Flea beetle is a term that is used to describe a type of tiny beetle that is often though of as a garden pest. Unlike other species in the leaf beetle family, they are jumpers, moving from plant to plant, chewing small holes. A swarm of flea beetles can cause extensive damage to certain vegetable crops, especially new plants.
Adult flea beetles often burrow into the soil until springtime. After the temperature is right, they will emerge and feed. A short time later, the female beetles will lay eggs near the base of plants. Generally, the larvae that emerge do not do much damage. One exception to this rule is the tuber flea beetle, whose larvae chew on the roots of many underground vegetables, especially potatoes.
Compared to many other types of beetles, adult flea beetles are quite small. Many times, most species will not grow to be longer than 1/8 inch (3.17 millimeters) long. While some of them are a plain black or brown, some have a pattern or their backs like stripes. Some may even be an attractive shimmering, metallic blue, silver, or green hue. Their large back legs enable them to jump great distances, similar to a flea.
Fleas beetles are not always considered to be garden pests, as sometimes they will consume weeds or other unwanted plants. Many species of flea beetles typically have a preference for certain types of plants, especially vegetable plants. The cabbage flea beetle, which feeds primarily on cabbage plants, is a prime example of this. Many times, just the adult beetle is responsible for damage to plants.
Evidence of flea beetles can often be clearly seen on plants. These beetles will chew tiny holes in the leaves. This is sometimes referred to as shot holing, since the damage strongly resembles that of buckshot damage from a shotgun.
Although a severe flea beetle infestation can cause older plants to wilt or die, younger newly established plants are the most susceptible to flea beetle damage. Crops that are grown for their leaves, like lettuce or cabbage, can become basically worthless after a flea beetle attack.
Farmers and gardeners can prevent extensive damage from flea beetles by closely monitoring their plants everyday. Any visible beetles should be removed. If more than a few beetles are found on each plant, other methods to get rid of flea beetles should be considered.
Trap crops are one way to control a flea beetle infestation. Planting a crop that is attractive to these beetles, such as radishes, can sometimes cause flea beetles to feed on these instead of the main crop. A trap crop is usually planted some distance away from the regular crop to lure the beetles away. If the trap crop method does not work, pesticides may be necessary.