Asparagus Beetle Control: How to Identify, Prevent and Get Rid of Asparagus Beetles

Asparagus beetles can wreak havoc. With its name, it is already pretty much obvious that it feeds on asparagus, damaging the barks and causing the top part to dry. Eventually, this leads to the death of the plant with the failure to execute the necessary solution. With this, in this post, we will tackle more about this pest, including how to get rid of asparagus beetle.

There are two types of this pest: common asparagus beetle and spotted asparagus beetle. Between the two, the common asparagus beetle is the more popular and causes a more significant damage. The two species have an oval body with an average length of ¼ inch. Common asparagus beetle has a metallic black to blue body with yellow spots on its wings. The spotted asparagus beetle, on the other hand, is bigger with an orange-red body. In each of the wings, there are six black spots. Because both species are capable of flying, they easily spread damage from one asparagus plant to another, even if they are not planted next to each other.

Spotted Asparagus Beetle

Spotted Asparagus Beetle

Asparagus Beetle’s Habitat

Common and spotted asparagus beetles live in North America, but the latter only lives in the eastern part of the Mississippi River. They may overwinter not only in asparagus, but also in the garden trash. They thrive on loose barks and hollow stems. They lay eggs and they will hatch within a week, multiplying the damage that it brings to the plant.

The common asparagus beetle usually appears first. In most instances and places, both of the species will appear from the second week of May to the last week of July.

Identifying Asparagus Beetle Damage

Plants Affected

Regardless of the species of asparagus beetle, they share one common characteristic – they affect only asparagus. This means that if you do not have an asparagus plant in the garden, there is nothing to worry. They start by feeding on the tips of the plant and once their body has the nourishment from the plant, they start laying their eggs.


Not sure if the asparagus beetle is causing damages to your crops? Below are some of the symptoms you should watch out for:

  • The most common is the appearance of small holes in the shoots and the leaves, which is where the pests feed. In turn, it damages the tissue of the plant, and hence, affecting its overall growth. In no time, you will notice that the plant will turn to brown from green. This is an indication that the plant is dying.
  • The larvae of asparagus beetles excrete a black or brown liquid. With this, pay attention to the staining or darkening of the color of the buds to determine if it is already a symptom of infestation.
  • Aside from the color of the spears, they will also appear to be visually weak, as if lacking life. This is because asparagus beetles lead to the loss of nutrients, and hence, negatively affecting the structure of the plant and making it prone to infestation of other insects as well.

Results of Infestation

The most common result of infestation is a condition known as Shepherd’s Crook Syndrome. This leads to twisting of the head of the asparagus, giving the plant an unsightly appearance. Also, there is a possibility of staining and scarring, causing visible damages to the plant. Severe defoliation will most likely be apparent as well. At the end of the day with the appearance of the symptoms, asparagus will end up not producing crops. The plant will die in no time because of the severe damage.

Asparagus Damaged

Asparagus Beetles on Damaged Stem of Vegetable

How to Get Rid of Asparagus Beetles

Organic and Natural Solutions

When dealing with asparagus beetles, the best solutions are those that are organic and natural. They are simple, cheap, and defective. Most of all, they get rid of the pest without harming the environment as they do not contain toxic chemicals.

  • Handpicking the pest is a simple solution you should try. This is especially true if you only have a few plants and taking out the beetles won’t be a hard task. Remove not only the beetles, but also the eggs.
  • Encouraging the presence of beneficial insects in the garden is also helpful, not only for combating asparagus beetle, but other common pests as well. Some of the most popular insects include lacewing, tiny wasps, and ladybugs. They help through feeding on the larvae before they fully grow and affect the plants.
  • It is also good to keep the garden bird-friendly. Attracting birds is a natural way to get rid of these pests. They will pick not only adult asparagus beetles, but even their larvae.
  • Beneficial nematodes also offer the perfect solution to control the infestation of asparagus beetles. They will attack soil dwelling insects without causing problems to humans and the environment. 

Chemical Solutions

While there are chemical solutions available, it is important to note that they are not for home gardeners. If you grow asparagus at home, organic solutions are better as the problem is possibly not that severe. If you are a commercial grower, on the other hand, the following are the active ingredients that are common in insecticides for the treatment of asparagus beetles: Malathion, Carbaryl, and Permethrin. 

How to Prevent Asparagus Beetle

Regular inspection of the plant is one of the best things to do to prevent infestation. Pay attention to the spears and the shoots of the young plants. If there are visible damages, act the soonest as asparagus beetles may wreak havoc in no time. Take out the eggs from the spears through wiping before they become a bigger problem. Also, to avoid larvae pupation, keep the garden clean. Throw away dry leaves and other plant debris that encourages the appearance of pests.

Another good thing to do is to harvest the asparagus before pests feed on them. Once they are cut, however, it is necessary to have thorough inspection to be sure it is safe for consumption.

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