Asian Longhorned Beetle
Written by Joe Boggs, Hamilton County Extension Educator
A. ASIAN LONGHORNED BEETLE IN OHIO.
On Friday, June 17, 2011, the United States Department of Agriculture, Animal and Plant Health Inspection Service (USDA APHIS) and the Ohio Department of Agriculture (ODA) announced that an Asian Longhorned Beetle (Anoplophora glabripennis) (ALB) infestation was found a few miles from the Village of Bethel in Tate Township, Clermont County. Consequently, the Governor of Ohio signed an Executive Order restricting the movement of hardwood logs, firewood, stumps, roots, and branches out of Tate Township. This is the first ALB infestation found in Ohio. USDA APHIS has responded with personnel on the scene to assess the extent of the infestation and to develop and implement a management plan.
As its name indicates, ALB is native to Asia and is considered a serious pest in China. It is well known that the beetle is capable of hitch-hiking across the globe in wood packing material (e.g. infested pallets). ALB was first discovered in North America in Brooklyn, NY, in 1996. Subsequently, other infestations were soon discovered in other parts of New York City, in several nearby New Jersey suburbs, and on Long Island. In 1998, ALB was discovered in and around Chicago, IL, and in Toronto, Ontario. The Chicago infestations have been declared eradicated while work continues on eradicating the other infestations. In 2007, the largest infestation to date was discovered in Worcester, MA, and in 2010 as relatively small infestation was found Jamaica Plain, a suburb of Boston, MA.
Trees that are preferred by ALB include all species of maples (e.g. sugar, silver, red, Norway, box elder) as well as birches, elms, willows, horsechestnuts, and buckeyes. Trees that may be hosts to ALB, but are rarely attacked include: ashes, European mountainash, hackberry, London planetree, mimosa, and poplars.
ALB is a large, striking looking beetle with very few look-a-likes found in North America. Indeed, many of the North American infestations, including the Worcester infestation, were discovered by people finding beetles rather than diagnosing the tree mortality caused by the beetles. Adults measure 1-1 1/2" in length. They are dark blue to bluish-black and covered with around 40 irregularly-shaped and -sized white dots. One of the Chinese common names for the beetle translates to the descriptively named "starry night beetle." As with most Cerembycids, ALB has exceptionally long antennae which are responsible for the common name. The antennae have alternating black and white bands.
ALB adults have been reported to emerge in other infestations in North America from July to October; however, adults were found in the Ohio infestation on June 16. Adult emergence holes are circular and very large measuring around 3/8-1/2" in diameter. Although the beetles are capable of flying several hundred yards in search of a suitable host, they prefer to remain close to the tree from which they developed in order to re-infest the tree if it will support another generation. After mating, ALB adult females chew oblong-shaped 3/8" wide oviposition pits through the bark and phloem exposing the xylem (white wood). A single egg is deposited into each pit; the females are capable of laying 35-90 eggs during her lifetime. The oviposition pits and adult exit holes, if found on living branches and stems, are strong diagnostic indicators for an ALB infestation.
Cerembycid larvae are commonly referred to as "roundheaded borers," and ALB larvae look like typical cerembycid larvae. The segments towards the front of the fleshy, thin-skinned, yellowish-white larvae are larger in diameter than the rest of the segments. This makes the larvae look like they have round heads and tapering bodies. ALB larvae develop through 5 instar stages. First and second instar larvae tunnel through and feed on phloem tissue. Their feeding activity produces weeping canker-like symptoms on the bark. Third, fourth, and fifth instar larvae bore deep into the white wood. The wood boring activity produces two diagnostic indicators of an ALB infestation. The first is course, white, sawdust-like frass that is exuded from the infestation sites. The second is a branch and stem breakage. In fact, one of the Worcester infestations was discovered by USDA APHIS personnel examining the ends of branches broken in an ice storm.
A special toll-free telephone number has been established by the ODA for Ohioans to report suspected ALB infestations or suspiciously large black and white beetles. The number is: 855-252-6450.
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