Wednesday, June 16, 2010

Snowbush Spanworms

Snowbush Spanworm (Melanchroia chephise)

If you have a snowbush (Breynia nivosa) in your yard you may want to look for these colorful creatures. The snowbush spanworm (a caterpillar), is a member of the “inchworm” family. The caterpillar (larva), also known as the snowbush spanworm, emerges from eggs laid on the leaves of the snowbush. They also love to eat the leaves of the snowbush, and can be voracious eaters. These caterpillars eventually pupate in the ground and emerge as the white-tipped black moth. This beautiful moth (adult) in turn lays eggs on the snowbush plant, thus continuing the cycle. One very interesting characteristic of this moth is that it flies during the day, while most moths fly at night.

White-tipped Black Moth (Melanchroia chephise)

Now, before you break out the pesticide, consider simply enjoying the multicolored moths and caterpillars along with your colorful snowbush foliage. That being said, if you have an unusually high number of caterpillars and no predators to control them, they may damage or even destroy the plant, so you have to decide for yourself if any action is necessary. If you need to control the population you have a few options:

-Find the salmon-pink colored eggs and smash them.
-Prune branch tips with many caterpillars and dispose of them.
-Spray small caterpillars with an insecticidal soap.
-Treat with Bacillus thuringiensis (B.t.) product such as Thuricide or Dipel. This is a biological control (a bacteria in this case) that is only toxic to a specific group of insects.

Please see the following fact sheet written by Doug Caldwell, an extension agent and entomologist in Collier County. This fact sheet contains more photos, including that of the eggs:

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