Mexican Bean Beetle: Get Rid Of Epilachna Varivestis

Ed Wike
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The epilachna varivestis, also called the Mexican bean beetle, is a small, six-legged beetle found in the southwestern United States.[1] These beetles can reproduce rapidly, and invade crops in large numbers. In addition to damaging crops, the Mexican bean beetle overwinters in large numbers in homes throughout the southwestern United States.

The life cycle of the Mexican bean beetle is short. The adult beetles can live for four weeks. During these four weeks, the females lay eggs in the soil surrounding crop plants. The eggs then hatch into larvae. The larvae feed on plant roots before transforming into pupae and finally emerging as adult beetles.

Beetles that emerge from pupae in the late spring or early summer invade crops to lay their eggs. Once the eggs hatch, the Mexican bean beetle life cycle begins again.

If the Mexican bean beetle is allowed to continue its life cycle, major crop damage can result. In addition to devouring beans, the beetles attack a variety of other crop plants such as corn, beetle, squash, and onion. The adult beetles use their large mandibles to sever plant tissues and feed on the plants’ juices. Young bean crops are particularly susceptible to Mexican bean beetle attack.

Mexican Bean Beetle Life Cycle

Mexican bean beetles are among the more common beetles found in North American gardens. There don’t appear to be documented cases of Mexican bean beetles attacking and killing celery plants, but they can be potentially devastating to gardens of corn, beans, potatoes and okra.

These beetles are generally black with reddish-orange heads. Adults grow to about 1/4-inch long and are oval-shaped with tiny wing covers. Several generations of these beetles can occur throughout the growing season. Mature beetles can fly for a short distance, but usually end up on the ground when disturbed.

Celery plants attacked by Mexican bean beetle become mottled, wilted and chewed up. Typically, it’s seeds or young plants that are most affected. If you find Mexican bean beetles in your celery garden, it’s important to act quickly to minimize damage.

Common Habitats

Also called the Mexican scarab beetle or Mexican bean beetle,.

Epilachna varivestis, is an attractive black beetle that grows to about 1/2 an inch in length. The beetle is dark green with red spots along its head and thorax.

Mexico bean beetle has been causing problems for gardeners since it was discovered in the United States. The beetle has been in this country since the 1930s when it was imported to San Antonio, Texas from Mexico.

It later spread to the Pacific Northwest and west coast, where it continues to thrive today.

Although its name suggests that it is most harmful to the Mexican bean plant, the larva of this beetle can also be found on other plants in the nightshade family. This family contains cabbages, eggplant, potatoes, tomatoes, peppers, and tobacco plants. Although the larva of the Mexican bean beetle prefers Mexican beans, it will feed on other friends of the nightshade family.

Everyone in the family is susceptible to Mexican bean beetle damage. Unfortunately, the Mexican bean beetle does not discriminate when it comes to its host plant. It can be found gnawing on beans, bush beans, tomatoes, potatoes, and even many weeds.

What Do They Eat?

Like the fire blight of roses, these beetles are not a favorite of any gardener. The grubs of these beetles can be a real issue in the garden. Like other grubs, they eat the roots and this weakens the plant.

If you’re dealing with bean beetles, it’s likely that the canes or leaves of your bean plant are affected. The grubs feed off the roots underground, which means that the leaves and canes will be stunted and thin.

When the grubs emerge, they leave behind gaping holes. Many people confuse these holes with caterpillar damage, however, the difference between a caterpillar hole and the damage of a bean beetle is apples and oranges.

The caterpillar’s damage is irregular, while the bean beetle damage is continuous. Also, caterpillar injury is found at the bottom of the plant, while the bean beetle injury—is found at the top.

As far as controlling them, the best solution is to get rid of them through biological warfare. The natural predator that attacks and eats them is a type of wasp. Creating infestations in your garden using these wasps is a great way to control them. If you’re dealing with an infestation of these beetles, contact a local pest control right away.

How To Get Rid Of Mexican Bean Beetles

Picture yourself, sitting by a lake, enjoying the day with your family and loved ones. It’s a warm and sunny day, a perfect picnic day with a blanket and some great food. You have a nice collection of wooden or stone picnic tables around the lakeside so that everyone would have a place to sit. You have your traditional picnic stuff, chips, hot dogs, burgers, and all other kinds of goodies.

But, there’s something that you have not planned for. It’s a layer of greenish-black small creatures that has spread all over your picnic tables, and it’s multiplying uncontrollably.

It’s Mexican Bean Beetle larva… and they are taking over your picnic area.

After a quick look into it, you’ll find out that they are very common and notorious for ruining people’s picnics, especially those who have wooden or stone benches or picnic tables. They eat on a wide variety of plants and are categorized as a little pest that can ruin your day.

But don’t worry, there’s a solution.

Organic Control

The Mexican Bean Beetle and Three-banded Bean Beetle are common pests for most gardeners and both beetles are considered a big threat to organic gardening.

Both species feed on beans, soybeans, corn, potatoes, eggplants, tomatoes, and many other plants.

Although the beetles are short-lived with adult Mexican Bean Beetles living just over a month, they are prolific breeders, producing as many as 200 eggs during their lifespan. The Mexican Bean Beetle can lay 30 eggs in a week.

Adults and larvae can be controlled with an organic pesticide made of salts of fatty acids.

You can make this pesticide easily at home and it is effective for the beetle and its larvae.

Environmental Control

You may not be able to see the Mexican bean beetle, but you will likely notice their strong presence – on your beans! The beetles are very shiny, black and green, about 3/8 to 1/2 inches long. They make an easily recognizable damage mark that resembles a bulls-eye from the top and a crescent from the bottom.

You can straighten damaged pods by hand, but do not rub off the leaves. During this phase of the Mexican bean beetle, Mexican bean beetles are highly mobile. While rubbing pods or leaves will kill the bugs on the surface, if any were on the inside they would be able to move to the next bean to lay their eggs.

As with any insect pest, environmental control is the most important aspect of management. Mexican Bean Beetle thrive in warm, humid conditions. The entire life cycle from adult to egg to adult take 1 month in temperatures around 77 to 85 degrees Fahrenheit. So, keeping the adult population in check is vital.

Control Mexican bean beetles by:

  • Streamlining your watering schedule to avoid excess moisture on the leaves or soil. Water early in the morning and not at night.
  • Clean-up any fallen leaves. Beetles will eat fallen hulls.
  • Spread a layer of straw or grass clippings on beds. mulch will kill all stages of this pest.
  • Monitor the adults and eggs in the field every several days.

Prevention Tips

Although this beetle can be beneficial to your garden by eating harmful pests, it’s natural predator, the ladybug, usually keeps things in balance. Trouble usually begins when the ladybug population starts to decline, leaving the beetle population uncontrolled.

There are two commonly used methods to control bean beetle damage to corn and tomatoes. One is the commercial use of insecticides, which is effective but can become toxic to your garden if used too often, and the other is companion planting.

Companion planting is an organic method that involves planting certain kinds of plant in close proximity with other kinds. Often, one plant attracts a beneficial insect that will help another plant in your garden. Plants that repel Bean beetles offer the best solution because you can attract them to your garden using common herbs, such as cilantro, tansy, or oregano.

Frequently Asked Questions

Get Rid Of The Epilachna Beetles

Ask exterminators about this plant-eating bug, and you’ll get all sorts of questions:

  • What are these pests?
  • What types of plants do they eat?
  • How do I get rid of the Epilachna beetles?
  • How do I kill the Mexican bean beetles?
  • Do we really need to get rid of the Mexican bean beetles?
  • Where do I even find the Mexican bean beetles?

We’ll answer these questions to help you get rid of the Mexican bean beetles from your flower and vegetable plants. The Epilachna beetles eat leaves. They chew holes out of leaves. They eat holes throughout the plant. They eat and destroy the beans and the leaves and they cause a lot of damage in the garden.

The Mexican bean beetles are small. Adults are about a quarter-inch long. They are a bright red color. There are several different colors of Mexican bean beetles. Some of the beetles are a light orange-red color while others can be an even brighter red color.

You will find them in your greenhouse and in your garden. You can usually identify the beetle from their eating habits. There are other beetles which are non-pest beetles that eat your plants.