Monday, October 3, 2011

Cool Weather Brings Not-So-Cool Pest Problems

By Mike Waldvogel and Patricia Alder

Fire Ants
Moist soils and warm weather have made conditions suitable for fire ant mounds to pop up in various places. If one of your schools has fire ants in a location that poses an imminent hazard to the students and/or staff, then a mound drench may be the best course of action. If there is concern about children coming into contact with the chemical, you can flatten the mound after it's been treated and the chemical has soaked down below the soil surface. Untreated soil can then be placed on top of the treated area. Your best best, however, is to treat the mound after school hours when children are not around, if possible. If the mounds are in less critical areas, then baiting may be a good option. Apply the bait according to label directions. Sprinkle the recommended amount around each mound (not on top of the mound itself). It is best to apply the bait in early morning or early evening, when most of the colony is closer to the soil surface.

It's also important to remember that your options for treatment are often limited by the target site of application. For that reason, Steve Bambara, recently retired Extension Specialist from NCSU, developed a program that you can use to select fire ant products based on application site and application preference (e.g., liquids vs. baits vs. granular insecticides). The program is accessible online:

Also, check out our fact sheets about fire ants:

Kudzu Bugs
Kudzu bug (Photo: Phillip Roberts, Univ. of GA.)
This is a relatively new pest that feeds on kudzu (but not enough to wipe it out). Unfortunately, it also favors soybeans and some other legumes where it has actually caused yield losses. Kudzu bugs are 4 - 6 mm long, somewhat oblong in shape, and olive-green colored with brown speckles. So far this year, it's been found in over 55 counties on kudzu and soybeans. The kudzu bug can be a significant nuisance when temperatures drop and days grow shorter. Like another well-known nuisance, the Asian lady beetle, the kudzu bug has the habit of invading structures while it seeks out somewhere to pass the winter. We've already heard of some complaints in Union County where the bugs have invaded homes. This has mostly been rural areas with homes adjacent to soybean fields (and likely some kudzu). If you have schools in rural areas near soybean fields and/or kudzu, then there is a chance that you may see the kudzu bug. Unfortunately, there is no real effective chemical control to stop the invasion. For more information about the kudzu bug, check out this fact sheet:

Multi-colored Asian Ladybird Beetles
Multi-colored Asian ladybird beetle
(Photo: Bill Ree, Texas A&M Univ.)
Most of us have probably encountered this insect by now. Adult multi-colored Asian ladybird beetles are convex in shape and about 1/4” long. Specimens from higher elevations are larger than those from the Piedmont and Coastal Plains. There are usually ten black spots on each forewing, but some have fewer spots or faded spots and some have no spots at all.

As temperatures start to drop in the fall, adult beetles begin to search for suitable overwintering sites. They tend to congregate on the sunnier or warmer sides of buildings, or on exposed, light-colored buildings. Of course, this doesn’t mean that buildings with dark-colored siding or brick buildings are immune to the lady beetle assault. On warm winter days, the beetles may become active and move towards light or bright surfaces. They are often found on windows, light fixtures and ceilings.

Ladybird beetles are primarily a nuisance. They do not eat wood or furniture. However, the beetles may stain fabric and painted surfaces if squashed. In addition, there have been concerns that large numbers of beetles may possibly cause air quality problems indoors that could trigger allergies and/or asthmatic reactions.

While it is not 100% effective, preventing the beetles from entering structures is one of the best long-term approaches for dealing with ladybird beetles. Install tight-fitting sweeps on exterior doors and weather stripping around door frames. Openings where utility pipes and wires enter the foundation and siding should be sealed. Make sure that window screens are in good condition. Indoor sprays tend to be ineffective against ladybird beetles. Invading beetles should simply be vacuumed up. The vacuum bag should be sealed up and disposed of. Outdoors, a residual spray insecticide applied around windows, doors, eaves, soffits, attic vents, etc. may provide temporary relief.

For more information on ladybird beetles, click here:

Brown marmorated stink bug
Brown marmorated stink bug
(Photo: David R. Lance,  USDA)
The brown marmorated stink bug was first detected in North Carolina in the Winston-Salem area in 2009. Adult brown marmorated stink bugs are slightly larger than 1/2” and vary in color from brown to gray. Adults have characteristic brown and white bands on the outer edge of the thorax, and white and brown banding on their antennae. 

In the fall, adult brown marmorated stink bugs aggregate on and inside structures in search of an overwintering sites. The bugs can give off a characteristic odor if they are crushed or disturbed.

Just as with ladybird beetles, exclusion goes a long way in preventing brown marmorated stink bug invasions. Make sure exterior doors have tight-fitting sweeps, seal openings where utility pipes and wires enter the foundation, and make sure window screens are in good condition. The use of pesticides indoors for controlling the brown marmorated stink bug is not warranted; invading stink bugs should be removed with a vacuum cleaner. Outdoors, a residual spray applied around windows, doors, soffits, attic vents, and other potential entry points may provide some relief.

For more information on the brown marmorated stink bug, check out our fact sheet:

Paper Wasps
Treatment of a paper wasp nest
(Photo: Patty Alder, NCSU)
Adult paper wasps are about ¾” to 1” long and reddish brown to dark brown in color with yellow stripes on the abdomen. Paper wasp colonies are annual; workers die off in the fall and only inseminated queens survive. The surviving queens are often seen hovering around chimneys and rooflines as they search for a suitable place to spend the winter. On warm winter days, the queens may become active.

Wasps that get indoors can be controlled mechanically, by swatting or vacuuming, or with an aerosol insecticide. Openings through which wasps can enter the structure should be caulked or sealed. If a paper was nest poses a hazard, use a Wasp & Hornet spray that will propel the insecticide about 10-15 feet and direct the spray into the nest opening for 5-10 seconds. The best time to treat a nest is at dusk, when most of the wasps are in the nest. 

More information about paper wasps can be found here:

Fall is also the time when our no-legged friends start seeking out shelter. Most of the snakes that people encounter are black rat snakes. Juvenile black rat snakes have distinct color patterns that immediately send people into a frenzy because they believe it's a copperhead. Although black rats can bite, they are more inclined to move away from a fight. As leaves start to drop, it's not unusual for the snakes to go unnoticed in leaf piles, under debris and under logs. Startled snakes will strike and bite. Copperhead bites are not typically fatal, but the bite can land you in the emergency room and potentially an overnight stay in the hospital. Obviously, children, the elderly, and other folks who might have health-related issues are more likely to have the more severe reactions to a bite. So, it's certainly nothing to take lightly, especially in school settings where there are lots of children around. The secret to avoiding encounters with snakes? Limit potential snake hiding places. And keep children away from potential snake harborage areas. Don't allow piles of leaves, sticks, logs, etc. to collect in areas children frequent (e.g., playgrounds, around sidewalks, etc.). Do what you can to keep snakes out of buildings - make sure all exterior doors have door sweeps and make sure doors aren't kept propped open. 

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