Japanese beetle

The Japanese beetle (Popillia japonica) is a species of scarab beetle. The adult measures 15 mm (0.6 in) in length and 10 mm (0.4 in) in width, has iridescent copper-colored elytra and a green thorax and head. It is not very destructive in Japan, where it is controlled by natural predators, but in North America, it is a noted pest of about 300 species of plants including rose bushes, grapes, hops, canna, crape myrtles, birch trees, linden trees, and others.

The adult beetles damage plants by skeletonizing the foliage, that is, consuming only the leaf material between the veins, and may also feed on fruit on the plants if present, while the subterranean larvae feed on the roots of grasses.

Japanese beetle
Popillia japonica
Scientific classification
P. japonica
Binomial name
Popillia japonica
Newman, 1841


Adult P. japonica measure 15 mm (0.6 in) in length and 10 mm (0.4 in) in width, with iridescent copper-colored elytra and green thorax and head. A row of white tufts (spots) of hair project from under the wing covers on each side of the body.[1]


P. japonica is native to Japan, but is an invasive species in North America.

The first written evidence of the insect appearing within the United States was in 1916 in a nursery near Riverton, New Jersey.[2] The beetle larvae are thought to have entered the United States in a shipment of iris bulbs prior to 1912, when inspections of commodities entering the country began. As of 2015, only nine western US states were considered free of Japanese beetles.[3] Beetles have been detected in airports on the west coast of the United States since the 1940s.

The first Japanese beetle found in Canada was in a tourist's car at Yarmouth, arriving in Nova Scotia by ferry from Maine in 1939. During the same year, three additional adults were captured at Yarmouth and three at Lacolle in southern Quebec.[4]

Japanese beetles have been found in the islands of the Azores since the 1970s.[5] In 2014, the first population in mainland Europe was discovered near Milan in Italy.[6][7] In 2017 the pest was detected in Switzerland, most likely having spread over the border from Italy. Swiss authorities are attempting to eradicate the pest.[8]


Lifecycle of the Japanese beetle. Larvae feed on roots underground, while adults feed on leaves and stems.
A typical cluster of Japanese beetle eggs
Japanese beetle pupa moulting 2017
A Japanese beetle pupa shortly after moulting

Ova are laid individually, or in small clusters near the soil surface.[9] Within approximately two weeks, the ova hatch, the larvae feeding on fine roots and other organic material. As the larvae mature, they become c-shaped grubs which consume progressively coarser roots and may do economic damage to pasture and turf at this time.

Larvae hibernate in small cells in the soil, emerging in the spring when soil temperatures rise again.[9] Within 4–6 weeks of breaking hibernation, the larvae will pupate. Most of the beetle's life is spent as a larva, with only 30–45 days spent as an imago. Adults feed on leaf material above ground, using pheromones to attract other beetles and overwhelm plants, skeletonizing leaves from the top of the plant downward. The aggregation of beetles will alternate daily between mating, feeding, and ovipositing. An adult female may lay as many as 40–60 ova in her lifetime.[9]

Throughout the majority of the Japanese beetle's range, its lifecycle takes one full year, however in the extreme northern parts of its range, as well as high altitude zones as found in its native Japan, development may take two years.[10]


Map showing the parts of the US infested by Japanese beetles, as of November 2006: They were present in many more sites as of July 2012.
Istocheta aldrichi egg on Japanese beetle
Egg of biocontrol, tachinid fly Istocheta aldrichi, introduced from Japan

Owing to its destructive nature, traps have been invented specifically to target Japanese beetles. These comprise a pair of crossed walls with a bag or plastic container underneath, and are baited with floral scent, pheromone, or both. However, studies conducted at the University of Kentucky and Eastern Illinois University suggest beetles attracted to traps frequently do not end up in the traps, but alight on plants in the vicinity, thus causing more damage along the flight path of the beetles and near the trap than may have occurred if the trap were not present.[11][12]

During the larval stage, the Japanese beetle lives in lawns and other grasslands, where it eats the roots of grasses. During that stage, it is susceptible to a fatal disease called milky spore disease, caused by a bacterium called milky spore, Paenibacillus (formerly Bacillus) popilliae. The USDA developed this biological control and it is commercially available in powder form for application to lawn areas. Standard applications (low density across a broad area) take from one to five years to establish maximal protection against larval survival (depending on climate), expanding through the soil through repeated rounds of infection.

On field crops such as squash, floating row covers can be used to exclude the beetles, but this may necessitate hand pollination of flowers. Kaolin sprays can also be used as barriers.

Research performed by many US extension service branches has shown pheromone traps attract more beetles than they catch.[13][14] Traps are most effective when spread out over an entire community, and downwind and at the borders (i.e., as far away as possible, particularly upwind), of managed property containing plants being protected. Natural repellents include catnip, chives, garlic, and tansy,[15] as well as the remains of dead beetles, but these methods have limited effectiveness.[16] Additionally, when present in small numbers, the beetles may be manually controlled using a soap-water spray mixture, shaking a plant in the morning hours and disposing of the fallen beetles,[14] or simply picking them off attractions such as rose flowers, since the presence of beetles attracts more beetles to that plant.[16]

Several insect predators and parasitoids have been introduced to the United States for biocontrol. Two of them, Istocheta aldrichi and Tiphia vernalis, are well established with significant rates of parasitism.


While the larvae of Japanese beetles feed on the roots of many genera of grasses, the adults consume the leaves of a much wider range of hosts, including these common crops:[4] bean, strawberry, tomato, pepper, grape, hop, rose, cherry, plum, pear, peach, raspberry, blackberry, corn, pea, okra, and blueberry.

List of adult beetle hostplant genera



Japanese beetle larva (grub)


Japanese beetle pupa


Japanese beetle adult

Japanese Beetle Feeding on Peach Tree

Adult Japanese beetles feeding on peach tree

Japanese Beetles, Ottawa

Mating, Ottawa, Ontario, Canada

Japanese Beetles on Pasture Rose, Ottawa

Feeding, Ottawa

FullSizeRender 36

Japanese beetle feeding on calla lily, Ottawa, Ontario, Canada


  1. ^ M.F. Potter; D.A. Potter; L.H. Townsend (January 2006). "Japanese Beetles in the Urban Landscape". University of Kentucky, College of Agriculture.
  2. ^ "Japanese Beetle Ravages". Reading Eagle. p. 26. 22 July 1923. Retrieved 28 September 2015.
  3. ^ "Managing the Japanese Beetle: A Homeowner' s Handbook" (PDF). www.aphis.usda.gov. United States Department of Agriculture Animal and Plant Health Inspection Service. Retrieved 21 August 2018.
  4. ^ a b "Popillia Japonica (Japanese Beetle) - Fact Sheet". Canadian Food Inspection Agency. 19 February 2014. Archived from the original on 4 December 2010. Retrieved 28 September 2015.
  5. ^ Virgílio Vieira (2008). "The Japanese beetle Popillia japonica Newman, 1838 (Coleoptera: Scarabaeidae) in the Azores islands" (PDF). Boletín Sociedad Entomológica Aragonesa. 43: 450. Retrieved 28 September 2015.
  6. ^ "First report of Popillia japonica in Italy". EPPO. Retrieved 28 September 2015.
  7. ^ "Popillia japonica Newman, 1841" (PDF) (in Italian). Assessorato Agricoltura, Caccia e Pesca, Regione Piemonte. Retrieved 28 September 2015.
  8. ^ "First report of Popillia japonica in Switzerland". EPPO. 2017. Retrieved 19 June 2018.
  9. ^ a b c Fleming, WE (1972). "Biology of the Japanese beetle". USDA Technical Bulletin. 1449.
  10. ^ ODA. "Or egon Department of Agriculture Insect Pest Prevention & Management Program Oregon.gov/ODA Rev: 3/ 30 /2017 2 Japanese Beetle Eradication Response Plan 2017" (PDF). www.oregon.gov/ODA/. Oregon Department of Agriculture. Retrieved 31 May 2017.
  11. ^ "Japanese Beetles in the Urban Landscape". University of Kentucky. Retrieved 28 September 2015.
  12. ^ Paul V. Switzer; Patrick C. Enstrom; Carissa A. Schoenick (2009). "Behavioral Explanations Underlying the Lack of Trap Effectiveness for Small-Scale Management of Japanese Beetles". Journal of Economic Entomology. 102 (3): 934–940. doi:10.1603/029.102.0311.
  13. ^ "Managing the Japanese Beetle: A Homeowner's Handbook". U.S. Department of Agriculture, Animal and Plant Health Inspection Service. May 2015. Retrieved 28 September 2015.
  14. ^ a b "Japanese beetle control methods". Landscape America. Ohio City Productions, Inc. Retrieved 28 September 2015.
  15. ^ "Tips on how to get rid of pests". selfsufficientish.com. Retrieved 28 September 2015.
  16. ^ a b Jeff Gillman (18 March 2010). "Disney and Japanese Beetles". Washington State University. Archived from the original on 14 March 2012. Retrieved 28 September 2015.

External links

Quisqualic acid

Quisqualic acid is an agonist of the AMPA, kainate, and group I metabotropic glutamate receptors. It is one of the most potent AMPA receptor agonists known. It causes excitotoxicity and is used in neuroscience to selectively destroy neurons in the brain or spinal cord. Quisqualic acid occurs naturally in the seeds of Quisqualis species.

Research conducted by the USDA Agricultural Research Service, has demonstrated quisqualic acid is also present within the flower petals of zonal geranium (Pelargonium x hortorum) and is responsible for causing rigid paralysis of the Japanese beetle. Quisqualic acid is thought to mimic L-glutamic acid, which is a neurotransmitter in the insect neuromuscular junction and mammalian central nervous system.


Rutelinae or shining leaf chafers is a subfamily of the scarab beetles (family Scarabaeidae). It is a very diverse group; distributed over most of the world, it contains some 200 genera with over 4,000 described species in 7 tribes. A few recent classifications include the tribe Hopliini, but this is not generally accepted.Unlike some of their relatives, their habitus is usually lacking in ornamentation, such as horns. They resemble the Melolonthinae in being fairly plesiomorphic in outward appearance. Many species have brilliant or iridescent hues, however, such as the genus Chrysina, and a number of species are serious pests (e.g., the Japanese beetle).


The Scoliidae, the scoliid wasps, are a family of about 560 species found worldwide. They tend to be black, often marked with yellow or orange, and their wing tips are distinctively corrugated. Males are more slender and elongated than females, with significantly longer antennae, but the sexual dimorphism is not as apparent as in the Tiphiidae.

Scoliid wasps are solitary parasitoids of scarab beetle larvae. Female scoliids burrow into the ground in search of these larvae and then use their sting to paralyze them. They will sometimes excavate a chamber and move the paralyzed beetle larva into it before depositing an egg. Scoliid wasps act as important biocontrol agents, as many of the beetles they parasitize are pests, including the Japanese beetle. Male scoliids patrol territories, ready to mate with females emerging from the ground. Adult wasps may be minor pollinators of some plants and can he found on many wildflowers in the late summer.

Scoliidae also has at least one species known to engage in pseudocopulation with an orchid. Flowers of the orchid Bipinnula penicillata in subtropical South America resemble females of Pygodasis bistrimaculata, tricking male wasps into attempting to mate and, in the process, provide pollination. Scoliids include some of the largest wasps in the world, with only the similarly large tarantula hawk wasps rivaling them in size.

The Blue Racer

The Blue Racer is a series of 17 theatrical cartoons produced from 1972 to 1974.

Ulmus americana 'Augustine'

The American Elm cultivar Ulmus americana 'Augustine' was originally selected in Bloomington, Illinois, in 1927.

Ulmus americana 'Aurea'

The American Elm cultivar Ulmus americana 'Aurea' was cloned from a tree discovered by F. L. Temple in Vermont at the end of the 19th century.

Ulmus americana 'Beaverlodge'

The American Elm cultivar Ulmus americana 'Beaverlodge' was selected as a seedling in 1925 at the Beaverlodge Experimental Farm, Morden, part of the Lacombe Research Centre, Alberta, for its hardiness and vigour, and released in 1954.

Ulmus americana 'Burgoyne'

The putative American Elm cultivar Ulmus americana 'Burgoyne' was grown at the Arnold Arboretum until removed in 1988. The tree was raised from seeds of the Burgoyne Elm, grown for the town of Weston, Massachusetts, in 1965. The name of the tree was first noted in records of the Plant Sciences Data Center of the American Horticultural Society, but is not formally recognized as a valid cultivar.

Ulmus americana 'Columnaris'

The American Elm cultivar Ulmus americana 'Columnaris' was propagated from a tree found by Mr John Dunbar at Conesus Lake, New York, before 1920. The tree should not be confused with U. americana var. columnaris Rehder, J. Arnold Arbor. 3: 42, 1922.

Ulmus americana 'Exhibition'

The American Elm cultivar Ulmus americana 'Exhibition' is a selection made by the Patmore Nurseries from seeds of a tree at Brandon, Manitoba. Released in 1952, 'Exhibition' was propagated by grafting.

Ulmus americana 'Fiorei'

The American Elm cultivar Ulmus americana 'Fiorei' was raised by the Charles Fiore Nurseries [1], Prairie View, Illinois, before 1956, but is no longer listed by the company.

Ulmus americana 'Jackson'

The American Elm cultivar Ulmus americana 'Jackson' was cloned from a selection made at Wichita, Kansas, which had reputedly shewn no signs of Dutch elm disease damage at >50 years of age.

Ulmus americana 'Lake City'

The American Elm cultivar Ulmus americana 'Lake City' was first described by Wyman in Trees Magazine 3 (4): 13, 1940.

Ulmus americana 'Miller Park'

The American Elm cultivar Ulmus americana 'Miller Park' is a selection made by the University of Minnesota. Originally identified as MNT-0365, it was cloned from an old elm surviving in Hennepin County, Minnesota. 'Miller Park' is currently (2016) being researched but no data have yet been published. The tree is named for the eponymous park in Eden Prairie, in the environs of Minneapolis.

Ulmus americana 'Moline'

The American Elm cultivar Ulmus americana 'Moline' was cloned from a wild seedling transplanted to Moline, Illinois, in 1903 and propagated from 1916 by the Klehm Nurseries, Arlington Heights, IL. Some authorities regard the tree as identical to 'Minneapolis Park'.

Ulmus americana 'Morden'

The American Elm cultivar Ulmus americana 'Morden' was cloned from a selection made by the Dominion Experimental Farm, Morden, Manitoba, in 1939 on account of its ability to withstand severe ice storms without breakage.

Ulmus americana 'Patmore'

The American Elm cultivar Ulmus americana 'Patmore' was selected and raised by R. H. Patmore from a native tree in Brandon, Manitoba, Canada. It may be synonymous with another cultivar from the same source, known as 'Brandon'.

Ulmus americana 'Washington'

The American Elm cultivar Ulmus americana 'Washington' is a tree of unknown derivation introduced by the U. S. National Park Service.


This page is based on a Wikipedia article written by authors (here).
Text is available under the CC BY-SA 3.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.