How Do You Control Ambrosia Beetles?

Just like you, the plants in your nursery get sick too. Nature tends to play out on its own, but when we build a garden or a nursery, we must take care of our plants and ensure that various diseases do not infest them.

Ambrosia beetles up closePin

What is Ambrosia Beetle?

Ambrosia Beetles, aka Pinworms, are a family of over 1000 species of Ambrosia worldwide.

These insects often attack ornamental wood and nut trees. They can cause severe damage to an orchard or garden if not taken care of in time.

The most common type of Ambrosia Beetle species is the Xylosandrus Crassiusculus, aka the Granulate Ambrosia Beetle.

A common sign of these is soft toothpick-like strands protruding out of the tree’s bark. These strands can be up to 1.5” inches long and often lie on the ground near the plant.



The Granulate Ambrosia Beetles make a circular hole when they dig into the host. Then they leave the wound covered in fungus a few days after the attack.

How Much Damage Can The Ambrosia Beetle Cause?

Thin-barked and deciduous trees are the Granulate Ambrosia Beetles’ prime targets when they emerge in the spring. The following trees are its most common victims:

Granulate Ambrosia Beetles attack young trees by boring into their bark and excavating the heartwood.

The female Beetle also infects the trees with Ambrosia Fungus from within, blocking its vital vascular transport.

These trees may die from boring damage, Ambrosia Fungus, or secondary pathogen infection. Wilted foliage or tooth-pick-like protrusions in the boring dust. are visible signs.

Infested trees generally die and are unusable. They should be either burned or chipped away before new adult beetles infect the other trees.

More Beetles In The Garden

How To Control An Ambrosia Beetle Infestation?

Watch for Granulate Ambrosia Beetles in the late winter and early spring. By spring, the insect is in full attack mode.

An easy way of preventive monitoring is ethanol-based traps. If you find a beetle in the trap, it is time to start taking precautionary action in your nursery and garden.

There are many different types of ethanol traps available for use. One of the most common and easy to use is the homemade soda bottle trap.

Other types of traps are the Lindgren funnel trap and the modified Japanese Beetle traps.

Soda bottle traps are the least expensive but lack durability. The Lindgren-style funnel traps are the most consistent way of trapping.

Pyrethroid insecticides can protect your vegetation from an infestation of the Ambrosia Beetles. You must do this as soon as possible.

The timing of preventive action is crucial to protect the trees. Once the Granulate Ambrosia Beetles enter the trees, it is impossible to kill them.

A few off-the-shelf products contain the active ingredients permethrin and bifenthrin. Be sure to read the label list carefully if you are looking for a borer insect there. Sometimes Granulate Ambrosia Beetles are not specified on the labels.

There are organic options available, too, such as the PyGanic or the Pyrenone to fend off Granulate Ambrosia Beetle attacks. But these products are expensive and not easy to find in small amounts.

The best thing you can do is take good care of your trees or shrubs and hope that it will outgrow the attack. Reduce the stress that your vegetation goes through.

The Granulate Ambrosia Beetles breed in the late winter and early spring. They target trees that produce ethanol when under stress.

To ensure less stress, irrigate your nursery or shrubs well and keep them in a healthy condition. Avoid excessive moisture, as that induces more stress on the plants.

If you live in an area where the natural moisture levels are high, be sure to keep a lookout for Ambrosia Beetles. You never know when they will bore a hole in your beloved plants.

JOIN Our FREE Plant Care Newsletter 

By entering your email address you agree to receive a daily email newsletter from Plant Care Today. We'll respect your privacy and unsubscribe at any time.