Garden Pest Identificatin Request

Asked June 30, 2020, 9:19 PM EDT

Hello, I am wondering if your office would be able to help me identify a bug that has been pestering my garden all year. I mainly lives on my brassicaceae and most of my leafy greens. I have some bright green worms and white butterflies, but critter in the attached image is certainly the most prominent pest in the garden. I would really appreciate your help in identifying this pest and possibly offering some remedies. Thank you, Alexis

Yamhill County Oregon

1 Response

Hi Alexis, seems like something is always out to eat our tasty veggies. The white moths that you see flitting erratically around are the adult version of the cabbage looper moth or the imported cabbage worm. They lay eggs on the leaves which hatch into those green “worms” that you see. Those green worms are actually caterpillars which dine on your brassicas until they are large enough to spin a cocoon prior emerging as an adult moth to start the cycle all over. They eat holes in the leaves of all brassicas. At the home gardeners’ level, the easiest control method is to search and destroy by hand. This publication from OSU Pacific Northwest Handbook Insect management on “Imported Cabbage Worm” contains more detailed information. This second publication is from UC Davis Integrated Pest Management page on the “Cabbage Looper”. It has clear photos of the culprit and the damage it causes in addition to yet more information on its lifecycle and control measures.

The other typical problem is our ever present friends-slugs. Put out slug bait to keep their population in check. I think that the slugs and the caterpillars are responsible for all the damage that you are seeing.

I am unable to determine the identity of the pictured insect, it just isn’t clear enough. Insect identification is best done with the physical specimen in hand. At this point in time Master Gardeners are not able to go into the Extension Office to work on gardening problems. If you need know the identity right away, you may leave a sample at the office at 2050 NE Lafayette Ave., McMinnville on Tuesdays or Thursdays between the hours of 10-3 and one of the staff may be able to identify it for you. Or you can wait until Master Gardeners are allowed to once again work with the public face to face.