The Year of the Corn Earworm
Nobody likes opening an ear of corn and finding uninvited worms; not customers, and definitely not the grower! Wormy corn can lose customers at the farm stand and in wholesale markets, and can be a problem in both frozen and canned supermarket products. To help growers manage these pests, NYSIPM—in partnership with our Cornell Cooperative Extension colleagues—has supported a network of pheromone traps since 1993. These traps help track the flights of the moths that lay the eggs that hatch into these worms.
In 2018, the trap network alerted growers to an over-the-top population of corn earworm, one of four major sweet corn pests. And because IPM spray recommendations for this pest are based on trap catch numbers, that important data helped New York growers respond effectively to this serious threat to a 33 million dollar crop grown on 26,700 acres. Unfortunately, when a grower or processor finds worms in harvested corn, it’s too late to act—but accurate ID can inform plans for the following season. Essential to success is deciding if and when to spray using the appropriate scouting methods and thresholds for each pest. But accurate ID? Easier said than done! Caterpillars can be hard to identify, especially smaller ones. That’s why we developed a larval ID fact sheet highlighting critical distinguishing features. It’s just another piece of essential information in the quest for worm-free ears.
(Above) Corn earworm invades the ear within hours or days of hatching from eggs laid on the silk, leaving no external damage. For this pest, scouting is ineffective. Pheromone traps that monitor adult flight are the grower’s best defense.
“I” is for Identification.
Good IPM starts with accurate pest identification—ID for short. Whether you see a pest or the evidence it leaves behind, correct ID is essential. Once you know what you’re dealing with, you can determine where it’s coming from, the risks it poses, and what conditions must change to eliminate it. Good ID makes IPM work. Even people who deal with pests all the time need to brush up on their ID skills, so we developed a Structural IPM Short Course to hone the diagnostic skills of pest management professionals, Master Gardeners, and others. Participants attend photo-filled lectures and get their hands on hundreds of real specimens. Critters are grouped by guild—their basic ecological niche—such as food pests, moisture-lovers, or blood-feeders. And specimens aren’t just bugs. Rodent droppings and gnawed wood get examined too. To aid learning and retention, we created a companion manual. We’ve offered the course 21 times, teaching the ABCs (you know: ants, bed bugs, and cockroaches) to over 700 people. And our learners learned: over three quarters gained knowledge of pest biology, while 100% improved their ID skills. We identify that as 100% good news for everyone but the pests.
(Above) These Master Gardeners from Rockland County, like their counterparts in 20 other Short Course workshops, left feeling more informed and confident in the IPM knowledge they’ll share with the public. IPM and Cooperative Extension: a perfect pairing.