Winter has made its presence felt across the western United States. Record rain, snow and winds have been recorded across the region including locations that don’t usually experience such extreme weather including Las Vegas, Reno and Phoenix.
What impact does winter’s extreme weather have on pests in these diverse geographic areas? Do they simply go away? The answer is no.
Sprague regional entomologist Dan Scott, B.C.E., says pests from mice to bed bugs remain active all year-around, and commercial property owners and managers should not fall into the trap of “out of sight, out of mind” when it comes to winter pest pressure.
“Insects and other pests are around us all the time and just because they aren’t seen as often during winter, doesn’t mean they aren’t there,” says Scott. “Some pests adapt better than others to winter, but generally their makeup encourages them to seek warmer, drier locations to ride winter out, and that can include inside commercial properties.”
Scott, who works with Sprague’s field teams in Arizona, Nevada and California, says the myth that pests simply ‘die off’ is just that, a myth. He says in general a pest’s metabolism slows down in the winter and they enter a ‘resting’ phase and use minimal energy. This doesn’t mean that all pests stop searching for food or shelter when evening temperatures drop in the Arizona and Nevada desert during winter.
“Even in winter, a food processing plant in Reno, an office complex in Las Vegas or the commercial kitchen at a resort in Phoenix provide a conducive microclimate that attract and allow pests to thrive,” says Scott. “These facilities have food, moisture, humidity and harborage that give pests everything they need to make it through winter.”
Weather Pest Activity
Arizona, Nevada and Southern California have varied climates that range from intense heat to heavy snowfall. What impact does weather have on pests across this diverse geographic area during the winter months?
“Our Phoenix and Las Vegas service centers experience the warmest weather over an extended period of time as do our Southern California branches in Los Angeles and Bakersfield, so pests in these locations will be impacted to a lesser degree by winter weather than in Reno,” says Scott.
Southern California and Arizona – The Argentine ant is the number one pest in Southern California and Arizona. When winter rains arrive – like they have in California in recent weeks – these underground nest dwellers will migrate inside structures searching for a drier place to live. They can gain access to a commercial property through openings under doors, weep screens on the side of stucco walls or through utility openings.
Arizona and Nevada – In Phoenix and Las Vegas, black widow and cellar spiders, and scorpions can migrate indoors during colder weather if they don’t find a suitable natural habitat (i.e., under leaf litter, wood piles, etc.). Both will slow their metabolism showing their natural adaptability to survive adverse weather conditions. Bark scorpions will cluster together to stay warm, the only species of scorpion to do so.
Nevada and Arizona – Roof rats are another winter pest that will seek shelter – and new sources of food – inside commercial structures during cooler weather. These opportunistic pests will take advantage of an open loading dock door or a missing screen on a ventilation opening to gain access.
Reno, Las Vegas and Phoenix – Winter’s consistently colder temperatures impact pest behavior more so in Reno than in Las Vegas or Phoenix. Pests will migrate inside structures at higher rates to escape the cold and identify food and moisture sources. Reno’s snow can provide a ‘blanket’ for the insects and rodents who opt to ride out the winter outdoors.
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