by Susan Himes, Texas A&M AgriLife Communications
Did you know there are 85 species of mosquitoes in Texas that have been identified by Texas A&M AgriLife Extension Service’s agricultural and environmental safety unit personnel?
That’s a lot of itch-inducing painful pests to worry about. Besides being a buzzing and biting nuisance, mosquitoes carry a host of diseases and viruses that can be dangerous to people, pets and livestock.
“It’s a mosquito’s world,” said Sonja Swiger, Ph.D., AgriLife Extension veterinary entomologist in Stephenville. “Whether you see them or not, they are all around us.”
Our state’s warm climate makes a prime breeding ground for vector-borne illnesses, so AgriLife Extension experts hope Texans will observe Mosquito Awareness Week on June 21-27 by learning how to prevent and control these pests.
Male mosquitos feed only on nectar, unlike their blood-sucking counterparts. Females also feed on nectar but need blood for egg production.
There are species of mosquitoes that feed during the day and species that feed at night. That may be why it seems like there are so many mosquitoes out at dawn and dusk – during these periods, the day and night feeders may overlap.
Swiger said during the day, grassy areas with tree coverage are where mosquitoes like to be to avoid the hot sun. Mosquitoes are cold-blooded and can’t regulate their body temperature. That’s why on warmer days, they seek shade and why they typically aren’t around when the thermometer dips below the mid-50s.
“People in the city may not even notice mosquitoes during the day,” she said. “But the species of mosquito that carries West Nile virus typically lives in more urban areas, so people in cities are more likely to contract West Nile virus and need to be aware.”
If you live in the country, you’ll typically encounter more mosquitoes during the day, especially when it’s wet, Swiger said.
“At night, no one is better off than anyone else when it comes to mosquitoes,” Swiger said. “Whether you live in the country, suburbs or a big city, you’ll have mosquitoes to contend with.”
Mosquitoes hibernate in the winter. Some mosquitoes spend their winter as eggs that then hatch when the weather warms up, while others hibernate as adults or larvae. Areas with a hot and humid tropical climate can experience mosquitoes year-round.
Mosquitoes and disease
Mosquitoes can transmit viruses such as Zika, West Nile, malaria, dengue and more to humans.
“In Texas, our biggest concern is West Nile virus,” explained Swiger. “It has been found throughout the U.S., and we here in Texas have experienced a large number of cases in the past. It’s something that varies year to year, so there’s no way of predicting what kind of year this will be.”
In 2012, Texas experienced its largest outbreak of West Nile virus in history with over 1,800 confirmed cases.
“Most of these victims reported they were bitten at home,” Swiger said. “So, it’s important that Texans be aware at all times and use repellant when necessary.”
She said dengue is the other most important mosquito-related disease Texans need to be aware of. While it is primarily seen in South Texas, the Lower Rio Grande Valley and areas bordering Mexico, someone that contracts it could travel anywhere.
“We also need to remember that Zika is still out there,” Swiger said. “That is something that pregnant women in particular need to be aware of.”
Mosquitoes and animals
Mosquitoes can transmit dangerous disease-causing parasites to dogs and horses too, including canine heartworms, Eastern equine encephalitis, Western equine encephalitis and West Nile virus.
“We don’t see Eastern equine encephalitis much, but even one case is cause for concern, since the mortality rate for horses with EEE is 75-80%,” Swiger said. “We typically see cases in East Texas and can expect to have cases in horses again this year. But we haven’t seen a case in humans yet.”
Swiger also noted while there are currently EEE, WEE and West Nile vaccines available for horses, there are none for humans as yet.
When you are outdoors in any area where there could be mosquitoes, it is wise to wear long sleeves and long pants. The tighter the weave of the fabric, the better protection it will offer from bites.
When it comes to topical protection, proven effective mosquito repellents will have at least one of these ingredients: DEET, IR3535, Picaridin or oil of lemon eucalyptus, which may also be listed as paramenthane-3, 8-diol.
The first step in mosquito prevention involves finding and eliminating mosquito breeding grounds. Mosquitoes lay their eggs in or near standing water, so any stagnant water is a potential problem. Any place around the home or property where water can collect and sit for seven to 10 days is a problem to address.
Check property for standing water in clogged rain gutters, birdbaths, old tires, children’s play equipment, potted plant trays, tarps, holes in trees, bowls and buckets — literally anything that can hold standing water. Make sure to regularly change the water in any pet bowls outside.
Dump or drain stagnant water and turn over or cover items that catch and hold water. Gravel or sand can be used to fill places where stagnant water collects.
If a mosquito problem needs wider control, it may be necessary to call a pest control company that specializes in mosquito management. For some do-it-yourself options, AgriLife Extension experts suggest:
– Treating standing water with insecticide/larvicide.
– Applying residual sprays on yard surfaces.
– Using mosquito foggers in the yard.
If opting for a chemical solution, always read the label first and carefully check to determine if it is harmful for human, animals, plants or beneficial insects.
To learn more about mosquitoes, AgriLife Extension offers a Mosquito Control website and a Mosquito Safari. The website also is where Mike Merchant, Ph.D., AgriLife Extension entomologist, Dallas, has created a series of informative mosquito videos. Follow Swiger on her blog for more about bugs and insects.