My crop of cabbages, collard greens and kales was my pride and joy until recently. To my horror, several large, irregular holes have appeared on them and to make matters worse, I also found accumulations of round pellets of what appeared to be the insects poop! What garden pests could be causing this damage and how can I control them?
Kihei home gardener
Two caterpillar culprits that could be causing this kind of damage come to mind: the cabbage looper and the cabbageworm caterpillars.
Dear Kihei home gardener,
Two caterpillar culprits that could be causing this kind of damage come to mind: the cabbage looper and the cabbageworm caterpillars. This week we will discuss the cabbage looper.
The cabbage looper is the larval stage of the cabbage looper moth. This caterpillar is green in its mature stage with three pairs of legs (known as prolegs). It has a habit of crawling by arching its back to form a loop and then projecting the front section of the body forward (hence the name cabbage looper). The cabbage looper feeds on a wide range of vegetables--particularly the cabbage family or crucifers, which includes broccoli, cabbage, cauliflower, Chinese cabbage, collards, kale, mustard, radish, rutabaga, turnip and watercress.
When very young, the cabbage loopers feed mostly on the lower leaf surface, leaving the upper surface intact. As they grow older, they chew large holes in the middle of the leaves. On cabbages, they feed on the outer leaves and the developing head, so you must check underneath the leaves and on the inside of the leaves as well.
These caterpillars have been known to eat three times their weight in plant material daily. They have a nasty habit of leaving feeding sites with large accumulations of sticky, wet fecal material (looper poop).
Cabbage loopers are best controlled by the following methods:
Wash off the caterpillars with a blast of water.
Pick up the caterpillars and either throw them in a bucket of soapy water or crush them.
Parasitic wasps and flies are excellent biological control agents for these caterpillars.
Use neem oil
Use Bt (Bacillus thuringiensis, sold under the names Dipel and Thuricide). This is a natural soil bacterium that produces toxins that eventually cause the caterpillar gut to become fatally paralyzed.
Keep the garden clean by removing heavily infested leaves.
To learn more or to sign up for a gardening class, contact Anne Gachuhi, founder/CEO of Home Gardening Support Network LLC, at (808) 446-236, email questions to firstname.lastname@example.org or visit www.homegardeningsupportnetwork.com.