Having a problem with the white moth/cabbage moth. How do we take care of it?
Linn County Oregon
The white imported cabbage butterfly is a common pest of all cole crops, including broccoli, cabbage, and kohlrabi. The best way to combat their velvety green caterpillars is to install row covers as soon as you plant the seeds or transplants. (See “How to Install Floating Row Cover” http://cru.cahe.wsu.edu/CEPublications/FS089E/FS089E.pdf) Row covers are unlikely to work this season because you would be confining the caterpillars to a handy, enclosed dining room.
For the rest of this season, management must rely on repeated search-and-destroy missions. Every day or two, examine the plants for the velvety green caterpillars (1/4- to 1-inch long; may be on the undersides of the leaves); eggs (upright spindle-shaped and laid singly, most often on the top surfaces of the leaves); and pupal cases. You can see images of all these life stages when you click on the links in “Imported cabbageworm – Pieris rapae” - http://ipm.ucanr.edu/PMG/GARDEN/VEGES/PESTS/importcabwrm.html.