La Niña sets scene for insect surge, Davis reports.
ST. LOUIS, Mo. — La Niña, the wet winter weather pattern that dumped record rain, sleet and snow across the country in late 2010 and early 2011, has not gone away quietly. Instead, it’s being blamed for creating the perfect storm of unwelcomed insects.
Termites, ants and other pests thrive in moist conditions, and they’re expected to be especially prevalent across America this spring, as record snow packs melt from the Sierra Nevada to Capitol Hill.
“When conditions are warm and wet, pests begin to swarm in search of food, shelter and mates,” said Dr. Bob Davis, entomologist, BASF Pest Control Solutions. “Unfortunately, this search brings many of these insects inside, where they can create a nuisance and destroy property.”
Just how bad your pest problem will be this spring depends on several factors, including the region where you live and your most recent weather.
Based on known climate conditions and predictable pest behavior, Davis offers the following pest problem outlook for specific U.S. regions:
With its hot, humid summers and temperate winters, the South offers ideal conditions for a wide range of pests, including many species of ants.
“Ants live in nests just below the soil surface, so once the ground gets soaked, they quickly begin moving their nests to higher locations,” Davis stated. “Once they get flooded, it doesn’t matter how clean your home is – no one is immune from an invasion.”
Ant populations are expected to grow across the South this spring, bolstered by an influx of feisty foreign invaders. For example, the Caribbean crazy ant had only recently been seen in Texas, but has already begun to spread to multiple counties in Southeast Texas and may now be in the neighboring state of Louisiana. These ants are aggressive enough to drive out the native ants.
“There are whole neighborhoods in Southeast Texas that are being overrun with millions of these invasive ants,” Davis said.
In most regions, colonies of crazy ants are relatively small, with multiple queens and a few thousand workers. However, in favorable environments such as Florida, larger colonies containing tens of thousands of ants may be linked by foraging trails.
The threat of termite infestations also could intensify this spring with some forecasts predicting average-to-higher temperatures and average precipitation in Florida, Georgia and surrounding states.
A season of intermittent rains with warming temperatures is conducive to termite swarming. Swarms occur when winged termites leave the nest to form new colonies – often right after a rainfall. But termites also can expand their colonies’ ranges without swarming. In fact, during years of reduced swarms, a single subterranean termite colony may split into multiple smaller ones underground.
Southeastern drywood termites, often found in the extreme Southeastern states, swarm from late May to mid-June. They can infest buildings, eating structural timbers, pieces of furniture, flooring, doors, window trim, even wooden picture frames. Many times interior swarms will be found near windows and doors because the swarming termites are attracted to lighted areas.
This past winter was severe in the West. Colder-than-normal temperatures and heavy precipitation hit many areas hard. Officials from the Department of Water Resources in California say the snowpack in the Sierra Mountains was 165 percent of normal levels.
While the snow is a blessing to previously drought-stricken California, it also sets the stage for heavier-than-normal bug infestations. Spiders, scorpions, beetles, termites can flourish when normally dry ground is flush with water.
One frequent menace is the Western subterranean termite. This native pest can enter structures through cracks less than one-sixteenth of an inch wide, including the tiny openings in concrete slabs, around drain pipes, and between the slab and a home’s foundation. Swarming can occur in the spring, but smaller swarms can occur throughout the summer and fall.
The wet conditions will also create a field day for ants, including the highly invasive Argentine ant, whose massive colonies can be found along the West Coast as well as parts of the Eastern and Gulf Coast states.
“The Argentine ant has few natural enemies here, so they can quickly knock out the native ants,” Davis said. “When Argentine ants get inside a house, they’re a force to be reckoned with. I’ve seen these ants travel in columns that were as wide as my wrist.”
Red imported fire ants have also invaded parts of the West, expanding their range every year. They are extremely resilient and have adapted so well that they can survive both floods and droughts. Fire ants are characteristically become ferocious if their nests are disturbed, and their painful stings carry venom that can be highly unpleasant or even lethal if an individual is sensitive to the venom or is stung excessively.
States from Missouri to Iowa to Wisconsin saw more flooding last year, with thousands of homes damaged by water. In fact, soil moisture conditions over many of these states are categorized as “extremely or very moist” The residual effect this year could be a proliferation of household pests that thrive in damp conditions, such as silverfish and spiders.
Moisture also increases the odds of termite invasions, especially in Midwestern states such as Missouri, Iowa, Ohio, Indiana and Illinois. The southern parts of the Northern states, such as Wisconsin and Minnesota, may also see increased termite threats, particularly from the Eastern subterranean termite – the most common and widely distributed termite in North America. This native pest feeds on cellulose materials, including structural wood, wood fixtures, paper, books and cotton, and will even attack the roots of shrubs and trees.
In the colder Northern states, carpenter ants are a greater threat to homeowners. Carpenter ants – which include some of the largest ant species in the United States – prefer to nest in trees next to homes, but they’ll come inside to nest if they can’t find enough wood outside.
There are many other ants in the Midwest, including the invasive odorous house ant, so named because it smells like a rotten coconut if it’s smashed. Indoor nests can be found in wet areas, such as bath traps, under toilets, in wall voids near hot water pipes or heaters, and in crevices around sinks and cupboards.
“Ants are omnivores, which mean they’ll eat plants or meat. When they invade our homes, they eat mostly whatever they can find,” Davis said.
With record snowfall and rain in the Northeast, wet conditions will likely persist into spring. Combined with the warming temperatures, this will create attractive conditions for a variety of invaders. Common culprits include the Eastern subterranean termite and the black carpenter ant.
Mature carpenter ants produce swarmers that spend their winters in nests and take flight in the spring. Indoor carpenter ants may be seen trailing along edges of cabinets, floors and furniture.
The Brown Marmorated Stink Bug is a new invasive species that was introduced into Pennsylvania in the 1990s. It has now spread to 33 states and can cause severe agricultural damage as well as become a very problematic overwintering pest of homes and buildings. Large numbers of these stink bugs can enter your homes and businesses in the fall looking for sites to overwinter. Though we can’t blame weather patterns for this one, another pest that continues to attract headlines along the East Coast is the bed bug. Once believed to be virtually eliminated from the United States, this ancient enemy is back and New York, Cincinnati and other Midwestern to Eastern cities have been hit especially hard. Scientists aren’t exactly sure why, but they suspect one cause of the insurgence is the rise in international travel to countries where bed bugs are still prevalent.
In addition to infesting many hotels – even some of our finest – bed bugs have also invaded thousands of apartments and houses. To avoid a bed bug infestation, Davis recommends thoroughly inspecting your luggage and lodgings during your travels.
If you suspect an infestation of any type, Davis recommends you call a professional pest control expert. You can find a pest professional in your area by visiting TermidorHome.com. For other information about termites, bed bugs and ants visit www.termiteinstitute.com, www.bedbuginstitute.com