Don't be bugged by beetles

July 26, 2008|By BOB KESSLER

Anyone who has ever grown potatoes is familiar with the Colorado potato beetle.

As larvae it is reddish in colors, while the adults are yellow and black striped with a brown head. They eat the leaves of the potato plant and will strip a plant bare if left uncontrolled.

Potatoes are damaged right now by the Colorado potato beetle because the plant is using all its energy to form the potato tubers.

The loss of leaf surface means less area to produce food, which will decrease your yield. Well-watered potatoes will help the plant be as effective as possible to form your tubers.


If you have small numbers of Colorado potato beetles, your best control is to pick off the beetles and larvae and drop them in soapy water. As the season progresses, their numbers increase and picking them off is not practical. To find the larvae, look on the underside of the leaves for orange egg masses and crush them.

If you have a large planting and you have a beetle problem, you may need to use an effective insecticide. We encourage this to be a last resort because the Colorado potato beetle has been very effective in developing resistance to insecticides such as carbaryl (Sevin) and Malathion. If you need to use pesticides, you can use Spinosad, which is good for insects that chew.

You can also use rotenone, which is an organic material. Another product you can alternate with is esfenvalerate. Because of the Colorado potato beetles' pesticide resistance, you should alternate applications.

For instance, spray one week with spinosad and the next with rotenone and the next use esfenvalerate and then go back to spinosad. This will reduce the chance of the insects building a resistant population.

Buzzing beetles

If you have had a big beetle buzz by you and then heard a bang into your house, it was probably the Green June beetle. The males are usually the ones flying around, especially in the afternoons, while the female flies over the lawn in early morning.

The adults do not feed on the leaves of your plants like the Japanese beetles do. They will feed on over-ripened damaged fruit and sometimes on sound fruit. Actually, there are not too many fruits they don't like.

Once the Green June beetles mate, the female will dig into the turf to lay her eggs in a compacted ball of soil the size of a walnut. They prefer a moist soil high in organic matter. The eggs will hatch in two to three weeks and the young grubs feed on decaying organic matter.

The grub of the Green June beetle is arge compared to the other soil grubs. They do not feed on the roots of the turf enough to cause damage to your turf. However, because of their size (they can be up to two inches long) they do disturb a lot of soil as they move through the soil. Their burrowing and mound building activities can make the soil rough and unattractive.

If you treat your lawn for grubs because you have had problems the material you use will usually control the Green June beetle grubs, too. However if you discover that you have turf damage from grub burrowing, you can use a treatment of Dylox or Sevin in the fall. But be prepared for a lot of dead grubs on the surface of your lawn. And a few hundred of these large grubs rotting on your lawn can ruin your patio party.

Blossom end rot

With our hot dry weather, and tomatoes are starting to get large fruit that will soon ripen, you may start to notice fruits with a black end. This is not a disease, but it is a condition caused by a lack of calcium in the developing fruit. This lack of calcium is made worse with a lack of water because of dry weather.

Blossom end rot starts as a small water soaked spot on the end opposite of the stem where the flower had been. As the fruit develops, a dark brown leathery area may be on half of the fruit. Of course this ruins the fruit for consumption and it is thrown away. As you inspect your tomatoes and you see this, you should pick off the fruit so the plant doesn't continue to use energy to ripen the fruit.

One way to help reduce blossom end rot is to be sure an adequate and even water supply is available to your tomato plants. You should use a soaker hose to water your plants and keep them mulched to conserve your soil moisture.

Test your soil to check if its low in available calcium and this can be only measured by a soil test. You will get recommendations that will correct the problem.

Safety day camp

All youths 7 to 18 years old are invited and encouraged to attend the Farm and Home Safety Day Camp from 8 a.m. to 3 p.m. Friday, Aug. 1 at the Chambersburg Rod and Gun Club.

Everyone can participate in workshops to learn about animal safety, kitchen safety, vehicle safety and lawn mower safety, 911, smoke detectors and watch a medevac demonstration and much more.

The event costs $4 per person and includes lunch. Registration is open until the end of the day today at the Franklin County Extension office at 181 Franklin Farm Lane in Chambersburg. Call (717) 263-9226 for more information.

Upcoming events

· Friday, Aug. 1, 8 a.m. to 3 p.m. - Farm and Home Safety Day, Franklin County, fairgrounds (Chambersburg Rod & Gun Club).

· Tuesday, Aug. 19, 10 a.m. - Franklin County Extension office's horticulture gardens open house; tour gardens, cut flower arranging demonstrations, Franklin County Master Gardeners and Franklin County Extension. Call 263-9226 for information.

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