I have something on my tomato plant that looks kind of like a squash bug but I don’t think it’s a squash bug. What in the world is it? KD

Odds are you are describing a stink but. People often confuse them with squash bugs but since it’s on a tomato plant, it’s likely a stink bug.

Their name already kind of lets you know that this bug is not a friend of plants and if you disturb them, you’ll likely find out where the name “stink bug” comes from. If I’m not being obvious enough, they can emit a strong smell when so inclined.

We have green and brown stink bugs here in Oklahoma. Both of these grow to between 1/2 and 1/3 of an inch in length and with sufficient numbers, they can do some damage.

Stink bugs overwinter as adults under plant debris, weeds, or leaves. They emerge in the spring and are not especially picky about which plants they dine on. Preferred plants are almost always wild or native plants, but as the population increases, they can move to vegetable crops such as okra, beans, and tomatoes.

In the spring, each female stink bug can deposit several hundred eggs in mid to late June. At first the eggs of the green stink bug are yellow to green in color but then turn to pink or grey. Brown stink bug eggs are whiteish.

Young nymphs of both varieties are shaped like their adult counterparts. However, green stink bug nymphs are mostly black but then grown into their green color. Interestingly, the nymphs of the brown stink bug are light green in color but then turn brown as they reach maturity. Initially, stink bugs feed close to one another but the spread out as they mature. There’s only one generation of green stink bugs per year but two generations of brown stink bugs with the second generation being active in July and August.

Stink bugs feed with what are called piercing-sucking mouth parts. They use these straw-like parts to suck liquid out of the plants. If this is done to a tomato, you will notice a hard-brownish spot on the outside with whitish tissue of the tomato beneath.

On younger green fruit, damage can look like dark pin pricks that are surrounded with a lighter colored area that tends to remain green or turn yellow as the fruit ripens. Very young fruits may appear deformed in some way as they grow. These damaged fruits are safe to eat but they may not taste like you expect a tomato to taste.

One way to control stink bugs would be to use row covers, but this covering would need to be removed once the tomato begins flowering. You could also hand pick or use sticky traps. Insecticidal soap can be effective on young stink bugs, however as they get larger, you will need to move to organics such as neem oil or pyrethrin. Be sure to spray under the leaves also.

As is true with all insecticides, be sure to read the label, use as directed, and spray in the early morning or late evening to avoid pollinating insects. Good luck.

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 

Whitney Cranshaw, Colorado State University, Bugwood.org