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Texas Invasive Species Institute

Texas Invasive Species Institute

Brown Fir Longhorned Beetle

Callidiellum villosulum

Class: Insecta
Order: Coleoptera
Family: Cerambycidae

Callidiellum villosulum

Photographer:Greg Bartman Affiliation:USDA APHIS PPQ Source:www.bugwood.org Copyright:CC BY-NC 3.0


Adult Description: Adults are 6-12 mm long, chestnut brown color, the entire body is thinly covered with long grayish setae. The head and thorax have shallow pits and square-shaped frons. There is a transverse ridge between the brownish-black antennae. The male antennae are slightly longer than the body, whereas the female antennae are about two-thirds of the body length. The scape of the antennae are coarsely punctured. The prothorax is wider than its length, and the two sides are rounded with no lateral spikes. The prothorax has some hardly visible raised tubercles. The ventral portion of the thorax and the femur of all appendages are brownish-red and thickened.

Larva Description: Larvae are about 10 mm long, light yellow in color, and the body is slightly flat. The mouthparts are blackish-brown. The pronotum has a pair of brown markings.The thoracic legs are receded. Pupae are 7-10 mm long, oval shaped, and cream colored. Antennae are kept close to the sides of the body and bend back near the second pair of thoracic legs

Host Plant: Chinese fir, Cunninghamia lanceolata and Japanese cedar, Cryptomeria japonica

Ecological Threat

Prefers trees of the family Taxodiaceae. North American examples include the sequoia, redwood, and bald cypress trees. Further, due to the geographic isolation of some of the Taxodiaceae species, especially the sequoias, an infestation of these beetles could be especially dangerous.


The genus Callidiellum is a small genus of Cerambycidae with representatives in Asia and North America. Two North American species are known; C. cupressi from coastal California and C. viridescens from Arizona. The brown cedar longhorned beetle, C. rufipenne, also native to Asia, has recently become established in several states in the eastern U.S..

Callidiellum villosulum has one generation per year in Zhejiang Province (southeastern coastal China). It overwinters as an adult inside the pupal cell, which is located at the end of the larval gallery in the sapwood. By the end of February, the adults become active inside the pupal cell, and chew an exit hole through the wood and bark. In early March, adults begin to emerge. Peak emergence occurs from late March to early April. Adults continue to appear into early May. Upon emergence, adults seek out mates. Mating usually occurs from 8 am to 10 am and multiple matings can occur. Oviposition occurs from mid-March through mid-May. Eggs are laid in the cracks of tree bark. Adults do not feed. Eggs hatch beginning in late March. The young larvae tunnel into the cambium. Larval galleries are rounded on the sides but flattened top to bottom. In late September, pupation begins and lasts from 10-15 days. In early October, the pupae transform into adults. By late November, the adult blocks the larval gallery with sawdust and overwinters inside the pupal cell. If spring temperatures are low, overwintering adults will suffer high mortality.


This beetle, like many other invasives, has been spread to the United States by humans but the main culprit continuously introducing Callidiellum villosulum to ports in the United States are trees important from China. Between 1999 and 2001 there have been around 20 interceptions of this species. In January 2005, APHIS conducted its fourth recall in a consecutive six month period for wooden decorative items imported from China.  The last recall was the result of the Maryland Department of Agriculture interception of multiple Callidiellum villosulum beetles that had emerged from kiln dried certified artificial Christmas trees manufactured in China. Because this insect appears to be capable of attacking living trees and could survive in the southern third of the United States, it is perceived as a high-risk pest, especially to indigenous trees such as the bald cypress and redwoods.

Native Origin


Current Location

Prefers woody trees like the Chinese Fir Cunninghamia lanceolata, in China. It is thought that the Giant Sequoia and Redwoods could be future North American host trees for this insect. Other potential hosts in the United States could be native fir trees like the Bald Cypress.

Established populations in North Carolina, Alabama, and Louisiana


Even though this beetle has not been established in Texas, Callidiellum villosulum has been found in the Port of Houston in trees imported from China. Also, with it being present and established in Louisiana the Brown Fir Longhorn Beetle is an eminent threat. How to manage this insect within a forest setting is not known but thorough heat treatment will kill larvae within logs.


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Hoebeke, E. R. 1999. Japanese cedar longhorned beetle in the eastern United States. USDA Pest Alert. APHIS document 81-35-004. 

Kelsey, Rick, and Gladwin Joseph. 2003. Ethanol in ponderosa pine as an indicator of physiological injury from fire and its relationship to secondary beetles. Canadian Journal of Forest Research. 33:870-884.

Chemsak, John, and Jerry Powell. 1964. Observations on the Larval Habits of Some Callidiini with Special Reference to Callidiellum cupressi (Van Dyke) (Coleoptera: Cerambycidae). Journal of the Kansas Entomological Society. 37(2):119-122

Zhu Chang-qing (editor). 1999. Insect fauna of Henan. Henan Scientific and Technological Publishing House





Dr. Jerry Cook - Sam Houston State University - jcook@shsu.edu


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