Japanese Beetle: Frequently Asked Questions (FAQs)
Pest Detection/Emergency Projects • 2800 Gateway Oaks Drive, Sacramento, CA 95833 • 916-654-1211
What does a Japanese beetle look like?
The Japanese beetle has several distinct characteristics that separate them from all other native insects in the state. Below is a graphic that shows the difference between the Japanese beetle and other look alike insects.
How did Japanese beetles come to the United States?
JB was first found in the United States in a nursery in New Jersey in 1916, where it is believed to have been imported with iris bulbs from Japan. Since then, JB populations have spread throughout the East Coast and Midwest, causing devastating impacts in home gardens and agricultural crops. Japanese beetles can spread by someone moving from an affected area with a potted plant. JB eggs and larvae live in soil and can be easily transported by accident, hidden from view deep in the soil.
Adult JB are active during the summer months and can enter California as hitchhikers in airplanes originating from the infested states and are a high risk for Japanese beetle introduction.
During the summer when adult JB are active, an intensive cargo aircraft inspection program is implemented at California airports where incoming aircraft arrive from airports in JB-infested states. The program is designed to find and remove JBs hitchhiking in cargo aircraft before they escape from the aircraft and enter the surrounding environment. In California, such inspections have occurred since 1960. In 2020, inspections yielded the interception of 291 Japanese beetles, with 3% of all 7,313 aircraft inspected found with one or more beetles.
What makes the Japanese beetle a problem?
Like many invasive species, Japanese beetles outside of their native habitat do not have natural enemies in the United States to balance out and stabilize their population. Throughout the Eastern and Midwestern United States, JB populations create large-scale destruction to a wide variety of both ornamental and agricultural plants. Because the beetle is a serious threat to many of California’s thriving industries, including nurseries, turf grass, and specialty crops, CDFA is working hard to contain the JB population through quarantine and treatment. The fight to eradicate and prevent invasive species such as JB is an effort to protect California’s agriculture and environment. California has historically been free of JB but has experienced the occasional infestation. These infestations have been successfully eradicated when found, and this has allowed the state to maintain its nationally-recognized JB-free status.
How do you treat turf and ground cover in an area for Japanese beetle?
What is being treated? For specific information about what treatment is, please visit our Treatment page.
Where is the treatment area?
Explore the maps of the Japanese beetle treatment area by visiting our Treatment page.
I live in or near the treatment area, how can I help?
Cooperation from those in the treatment area is critical to protect California agriculture and your environment! Here’s what you can do to help:
Report insects that you suspect could be Japanese beetle by contacting our Pest Hotline: 1-800-491-1899Report any extensive beetle damage to lawns, roses, grapes, fruits, or other trees and shrubs by contacting our Pest Hotline: 1-800-491-1899
Cooperate with CDFA and county staff when they request permission to place Japanese beetle traps on your property and conduct treatment for the pest.
Comply with quarantine regulations that stop the movement of plants and soil from infested eastern states, unless the material is certified by state agricultural officials to be free of Japanese beetle or has been properly treated to eliminate any beetle life stages.
Where can I get a trap for my property?
If you have reason to believe your property or location is particularly hospitable to Japanese beetle and would like to volunteer your property for trapping, contact our Pest Hotline: 1-800-491-1899.
What is the pesticide that the CDFA will treat my turf and ground cover with, and will it harm humans, pets, or other insects?
Acelepryn® is a targeted insecticide that kills certain pests in their larval state in the soil. The pesticide product Acelepryn® (EPA Registration No. 100-1489) contains 18.4% chlorantraniliprole as its active ingredient. The U.S. Environmental Protection Agency (EPA) classifies chlorantraniliprole as a “Reduced Risk” pesticide. This means that chlorantraniliprole poses a lower risk to human health and the environment than other pesticides allowed for the same uses. It is not considered to be a health threat for humans, pets, and other insects that don’t go through a larval stage in treatment areas (including pollinators) when applied correctly.
According to the label, Acelepryn® is recommended for Integrated Pest Management programs on turf and landscape ornamentals because it does not directly impact natural arthropod predator and parasitoid populations including ladybird beetles.
Will my vegetable garden or fruit trees be treated?
Vegetable gardens, fruit trees, and other edible shrubs or plants are not subject to treatment at this time.
For more information about the insecticide Acelepryn®, please visit the Japanese beetle (JB) page.
Can I plant a vegetable garden next year in areas treated this year?
As a precaution, you may avoid planting vegetables or herbs directly into the treated soil for one year.
It is possible plants could take up residue since chlorantraniliprole lasts in the soil for many months. However, the risk to the general population from consumption of home garden fruits and vegetables grown in soil following Acelepryn® application is expected to be hundreds to thousands of times below a level of concern. The EPA label for chlorantraniliprole registered for use on food crops specifies that applicators not use on crops less than one day before harvest.
What types of yard debris are at “high-risk” of moving Japanese beetle and should be disposed of in standard curbside green waste bins?
- Grass clippings
- Plants with roots or soil attached
- Sod or removed turfgrass
- Growing media (i.e. potting soil from raised beds or potted plants, NOT fill dirt)
- Bulbs or tubers of ornamental plants
Is it safe to put yard debris in the curbside green waste container after it was treated with Acelepryn®?
Yes, please place yard debris directly in the curbside green waste bins. The concern with disposing of yard debris is due to the possible presence of beetles, not the insecticide.
I live in the treatment area and participate in my local garden club’s plant swap, can I swap plants from my yard if no beetles are visible?
No. You should not swap plants from the treatment area. JB can be moved in a variety of ways, including in potted plants.
CDFA maintains a JB State Exterior Quarantine (Title 3, CCR, section 3280) which prohibits all containerized nursery stock and plants with roots and soil from entering the state unless it meets the quarantine certification requirements. We inspect shipments at 16 strategically located Border Protection Stations (BPS) on our highways to ensure compliance with this regulation prior to entry into the state. BPS staff also inspect shipments of nursery stock and potted plants for JB larvae and pupae that may be hiding in the soil and roots.