If you are a regular reader of this column, last Tuesday we began a discussion about Integrated Pest Management (IPM) with integrated pest management being defined as an approach to gardening in which we attempt to manage or minimize the problems we have with pests in our gardens without reaching for the pesticide as a first response.

Last week we talked about Cultural Controls; things you could do to help minimize the opportunity for a pest problem to arise. In the case of disease, you could purchase disease resistant seeds or plants. You could make sure your plants are planted in a location that meets their needs for sun and moisture. You could be diligent to inspect your plants for signs of disease or insect damage. When found, diseased leaves or damaging insects can be removed by hand before they become a bigger problem. And last but not least, we talked about how a good layer of mulch can help to minimize the opportunity for disease to transfer from the soil up to the leaves of your plant. Cultural controls are always a good first step. But what’s the next step or next rung up the IPM ladder? Biological Control.

Biological Control

Biological control can sound kind of mysterious like we have some sort of superpower over biology, but it really just means using the good bugs to fight the bad bugs. Granted, no bug is necessarily a bad bug, except mosquitos possibly, but even they have a place in our ecosystem. But yes, we can utilize good bugs to help us control the bad bugs.

A great example of this would be to use Lady Beetles (Lady Bugs) to help minimize or eliminate problems we might be having with aphids. Lady beetle larvae and adults love to dine on aphids, so much so that an adult lady beetle can eat upwards of 50 aphids per day. So, if you find that you are having an issue with aphids on your plants, you can purchase containers of lady beetles at most of our local garden centers. Once you have your lady beetles, take them home and release them in the vicinity of your resident aphids. Problem solved. Just know that once the aphid buffet has been emptied, they will likely leave your garden in search of another nearby all-you-can-eat place to dine.

You won’t necessarily need to purchase lady beetles if you have lady beetles in your landscape and the way you do this is by having a wide variety of flowering plants. These plants will naturally attract a variety of beneficial insects to help not only pollinate your vegetables, but also help to rid your garden of pests.

Another way to encourage natural biological control is to have a bird friendly yard. Birds can be attracted to your yard by the addition of bird feeders and bird baths. But there are a variety of things you can do to help attract birds to your landscape naturally such as providing a natural place of shelter for birds such as a larger holly or similar type of dense, larger shrub.

I know in our yard; we have a bird feeder with the feeder being located only a few feet away from a sizable holly shrub. Smaller birds like finches etc. will go back and forth from the feeder to the shrub while feeding. Any little disturbance and boom, all the little birds have ducked into the holly for safety. So, a spot for shelter is a good idea.

Why do we want birds in our garden? Because they will eat a variety of insects if given the opportunity, especially those juicy, delicious caterpillars. For example, I’ve read that chickadee babies can eat 350 to 500 caterpillars each and every day. A feeding frenzy of that magnitude will probably make a sizeable dent in caterpillar population dining on your cabbage in short order. Problem solved, and baby birds fed.

Biological controls can also help minimize the problem with the dreaded tomato hornworm. Tomato hornworms can do some damage to our tomato plants pretty quickly. We tend not to notice them at first but after a few stripped leaves start showing up, if we give our plants a quick scan, there’s likely a tomato hornworm or two eating away. One strategy is to just physically remove them from your plant and dispose of them. However, there is a small little wasp that does a much better job. I’m talking about the braconid wasp.

Braconid wasps lay their eggs inside of the tomato hornworm caterpillars. When these eggs hatch, they dine on the insides of the caterpillar. When the appropriate time comes, these larvae exit the caterpillar to build a cocoon in which to mature. That is what you see in the photo. If you come across something that looks like this, your natural tendency might be to remove this spectacle of a caterpillar and transfer it to the trash. However, let it be. Its days are numbered, and it is serving as a host to a lot of little braconid wasps that will search out other tomato hornworms to devour. Biological control at its best.

So, now that we have talked about the first two steps in IPM, next Tuesday we’ll move on to the remaining strategies. See you in the garden!

You can get answers to all your gardening questions by calling the Tulsa Master Gardeners Help Line at 918-746-3701, dropping by our Diagnostic Center at 4116 E. 15th Street, or by emailing us at mg@tulsamastergardeners.org. Photo: David Cappaert, Bugwood.org