
Locust Borer showing "longhorn" antennaeThe locust
borer beetle is native to North America. It attacks only black locust
trees of the genus Robinia, which originally grew only in the Allegheny
and Ozark mountain regions. Due to its ability to thrive in poor soils,
the black locust has been widely used as a shade tree and in reclaiming
land damaged by farming and strip mining. The locust borer beetle has
extended its range as a result. It is now found over most of the U.S.
and southern Canada.
This is one magnificent insect - about 3/4" long, stately and
impressive. I'd never seen one before I stumbled across this guy. The
whole time I was shooting, I was saying, "What the hell is this thing!?
What a COOL bug!" (Yes, I frequently talk to myself and my subjects when
photographing them. People must think me crazy).
Locust borer larvae tunnel
into a tree's trunk and branches, weakening the tree and making it
susceptible to wind breakage. The damage from borer tunneling and wind
breakage often results in deformed trees or clumps of sprout growth.
Habitiat and Life Cycle: The
brightly colored adults appear when goldenrod (Solidago sp.) is in
bloom, generally mid-August through September here in the midwest. I
took photos of this specimen feeding on goldenrod pollen in the midst of
a large mown field, hundreds of yards from trees of any variety, and so
it's obvious to me the beetles will range far from their host plants in
search of food. Females start laying eggs in the early afternoon and
continue until dusk, August - October. Eggs are laid under the bark,
around pruning wounds and wind breakage and in cracks in the bark -
rarely where they can be easily detected. About a week later, the eggs
hatch and small white larvae bore into the inner bark, where they make a
small hibernation cell and overwinter. In the spring, the larvae bore
into the woody part of the tree, eventually enlarging their tunnels
until they are 3-4 inches long and 1/4 inch in diameter. By mid-July,
most of the larvae begin the pupal stage, which lasts about 2 weeks. The
mature adult beetles emerge through the holes made by the larvae. |