If you’ve ever grown asparagus, you know that it can be plagued by so-called “false crawlers” or ambrosia beetles. While they don’t usually pose a threat to the asparagus in your garden, a combination of factors may lead to an outbreak of these pests. If your asparagus bed is under attack by ambrosia beetles, it’s not too late to take action. Here are some tips on how to get rid of ambrosia beetles and protect your asparagus plants from further damage next year.
What is an Ambrosia Beetle?
Ambrosia beetles are pests that feed on the sap of certain plants. Most commonly, they feed on the roots of asparagus plants. But, they can be found on other types of crops and ornamental plants as well. Ambrosia beetles are typically reddish-brown or black and about 3/8 of an inch long.
They are also highly specialized, with a mouth that has bristles. And a “mouth part” that is designed to grind up the woody substances found in the roots of asparagus plants. Other than asparagus, ambrosia beetles are very picky about their food source.
They have been known to feed on some types of trees. But in those cases, the trees have to be severely stressed. The trees have to be very old and unhealthy or suffer from a soil-borne disease before they become a source of food for these beetles.
How to Identify an Ambrosia Beetle Infestation
You can use a few different detection methods to determine if you have an outbreak of ambrosia beetles in your asparagus bed. If you are lucky and find a beetle, you can identify it through visual inspection. However, this method is not reliable because the beetles are so tiny. And they are only present during certain times of the year.
When they are not feeding, they are inside the soil. Therefore, finding a beetle on the surface doesn’t tell you much about what is going on inside the roots. A better way to determine the extent of the ambrosia beetle problem in your asparagus bed is to look for external signs of an infestation.
Look for asparagus stalks that are wilting, dying, or have been chewed off at the soil level. If you find these signs, you can be almost certain that you have a problem with ambrosia beetles.
Asparagus Shambler (ASB) Control
If you’ve confirmed you have an ambrosia beetle infestation, the best thing to do is to act fast. Once the beetles have chewed their way through the roots of your asparagus plants, they are very difficult to get rid of. This is especially true if you have an asparagus shambler beetle (ASB) infestation.
ASBs are a common type of ambrosia beetle that can be found in the entire asparagus-growing region of the United States. They are larger than the typical ambrosia beetle, and they have a distinct orange/yellow stripe on their back. ASBs feed on the roots of asparagus plants, causing the plants to die.
This is especially problematic since the beetles are also capable of chewing through the thick stalk of the asparagus plant. This means that once the plant is infested with ASBs, it will die much faster than it would without the beetles present.
Fortunately, you can prevent the arrival of ASBs in your asparagus bed. It is done by taking steps to prevent other types of ambrosia beetles from getting there.
How to Get Rid of Ambrosia Beetles? Strategy Explained
The best way to get rid of ambrosia beetles is to prevent them from getting into your bed in the first place. However, if you do have an infestation, you can still get rid of the beetles. Here are some tips on how to do that:
Step 1: Discard any damaged asparagus stalks
If you’ve already found signs of an ambrosia beetle infestation, you should immediately discard any asparagus stalks that have been chewed off by the beetles. Since the beetles are inside the soil, you can’t see them, so it’s next to impossible to tell which stalks are infected.
The best way to determine which stalks are damaged is to turn over the soil around the asparagus plants. If you see that a limb has been severed (or partially severed) at the soil level, it is most likely infected.
Step 2: Rotate your crops and grow other veggies
The best way to avoid an ambrosia beetle infestation is to rotate your crops. This means that you don’t plant asparagus in the same spot every year. The problem is that asparagus is an annual vegetable. So you can’t grow it in the same spot over the long term.
However, by rotating your crops and planting asparagus in a different part of the garden each season, you greatly reduce your risk of an ambrosia beetle infestation. This is especially important if you have a bed with particularly soft soil, as this type of soil is attractive to ambrosia beetles.
Many experts recommend growing other vegetables in the bed that previously held asparagus. This is because it will take a few years for the soil in that bed to become less attractive to ambrosia beetles.
Step 3: Spray Neem Oil on the soil around your asparagus plants
Another way to keep ambrosia beetles out of your asparagus bed is to spray neem oil around the periphery of the bed. Neem is a natural pesticide and insect repellent that is completely safe for humans and animals. It is best to apply neem oil before you notice signs of an ambrosia beetle infestation.
That way, it can protect the roots in your asparagus bed and keep the beetles out. It is important to make sure that you spray the oil directly on the soil. If you spray the foliage, it won’t do any good.
Step 4: Roll up your sleeves and manually remove the beetles by hand
If you have a serious ambrosia beetle infestation, you may have to resort to manually removing the beetles. This is a very labor-intensive process, so you should only do it if you have no other choice. Ideally, you want to get rid of the beetles before they have had a chance to create an infestation in your bed.
Once they are inside the soil, they are nearly impossible to get out. Thus, it is important to check your asparagus bed regularly for signs of an ambrosia beetle infestation.
If you see that the beetles have chewed their way into your asparagus bed. Then you should immediately remove the infected stalks. This will prevent the beetles from doing more damage.
Step 5: Conclusion
Ambrosia beetle infestations are a common problem for asparagus growers. Fortunately, it is possible to get rid of the beetles by taking the right steps.
The best way of how to get rid of Ambrosia Beetles is to rotate your crops, grow other vegetables in the bed that previously held asparagus. And spray neem oil on the soil around the plants.
