By: Mark Abrahamson, Plant Protection Division, Minnesota Department of Agriculture (MDA)
During 2016, the Minnesota Department of Agriculture (MDA) uncovered two separate instances where large amounts of insect-infested log furniture were imported into the state from Asia and sold to customers in Minnesota and elsewhere in the U.S. The first incident was brought to MDA's attention in March after customers reported insects emerging from furniture sold by a Minnesota company.
In this case the furniture was manufactured from pine and the insect was identified as the brown fir longhorned beetle (Callidiellium villosulum). This is not an insect that is known to occur in Minnesota or North America, and customers purchased this furniture in over 40 states. As a result, the seller, the USDA and state governments across the country worked quickly to retrieve and destroy the infested furniture.
Just about the time that the last pieces of infested pine furniture were being collected and destroyed, the MDA received another report of insect infestation in a different line of log furniture manufactured in China. In this case the furniture in question was manufactured from walnut although advertised as hickory, and the insect involved was the velvet longhorned beetle (Trichoferus campestris). This insect has been reported a number of times in North America including Minnesota where USDA insect trap monitoring near the Minneapolis/St. Paul airport has resulted in finds of this species each of the last three years. However, the only places in North America where it has been documented infesting trees have been Ontario and Utah. Much is still unknown about the biology of this insect but it is considered a potential forest threat. Similar to the first incident, customers were present in Minnesota as well as many other states. However, unlike the first incident which was discovered within a few months of the furniture entering the country, much of the furniture in this incident has been in the U.S. for one or even two years. This case has taken longer to resolve due to the amount of time the furniture has had to move and change hands. The MDA continues to work with the importing company, USDA and other States to resolve the issue.
These events have illustrated the potential for exotic insects to enter the U.S. via log furniture. Now that the problem is known, future incidents may be prevented. However, it is possible that this has happened more times in the past than have been discovered. The MDA has been working with partners to address the issue and is seeking help from citizens to identify any other instances where insect-infested furniture may have been imported into Minnesota.
Customers who have purchased log furniture in the last two years or are considering a purchase of log furniture should be aware of this issue. It is important to determine the origin of the furniture. An origin in the U.S. is good; however, while the primary concern is furniture originating outside the U.S., there are also wood-boring insects present in some areas of the U.S. that should not be moved to other parts of the country. So, any signs of insect activity in log furniture should be investigated.
The strongest indicator that insects may be actively tunneling in a piece of log furniture is the appearance of sawdust on or below the furniture. Emergence holes and tunnels are also signs of insect activity, but they may simply be evidence of old damage to the wood before the furniture was crafted.
For more tips on diagnosing potential insect infestation in log furniture, visit the MDA website
For questions or to report suspected insect activity in log furniture, contact the MDA at email@example.com or 888-545-6684.