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. In most cases, there is still plenty of time to bait the ants. If someone has fire ants in locations that pose an imminent hazard to the public (e.g., playgrounds, school grounds, etc.), then a mound drench may be the best course of action. Any of the common pyrethroids labeled for turf will work. 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. If the mounds are in less critical areas, stick with using baits.

It's also important to remember that your options for treatment are often limited by the target site of application. There are many more products available for lawns and similar areas as compared to field crops, vegetables, and pastures (depending on the type of animals grazed). 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: http://insects.ncsu.edu/fireant-products.

Check our information about fire ants:
http://www.ces.ncsu.edu/depts/ent/notes/O&T/lawn/note145/note145.html
http://insects.ncsu.edu/Urban/ifa.htm

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. On the homeowner side of things, this critter 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 homes while it seeks out somewhere to rest its legs (all six of them) and 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). There is no real effective chemical control to stop the invasion. So, be prepared for a lot of frustrated callers. For more information about the kudzu bug, check out this fact sheet: http://insects.ncsu.edu/Urban/kudzubug.htm.

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 people with dark-colored siding, brick or log homes 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. Recommend that clients 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:
http://www.ces.ncsu.edu/depts/ent/notes/Other/goodpest/note107.html

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 the next to last antennal segment. 

In the fall, adult brown marmorated stink bugs aggregate on and inside houses, sheds and other 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:
http://www.ces.ncsu.edu/depts/ent/notes/O&T/trees/note148/note148.html

 
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 and may move into living areas of the home through openings such as heating vents, baseboards, and gaps around light fixtures. Wasps that invade homes 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. In homes, attic vents should be properly vented to exclude overwintering queens. 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.

More information about paper wasps can be found here: http://insects.ncsu.edu/Urban/paperwasp.htm.

Spiders

Yellow garden spider
(Photo: Ronald F. Billings,
Texas Forest Service)

At this time of year, many of the orb-weaving spiders are very conspicuous. Among those prominent species is the yellow garden spider, Argiope aurantia, which is the distinctively colored (black and yellow), large spider that is frequently seen in gardens, yards and along walls typically near lights or "flyways" where moths and other flying insects are likely to travel and get snared. The female builds a web that has a conspicuous zig-zag band of white silk in the center of the web. For this reason, these spiders are often called "writing" spiders. People often assume that because of the bright colors that this spider is particularly dangerous, which is true if you're a moth. If callers ask about what they should do about the spider, tell them to thank it for catching stuff that probably is laying eggs in the fall garden or eating other plants in the yard. Suggest that they just leave them alone to do their job. Since fall is often a time of yard work and cleanup before the winter, people are out moving debris, firewood, etc. and encounter spiders. You may see black widow spiders and a host of other spiders out there. Any spider with a marking on its back usually gets declared to be a brown recluse and in North Carolina about 99.99% of the spiders sent to us as brown recluses are in fact, fishing spiders, cellar spiders and wolf spiders. If people want to know about control, the best choice is to leave the spider alone to eat critters that folks equally dislike. When working outside and particularly if you're moving debris and items that haven't been disturbed in several days/weeks, take simple precautions like wearing long pants and gloves (and of course your other clothes so as not to upset your neighbors). Check out our note: http://www.ces.ncsu.edu/depts/ent/notes/Other/note137/note137.html

Snakes
Fall is also the time when our no-legged friends start seeking out shelter. From my experience under and around houses, 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. And they're not about to stop to look at the shape of the head or eyes before they beat it to death or cut into pieces with a shovel. Although black rats can bite (I can attest to that personally), they are more inclined to move away from a fight. There will be encounters with copperheads, and one wildlife management company recently pulled three juvenile copperheads from under a porch. 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 (of course "not typically" isn't much comfort to people!) but the bite can land you in the ER 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. The secret to avoiding snake bites? Avoid snake bite opportunities. Follow the same advice about work clothing appropriate for encounters with spiders.

Chimney Swifts
Cold weather means people will be stoking the fires in the fireplace soon and so it's a good idea safety-wise to make sure their chimney is in good working condition. This includes making sure they don't have a build-up of soot and creosote or have cracks in their chimney/flue. Another unwanted item is the nests of chimney swifts. These birds often drive people crazy when they hear the chirping coming from their fireplace and they proceed to burn logs to drive the birds out. Chimney swifts are protected by the Migratory Bird Treaty Act, which means that while nesting in your chimney, you are not allowed to kill/disturb them. And of course that is not something most people want to hear particularly now because their is a bed bug relative that on some occasions may drop down the chimney and show up indoors. That's not meant to scare people and cause them to go to extremes like setting off foggers in their fireplace or starting fires to drive out the birds. At this point of the year, the birds have already bailed out of the nests. So tell your local clients that NOW is the time to clean their chimney to remove the nesting material and/or put a screen cap on their chimney to prevent the birds from building nests next year. A good chimney cap will also keep out other unwanted visitors in search of a home - namely raccoons and opossums. If you think the birds are a problem, try serving an "eviction notice" next year to a mother raccoon that decided your chimney was an ideal home.