Column
Galls and Insect Problems on Squash, Melons, Pumpkins, and Pickles
By John Fulton

[May 28, 2015] Galls - One group of problems showing up is galls. Galls are swelling of leaves, twigs, or other plant parts. Most are caused by mites or wasps. They damage the plant parts and the plant responds with a gall. In the case of leaves, the swelling is actually leaf tissue.

This is something I like to refer to as similar to you getting a mosquito bite. The damage comes in and a swelling occurs. There is no way to get rid of it without tearing a small hole in the leaf. The maple leaf bladder gall will be easily spotted on silver maples in the area shortly, and oak leaves in the red oak group are also showing galls.

Oak trees probably have more galls than any other group of trees. Several samples have also been brought in of the stem types of galls. I saw three different types of galls on one branch this week. Fortunately, the oak galls are usually not the type to kill tissue beyond them. However, the galls aren’t the most pleasant things to look at. That is the main thing – they are unsightly.

There is no cure for galls, as they are caused by insects before you see the swellings. The timing would be impossible to try and prevent the insects.
 

Insect Problems on Squash, Melons, Pumpkins, and Pickles

Everything in the squash, melon, pumpkin, and cucumber families are cucurbits. There are several potential insect problems with them, and today’s column attempts to help minimize or prevent these problems. The first group of insects is the cucumber beetles. These can be green, black and yellow striped, or black and yellow spotted. The importance of the beetles is not that they eat small holes in the leaves, but that the beetles can transmit a bacterial wilt to the plants as they eat. The first thing you see is you have a plant that suddenly wilts on various runners, or the entire plant can wilt. The best means of controlling this disease is a good beetle control program. Current homeowner recommendations would include these products with the days to harvest restrictions in parenthesis: carbaryl (0), bifenthrin (3 days), or rotenone (1 day).

Of course, Japanese beetles love cucurbits as well. Their damage is direct leaf feeding. Remember they feed in groups, so once they get started you will have a battle on your hands. The carbaryl and bifenthrin are both good control measures. Look for Japanese beetles to start in earnest in about a month.

 Squash bugs are the next problem to discuss. Squash bugs are usually dark gray to black in color and like a long stink bug. Their eggs usually hatch mid-June to mid-July. The best timing for control is when the eggs first hatch. Non-restricted products are sabadilla (1 day), which is an organic product that might be a little hard to find, and bifenthrin (3 days to harvest). One last note, if the squash bugs get past their early growth stages then physically removing them is about the only control method available, or as the old joke goes you brick them (one brick in each hand clapped on the squash bug).

The last insect problem on cucurbits is squash vine borers. These borers usually drill into the new runner areas and kill off individual runners at a time. The adult of these larvae are red and black clear-winged moths. Scout your plants and look for the adults, as well as entrance holes and the chewed-up plant material. Treat as soon as early damage occurs and use one of the following products for homeowners: carbaryl, bifenthrin, or rotenone. Days to harvest restrictions have already been covered (and these would also apply to pumpkin blossoms).

[By JOHN FULTON, COUNTY EXTENSION DIRECTOR SERVING LOGAN, MENARD, AND SANGAMON COUNTIES]