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Douse the lights to ward off black beetles
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I have already had a call about the black scarab beetle this year, and seeing how they caused such a problem for a lot of Georgians last year, I wanted to touch on the subject.

Spring and late summer of 2010 saw mass emergences of the beetle. The identification is still not confirmed; however, evidence suggests it is either the sugarcane beetle or rice beetle.

Since not much is known about either species, much of what is suggested by UGA Extension Entomologist Dan Suiter is educated guesses. It appears there may be two generations per year of this insect in Georgia given the mass emergences reported in April, May and again in August 2010. It is expected that the mass emergence that occurred last August resulted in a generation of beetles that overwintered as larvae, completed development and have resulted in the emergence we see now.

As noted by pest control companies and county agents, in addition to being a nuisance, this beetle can cause significant damage to soft, pliable roofing materials or caulk between a wall and flat surface. Because the beetles have an aversion to sunlight, they attempt to burrow. These strong beetles are successful at penetrating these materials and can cause significant damage.

Based on what little is known about this beetle, control is going to be difficult. As they complete development, beetles emerge from the grass, where they feed on the roots, and are attracted to lights on buildings (they are nocturnal). During the mass emergence, they presumably are mating and going back to sites to lay eggs, where they emerge the following spring.

The key question is: Where are these sites? If we knew, we could apply a granular product to kill them as they re-enter the ground after the August emergence. If this cannot be accomplished, we must deal with consequences of the mass emergence.

To do this, several things can be done. First and most important is light management. If possible, some or all lights should be turned off while beetles are active. Lights on the building can be changed to yellow, which is less attractive to beetles; never use mercury vapor lighting unless you're trying to attract them.

The problem with this partial solution is that beetle emergence may be finished by the time lights are changed, as mass emergencies typically complete in three weeks or so. If lights must stay on, alter the way they face or relocate them away from, but still illuminating, the building.

Another idea is to try a "bait" or "interceptor" light. These lights should be highly attractive and placed in an area that attracts the beetles away from the building or entryways.

Chemical sprays likely don't do much. Always read and follow the label if an insecticide spray is chosen for use. You are responsible for proper insecticide treatments.

Treatments should be made around lights or areas where beetles congregate (corners, lines along the intersection of a wall and flat surface), so they will be exposed when they land.

Adapted from "Pest Control Alert: News to use from UGA Extension," Invading Black Scarab Beetles by Daniel R. Suiter, Department of Entomology, University of Georgia, Griffin.

Michael Wheeler is Hall County extension coordinator. Phone: 770-531-6988. Fax: 770-531-3994.

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