The recent heavy rainfall across much of the state will
force a lot of common pests (and a few unusual ones) out of their typical
habitats and also contribute to surges in populations of others.
Millipedes -
Millipedes continue to gain momentum and people's
attention. In past years, millipede invasions
were triggered primarily by very dry conditions. This year, we have the
opposite situation. The critters are trying to keep their thousand
legs somewhat drier so they're hiking to higher ground. (NOTE:millipedes don't actually have
1000 legs; it's closer to that more scientifically accurate
determination of "right many legs")
Buildings on slab construction may face more problems in that the millipedes have a somewhat shorter trek
up the exterior surface of the slab (or exterior wall if it's a supported
slab) and gain entry into the homes and commercial buildings. Of
course, they can simply crawl under the door! Millipedes are prolific climbers and often make their way
up to the second floor and even the roof of a house.
Quite commonly, you will find millipedes (alive
or dead) along the walls indoors. If you pull back the carpeting, you will
often find more millipedes underneath
and you now have to contend with them as well as figure out how to tack the
carpeting back down so it looks as good as when it was first laid out
professionally. Millipedes do
not survive very long indoors, but typically they outlast the patience of the
frustrated callers to whom you've been preaching patience.
You'll also find that they invade other areas
where moisture tends to accumulate, usually crawlspaces, basements and garages.
Homeowners often find piles of dead millipedes outdoors along walls and
on driveways, such as you can see in the picture at:
http://insects.ncsu.edu/Urban/millipedes.htm
I've talked to many pest control companies
about millipede control and I
get the usual mix of "this works" and "this hasn't
worked". The problem is that I hear the same chemicals mentioned in
both categories. In drier years, I typically attribute this disparity to
differences in spray volume applied to a site. Dry mulch or soil surfaces
tie up a lot of the chemical and it doesn't have an impact on the millipedes. In contrast for this year,
the problem is more likely that the chemical is being diluted or displaced by heavy rains.
If homeowners want to try to treating their property themselves, then given the
amount of soil moisture we have around the outside of homes, granular
insecticides (such as those made by Bayer Advanced, Ortho or Spectracide) might
be good choices. Avoid applying granulars if the grass is wet from rain
or dew because the chemical is likely to get stuck up on the foliage and not
reach the soil where it belongs.
Under drier conditions, I would suggest using a garden hose sprayer in
order to get the necessary coverage and volume. If there is a thick
layer of dry mulch around the house at that might, it needs to be pulled back at
least 3-feet so the soil underneath can be treated. Most treatment areas
consist of about 3-5 feet around the house, plus about 2 feet of the foundation
wall as well. Any of the common outdoor insecticides that you find at the
common retail and garden center can be used. Again, the most common
(but not only) brands are Bayer, Ortho and Spectracide. Some people
use dust formulations (e.g., dust formulations of Sevin or
permethrin) to make barriers around the outside of their homes. You
get a lot of dead millipedes but my concern is for homes/yards with children
and pets that might come into contact with these chemicals.
As for indoors, that's somewhat of a losing battle if you try
a conventional baseboard sprays. You'll see dead millipedes, but there is a good chance that
they would have died regardless of any chemical simply because it's too dry
indoors. Vacuuming up dead millipedes is
the best approach and will get people into shape for the fall invasion of Asian
lady beetles, kudzu bugs and brown marmorated stink bugs.
"Scuds"
Those of you on the coast may have gotten calls from people
that see piles of dead "bugs" that turn red like boiled shrimp and
then darken. What they're seeing are amphipods or "scuds"
which are tiny crustaceans that live in very moist areas. When we get
very dry or very wet weather, these little critters are on the move and will
end up on patios, car ports, doorways, etc. They usually don't invade
homes but the piles of them outdoors either gross out or aggravate people.
Of course, you can really irritate them by telling them to wait until the
millipedes show up! Spraying for scuds doesn't do anything.
They'll still die on the pavement whether you spray them or not.
So, get out the broom and sweep them back into the grass or landscaping.
Rodents
Burrow and cavity nesting rodents including Norway rats and
cotton rats may get displaced by flooding in some areas. "High
ground" for them may be areas around or potentially in homes and
businesses (Norway rats are more likely to take up residences indoors than
cotton rats). I strongly discourage the use of baits indoors (including
attics and crawlspaces) for rodents. There's an urban legend that rats
eat poison baits and will go outdoors to find water. More likely, the
rodent will get sick and simply die in 2-3 days of consuming the bait and if it
does so indoors, you'll know it when the odor and flies show up.. Also,
baiting outdoors needs to be done very carefully to make sure that wildlife,
pets and kids don't accidentally consume carelessly placed baits. Baiting
outdoors should use bait boxes or make sure that baits are placed into active
rodent burrows. When baiting outdoors, also make sure that you check the
surrounding area for poisoned rats which should be removed immediately to make
sure that pets and/or wildlife do not eat them (and become ill from the rat
poison). Note that baits are not to be used for cotton rats around
residences. Snap traps are a better choice, but they need to be checked daily.
Flies
Deer flies and horse flies have been painfully noticeable
the last few weeks. Deer flies are about 1/2" in size with
greenish-yellow bodies and smoky-colored wings. They are often
encountered along hiking trails, narrow lanes and roads and at the edges of
woodlands. They are numerous and annoying along the coast and near their
breeding and natural feeding sites such as flood plains of swamps, streams and
rivers and around ponds, salt marshes, and beaches. The flies are
aquatic or semi-aquatic in breeding habits, laying their eggs in clusters on
objects, such as plant stems and leaves, near the water. Adults are
prominent now through August. Because of their breeding sites not easily
identified, control of the larvae is not really feasible. Repellents are
less successful at stopping them as compared to repelling mosquitoes.
Biting MIdges (no-see-ums).
Even as water recedes (or soaks into the soil), pockets of
very wet decaying vegetation are likely to be a source of no-see-ums in the
next few weeks. Note that these are not the mosquito-like non-biting
chironomid midges that breed lakes and ponds. A quick approach to dealing
with them is (where possible) to remove piles of decaying material such as mats
of seaweed washed up onto the shore along coastal areas. Spray programs
similar to those for mosquitoes are largely ineffective as more adult midges
will invade the area once the pesticides diminish. Personal protection
using repellents is a better choice if you're going to be outdoors in areas
with high populations of biting midges.
Mosquitoes
You may hear stories about a "new" mosquito
species that flies during the day and is wreaking havoc in some areas,
notably the northeastern US. This is old news to us in the Old North
State because they're talking about the Asian tiger mosquito. As I've
mentioned previously, mosquito populations will spike in the ensuing weeks
following heavy rains. Urge people to be proactive and eliminate by
"Tipping and Tossing" standing/stagnating water found in clogged
drainage ditches and gutters, flower pots on open decks/porches, used tires and
other objects such as empty paint cans and other containers. Flush out bird
baths and pet water bowls. Water that can't be eliminated can be treated
with products such as "Mosquito Dunks" that contain a bacteria that
is toxic to mosquitoes and some flies but not other insects, fish, wildlife and
people. Other conventional pesticides can be applied to mosquito resting
areas - shrubs and lawns. Some people use fogging equipment to treat
their yards. I'm not real keen on "Do-It-Yourself" area
fogging. While this does knock down mosquito populations, realize that fogs
easily drift to adjoining properties and so it's prudent for people to make
sure that their neighbors don't object (particularly those people that may have
vegetable gardens or bee hives adjacent to your treatment site). Also,
make sure with any outdoor applications (fogs or liquids) that you treat when
wind speeds are low (preferably 3mph or lower), keep everyone out of the target
area, and cover or remove children's toys, pet food/water bowls, and barbecue
grills. And, bear in mind again that mosquitoes do not have any real
understanding of property lines. So, one person's treasure trove of
"collectibles" (collecting water in this case) can become the
neighborhood mosquito nightmare.
Use repellents when for outdoor work and recreation
activities. There are a number of products available. Avoid home remedies
and "urban legend" products such as using "Bounce" dryer
sheets (for which there is no scientific data to back up those claims of
repellency). Apply repellents only to exposed skin (not covered by
clothing). For children, use repellents with low concentrations of
chemicals and always apply the products to small children (don't let them treat
themselves).
As mosquito populations increase particularly in central and
eastern NC, horse owners should consider protecting their horses against
eastern equine encephalitis. There is no post-infection cure for the
disease and animals may die within 72 hours of manifesting symptoms.
There is a preventive vaccine available for horses (not for humans) and
so equine owners may want to talk to their veterinarian about it.
Ticks
No.. the heavy rains won't stop the ticks. They'll
simply leave with their current hosts (mice, groundnesting birds, deer, etc.)
or climb onto foliage and wait for you to come along to clean up your
yard... Keep that in mind while doing cleanup particularly in
heavy brush or weedy areas. Tuck your pants into your socks...
Yes.. you do look like a dork but you'll be dork with ticks chomping on
your leg. Repellent applied to your socks and pants can help. Check
yourself over carefully after working outdoors. If you do find a tick that's
feeding on you, remove it carefully with a pair of tweezers. At this
early stage following the bite, getting (or asking your doctor about) a blood
test isn't helpful because the blood tests for diseased like Rocky Mountain
Spotted Fever and Lyme Disease rely heavily on testing for antibodies
developing in response to the pathogen and this can take takes weeks to reach
detectable levels. Also, 20% or more of people infected the Lyme Disease
pathogen do not develop the classic "bull's eye" rash and often 10%
of infected people do not develop the body rash associated with Rocky Mountain
Spotted Fever. The best approach is to circle the date of the "tick
encounter" on the calendar and if you develop flu-like symptoms, severe
headaches or joint pain within the next 3-14 days, contact your physician.
Fire ants -
They originated in areas of South America where rivers
flood. Our rains won't phase them. They're waiting out the receding
waters and mounds will be active again (if they're not already).
--
________________________________________________________
Michael Waldvogel, PhD
Extension Assoc. Professor & Specialist, Structural & Industrial Pests
North Carolina State University
Dept. of Entomology, Box 7613, 100 Derieux Place
Raleigh, NC USA 27695-7613
http://entomology.ncsu.edu/waldvogel
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