For Release October 23, 2005

The Little Black Moths

AGRI-VIEWS
by Chuck Otte, Geary County Extension Agent

I wish I had a dollar for every time someone has stopped me, the past couple of weeks, and asked me what all the little black moths are that are everywhere. People are stopping me on the street, in the grocery store, calling my office or visiting me at social gatherings. The little black moth is the adult of the green cloverworm, so it's the green cloverworm moth. More on that shortly.

Moths, and butterflies, are the adult form of species in the insect order known as lepidoptera. Little butterflies do not grow up to be big butterflies. Once an insect has wings and can fly, they have reached their final life form. There will be no more molts and no other changes. Adult lepidoptera have a sucking mouth part. They have a little tube that they can curl up and all they can do is suck nectar and liquid. A very few moth species have no functional mouth parts and only live a few days on the fat stored in their body.

So, moths can not eat your clothing. Moths can not get into your dry dog food or flour or grain products and eat them. However, the larvae of all lepidoptera species have chewing mouth parts. These are the damaging forms. The caterpillar (larva) of the clothes moth will eat up your woolens. The caterpillar (larva) of the Indian meal moth will get into your dry cereal or bird feed and eat up the grain and leave a webby mess.

In the late summer and early autumn, there are many native plants that are in bloom. These plants provide a great food source, and attraction, to many insect species including butterflies and moths. But when we have an extended warm spell well into October, like this year, many of these native plants just quit blooming and concentrate on making seed. Often, the only remaining flowers are the nonnative flowering annuals and perennials that are in our yards and gardens. These flower beds become the last nectar oasis for many of these butterflies and moths. Some of these will continue to lay eggs and then die with the first freezes of winter. Some of them will actually find a place to hibernate and spend the winter. And other species will go through the winter in a cocoon or chrysalis, waiting until spring to emerge as an adult.

The green cloverworm larvae feeds primarily on legume plants, obviously like clover, but also alfalfa and beans, including soybeans. We have green cloverworms every year in Kansas. But natural predators, including a fungus often prevent the green cloverworm from developing into large populations.

Something different happened this year. In late August and September, the green cloverworm populations exploded. And the cooler damper weather that usually triggers the fungus to start developing on the cloverworms, didn't come along. The cloverworm populations were very obvious in virtually every soybean field in eastern Kansas. If you were watching closely you may have noticed that the soybeans started looking funny in September. This was caused by green cloverworm feeding damage. A few fields were so heavily infested they had to be sprayed.

With these high populations of green cloverworm larvae, we shouldn't be surprised that a few weeks later we have high populations of green cloverworm moths and they all were attracted into town to our flowers. They are not a problem, you do not need to spray for them, and high populations may or may not lead to large numbers of green cloverworms next year. Once we have a few hard freezes, they will be gone. Until then, enjoy yet another little marvel of the natural world!

-30-

Return to Agri-Views Home Page

Return to Ag Home Page