryland lost up to 20% of their crops.  Pennsylvanians found them chewing on everything from soybeans to sweet corn.  Soon after, homeowners started hearing strange buzzing sounds, and the tell-tale “pop” of something hitting a lampshade, or plunking onto a counter.  They hang out on your water faucet, or perch on the lip of your wine glass.  And if you annoy them, or try to pick them up, they spray a noxious odor that smells like a skunk wearing dirty socks.  And that, some say, just attracts more of them.

Yep, it’s the invasion of the stink bugs.  Halyomorpha halys, the Brown Marmorated Stink Bug, is a dime-sized, shield-shaped, tough-skinned beetle that came from China, where it is a pest.  It arrived in Pennsylvania as early as 1998 and until recently was just a minor nuisance.  But then, in the summer of 2010, stink bugs were suddenly everywhere, eating everything.  And a lot of people started smelling a big problem.  “I’ve never seen such a serious pest enter the U.S. agricultural system,” said Tracy Lesky, research entomologist with the West Virginia-based Appalachian Fruit Research Station, “if only because they attack so many crops.”  Stinkbugs are tough, reproduce quickly, can fly long distances, and are very good at hitchhiking inside clothes and vehicles.  They can live in wet and dry climates, both cold and warm, and will eat almost anything.  They have been reported in 33 states.  And they may have reached a critical mass.  Said Mike Raupp of the University of Maryland, “If 1 in 10 people had stink bugs in 2010, 9 in 10 people will have them in 2011.  I think it is going to be biblical.”

But help may be on the way, in the form of something as small as the comma in this sentence.  At the Louis A. Stearns Laboratory in Newark, Delaware, some tiny parasitic wasps are wiping out stinkbugs before they start.  The wasps locate stink bug egg colonies and inject their own eggs inside.  There, the wasp larvae eat their way through the stink bug eggs and destroy them before they can hatch.  The Department of Agriculture has been studying this since 2005. They are considering releasing the wasps into the environment, but first they have to determine that the wasps won’t attack other beneficial bugs or cause some other great damage.  That research won’t be complete until at least 2013.  But that may be too late for some.  Said Maryland apple farmer Robert Black, “I had 30 to 35 percent damage last season, and I can’t handle 40 to 50 percent. That’s what I’m scared about.”

Are we headed for the ultimate bug battle, the stinkers vs. the stingers?  Perhaps.  In the meantime, we’re in for one smelly summer.