-Joseph Ingerson-Mahar
What a difference 20 degrees makes! Trap catches in the Vegetable IPM Program
blacklights have been very light over the past week. When night-time temperatures drop below 60
degrees F, insect activity subsides.
Contributing to the reduction of insects in the traps is the end of the
first generation flight of European corn borer moths and something of a break
in the early season flight of corn earworm.
However, in the past two days night-time as well as day-time
temperatures have risen and suddenly our traps are filling with insects. The majority of these are beetles – large
numbers of scarab beetles – that are normally abundant at this time of
year. Several species of these beetles
feed on plant foliage and many species are nocturnal feeders so that feeding
damage appears overnight. Backyard
gardens as well as commercial plantings are susceptible to these pests.
Some of the more common beetle species that are now out are
various June beetles, chafers, Asiatic garden beetle, carrot beetle, Japanese
beetle and false Japanese beetle. These
beetles feed on plants sometimes causing significant damage to vegetable crops
and ornamentals. Their damage appears as
ragged holes usually on leaf margins, but sometimes within the leaf.
The oriental beetle is also
abundant. Its a pest of root crops but larvae also feed on the
roots of sod, blueberries, ornamentals and row crops like field corn. The larvae feed on the roots
but the adults either don’t feed or feed very little on foliage.
The sudden change in temperature has helped bring out our
native brown stinkbugs, the Euschistus species. These are normally pests of fruiting
vegetables but they are just now beginning to make their appearance in the
adult stage. There has been some
interest in whether the brown marmorated stinkbug would outcompete the native
stinkbugs.
Joseph Ingerson-Mahar
