What are Flea Beetles?

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.

Flea beetles are small, jumping insects belonging to the leaf beetle family Chrysomelidae. They are named for their flea-like appearance and remarkable ability to leap when disturbed. These beetles are typically 1/16 to 1/8 inches long and can be various colors, often with a shiny or metallic sheen. They are known for their voracious appetite for plant foliage, particularly in the early stages of crop growth.

Flea beetles damage plants by chewing small holes or pits in the leaves, creating a characteristic "shot-hole" appearance. This feeding can stunt plant growth, reduce yields, and in severe cases, kill young plants. Their larvae can also harm crops by feeding on the roots. The damage is especially detrimental to seedlings and can significantly impact agricultural productivity.

Flea beetles have a broad range of host plants but are particularly attracted to cruciferous vegetables like cabbage, broccoli, and radishes, as well as solanaceous crops such as tomatoes and eggplants. They also target ornamentals and weeds, which can serve as reservoirs for the beetles between cropping seasons.

Yes, flea beetles have several natural predators that help control their populations. These include predatory insects like lady beetles, lacewings, and parasitic wasps. Entomopathogenic nematodes and fungi also play a role in managing flea beetle larvae in the soil. Encouraging these beneficial organisms can be an effective part of integrated pest management strategies.

Flea beetles are capable of transmitting viral and bacterial diseases to plants. For example, they can spread Stewart's wilt, a bacterial disease affecting corn, and various mosaic viruses that impact vegetable crops. The physical damage they cause can also make plants more susceptible to secondary infections by pathogens.

Controlling flea beetles involves an integrated approach combining cultural, biological, and chemical methods. Crop rotation, the use of row covers, and timely planting can reduce beetle populations. Biological controls include encouraging natural predators and using microbial insecticides. Chemical controls should be used as a last resort and involve targeted applications of insecticides to minimize environmental impact.