Introduced to the U.S. in the 1990s, the Asian Longhorned Beetle is a threat to hardwood trees because of its lack of natural predators and limited options for control.
The Asian Longhorned Beetle in the U.S.
Originally introduced to the U.S. from Asia, the finding of the beetles in areas of New York City in 1996 caused the Secretary of Agriculture to declare an "extraordinary emergency" to combat the infestation with regulatory and control actions.
In what is believed to be a separate introduction of the long-horns, the beetles were discovered in trees in suburbs of Chicago in 1998.
Since then, the U.S. has seen a gradual spread of the beetles, first to areas of the New England states, then into the Midwest, with most recent discoveries of the destructive insect occurring in 2011 in Ohio, causing the state to issue quarantines and restrictions on the removal of any associated hardwood the beetles are known to infest. As of Dec. 28, 2011, 5,081 infested trees were identified within Tate Township, and 27 infested trees in Monroe Township. As of the start of 2012, the U.S. Department of Agriculture's (USDA) Animal and Plant Health Inspection Service was continuing infested-tree removal operations in Bethel, Ohio.
Trees favored by these beetles include maples, horsechestnuts, poplars, willows, elms, mulberries, and black locusts. The beetle is a threat because it has no natural predators and it destroys the hardwood trees it infests. Not only does it feed on the leaves and twigs, but the female chews holes into the bark of the wood to lay her eggs-up to 90 at one time. Once hatched, the larvae tunnel under the bark and bore deep into the wood.
According to an article from Columbia University:
"The ALB (Asian Longhorned Beetle) has the potential to cause more damage than Dutch elm disease, chestnut blight, and gypsy moths combined, destroying millions of acres of America's treasured hardwoods, including national forests and backyard trees. The beetle has the potential to damage such industries as lumber, maple syrup, nursery, commercial fruit, and tourism accumulating over $41 billion in losses."
The Asian Longhorned Beetle has:
- a body length of 3/4 - 1 1/4 inches
- long black and white antennae that are longer than its body
- a long, narrow glossy black body with spotty white speckles.
It is most frequently seen from late spring to fall, depending on the climate, when it is actively feeding and breeding in the trees. In fall, the adult beetles die, while the larvae overwinter deep within the trees. During this time, it is almost impossible to detect the beetles, thus it can be unknowingly transported in firewood and wood-packing materials.
In addition, the longhorned beetle can fly more than 400 yards and will migrate if enough host materials are not available for the population.
Thus infestations can easily spread causing further untethered damage.
The only known means of control once a tree is infested is the cutting down of the tree, burning of the wood, and grinding of the stump.
But application of the insecticide, imidacloprid, through tree trunk or soil injections to susceptible or infested trees, under USDA supervision, can help protect nearby trees from becoming infested. The insecticide moves upward into the leaves, stems, and twigs on which the beetles feed and lay their eggs. It is important that all potential host trees in an area of infestation be treated, so that the infestation does not move from tree to tree.
If a treated tree does become infested, the only option is to remove and destroy it as well.
Currently, all the upper Northeast states of the U.S. are considered to be at risk for Asian Longhorned Beetle infestation, along with Pennsylvania, Ohio, and Illinois.