Bagworm and Beetle Season is Here

Bagworm moths - Fall webworm moth

Bagworms and Japanese Beetles are the biggest insect-related threats to this region’s trees during the summer months.

Here are some things to watch out for and what you can do if your trees are at risk from Bagworms and Japanese Beetles:


Bagworms typically begin to hatch out during the beginning of June. At CVTS-L, we allow a week or two for all of the bagworms to hatch out before we start to spray, and expect to receive inquiries pertaining to Bagworms through the end of July. However, these dates can vary widely because the lifecycle of the Bagworm is weather dependent.

What to Look For

During these summer months, people with evergreen trees on their property should be alert for abnormal browning in the branches. If this is occurring, then they should examine the tree closer to see if Bagworms can be seen feeding on the foliage. For the rest of the year, they can be seen hanging on the tree in bags that resemble pine cones.

What to Do

The two primary methods of controlling Bagworm populations are spraying them with insecticide during their active phase and plucking the bags off of the branches during their inactive phase. If left untreated, Bagworms can cause extensive damage to – and even kill – otherwise healthy trees.

Japanese Beetles

Japanese Beetles generally begin to emerge around the end of June. This year, in our region, it was during the third week of June. We can get called out to spray for them until late July, but if we get a hot, dry cycle, their season can end much sooner. If the weather stays moist and the ground stays soft, Japanese Beetles will remain active in a life cycle that consists of feeding in the trees, mating, laying eggs in the turf and returning to the trees. However, if the turf turns dry, then they are unable to lay eggs, and it breaks the cycle. The year following a particularly dry summer will have fewer Japanese Beetles.

What to Look For

Generally, Japanese Beetle infestations are easy to identify because we can see them flying around and we can see the distinct damage they do to the leaves of deciduous trees. They “skeletonize” the foliage so the shape of the leaf is there, but they eat everything else – leaving a “skeleton” of the leaf behind.

What to Do

At CVTS-L, we use insecticide sprays to help manage Japanese Beetle and Bagworm infestations, but for trees that are too large to spray (or if the client doesn’t want us to spray on their property), we have soil injections that we can apply around the base of the tree that will move up through the tree and out through the foliage.

“Green Solutions Plant Health Care Program”

CVTS-L offers a monthly inspection program that strives to prevent the diseases and insect problems of tomorrow through careful monitoring today. Our “Green Solutions Plant Health Care Program” ensures that insect problems are either prevented or caught and treated early.