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Topic Tuesday: Asian Longhorned Beetle

Wow how time flies! We are already in August and that means it is Tree Check Month! The USDA’s Animal and Plant Health Inspection Service is reminding people this month to check their trees for signs of the Asian Longhorned Beetle (ALB). This beetle is a destructive invasive pest that can kill certain hardwood trees. Read on to learn more about the ALB and how you can participate in Tree Check Month.

What is the Asian Longhorned Beetle?

ALB is an invasive, woodboring beetle that feeds off and can kill hardwood trees such as maple, birch, elms, ash, and willow. The beetle is native to China and Korea. Adult beetles are large insects measuring 1 to 1.5 inches in length, have glossy black bodies with small irregular white spots, and have long black and white banded antennae.

Females will chew depressions into tree bark and lay up to 60 eggs. Once the eggs hatch, the larvae will bore deeper into the tree, feeding on the tissue just underneath the bark. This will disrupt the nutrient and water flow within the tree. Larvae will bore deeper into the tree, continuing to feed till they pupate and emerge from the tree to start the process over again.

Beetle Damage:

“Knock on wood” this beetle has not made its way to Florida yet. The beetle has been observed in New York, Illinois, New Jersey, Massachusetts, and Ohio. The beetle spreads slowly and tree death is slow to occur, about 7-9 years after initial infestation. Early detection is imperative since it is such a destructive pest. External signs of ALB are:

  • Oviposition pits – round depressions in bark where adults will lay eggs
  • Sap – will ooze from egg-laying sites and exit holes
  • Dead branches or limbs – these can fall from healthy looking trees
  • Exit holes – round holes in branches and tree trunks where adults emerge
  • Saw dust or frass – located at the base of a tree or branch
If you see signs of infestation:
  • Make note of where you found it
  • Take a photo
  • Capture the insect by placing it in a container and freezing to preserve it
  • Report findings by calling 1-866-702-9938 or completing the online form
Similar looking beetles:

The Cottonwood Borer has a yellow or creamy white body with black rectangular patches and long black antennae. It is not common to Florida and found mostly in cottonwood trees but can also be found in poplars and willows.

The Southern Pine Sawyer has a mottled gray and brown body with irregular dark brown spots and very long tan antennae.

 

The Pine Sawyer has a brown body with irregularly mottled patches of brown and very long brown antennae that are almost 2-3 times the length of the body. It is found mostly in pines.

 

The Metallic Wood Borer Beetle has a flattened appearance with a metallic black colored body with short antennae.

 

The Long-Jawed Longhorn Beetle has a black body with burnt orange patches, long mandibles jaws, and extremely long black and orange antennae.

There are more than 200 Longhorn Beetle species in Florida. The Longhorn Beetle is a diverse and important component of the beetle fauna in Florida woodlands. Many of the beetles feed on trees and woody plants as larvae, mostly attacking dying or dead trees. They are harmless and are even beneficial to the human economic interest, helping recycle dead wood back into the soil. If the beetle does not look like a Florida native or you have insect identification questions, visit the USDA website for further clarification. All pictures courtesy of the University of Florida and USDA.

 What can you do:
  • Check your trees
  • Follow proper water management practices
  • Remove infected trees and re-plant with non-host trees
  • Treat wood packing materials
  • Do not move firewood across state lines

UF/IFAS Extension in Suwannee County is an Equal Opportunity Institution.