PAT MELGARES
K-STATE Research and Extension News Service
MANHATTAN, Kan. – For many, the onset of summer means outdoor picnics, walks and time at the park, but a blood-sucking insect whose lifespan rarely lasts past two months often can put a bite in those plans.
Kansas State University entomologist Jeff Whitworth said May and June tend to be the time of year when adult mosquito populations rise in Kansas. Many parts of the state received adequate rainfall during those two months, which promoted ideal conditions for mosquito breeding.
“If it keeps raining,” Whitworth said, “you ain’t seen nothing yet, because they’re going to keep coming.”
He said mosquitos lay their eggs on the surface of water, so anywhere that there is standing water – bird baths, old tires, eaves around the house, feeding troughs on farms are among some of the areas – mosquitos are likely to multiply.
“There are 40-50 species of mosquitos in Kansas, and they will lay anywhere from 200 to 300 eggs at a time,” Whitworth said. “Some species will lay eggs in a low spot that’s just damp, and when the water comes in, the eggs will hatch. But they have to have moisture to hatch the eggs, which happens 4-5 days after the adult mosquito lays the eggs.”
Thus, Whitworth said, reducing mosquitoes around a property comes down to reducing areas where water sits idle.
“If you live out in the country, it’s really difficult to get rid of all of these sources of mosquito larvae,” Whitworth said. “But that’s what you want to shoot for. You want to try and get rid of the eggs – the larvae or pupae – before they become adults.”
Once adults, mosquitoes mate. Males have a very short lifespan; typically 10 days during which time they are harmless. Females need a blood meal in order to produce fertilized eggs, so they are aggressively seeking a blood source prior to depositing their eggs.
“They’re very persistent, and very good at finding a source of that blood meal,” Whitworth said.
Whitworth said mosquito control efforts in towns and cities are generally not effective ways to kill adult mosquitoes. The females will fly as far as three miles searching for its next meal, “and by the time they get there, the residual activity (of the insecticide) is very, very little.”
“The chances are very small that they are going to land on something that has a little chemical on it,” Whitworth said. “They fly right in from where they are going and directly on to a human, bird, chicken or whatever their next blood meal is.”
For humans, the best way to protect from mosquitoes is to stay inside. When going outside, wear long sleeve shirts and pants. A repellent containing DEET will work against mosquitoes, but needs to be re-applied every two hours.
“The presence of mosquitoes is not going to get any better until it dries out, or at least until the corn, sorghum and soybeans are harvested and in the bin in the fall,” Whitworh said. “Even so, the mosquito is not going to go away. It's best to try and control the habitat that is producing them.”