Mosquito Myths Busted What You Need To Know

Mosquitoes are a familiar summertime nuisance for most of us, but beyond the annoying bites, they also pose serious threats to our health by spreading potentially deadly diseases. And despite how common these insects are, people continue to latch onto some very popular misconceptions about them.

“There are many myths about mosquitoes ‘buzzing’ around that our team of entomologists encounter,” said Jim Fredericks, a board-certified entomologist and senior vice president of public affairs at the National Pest Management Association. “Some of them are silly, but some misconceptions could actually put people at risk.”

To help keep people safe and informed, HuffPost asked Fredericks and other experts to set the record straight. Keep scrolling for 14 myths about mosquitoes.

“Not all mosquitoes feed on blood,” Fredericks said. “The mosquito species that do bite require blood to develop their eggs. Mosquitoes actually feed on nectar and plant juices, just like butterflies.”

He noted that of the mosquitoes who do feed on blood, only females bite humans and other animals.

“If you get bitten or stung by any insect, it’s almost always a female,” said Raymond J. St. Leger, a professor in the department of entomology at the University of Maryland. “Male mosquitoes are harmless feeders on nectar. Female mosquitoes are drawn to various animal volatiles and excretions, to which the males are indifferent.”

“While several papers have been published linking mosquito attraction to different blood types, many questions remain as to what is actually attracting mosquitoes,” said Zachary DeVries, an associate professor of urban entomology at the University of Kentucky. “It is difficult to isolate blood type as the sole factor responsible for differences in attraction, not to mention blood does not usually have a perceivable odor given its presence inside (not outside) our bodies.”

He noted that several of those papers regarding blood type and mosquitoes have been retracted and pointed to other elements that can play into mosquitoes’ preferences for certain individuals.

“Factors such as body odor, carbon dioxide production and skin bacteria can make some individuals more attractive to mosquitoes,” said Lee Haines, a professor of medical entomology at the University of Notre Dame. ”However, sometimes a person gets just as many, or more, bites but they do not have a reaction (they have become desensitized), so they appear to be bite free when they are not.”

Mosquitoes can be attracted to body heat and certain chemical compounds in sweat as well.

“They are also attracted to the color of the clothes that you’re wearing, and are especially attracted to red, orange and black colors,” Fredericks said. “Blood sugar levels have nothing to do with it. Factors like pregnancy, exercise and even whether you recently had an alcoholic drink play a much bigger role in whether a mosquito is attracted to you or not.”

“Mosquitoes can bite through thin or tight-fitting clothing,” Haines said. “Scientific studies have demonstrated that mosquitoes can penetrate lightweight fabrics, with bite resistance depending on fabric thickness, pore size, and weave density rather than simply the presence of clothing.”

She added loose-fitting, tightly woven fabrics, or clothing that has been treated with insecticide are more effective at reducing mosquito bite risk.

“While many mosquitoes are most active at those times, several species are daytime biters that can cause problems all day (and night) long,” Fredericks said. “Female mosquitoes feed on blood, which means they’re looking for meals whenever they prepare to reproduce.”

Asian tiger mosquitoes, for example, are active during the day, while Aedes aegypti have biting peaks in the morning and late afternoon.

“Different mosquitoes are active at different times of day, although most are active at dusk and dawn,” DeVries said. “Also, your environment can influence your exposure risk. Shady areas can lead to bites from mosquitoes outside of the times they are normally active. As such, you should always be aware of your surroundings and take appropriate measures to reduce being bitten, even in the middle of the day.”

“Some individuals will state that mosquito repellents are not effective,” said Aaron Ashbrook, an assistant professor of urban and peri-urban entomology at Louisiana State University. “However, EPE-approved mosquito repellents are tested for their efficacy ― otherwise, they cannot be labelled as a repellent.”

He noted that mosquito repellent is often washed off by sweat and other forms of moisture.

“Therefore, it loses efficacy and needs to be reapplied if you are starting to be bitten by mosquitoes after the initial application,” Ashbrook said. “When I am out in the woods, I bring my repellent with me to reapply it as needed.”

“Mosquitoes are considered by many to be the most dangerous animal on the planet due to the death they cause through transmission of things like malaria, dengue and West Nile,” DeVries said. “However, there are many mosquito species that either do not transmit diseases or are not good at transmitting diseases.”

St. Leger similarly emphasized that the many mosquito species differ in their ecologies and behaviors and that different species carry different diseases.

“A big surprise has been that despite their differences they all seem to be benefiting from how we are changing the world,” he added. “Much of the U.S. has become more hospitable to really dangerous disease-carriers like Aedes aegypti and Anopheles stephensi.”

Furthermore, DeVries explained that you need three things for disease transmission to occur ― a pathogen source, a viable host and a way of transmitting the disease.

“For mosquito-borne diseases that affect humans, the host (humans) and way of transmitting the disease (mosquito) are usually set, but often times the source is not,” he noted. “If you do not have the disease present, there can be no transmission. However, it is important to note that oftentimes the source can be introduced, leading to localized disease outbreaks as we often see in the U.S. with things like Zika and West Nile viruses.”

“The myth that mosquitoes only breed in dirty water is dangerous since it gives people a false sense of security,” Fredericks said. “The truth is mosquitoes can breed in any standing water, clean or dirty. All they need is half an inch of standing water to lay their eggs. That’s the size of a water bottle cap. Our team has found mosquito eggs in birdbaths, flowerpot saucers, children’s toys, old tires ― anything that can gather and collect water.”

He added that a good way to prevent mosquito breeding grounds is to ensure standing water is removed, especially after rainstorms. Change out the water in birdbaths regularly as well.

“While draining swamps helped eliminate malaria in the U.S., tiny puddles suffice for Aedes aegypti and Anopheles stephensi, making them well suited for urban life,” St. Leger said. “They are heading our way and we’re not really prepared for the consequences.”

“While many natural products can be quite effective, either as repellents or when applied directly onto mosquitoes, they tend to have a short residual lifespan, meaning they will stop working shortly after being applied,” DeVries said. “This is not to say they do not work, but rather expectations should be set properly following their use.”

For instance, essential oil sprays or candles could be a good option for a couple of hours, but you’ll want something more powerful for longer-term application.

“While citronella and lavender sprays may have some minor repellent properties, their effectiveness is limited and often short-lived, meaning they require continual reapplication to the skin,” Haines said. “Research has shown that citronella products provide significantly shorter protection times compared to DEET, the gold standard.”

“While it would be nice to take a vitamin to get rid of mosquitoes, there’s no scientific evidence to support that,” Fredericks said.

He added that the most effective repellents are topical products with EPA-registered ingredients like DEET, picaridin or lemon eucalyptus oil.

“There is no scientific evidence to support the idea that consuming spicy foods or garlic repels mosquitoes,” Haines said. “However, using garlic oil, appears to be effective for roughly half and hour, unlike other more effective essential oils like cinnamon or clove oil. However, essential oils can be damaging to your skin, and your pets! Diet alone is insufficient to reliably protect you from mosquito bites.”

“Another important point is mosquitoes don’t die after biting you,” Fredericks said. “A single female mosquito can bite multiple people and animals and potentially spread disease between them.”

That’s why effective mosquito control is such an important aspect of public health.

“Female mosquitoes must drink blood to produce eggs and can feed multiple times during their short lives,” Haines echoed. “DNA studies have shown that ~20% of female malaria-transmitting mosquitoes take multiple human blood meals within a single egg-laying cycle, and mosquitoes can complete several reproductive cycles during their lifetime.”

“The absence of pain during a mosquito bite does not indicate the absence of disease transmission,” Haines said. “Transmission of viruses and parasites can occur during the initial probing phase when mosquitoes inject saliva, which is a type of partial bite that often goes undetected.”

Thus, blood-feeding is not even required for transmission of an infectious microbe from a mosquito to a human.

“Many mosquito-borne diseases can be transmitted without noticeable symptoms and show up long after exposure to the bite,” Haines said.

“While backyard mosquito treatments can have a significant effect on our ability to live and use our outdoor spaces, they are not an elimination service, but rather a reduction service,” DeVries said. “After treatment, it is completely reasonable to still see some mosquitoes, although the numbers should be lower than before treatment.”

He emphasized that mosquitoes do not respect property lines and can travel, so it’s difficult to completely get rid of them. If you’re being bitten by mosquitoes after yard treatment, it’s likely from new arrivals.

“There are many sources of mosquitoes in an area, and just because an area was treated, does not mean that mosquitoes in a wide area will be eliminated,” Ashbrook said. “In optimal conditions, a mosquito larva can develop to adulthood in about a week. Additionally, some mosquitoes can travel long distances.”

That’s part of why insecticides alone cannot eliminate mosquitoes.

“We need to use integrated pest management, which combines a variety of approaches, including proper identification of mosquitoes, monitoring mosquito populations, using different management techniques to achieve optimal mosquito management outcomes and reducing environmental impacts,” Ashbrook added.

“While we should support our bats and birds by providing habitat, and they do consume lots of insects, mosquitoes are not the primary target and will not be significantly reduced by them,” Ashbrook said. “Bats are often consuming moth and beetle pests of agricultural concern. The little brown bat is the bat species primarily responsible for consuming mosquitoes, and their populations are in decline due to the pathogenic fungus, Pseudogymnoascus destructans, which causes white nose fungus.”

He noted that bats and birds are not effective replacements for mosquito control districts or pest management services.

Don’t assume chilly weather puts an end to mosquito troubles.

“Some mosquito species can survive cold winters by entering a state of hibernation or by laying eggs that can withstand freezing temperatures,” Haines said. ”Research has shown that many mosquito species undergo diapause, a form of developmental arrest that allows them to survive harsh winter conditions, with optimal survival occurring at temperatures between 36-43 degrees Fahrenheit.”