On the Road with the Gypsy Moth Team

Karla Salp
Pest Program

I entered a strange new world today – the world of monitoring for gypsy moths. Today’s mission: to boldly go where no gypsy moth sterile egg mass had gone before. Don Kitchen, an entomologist with our Pest Program, was captain of this mission and he let me tag along to see what it was all about.

Don holding the sterile egg mass 

An egg mass is just what it sounds like – a fuzzy, mass of gypsy moth eggs that look a lot like piles of brown to cream colored cotton. We use them like a kitchen timer – when the caterpillars on a monitored egg mass begin to emerge, it’s a good sign that egg masses we haven’t found are also starting to hatch.

On a gray, rainy day, we drove south to Vancouver, where Don stopped to scope out potential locations, looking for one that was easy to reach but hidden from passersby.  

Hidden but Accessible

Stapling egg mass to a tree

Sterile egg mass on tree

After finding an ideal spot, Don stapled the egg mass to the tree.  Ease of access is important as Don will visit the sterile egg mass every three weeks. He’ll watch for signs that it is swelling – an indication that the eggs are almost ready to hatch. When this happens it is time to start treating the area for gypsy moth.

Egg mass monitoring provides the most reliable information about when caterpillars will emerge. An especially warm spring, for example, will result in earlier hatching of the gypsy moth caterpillars and require earlier treatment.

Getting Tangled

After stapling the egg mass to the tree, Don pulls out one of his secret weapons: Tanglefoot.

Tanglefoot is a sticky product that is put around the egg mass. If any newborn caterpillars try to crawl away from the egg mass before it is removed, they get stuck in the surrounding sticky goo. Our goal is to protect Washington from a gypsy moth infestation, so we don’t want any wandering off.

Before Don put the egg mass in place, it was sterilized.  Sterilization provides another assurance that should caterpillars miraculously escape even the sticky trap, they won’t be able to reproduce.

GPS for Gypsy Moth

Don logging the egg mass location

Once the sticky trap is set, Don records the egg mass location. A GPS app on his cell phone allows him to map it. The app feeds back into an extensive mapping program that the Pest Program maintains. Not only do they track egg masses, but later in the year they also track where they place thousands of traps around the state and where gypsy moths are detected.

With the egg mass placed and logged, it was time to pack up and head home. Now we'll wait to see how that egg mass develops and when it signals to the world that, "The caterpillars are coming!"

Don’t forget to visit agr.wa.gov/gypsymoth to learn more about this pest and our efforts to keep it out of Washington State.