As weather warms, mosquitoes seemingly come out of the woodwork. How is it that they are always able to find you?
Mosquitoes use a highly tuned sensory system to zero in on their next blood meal. About 200 feet away, mosquitoes get the first whiffs of carbon dioxide we exhale as we enjoy a bit of gardening or a jog down the pathway. Following the plume – whether it is emitted by us, our furry companions, or a mockingbird up in the trees – brings them closer to the potential host.
Once the carbon dioxide has drawn her within sight, she is further attracted by dark colors and high-contrast patterns. Remember this the next time you reach for something to wear to the neighborhood picnic. Long, loose, light-colored clothing with a tight weave is a good first defense against the piercing mouthparts of the female mosquito. She seeks a blood meal, not to feed herself, but in pursuit of protein to make eggs. You might be surprised to know that mosquitoes drink plant nectar to fuel their bodies, and pollinate plants in the process.
When within three feet the mosquito can sense the heat signature of your body, differentiating you from say, a park bench. Investigating further, she hones in on a specific area to land using “smells” she picks up through her antennae. Lactic acid, uric acid, and ammonia in sweat, as well as the scent of fabric softeners, perfumes and colognes can all attract mosquitoes.
Mosquito repellants can employ a couple different mechanisms in your defense. One is to jam chemical signals from reaching a mosquito’s antennae. The other is to be offensive to the mosquito once she lands and can “taste” it with her feet. Repellents may use one or both mechanisms – termed primary and secondary repellency.
As we each have a unique chemical signature, try a few repellents to find the one that’s most effective for you. Look past the brand name on the front of the bottle to the bottom. There you’ll find one of the active ingredients the CDC recommends: Picaridin, Oil of Lemon Eucalyptus, DEET, or IR3535. What works best for you might be different from your partner or kids.
The Mosquito Surveillance & Education Program of The Woodlands Township uses the mosquito’s keen sensory perception to our advantage. We use a variety of lures and baits to attract mosquitoes into traps for weekly monitoring throughout the Township. For example, the Biogents Sentinel trap uses a lure that smells a lot like stinky gym socks. It also has a high-contrast color pattern and can be made more appealing by the addition of dry ice to emit carbon dioxide. These three features mimic a human host, drawing the mosquitoes close enough to be sucked into a net by a battery-powered fan. The captured mosquitoes are collected the next morning and sent to a laboratory for identification and disease testing. Tracking changes in the number of mosquitoes caught, species present, and disease trends over time provides the foundation for mosquito control activities in The Woodlands.