Corymbia succedanea

 
IDENTITY
Name:   Corymbia succedanea
Pest Authorities:  (Lewis)
Taxonomic Position:  Insecta: Coleoptera: Cerambycidae
Sub-specific Taxon:  
Pest Type:   Insect
Common Name(s):
   Asian conifer borer (English)
Synonym(s):
   Anoplodera succedanea (Lewis)
   Leptura succedanea Lewis
 
RISK RATING SUMMARY
Numerical Score:  6
Relative Risk Rating:  High Risk
Uncertainty:   Very Uncertain
Uncertainty in this assessment results from: The ability of Corymbia succedanea to adapt to North American conifers, compete with native Cerambycidae, serve as a vector of Asian wood nematodes of the genus Burasphelenchus, and/or become an aggressive tree killer is unknown.

RISK RATING DETAILS
Establishment Potential Is Moderate Risk
The relevant criteria chosen for this organism are:  
  • Suitable climatic conditions and suitable host material coincide with ports of entry or major destinations.
  • Organism has high inoculum potential or high likelihood of reproducing after entry.
Justification: This insect would find suitable climatic conditions and hosts at most North American ports of entry and is, therefore, judged to have a high probability of reproducing if introduced.

Spread Potential Is High Risk
The relevant criteria chosen for this organism are:  
  • Organism is capable of dispersing more than several km per year through its own movement or by abiotic factors (such as wind, water or vectors).
  • 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.
  • Eradication techniques are unknown, infeasible, or expected to be ineffective.
  • Organism has broad host range.
Justification: Adults are strong fliers, capable of flying several km in search of suitable host material. Larvae, pupae and callow adults could be transported via international trade in unprocessed logs, wood products or crating, dunnage and pallets. This insect has a broad host range and a high reproductive potential. Suitable coniferous hosts have contiguous distributions across many parts of North America. This insect has a cryptic habit. Therefore, detection of infestations is expected to be difficult and eradication programs could be difficult to implement and of questionable effectiveness.

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.
  • Organism has potential to be a more efficient vector of a native or introduced pest.
Justification: Primary damage caused by Corymbia succedanea is loss of wood quality and value due to larval boring. Its ability to become an aggressive tree killer in North America is not known. This insect is considered a potential vector of wood nematodes of the genus Burasphelenchus. The pathogencity of Asian species of Burasphelenchus to North American conifers is not known.

Environmental Potential Is Moderate Risk
The relevant criteria chosen for this organism are:  
  • Introduction of the organism would likely result in control/eradication programs that may have potential adverse environmental affects.
Justification: Assuming that it would confine attacks to stressed, weakened or dying trees, as it does in its natural range, Corymbia succedanea, is expected to become one a large complex of wood boring insects instrumental in the decomposition of dead wood.

 
HOSTS
Corymbia succedanea infests all conifers in its natural range. Preferred hosts are Korean pine, Pinus koraiensis; Japanese stone pine, Pinus pumila and spruce, Picea spp. (Pavlovskii and Shtakelberg 1955, Cherepanov 1979).

 
GEOGRAPHICAL DISTRIBUTION
Asia:
     This insect is widely distributed in Asian Russia, including Transbaikalia, the southern parts of the Russian Far East, the Amur and Primorye Region and Sakhalin. It also occurs in northern China, Japan and Korea (Plavilshchikov 1936, Pavlovskii and Shtakelberg 1955, Cherepanov 1979).
 
BIOLOGY
The genus Corymbia consists of at least four species of Asian and eastern European Cerambycidae. This genus is not represented in North America but is apparently closely related to Anoplodera, a relatively large genus, which infests dying and dead conifers (Knull 1946).

Corymbia succedeana has one generation a year. Adults fly from late June to early September with peak flight from late July to early August. Adults live about 3-4 weeks and feed on flowers.

Attacks typically occur in stressed or dying trees, recently felled logs and freshly cut stumps. Females deposit eggs in bark crevasses. One female may lay as many as 200 eggs.

Embryonic development lasts about 3 weeks and the larvae hatch until September. They construct longitudinal galleries, initially in the cambium and later into the wood. Galleries are 10 to 16 mm wide and filled with frass. The larvae overwinter in the galleries and, in the spring, continue to feed and construct pupal cells in the sapwood, parallel to the surface of the trunk.

Pupal cells are 35-50 mm long and 10-14 mm wide and pupal development takes 16-18 days. The callow adults remain in the pupal cells for about one week (Plavilshchikov 1936, Pavlovskii and Shtakelberg 1955, Cherepanov 1979).

 
PEST SIGNIFICANCE
Economic Impact:    Corymbia succedanea is a pest of conifers in its natural range. It attacks stressed and dying trees of different ages. Infestations may result in loss of tree vigor and loss of structural integrity of wood because of larval galleries. Infestations are frequently associated with trees stressed by defoliating insects, diseases, fire or wind (Plavilshchikov 1936, Pavlovskii and Shtakelberg 1955, Cherepanov 1979).

Corymbia succedanea has been listed as a potential vector of the pine wood nematode Bursaphelenchus xylophilus (Kulinich and Orlinskii 1998).

Environmental Impact:   Corymbia succedanea is one of many wood boring insects instrumental in the decomposition of dead wood and has little or no adverse environmental impacts.

Control:    Control measures include silvicultural techniques designed to increase resistance of forests to attack, cutting and processing of infested trees and insecticide treatments (Maslov 1988, Vorontsov 1995).

 
DETECTION AND IDENTIFICATION
Symptoms:    Symptoms of infestation include presence of oval shaped exit holes on infested trees, larval galleries in the cambium and wood and, possibly, tree mortality. These symptoms are associated with a large number of woodborers, however, and are not specific to Corymbia succedanea.

Morphology:    The egg is white, elongated, 1.8 mm long and 0.5 mm wide. It is pointed at one end, widely rounded at the other, and covered by well-developed 5-6 sided sculptured cells (Cherepanov 1979).

The larva is white, and reaches 34 mm in length when mature. It has a reddish-orange head, about 5 mm wide, covered with sparse, reddish hairs, with a red labrum and black mandibles. The hypostoma is prominent, the epistoma is depressed, with a brown longitudinal suture in the middle. The pronotum is transverse, slightly widened to the front, covered from the lateral sides by long hairs. Dorsal ambulatory warts (ampullae) on the 1st to 7th abdominal segments are prominent, well sclerotised, with hyaline granules forming two transverse ellipsoids (internal and external). Within the internal ellipsoid, there are 4-6 bristles. The weight of the mature larva ranges from 300-560 mg (Cherepanov 1979).

The pupa has an elongated body and is 20-24 mm long and 4-5 mm wide. The head is depressed behind the antennae, which are curved toward the body. There are four short, acute thorns at the base of the antennae. The pronotum is prominent, slightly narrowed to the front, with a longitudinal fissure in the middle. The mesonotum is covered with small thorns. The abdomen is elongated, slightly narrowed toward the front and more narrowed toward the back. Abdominal tergites have multiple acute thorns that form transverse stripes and wide longitudinal fissure in the middle. The top of the abdomen has a pair of well-developed urogomphal outgrowths, which finish by acute thorns curved upwards and to the exterior. The weight of the pupa ranges from 170-416 mg (Cherepanov 1979).

The adult is elongated, 12-21 mm long. The head is covered with brownish hairs and dense punctuation and has a clear longitudinal fissure in the middle. Antennae are serrate, and about one half the length of the body for females and almost the length of the body for males. The 3rd antennal segment is slightly longer than the 5th segment and much longer than the 1st and 4th segments (which are of equal length). The pronotum is red, sometimes black at the base and top, longer than wide, covered with small hairs and dense round punctuation, much narrowed to the front, with a deep transversal fissure at the base. The elytra are red, 2.5 times longer than wide, narrowed to the back, cut at the top and covered with small yellowish hairs. The ventral surface of the body is black. The rear tarsus is longer than the tibia. The 1st segment of the rear tarsus is longer than all other tarsal segments combined. Femora and tarsi are black and the Tibiae are red, sometimes black at the top. Hind tibiae are black. The weight of an adult beetle ranges from 102-359 mg (Plavilshchikov 1936, Cherepanov 1979).

Testing Methods for Identification:    Examination of adults by a taxonomist with expertise in the family Cerambycidae is required for positive identification. However adults have sufficient characteristics to permit preliminary field identification.

 
MEANS OF MOVEMENT AND DISPERSAL
Adults are capable of flights of several km in search of suitable breeding sites. Since the larvae remain in the wood of host trees for long periods, long distance spread of this insect could occur via international trade in wood products or wooden crating, pallets or dunnage.

 
BIBLIOGRAPHY
Cherepanov A. I. 1979. Longhorn beetles of Northern Asia (Prioninae, Disteniinae, Lepturinae, Aseminae). Novosibirsk: Nauka, 526 pp. (in Russian).
Knull, J. 1946. The long-horned beetles of Ohio (Coleoptera: Cerambycidae). Ohio Biological Survey, Columbus, Ohio, Bulletin 39, 354 pp.
Kulinich O. A., Orlinskii P. D. 1998. Distribution of conifer beetles (Scolytidae, Curculionidae, Cerambycidae) and wood nematodes (Bursaphelenchus spp.) in European and Asian Russia. EPPO Bulletin, 28 (1/2): 39-52.
Maslov A. D. 1988. Guide on forest protection against pests and diseases. Moscow: Agropromizdat, 414 pp. (in Russian).
Miroshnikov A. I. 1998. New classification of longhorn beetles of the complex Anoplodera, tribe Lepturini (Coleoptera, Cerambicidae) of Golarctic fauna. Entomologicheskoe Obozrenie 77(2): 384 - 420 (in Russian).
Pavlovskii, E. N. and Shtakelberg, A. A. (Editors) 1955. Forest pests guide. Moscow - Leningrad: Edition of Academy of Sciences of the USSR, 2: 422 - 1097 (in Russian).
Plavilshchikov N. N. 1936. Leptura succedanea Lew. In: Fauna of the USSR; Coleopterous insects, v. XXI; Long horn beetles. Part 1, pp. 362-363 (in Russian).
Vorontsov A. I. 1995. Forest entomology: Manual for universities, 5th edition. Moscow: Ecologia, 352 pp. (in Russian).
 
AUTHOR(s)
Name(s):
Andrei Dorian Orlinski
T.V. Bassova 
 
Name and Address of the First Author:
Andrei Dorian Orlinski
Europe
EPPO
1, rue Le NĂ´tre
Paris,
France 75016
 
CREATION DATE:        05/16/02
MODIFICATION DATE: