Summer is one of the most anticipated seasons of the year. With kids out of school, many families use this time to go on vacation to enjoy the sunshine and warm weather. However, people aren’t the only ones who enjoy the tropical temperatures. Mosquitoes thrive in the summer months and can become more than just a nuisance, in some cases posing health risks by spreading diseases.
In almost every state this summer, there is a chance you will encounter these insects. How can you enjoy the summer without letting mosquitos ruin your time in the back yard or on vacation? Ali Afify, PhD, an assistant professor in the biology department in the College of Arts and Sciences who researches different mosquito behaviors, spoke with the Drexel News Blog to tell us a little more about these pests and what we can do to avoid them over the next few months.
Why are mosquitoes considered to be among the world’s deadliest animals?
Mosquitoes are considered the world’s deadliest animals because they transmit diseases that kill around a million people every year. This includes malaria, which kills more than 500,000 people every year. They also transmit dengue, Zika, West Nile virus, and yellow fever, affecting billions of people worldwide.
What environmental conditions typically lead to increased mosquito activity this time of the year?
Mosquito activity increases in the summer due to three things: warm temperatures, high humidity and standing water from rain, which is where mosquitoes lay their eggs. Their activity decreases in extreme heat (above 36° Celsius) because it can cause dehydration and they usually hide in cool and humid areas.
Why is it that mosquitoes bite some people, but not others?
One of the most important factors is how you smell to mosquitoes. We have many scent chemicals on our skin that attract mosquitoes and help them find us. Some people have more of those chemicals and therefore get more mosquito bites, while others have less of these chemicals and rarely get bitten. Other factors also play a role such as body size (larger people exhale more carbon dioxide, which mosquitoes can detect from a distance) and body temperature (warmer body temperatures attract mosquitoes more).
Do both male and female mosquitoes bite and why do they seek out humans?
Only female mosquitoes bite. They do this because they need nutrients in blood to make their eggs. Male mosquitoes, on the other hand, are vegetarians that only feed on flower nectar. Female mosquitoes also feed on nectar for survival but take blood meals specifically for egg production.
How do mosquitoes find us in the dark?
Mosquitoes can detect multiple chemical, visual and temperature cues to find us. This allows them to find us even when one of the cues is absent. For example, in the dark, when visual cues are absent, mosquitoes can detect body odors, temperature and exhaled carbon dioxide and use them to navigate towards us.
What are some of the things that attract mosquitoes and what products should we avoid?
Any personal care product we use on our skin can change our smell and affect how we attract mosquitoes. A recent study found that soaps change how attractive we are to mosquitoes, with some products increasing attraction while others repel mosquitoes. However, the duration of the effect is not known as mosquito attraction was tested within an hour of soap application.
Are mosquito repellents effective and what are their limitations?
Yes, some mosquito repellents are very effective in preventing bites. However, repellents have some drawbacks. For example, DEET, the gold standard in mosquito repellents, can cause skin irritation in some people and melts plastics and rubbers. Also, repellents, particularly those containing natural oils, need to be reapplied frequently on the skin to stay effective, and they often have an oily feel and strong smell that make them less appealing to many people.
What are some measures you would recommend to avoid getting bitten by mosquitoes this summer?
There are different measures that can decrease mosquito biting and using more than one approach can significantly increase protection. For example, wearing light-colored clothing can decrease mosquito attraction and also loose-fitting, tightly woven clothing can prevent biting. Combining this with a good repellent is optimal for decreasing mosquito bites. Also, to decrease mosquitoes around your home, get rid of standing water in your yard. It serves as a breeding site for mosquitoes, and eliminating it can significantly decrease mosquito populations and bites.
Reporters interested in speaking with Afify should contact Mike Tuberosa, assistant director, News & Media Relations, at mt85@drexel.edu or 215.895.2705.
