Asparagus Beetle

A Comprehensive Guide to Identification, Damage, and Control

Asparagus beetle, scientifically known as Crioceris asparagi, is a common pest that attacks asparagus plants. This beetle has two species, the common asparagus beetle (Crioceris asparagi) and the spotted asparagus beetle (Crioceris duodecimpunctata). The common asparagus beetle is the most widespread and destructive of the two species.

Identification

Adult asparagus beetles are oval-shaped, about 1/4 inch long, and have a shiny, metallic blue-black or brownish-black color. They have six reddish-orange spots on their wing covers. The larvae are gray and have three pairs of legs. They feed on asparagus foliage and can grow up to 1/2 inch in length.

Damage

The asparagus beetle feeds on the foliage and stems of asparagus plants, which can lead to a decrease in yield and plant vigor. The adult beetles chew on the foliage, while the larvae feed on the spears, which can cause significant damage to the plant. If left uncontrolled, the asparagus beetle can defoliate and weaken the plant, making it more susceptible to other pests and diseases.

Identification of Asparagus Beetle Damage

The damage caused by asparagus beetle is easy to spot. The adult beetles leave a distinctive pattern of holes and notches on the leaves, while the larvae create small tunnels in the spears. The foliage of the asparagus plant may turn yellow and dry up, and the spears may become distorted or stunted.

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Natural Control Methods

There are several natural control methods that can be used to manage asparagus beetle populations in Live Oak, FL (USDA Zone 8B). Here are some effective methods:

  1. Handpicking: One of the easiest and most effective ways to control asparagus beetle is to pick them off by hand and drop them into a bucket of soapy water. This method is best done early in the morning or late in the evening when the beetles are less active.
  2. Row Covers: Covering the asparagus plants with lightweight row covers can help prevent adult beetles from laying eggs on the foliage. This method is especially effective in the early spring when the beetles are first emerging.
  3. Beneficial Insects: Encouraging beneficial insects, such as ladybugs and lacewings, can help control asparagus beetle populations. These insects feed on the larvae and eggs of the beetle, helping to reduce their numbers.
  4. Companion Planting: Planting companion plants, such as marigolds, can help deter asparagus beetle by masking the scent of the asparagus plant. Additionally, marigolds attract beneficial insects, which can help control the beetle population.
  5. Neem Oil: Applying neem oil to the asparagus plant can help control asparagus beetle. Neem oil is a natural insecticide that disrupts the beetle's feeding and breeding habits, effectively controlling their population.

Pest Management of Asparagus Beetle

If natural control methods are not effective, there are several chemical control methods that can be used to manage asparagus beetle populations. Here are some options:

  1. Insecticidal Soap: Insecticidal soap is a natural and safe option for controlling asparagus beetle. It works by suffocating the beetle and is safe for both the plant and the environment.
  2. Pyrethrin: Pyrethrin is a natural insecticide that is derived from chrysanthemum flowers. It is effective in controlling asparagus beetle but can also harm beneficial insects.
  3. Spinosad: Spinosad is a natural insecticide that is derived from soil bacteria. It is effective in controlling asparagus beetle and is safe for beneficial insects and the environment.When using chemical control methods, it is important to follow the manufacturer's instructions carefully and use the appropriate protective gear.
  4. Carbaryl: Carbaryl is a synthetic insecticide that is effective in controlling asparagus beetle. However, it is toxic to beneficial insects and can have negative environmental impacts.
  5. Permethrin: Permethrin is a synthetic insecticide that is highly effective in controlling asparagus beetle. However, it is toxic to beneficial insects and can have negative environmental impacts.

Conclusion

Asparagus beetle can be a significant pest in asparagus plants, causing damage to the foliage and spears. However, there are several natural and chemical control methods that can be used to manage asparagus beetle populations. Natural control methods, such as handpicking, row covers, beneficial insects, companion planting, and neem oil, are safe and effective options. If natural control methods are not effective, chemical control methods, such as insecticidal soap, pyrethrin, spinosad, carbaryl, and permethrin, can be used. It is important to follow the instructions carefully when using chemical control methods and to use protective gear to minimize exposure to the chemicals. By using a combination of natural and chemical control methods, asparagus beetle populations can be effectively managed, allowing for a healthy and productive asparagus crop.