Why Ticks Are Gonna Be Bad This Year
Everywhere you turn, someone is saying this year's mild winter will unleash a ferocious tick season.
Richard S. Ostfeld says they are all wrong.
Ostfeld, a disease ecologist, should know. For more than two decades, he has studied the life cycle of ticks at the Cary Institute of Ecosystem Studies in Dutchess County.
Ostfeld agrees that the 2012 tick season will be a bad one, but he said weather isn't the cause. Instead, he blames the white-footed mouse and the acorns they devour.
"There is simply no evidence of warm winter weather having any impact on tick populations at all," said Richard S. Ostfeld, a disease ecologist at the Cary Institute of Ecosystem Studies in Dutchess County.
A bumper crop of acorns in 2010 led to a surge in the population of white-footed mice in 2011, which in turn fed a thriving generation of young ticks, Ostfeld said. The mice are the favorite blood meal of baby ticks, and often they are infected with Lyme.
The mouse outbreak "was unprecedented, and we've been monitoring it for 20-plus years," Ostfeld said.
Black-legged ticks, better known as deer ticks, generally take three blood meals over their two-year lifespan. An adult female tick lays about 3,000 eggs in the spring. The baby ticks, called larvae, hatch in the summer and are disease-free until they feed on an infected animal. Often, their first blood meal is from a mouse. That first meal lasts them through winter, which they survive in pockets of the soil in a state of suspended animation.
They awaken the next spring as hungry teenage ticks called nymphs. Nymphs, which are about the size of a poppy seed, prefer to feed on deer, mice and small mammals, but a human will suffice. Nymphs are most active in May and June. By fall, they have reached adulthood and are looking for one more blood meal before they reproduce and die. Adult ticks that fail to find a meal may survive one more winter to continue their search for a host in the fall.
When the baby ticks hatched in 2011, Ostfeld said they had an abundance of mice to feed on. Each mouse can carry hundreds of larvae, which are about the size of the period at the end of this sentence. But this spring, the massive legion of teenage ticks will awaken to a different world because the 2012 acorn crop failed and the mice population crashed.
"This will make matters worse," Ostfeld said. "Those infected nymphs are more likely to crawl on us because there won't be all those little mice vacuum cleaners sucking them up."
The mild winter doesn't change the number of ticks out there, but it does affect their behavior, he said. Ticks wake up when the temperature reaches the upper 30s, so the early warm-up means that adult ticks who failed to find their final blood meal last fall are already on the prowl for a host right now.
"It's the perfect storm," Ostfeld said.
The state Department of Health advises people use DEET, wear long pants and long-sleeve shirts, and check themselves for ticks when visiting wooded areas.
"One tick is just as dangerous as 30 ticks," said Peter M. Constantakes, a DOH spokesman. "We stress taking precautions."
Ostfeld has some good news. The dying mouse population means this year's batch of baby ticks will struggle to find their first meal.
"They may die off and 2013 may be a better year," he said.
Read more: http://www.timesunion.com/local/article/Nature-the-trickster-3419367.php#ixzz1pfmYcxfi