Armyworms On The March, Leaving Dead Lawns In Their Wake In Kansas City Area

Masses of the green or black worms are chomping across lawns and leaving hundreds of homeowners with nothing but shriveled roots in their wake, area experts say. And the infestation is slowly creeping into Missouri turf.

"These guys are just devastating a lot of area lawns," said Dennis Patton, Johnson County extension horticulture agent. "We've been inundated with calls."

Patton and many lawn care experts call it the worst destruction they've ever seen from the armyworm, largely because the mild winter and, until recently, the mild summer have provided ideal breeding conditions.

The worms, no longer than an inch and a half, not only can destroy lawns, but they also shoot right off the yech scale.

The owners of one Johnson County home told their lawn care service that after a morning walk, their shoes were covered in green goo. Another insisted her yard was blanketed with mucus.

Even the most doting lawn owners are susceptible. In fact, the worms have shown a highly selective appetite so far. "These little worms may not be very high on the evolution scale, but they certainly know where a good buffet is," Patton said.

That tidbit of information came too late for Becky Ross of Lenexa, a Johnson County master gardener. Her landscaping has graced the pages of national magazines, but come fall she will be reseeding, just like many others. "I'm a master gardener, but it didn't do me much good," Ross said. "I've never heard of armyworms before in my life. We've had birds in our yard – now I think I know why."

Ross said she noticed dry patches in the yard but assumed it was the intense heat browning the grass.

Dead grass is all that many homeowners will notice, but with close inspection on bended knee, they're likely to see masses of the worms. If not, many homeowners may not discover the damage until fall, when lawns typically recover from summer stress. It may be too late by then, Patton said.

There is good news, though. The worms can be easily killed with an insecticide, and they are only expected to feed for another week or two. At that point, they'll burrow into the ground and transform into their pupate stage, similar to a cocoon, for the winter. Come spring, the pupae will become moths. However, unless there's a repeat of this year's weather, chances are armyworms won't be as abundant next year.

Unlike grubs, which eat roots, armyworms feed on the grass blades and expose the critical base to the intense heat. As temperatures soar this week, lawn-care experts think the damage is likely to kill many area lawns.

Patton said as many as 100 worms per square foot have been reported in the Wichita area, where homeowners have been battling the worms for a few weeks. The destruction hasn't reached that level yet in the Kansas City area, but 75 percent of the customers at the Grass Pad in Leawood are asking for pesticides that kill the aggressive worms, said manager Corby Predmore.

The calls for help are also continual at TruGreen ChemLawn branches in Shawnee and Kansas City. Agency employees said they even found a few of the worms eating their way across the Shawnee property where the business moved a month ago.

It's difficult, if not impossible, to predict and prevent such outbreaks, Patton said. It wouldn't be reasonable to expect agencies to treat for the armyworms in a typical year, he said. "Putting an insecticide on a month ago would not have helped a week ago," he said. "Things just happen and for some reason, bingo, we got it this year."