Anoplophora chinensis

Name:   Anoplophora chinensis
Pest Authorities:  (Forster)
Taxonomic Position:  Insecta: Coleoptera: Cerambycidae
Sub-specific Taxon:  
Pest Type:   Insect
Common Name(s):
   Citrus longhorned beetle (CLHB) (English)
   Sky ox beetle (English translation of Asian common name for Anoplophora spp.).
   Starry night sky beetle (English translation of Asian common name for Anoplophora spp.).
   White spotted citrus longhorned beetle (English)
   Anoplophora malasiaca Thomson
   Cerambyx chinensis Forster
Numerical Score:  9
Relative Risk Rating:  Very High Risk
Uncertainty:   Very Certain
Establishment Potential Is High Risk
The relevant criteria chosen for this organism are:  
  • Organism has successfully established in location(s) outside its native distribution
  • Suitable climatic conditions and suitable host material coincide with ports of entry or major destinations.
  • Organism has demonstrated ability to utilize new hosts
  • Organism has active, directed host searching capability or is vectored by an organism with directed, host searching capability.
  • Organism has high inoculum potential or high likelihood of reproducing after entry.
Justification: CLHB has recently become established in Italy (Colombo and Limonta 2001). This insect would find climatic conditions suitable for its survival at most North American ports of entry, especially in the humid regions of the southeastern U.S, which have a climate similar to its native environment. Moreover, its broad host range virtually assures that it would easily adapt to trees indigenous to North America and would have a high likelihood of reproducing after entry.

Spread Potential Is High Risk
The relevant criteria chosen for this organism are:  
  • Organism has demonstrated the ability for redistribution through human-assisted transport.
  • Organism has a high reproductive potential
  • Potential hosts have contiguous distribution.
  • Newly established populations may go undetected for many years due to cryptic nature, concealed activity, slow development of damage symptoms, or misdiagnosis.
  • Organism has broad host range.
Justification: While adults prefer to reproduce close to trees from which they emerged, they are relatively strong fliers and capable of traveling several km. CLHB is easily transported in live plant materials (e.g. bonsai), and could also be transported in wood products including logs, lumber, wooden packing materials, pallets or dunnage. This insect has a high reproductive potential and could find suitable host material in most forest, urban or fruit producing areas of North America. Adults are large, conspicuous insects that could easily be detected but the immature stages are in wood and difficult to detect. Moreover, low-level populations during the early stages of an established infestation might be difficult to detect.

Economic Potential Is High Risk
The relevant criteria chosen for this organism are:  
  • Organism attacks hosts or products with significant commercial value (such as for timber, pulp, or wood products.
  • Organism directly causes tree mortality or predisposes host to mortality by other organisms.
  • Damage by organism causes a decrease in value of the host affected, for instance, by lowering its market price, increasing cost of production, maintenance, or mitigation, or reducing value of property where it is located.
  • Organism may cause loss of markets (domestic or foreign) due to presence and quarantine significant status.
  • No effective control measure exists.
Justification: If this insect were to become established in North America, the potential for economic impact is significant. Like the Asian longhorned beetle, Anoplophora glabripennis, this insect can kill trees. Furthermore the ability of this insect to attack a wide range of fruit and nut trees is expected to have a negative impact on food crops. This would result in higher production costs and higher costs to the consumer.

Environmental Potential Is High Risk
The relevant criteria chosen for this organism are:  
  • Organism is expected to cause significant direct environmental effects, such as extensive ecological disruption or large scale reduction of biodiversity.
  • Organism is expected to have direct impacts on species listed by Federal, Provincial, or State agencies as endangered, threatened, or candidate. An example would be insuring a listed plant species.
  • Organism is expected to have indirect impacts on species listed by Federal, Provincial, or State agencies as endangered, threatened, or candidate. This may include disruption of sensitive or critical habitat.
  • Introduction of the organism would likely result in control/eradication programs that may have potential adverse environmental affects.
Justification: Establishment of CLHB could result in significant changes in the species composition and biodiversity of many North American forests with resulting environmental disruption. In addition, establishment would necessitate removal of infested trees in urban areas and an increased dependency on pesticides to eradicate or control infestations, especially in urban or agricultural areas.

CLHB infests a wide range of trees, which are important in agriculture, arborculture and forestry. These include representatives of the families Aceraceae (maple), Anacardiaceae, Araliaceae, Betulaceae (birch), Eleangaceae, Fagaceae (beech, chestnut, oak), Lauraceae (laurel), Oleaceae (ash), Polygonaceae, Styracaceae, Rutaceae, Rosaceae, Salicaceae (poplar and willow), Ulmaceae (elm), Moraceae (mulberry), Meliaceae, Leguminosae, Juglandaceae (walnut), Aquifoliaceae, Platanaceae (sycamore), Euphorbiaceae, Casuarinaceae, Verbenaceae, Sapindaceae, Theaceae and Taxodiaceae (yew) (Lingafelter and Hoebeke 2002).

Lingafelter and Hoebeke (2002) list more than 100 plants as recorded hosts of this insect. These include lime, Citrus aurantifolia ; sour orange, Citrus aurantium; mandarin lime, Citrus limonia; pummelo, Citrus grandis; tangor, Citrus nobilis and sweet orange, Citrus sinensis. Other reported hosts are pecan, Carya illinoensis; Persian walnut, Juglans regia; pear, Pyrus communis; peach, Prunus persica; plum, Prunus spp.; cherry, Prunus spp; white mulberry, Morus alba; paper mulberry, Broussonetia papyrifera; pigeon pea, Cajanus cajan; Tea, Camellia sinenesis; jujube, Ziziphus jujuba; Australian pine or beefwood-tree, Casuarina equisetifolia and Casuarina stricta; willow, Salix sp.; hibiscus, Hibiscus spp.; China-berry or Indian lilac, Melia azedarach; apple, Malus pumila; Chinese pear leaved crabapple, Malus spectabilis; poplar or aspen, Populus spp.; sycamore or plane tree, Platanus spp.; fig, Ficus spp.; litchi, Litchi sinensis; oval kumquat, Fortunella margarita and Japanese red cedar, Cryptomeria japonica.

CLHB is capable of surviving in small diameter trees and attacks bonsai (USDA APHIS n.d.).

     Indigenous to Asia and occurs primarily in China, Korea and Japan. However, a few specimens have been reported from Vietnam, Taiwan, Indonesia, the Philippines and Malaysia (Lingafelter and Hoebeke 2002).
     Introduced into England (Cooter 1998) and recently established in the vicinity of Milan, Italy (Colombo and Limonta 2001).
North America:
      CLHB has been intercepted at North American ports of entry and recovered from bonsai and nursery stock imported from Korea and Japan in Georgia, Wisconsin (USDA APHIS n.d) and Washington (Washington State Department of Agriculture 2001. Infested plant materials have been destroyed and this insect is not considered established in North America (Lingafelter and Hoebeke (2002).
The genus Anoplophora consists of 36 species of woodboring beetles that occur throughout Asia. Many are large beetles, striking in their appearance and have exceptionally long antennae. Several species are considered major tree pests in their native habitat (Lingafelter and Hoebeke 2002).

Citrus longhorned beetle, Anoplophora chinensis, and white spotted longhorned beetle, A. malasiaca Thomson have recently been combined under the name A. chinensis (Lingafelter and Hoebeke 2002). At least one North American interception of this insect is reported as A. malasiaca (USDA APHIS n.d)

CLHB typically has one generation per year although some individuals may require two years to complete development, especially in the northern part of its range. Larvae may be present throughout the year.

Adults feed on the bark, leaves, and leaf petioles of host trees. Females deposit eggs in T-shaped oviposition holes cut in the bark on the lower trunk or exposed roots of host trees. The larvae feed in the outer wood (sapwood) and third instar larvae begin to bore deep into the woody tissue. Pupation and adult development takes place in the wood and adults emerge leaving a distinct round or slightly oval shaped exit hole on the bark surface. Adults emerge from April to August and are most common in May to July. Adults are strong fliers. However, females, heavily laden with eggs, prefer to oviposit either on trees from which they emerged or within a close proximity.

Wang (1998) reported that the host tree attracts aggregations of adult CLHB, while a pheromone produced by the female is likely a contact pheromone used to attract males already present on the host.

Economic Impact:    Boring by larvae of Anoplophora chinensis can kill trees. Moreover, heavily mined branches and stems commonly break, especially during strong winds.

The ability of Anoplophora chinensis to attack and kill healthy citrus and other fruit trees, forest and ornamental trees makes the potential economic impact of its establishment even more serious than the closely related Asian longhorned beetle (ALB), A. glabripennis, (USDA 1999). Between 1996 and 2001, control of relatively localized infestations of ALB in the United States cost over $US 5 million. If CLHB were to become established, we would not only be faced with eradication costs similar to ALB, but the impact on the citrus industry would also affect consumers as the increased costs of production and relative scarcity of the produce drives up prices at the marketplace.

Environmental Impact:   Establishment of this insect and associated tree mortality could cause major ecosystem disruptions and associated adverse effects on biodiversity. Furthermore, establishment would result in the increased use of pesticides to minimize their impact in citrus and fruit orchards. This insect has been recorded on pecan, Carya illinoensis, and many other forest trees. It is reasonable to assume that this insect could also reproduce on other Carya spp., walnut, Juglans spp. and other nut producing trees and have a negative impact on the animals that depend on these important mast-producing trees.

Control:    Control of wood-boring insects is difficult because they spend so much of their life cycle inside the host tree. Attempts to eradicate similar insects, such as Asian longhorned beetle, requires complete removal and destruction of infested trees (USDA 1999).

A gregarious larval ectoparasite, Ontsira anoplophorae (Hymenoptera: Braconidae), has been found associated with Anoplophora chinensis (reported as A. malasiaca) and is considered to be a potential biological control agent for several species of Anoplophora (Smith n.d.). An entomogenous nematode, Steinernema feltiae, applied in bark compost has been tested as a biological control agent in Japan.

Because some individuals of this insect can require two years to complete a generation, the European Union (EU) requires maintentance of Japanese bonsai plants under quarantine conditions for two years prior to their export.

In Japan, and probably China, people collect and kill adult beetles in orchards in an attempt to reduce population numbers. Young children are often paid by growers to collect and kill adult beetles.

Symptoms:    Symptoms of CLHB infestation on dwarf trees or bonsai include scraped sections of bark, chewed leaves,T-shaped slits cut in the bark where females deposit eggs, sawdust-like frass or wood-pulp around small holes and larval tunnels in the wood under loose or thin bark (USDA APHIS n.d.)

Adult damage observed on crepe myrtle plants appears as a vertical, rectangular section of scraped bark, measuring about 2 x 2.54 cm.

Morphology:    Larvae are typical roundheaded woodborers. They are white, opaque, legless grubs, 45-60 mm long and 10 mm wide when mature with an amber colored head and black mouthparts.

Adults are attractive longhorned beetles, 25-40 mm long, shiny black in color with a series of white markings on the thorax and elytra. Antennae are marked with alternating black and white segments and are at least as long as the body. The ventral surface is pubescent. In mainland China populations, the pubescence is white whereas in Japan, on populations formerly designated as A. malasiaca, the pubescence is blue (Lingafelter and Hoebeke 2002).

An important identifying characteristic of Anoplophora chinensis is the presence of two pairs of polished white tubercles at the base of the elytra. These are visible with a 10x hand lens and are not present on the Asian longhorn beetle, Anoplophora glabripennis. (FSCA n.d.)

Testing Methods for Identification:    Detection of any cerambycid beetle suspected of belonging to the genus Anoplophora should be a cause for concern. Positive identification of A. chinenis must be made from the adult stage. While the tubercles on the base of the elytra are an important identification characteristic, Anoplophora is a large genus of Asian Cerambycidae, many of which are somewhat similar in appearance (Lingafelter and Hoebeke 2002). Moreover, some beetles of the genus Anoplophora superficially resemble the indigenous white spotted sawyer, Monochamus scutellatus, a common wood borer of North American conifers. Therefore, positive identification is best left to a taxonomist with expertise in the family Cerambycidae.

Adults are strong fliers but females, heavily laden with eggs, tend to prefer to oviposit either on trees from which they emerged or within a close proximity. Larvae and pupae can be transported over long distances via international trade in infested plant materials or wood products.

Colombo, M.; Limonta, L. 2001. Anoplophora malasiaca Thomson (Coleoptera Cerambycidae Lamiinae Lamiini) in Europe. Bollettino di Zoologia Agraria e di Bachicoltura, Ser II, 33(1):65-68.
Cooter, J. 1998.. Anoplophora chinesis (Forester, 1771) (Col., Cerambycidae) in Herefordshire. Entomologist’s Monthly Magazine 135: 196.
FSCA (Florida State Comission of Agriculture). n.d.. Pest alert: Citrus longhorned beetle (CLB). On line: www:
Lingafelter, S.W.; Hoebeke, E.R. 2002. Revision of the genus Anoplophora (Coleoptera: Cerambycidae). Washington D.C.: Entomological Society of Washington, 236 pp.
USDA APHIS (Animal Plant Health Inspection Service). n.d.. Longhorned beetles in bonsai nursery stock. On line:
USDA. 1999. Asian longhorned beetle (Anoplophora glabripennis): A new introduction. Forest Service and Animal Plant Health Inspection Service, NA-PR-01-99.
Washington State Department of Agriculture 2001. Citrus longhorned beetles found in Tukwila. Press Release dated August 15, 2001, Olympia, Washington.
Dennis N. McDougall
Name and Address of the First Author:
Dennis N. McDougall
Forest Health Protection
USDA Forest Service, State and Private Forestry
1992 Folwell Avenue
Saint Paul, MN
USA 55104
CREATION DATE:        07/17/01
MODIFICATION DATE:        07/17/01

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Photo by Washington State Department of Agriculture Archives,


Photo by Washington State Department of Agriculture Archives,