There are two types of cucumber beetles that may attack your garden. The striped cucumber beetle has a yellow body with three black stripes along its back. The spotted cucumber beetle is yellow, with twelve black spots. Both are the same size, roughly a quarter of an inch long. The larvae are white grubs with a brownish head.
Adult cucumber beetles overwinter, and emerge in spring.
They feed on weeds and other plants until their preferred food source, cucurbits (such as cucumbers, squashes, and melons) are available. Once they locate cucurbits, they will feed on the plants, and the females will lay their eggs in the surrounding soil. The eggs hatch, and the larvae feed on below-ground cucurbit roots and stems until they pupate.
Then they emerge as adults, and the cycle starts all over again.
Signs of Cucumber Beetle:
It’s very easy to spot the cucumber beetle in the crops. The most common signs of cucumber beetle are scarring on the fruit, girdled stems and feeding on the leaves. The most favorite crops of cucumber beetles are cucumbers, pumpkins, melons, and squashes. But, they can also attack some garden crops and tomatoes in case the cucurbits are not available.
Effect on Garden Plants:
Chewed leaves, girdled stems, and they can leave marks on the fruits. The most serious damage occur due to bacterial wilt. The bacteria comes from the stomach of beetle and it gets spread on the plant when they munch. It affects the vascular system of plants, resulting the leaves to wilt.
If the farmer doesn’t locate the infected stems and remove them, the wilt can affect the entire plant in no time. Another disadvantage of infected stems is that they attract more beetles who eat further plants and affect the whole garden.
Organic Control of Cucumber Beetles:
You can protect young cucurbit seedlings from cucumber beetles by covering them right after planting with floating row covers, individual screens, or cones. It’s also a good idea to plant cucurbits later in the season — those planted early (by your neighbors, perhaps) will attract any beetles in the area, and your plants may be spared. Also, remove and destroy (don’t compost) plants infected with bacterial wilt immediately so that they wont’ attract more beetles to the area. Adult beetles found on plants can be hand-picked and squished.
Read original article here: http://organicgardening.about.com/od/pestcontrol/p/cucumberbeetle.htm