Figure 2—S-shaped tunnels, made by EAB larvae,
riddle infested ash trees.
The emerald ash borer (EAB) is a very small but
very destructive beetle. Metallic green in color, its
slender body measures 1/2 inch in length and 1/8 inch
wide. The average adult beetle can easily fit on
a penny.
Native to China and eastern Asia, the EAB probably
landed in North America hidden in wood packing
materials commonly used to ship consumer goods,
auto parts, and the like. Although no one can say for
sure when EAB arrived in southeastern Michigan, the
scientific community now believes the beetle went
undetected for up to 12 years, based on its wide-
spread distribution and destruction. EAB was offi-
cially identified in the summer of 2002.
This beetle is currently known to be responsible for
the death or decline of more than 15 million ash trees
in a 20-county area around Detroit. EAB has also
impacted various communities in Ontario, Canada.
Essex County, across the river from Detroit, was
declared infested with EAB in 2002. Canadian offi-
cials estimate that between 100,000 and 200,000 ash
trees are infested and will die in Essex. The neighbor-
ing county, Chatham–Kent, has recently been declared
to be infested with EAB.
Although large EAB infestations are concentrated
in Michigan and parts of Canada, the States of Ohio,
Maryland, Indiana, and Virginia have also found EAB
in smaller, somewhat contained areas.
In terms of the range and extent of the EAB infesta-
tion in North America, the human element is of par-
ticular significance. Unknowingly, people’s behaviors
associated with everyday living and commerce have
greatly contributed to the spread of the EAB. The
movement of any ash tree products (e.g., branches,
logs, woodchips, nursery stock, and firewood) advanc-
es the spread of EAB. Consider this: current research
suggests that the natural spread or movement of the
EAB is about 1/2 mile each year. If that estimate is
accurate and the length of time EAB has been pres-
ent is 12 years