Japanese Beetle (JB)


  • No quarantines at this time.
    • Carmichael - No treatment
      • No JB life stages detected in 2018
      • Reverts to standard detection levels, 2 traps per square mile, as project has ended
    • Cerritos - No treatment
      • No JB life stages detected in 2018
      • 25 traps per square mile beginning May 1, 2019 (standard high hazard density)
    • Fair Oaks - No treatment
      • No JB life stages detected in 2018
      • Delimitation trapping only beginning May 1, 2019
    • Goleta - No treatment
      • No JB life stages detected in 2018
      • Delimitation trapping only beginning May 1, 2019
    • Hawaiian Gardens - No treatment
      • No JB life stages detected in 2018
      • Delimitation trapping only beginning May 1, 2019
    • La Palma - No treatment
      • No JB life stages detected in 2018
      • Reverts to standard detection levels, 2 traps per square mile, as project has ended
    • Salinas - No treatment
      • 4 JB adults found in a regulatory situation in 2018
      • Delimitation trapping only beginning May 1, 2019
    • Seaside - No treatment
      • 2 JB adults detected in 2018
      • Delimitation trapping only beginning May 1, 2019
    • Stockton Airport - No treatment
      • 21 JB adults detected in 2018
      • Delimitation trapping only beginning May 1, 2019 surrounding find sites plus 5 traps per square mile in buffers 2 and 3
    • Carmichael - No treatment
      • No JB life stages detected in 2017
      • Enhanced delimitation trapping beginning May 1, 2018
    • Cerritos - No treatment
      • One JB life adult detected in 2017
      • 25 traps per square mile beginning May 1, 2018 (standard high hazard density)
    • Fair Oaks - No treatment
      • One JB life adult detected in 2017
      • Delimitation trapping only beginning May 1, 2018 surrounding new find site
      • Other areas revert to standard detection levels, 2 traps per square mile, as project has ended
    • Goleta - No treatment
      • One JB adult detected in 2017
      • Delimitation trapping beginning May 1, 2018 surrounding new find site
    • Hawaiian Gardens - No treatment
      • One JB life adult detected in 2017
      • Delimitation trapping only beginning May 1, 2018 surrounding new find site
    • La Palma - No treatment
      • No JB life stages detected in 2017
      • Delimitation trapping beginning May 1, 2018 surrounding new find site
    • Stockton Airport - No treatment
      • 28 JB adults detected in 2017
      • Delimitation trapping only beginning May 1, 2018 surrounding find sites plus 5 traps per square mile in buffers 2 and 3
    • Sunnyvale - No treatment
      • No JB life stages detected in 2017
      • Reverts to standard detection levels, 2 traps per square mile, as project has ended
    • Trap detections outside high risk facilities (2 adults):
      • 2 adults in Seaside (Monterey County)
    • Regulatory inspection outside high risk facilities (4 adults):
      • 4 adults in Salinas (Monterey County)
    • Trap detections at high risk facilities:
      • 46 adults at airports and freight forward facilities in Los Angeles, Sacramento, San Bernardino, San Diego, San Joaquin, and Santa Clara counties.
    • Aircraft visual inspection detections (untrapped):
      • Adults found on 871 aircraft at airports in Alameda, Los Angeles, Orange, Sacramento, San Bernardino, San Diego, San Joaquin, and Santa Clara counties.

How We Can Stop the Japanese Beetle:

The Japanese beetle (JB), Popillia japonica, is native to Japan. Adults feed on the fruit, flowers, and leaves of a wide variety of plants, while the larvae live underground and feed on roots and decaying material, favoring grass roots. JB is most common on the northern Japanese islands of Honshu and Hokkaido. It is not common on the more southern islands of Japan because it competes with other related species and because these islands lack the abundant grasslands of the north that are conducive to JB larval feeding. It is not considered much of a pest even on the northern islands because population levels remain constrained by the cool climate, which causes the JB to have a two-year life cycle, and by a parasitic fly that is well synchronized with the JB life cycle.

In 1916, JB was discovered in a nursery in New Jersey, possibly arriving inadvertently in potted bulbs from Japan. The environment it encountered in the United States (US) was warmer than its native range, and this allowed it to complete its life cycle in only one year, leading to a more rapid population buildup than in its native range. In addition, the abundance of grass grown in lawns in urban areas provided a ready larval food source, and this combined with the absence of its main parasitic fly further allowed the fledgling infestation to grow quickly and spread. As a result, in the 100 years since it was discovered in the U.S., it has completely colonized 20 states and partially infested another 15. Its US distribution now ranges from Maine south to Georgia and westward to the Mississippi River, with additional areas scattered across the Great Plains to central Colorado. California has historically been free of JB, but has experienced the occasional infestation. These infestations have been aggressively eradicated when found, and this has allowed the state to maintain its nationally-recognized JB-free status.

No, JB is not established in California. While the JB is established in most eastern states, it is not established in California or the rest of the western US. As localized infestations are detected here, we work to isolate and eradicate them before they can become footholds that could lead to wider infestation and establishment.

    The JB feeds on a broad range of plants, so if it became permanently established in California it would pose a serious threat to some of our native plants, including some of California’s threatened and endangered species that are related to one or more known host plants. A discussion of these species follows, and those recognized nationally are denoted as federally endangered (FE) or federally threatened (FT), while species on the California lists are state endangered (SE) or state threatened (ST).

    Members of the rose family (Rosaceae) are commonly attacked by JB. Roses (Rosa spp.) are preferred hosts. Small-leaved rose (Rosa minutifolia; SE) occurs only in San Diego County in the United States. The Mt. Shasta snow-wreath (Neviusia cliftonii; Rosaceae) is found only in the Mt Shasta region and is closely related to Kerria japonica, a plant that is a known host for JB. Hickman’s cinquefoil (Potentilla hickmanii; FE; SE) is an endangered plant of the Central Coast of California that is in the rose family.

    A range of grasses (Poaceae) are attacked by JB, especially in its larval stage. Rare grasses in California that might be attacked by JB include Napa bluegrass (Poa napensis; FE; SE) and Sonoma alopecurus (Alopecurus aequalis ssp. sonomensis; FE). In addition, California is the only home of a group of grasses endemic to vernal pools including such species as hairy Orcutt grass (Orcuttia pilosa; FE; SE) and Tuctoria mucronata (Solano grass; FE; SE).

    The mustards (Brassica spp.) are attacked by JB. California is home to many rare, endemic members of the mustard family (Brassicaceae). Examples include California jewelflower (Caulanthus californicus; FE; CE), Metcalf Canyon jewelflower (Streptanthus albidus; FE), and Mt Hermon wallflower (Erysimum teretifolium; FE; CE).

    The mallow family (Malvaceae) has many members that are attacked by JB. Examples of California genera containing rare species in this group include checkermallows (e.g., bird‐foot checkerbloom, Sidalcea pedata [FE; CE] and Keck’s checkermallow, Sidalcea keckii [FE]) and California hibiscus (Hibiscus lasiocarpus var. occidentalis).

    JBs attack several genera of the legume family (Fabaceae), including theclovers (Trifolium spp.). Rare clovers in California include showy Rancheria clover (Trifolium amoenum; FE)andMonterey clover(Trifolium trichocalyx; FE; SE). The legume family also includes lupines, the larval food plants of several endangered invertebrates. Lupines, especially L. arboreus, are the larval food plant of the Mission blue butterfly (Plebejus icarioides missionensis; FE) and Boisduval’s blue butterfly (Icaricia icarioides; FE).

    Several genera of the knotweed family (Polygonaceae) are attacked by JB. In California, Hickman’s knotweed (Polygonum hickmanii; FE; SE) and Ione buckwheat (Eriogonum apricum spp. apricum; FE; SE) are examples in Polygonaceae of rare species that potentially could be attacked by JB. The genus Eriogonum contains several species that are the obligate host plants of endangered invertebrates such as El Segundo blue butterfly (Euphilotes battoides allyni; FE), Smith's blue butterfly (Euphilotes enoptes smithi; FE), and Lange's metalmark butterfly (Apodemia mormo langei; FE; SE).

    The exceedingly large daisy family (Asteraceae) contains several known hosts of JB such as sunflower (Helianthus annuus) and horseweed (Erigeron canadensis). Closely related species of concern in California include Algodones Dunes sunflower (Helianthus niveus ssp. tephrodes; FE; SE) and Parish's daisy (Erigeron parishii; FT).

California maintains a five part pest prevention system composed of 1) Pest Exclusion to prevent the introduction and spread within the state of newly introduced pests, 2) Pest Detection to detect incipient infestations as soon as possible, 3) Pest eradication to eliminate incipient infestations when feasible, 4) Pest Management for infestations that are not feasible to eradicate but which can be controlled, and 5) Pest Identification and Outreach to ensure timely and accurate identification of pests and to educate the public about pest management activities.

The United States Department of Agriculture maintains a JB Federal Domestic Quarantine (7CFR section 301.48) which enables the regulation of any airport or portions of an airport in a quarantined state. Regulated airlines are required to implement safeguards to prevent JB from entering the cargo holds and passenger areas of planes. Planes landing in this state from high risk regulated airports are inspected upon arrival for the presence of JB. In California, such inspections have occurred since 1960.

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 larva and pupa that may be hiding in the soil and roots.

For packages being shipped to California, the County Agricultural Commissioners’ staffs perform inspections of incoming shipments at Postal/Fed Ex/UPS facilities. Our Dog Team Program strategically places inspector dogs and their handlers in various counties to increase the efficacy and efficiency of package inspections at the Postal/Fed Ex/UPS facilities. The dogs are trained by the USDA to detect packages containing plant material. County staff also perform destination inspections of incoming nursery stock arriving from states under quarantine for JB.

The following tables summarize the Japanese beetle interceptions by multiple facets of our pest exclusion system.

PDR, Rejections and Interception Totals for 2005-2015

Partial year Interceptions Rejections PDRs Totals
2005 0 12 5 17
2006 0 7 14 21
2007 0 11 51 62
2008 0 7 28 35
2009 218 7 5 230
2010 251 26 10 287
2011 272 45 6 323
2012 337 36 14 387
2013 103 18 1 122
2014 108 36 3 147
2015 3 8 1 12
Totals 1292 213 138

***database collection did not begin until 2009

Interceptions = shipments of JB host material.

Rejections = shipments arriving which are not in compliance with our JB Exterior Quarantine requirements and denied entry.

PDRs = JB actually detected.

JB Airport Interceptions

County Total 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014
Alameda 15

3 11 1
Fresno 14 4 10
Los Angeles 893 107 241 221 79 62 15 86 21 38 7 16
Orange> 12 3 3 3 1 2
Sacramento 48 6 2 2 25 4 3 4 2
San Bernardino 154 13 66 16 20 12 27
San Diego 29 6 4 5 5 1 8
Santa Clara 1 1

These were intercepted on incoming aircraft flights.

JB County Rejections 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015
Alameda 1 3 5 1 2 0 0 0 3 1 10
Butte 0 0 0 0 0 0 1 0 0 0 0 0
Calaveras 0 0 0 0 0 0 1 3 1 0 1 0
Contra Costa 0 14 14 7 3 5 1 0 2 3 5 0
El Dorado 0 0 0 0 1 0 0 0 0 0 0 0
Fresno 6 0 1 9 8 0 0 1 0 0 0 0
Humboldt 0 0 0 13 9 1 0 0 0 0 0 0
Los Angeles 0 0 0 0 0 0 0 0 1 0 0 0
Orange 0 0 0 1 0 1 0 0 0 0 0 0
Placer 4 6 1 0 0 1 1 1 1 5 3 0
Riverside 0 0 0 0 3 0 0 0 0 0 0 0
Sacramento 1 6 0 0 3 6 2 1 0 1 0 0
San Bernardino 0 0 0 3 22 1 0 2 0 0 0 0
San Diego 4 0 0 0 1 0 0 0 0 0 4 0
San Joaquin 1 0 3 1 0 0 0 0 0 0 0 0
San Jose 1 2 0 0 0 0 0 0 0 0 0 0
San Luis Obispo 6 8 11 0 2 1 0 0 0 0 0 0
San Mateo 1 1 0 0 0 1 0 2 0 2 0 0
Santa Barbara 0 0 0 2 1 0 1 1 1 0 0 0
Santa Clara 3 1 0 0 0 0 0 1 0 0 2 0
Santa Cruz 32 31 31 10 15 11 0 3 0 1 12 1
Shasta 1 0 0 0 0 0 0 0 0 0 0 0
Solano 0 0 0 0 32 0 0 0 0 0 0 0
Sonoma 0 2 7 9 2 1 0 0 0 0 0 0
Tulare 2 0 1 0 0 0 0 0 0 0 0 0
Yuba 0 0 0 0 0 3 0 0 0 0 0 0

These are rejections made of incoming parcel shipments which do not meet the requirements of our JB Exterior Quarantine.

CDFA also conducts inspections of outdoor items from the east coast for the gypsy moth. During these inspections an adult JB was found in Orange County in 2007 and Humboldt County in 2015 associated with outdoor items being moved here from the east coast. In 2011 the Fresno County dog team intercepted JB in a single plant being shipped into the state through a parcel service.

In California, trapping for JB has occurred for many years. Approximately 12,000 traps are placed and monitored statewide during the JB flight season. General residential trapping for JB is currently conducted at two traps per square mile. If a JB is detected, then intensive trapping is triggered. The objective is to determine the extent and epicenter of an infestation. The trap density is increased to 50 traps within the one-square-mile core surrounding each adult find (0.5-mile radius). This may be increased to 100, 160 or 640 traps to further refine the data about the population if additional beetles are detected, and additional traps may be placed in the buffers. In addition, the trap density is 25 traps per square mile in a one-mile buffer area surrounding the core, and five traps per square mile in a two-mile buffer area surrounding this buffer, thereby resulting in a 49-square-mile area (3.5-mile radius). Traps in the core are monitored daily and buffer traps are monitored at least once during the first week following a detection, and all traps are monitored weekly thereafter. Visual surveys may occur up to 400 meters around each detection. High hazard JB trapping is also conducted around airports and DHL/FedEx/UPS facilities. In California, trapping at airports was first implemented in 1945.

Despite the numerous instances in which our efforts have succeed in keeping JB from entering California, the pest has been introduced into and caused incipient infestations several times in the state. The following is a chronology of JB eradications in California. Each time JB has been introduced, it has been successfully eradicated. The fact that JB has been introduced numerous times into the state and subsequently eradicated supports the contention that JB can be successfully eradicated from the two current infestations in Sacramento County.

Japanese Beetle Eradications in California

Year(s) of Finds City County Adults Larvae
1951* Lennox (LAX) Los Angeles 1 0
1954* Hawthorne (LAX) Los Angeles 1 0
1956* Fairfield (TAFB) Solano 1 0
1961-1962 Sacramento/West Sacramento Sacramento/Yolo 449 71
1973-1974 Balboa Park San Diego 24 0
1974* San Diego (SAN) San Diego 1 0
1983-1984** Orangevale/Citrus Heights Sacramento 93 8
2002* Rancho Cordova (MHF) Sacramento 5 0
2006-2007 Vista San Diego 3 0
2010-2012, 2014 Fair Oaks Sacramento 10 0
2014-2015 Carmichael Sacramento 10 0

* = Trapped at or near Los Angeles Airport (LAX), Mather Field Airport (MHF), San Diego Airport (SAN), or Travis Air Force Base (TAFB). Considered quarantine treatments at point of introduction.

** = This was the only time CDFA implemented a JB Interior Quarantine, from 1983-87.

The two lists below include all beetles trapped or visually collected in the environment in Sacramento County since 1987 (the earliest year for which records have been entered into the CDFA electronic records database). The lists do not include beetles found on planes during inspections.

A. High Hazard Detections - Trapped
This list summarizes the JB trapped at or just outside the two major airports for cargo planes in Sacramento County, namely Sacramento International (SMF) and Mather Field (MHF). They are presumed to be the result of JB leaving the planes upon arrival, so they normally do not trigger treatments. However, because there were five beetles in 2002 at Mather Field, the CDFA did treat the turf on the airport and 16 bordering trailer park properties with imidacloprid that year as a precaution.

Year Detections Location
1991 1 SMF
1996 2 MHF and SMF
2000 1 MHF
2002 5 MHF
2003 2 MHF and SMF
2005 1 SMF
2006 2 MHF
2011 1 SMF
2012 1 MHF

B. Residential Detections - Trapped or Visual
This list summarizes the JB trapped or collected visually in residential neighborhoods outside of the high hazard airport trapping in Sacramento County.

Year Detections Location and Comments
199 1 Fair Oaks; 2.5 miles SE of current Fair Oaks and 4.3 miles NE of current Carmichael infestations; trapped; no treatment
1998 1 Carmichael; 620 meters NE of first find in current Carmichael project; adult reportedly collected by resident who turned it in said it was collected at that address "a number of years ago"; no treatment
2010 1 Fair Oaks; trapped; treatment occurred
2011 2 Fair Oaks; trapped; treatment occurred
2012 4 Fair Oaks; trapped; treatment occurred
2014 3 Fair Oaks; trapped; treatment occurred
2014 3 Carmichael; trapped; treatment occurred
2015 7 Carmichael; trapped; treatment occurred

At the project sites impartial third-party monitoring is conducted. A pesticide monitoring program is used to evaluate program effectiveness and environmental impact. Pesticide monitoring is a cooperative effort involving state and county personnel. The evaluation is designed to effectively address agency, cooperator, and public concerns.

The Sacramento County Agricultural Commissioner's Pesticide Use Enforcement staff makes regular inspections of mixing/loading, equipment and treatment activities, and pesticide container storage.

CDPR's Division of Pest Management Environmental Hazards Assessment Program staff monitor for detectable levels of pesticides in and around treatment areas. This may include sampling of air, foliage, food crops, water, soil, or other media. Monitoring results will indicate program effectiveness by measuring persistence of pesticides in pest host materials, and discover any environmental impacts by measuring residues in non-target environmental components.

CDFA has a National Pollutant Discharge Elimination System (NPDES) permit issued by the State Water Resources Control Board to ensure no pollutants are discharged into a body of water. CDFA has never failed to comply with the terms of its NPDES permit.


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