Identifying EAB

EAB adults are a metallic green color and are approximately 3/8″ – 1/2″ long and 1/8″ wide.  Adults typically emerge in June and early July and can be active through the summer.  Adults cause minimal damage to ash trees, but do mate and lay eggs during the summer months.

Larvae emerge from the eggs, and tunnel into the cambial layer of the tree (just beneath the bark).  Larvae then feed on these vital tree tissues, causing a significant amount of damage.  Larvae are cream-colored, with bell-shaped body segments.  Full-grown larvae can be over 1″ long.

EAB Look-Alikes

Several Potential EAB look-alikes exist in Wisconsin.  Some of these insects can be quite common.

Blister Beetle (Family Meloidae)

 

Blister beetles can be commonly encountered during the summer months in Wisconsin.  These beetles can often be found on flowers or on the ground, but can be found in a variety of other places as well.

 

Dogbane Beetle (Family Chyrsomelidae)

 

 

Dogbane beetles are metallic-green in color with hints of red and orange.  These beetles are occasionally encountered and adults can be found feeding on Dogbane plants.

 

 

 

Ground Beetle (Family Carabidae)

 

A large number of ground beetle species exist in Wisconsin.  These beetles are excellent runners and can often be seen scurrying on the ground or on tree trunks.  Some species can have a metallic green appearance. Some can be up to 1″ long.

 

Tiger Beetle (Family Carabidae)

 

 

Tiger beetles are a type of predatory ground beetle.  They are often found on the ground in open sandy areas, where they are active hunters.  Most tiger beetles are shiny, metallic colors.

 

 

Japanese Beetle (Family Scarabaeidae)

 

Japanese beetles can be all too common during July, August, and September in Wisconsin. These beetles feed on over 300 plant species, including many ornamental and garden plants, and are seen by many as pests.  They are readily identified by their metallic green and copper colors, and a series of white dots along the side of the body.

 

 

Green Immigrant Leaf Weevil (Family Curculionidae)

 

Several weevils can have a metallic green appearance.  These insects can be quite common in parts of the eastern U.S.  Weevils, such as this one, can often be readily identified by the snout-like projection on the head.

 

 

 

Linden Borer (Family Cerambycidae)

 

Linden borers belong to a group called the “long horned” beetles and their long antennae reach nearly to the back of their body.  Linden borers are beige in color and attack Linden trees.

 

 

 

 

Metallic Wood Borer (Family Buprestidae)

 

 

The metallic wood boring beetles (Family Buprestidae) includes EAB and its relatives.  There are over 100 native species in our area and only a few are considered pests.  These insects are known for their colorful, metallic bodies.