Tag Archives: Wasp

14. Put off by Persistent Pests

5 Nov

This is perhaps the first in a series of Persistent Pests articles I might do in this challenge.

Small and Large Cabbage Whites

The Adult Cabbage White is an attractive looking pale white to yellow Butterfly of the pieridae family of lepidoptera. Introduced to our shores somewhere about 1860, this species of butterfly is highly invasive. In its homelands of Europe and Asia it has one maybe two annual flights, but here in the Americas it can be seen year round in most parts except northern most Canada and the Desert plains of the Southwest. It feeds on the nectar of flowers and since it visits many in its lifetime, this makes it an effective pollinator.

 

cabbage white in California

cabbage white in California (Photo credit: Mollivan Jon)

 

I am not an expert in butterflies, let alone this one. All the information and facts displayed here are an aggregation of facts and photos gathered from a few quick searches on Google and Wikipedia. Since I am currently dealing with this particular pest in my gardens I thought I might quickly compile some information as I learn and find it.

As beautiful as butterflies are and beneficial as they are to a gardener’s efforts in pollination, it is often their more destructive children that get overlooked in the larger picture of pollinators. In this case, after mating the beautiful female Cabbage White lays single eggs on the leaf underside of just about any suitable host plant. Its usual choices are green leafs in the radish and mustard families; this includes cabbages, collards, and kales. Here in North America, since this butterfly flies year round, a single adult female can lay her eggs several more times than her European counterpart.

Estimates show that a single female of this species might be the progenitor in a few generations of millions.

Wikipedia

These eggs then hatch to become the fuzzy green cabbage worm. In larvae of the Cabbage White will continuously munch on the tender green leaves of the host plant until they become a chrysalis and metamorphose into the adult butterfly. As they feed and live the younger worms will start on the underside of the leaves but graduate to the upper face of the leaf. Their fricasse will collect in the center stalk of the plant, looking like little black dots at the base of each leaf. Even though their damage can be hard to look at, if the plant is otherwise healthy, it will continue to grow new greens. Any greens damaged by the worm are still safe for human consumption if there is enough left of it. Just make sure the worm and its fricasse are no longer on the leaf when you munch on it.

Lacinato Kale damaged by the imported cabbage worm

Lacinato Kale damaged by the imported cabbage worm

 

Controlling the Imported Cabbage Worm

Manually removing the worms is by far the best way to control the imported cabbage worm in smaller, garden sized situations. This can be accomplished by simply picking the worm off the plant and dropping it into a solution of soap and water. If you happen to keep chickens, then feel free to feed them to the birds instead.

If you are not so inclined to hand picking the worms, whether because time or preference, then there are safe and organic solutions which can be applied in order to control and/or break the life-cycle of this pest.

  • Garlic Oil – applied in solution will kill the eggs and young larvae and can repel the older larvae and adults.
  • Hot Pepper Sprays – applied in solution will provide similar benefit as garlic oil. Just be careful not to breathe it in yourself.
  • Soaps – applied in solution will cause young larvae to dehydrate
  • Neem Oil – follow package instructions
  • Bt – by far the best organic solution for all caterpillars and leaf-eating worms. This biologic toxin safely targets only caterpillars and leaf-eating worms by poisoning their stomachs. Infected worms are killed in a matter of days. The downside is that Bt breaks down in a matter of 3-4 days of sunlight. Frequent applications may be necessary.

Establishing an inviting habitat for predatory insects and birds is always an effective way to control pests in the garden. Predatory Wasps will lay their eggs inside the soft bodies of these worms and caterpillars. As the eggs hatch the mature, the larvae feed on the insides of the host worm effectively killing it.

Installing physical barriers is an effective way of controlling the spread of this and other insects within your garden. Spun netting framed over the plants will prevent the adult from landing and laying its eggs.

If you like, you can even try catching the butterfly in a butterfly net. Just make sure you dispose of it properly and not in another garden or yard. This is not an endangered or protected species either.

Another method includes using eggshells strewn around your garden beds. Since this butterfly is territorial, it often mistakes the white shell as another adult and will fly away. You can also use an number of home made crafts to bluff or mimic the butterfly away.

I hope this helps. I know I learned a lot more than I bargained for.

Grow it Forward

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