While citronella candles, similar to coils, confuse mosquitoes—they are among one of the least effective repellents available, according to a study by the Journal of Insect Science.
Researchers from New Mexico State University came to the conclusion that spray-on repellents that contain DEET or PMD are actually the most effective options available.
In the comparison study, 11 different types of repellents, including spray-ons, citronella candles, and wearable devices were tested. It was noted that the candles had little to no effect on the mosquitoes whereas the chemical sprays performed well.
In terms of devices, the OFF! Clip-On was the only wearable that was effective. Other devices, including bracelets containing herbal extracts and sonic devices that claim to ward off mosquitoes by using high-frequency sounds, were determined to be highly ineffective.
While the most effective repellents in the study were Cutter Lemon Eucalyptus and Ben’s Tick & Insect Repellent sprays, the study also determined that bug sprays “based on essential oils often have shorter repellency effects,” in comparison to those which include chemicals like DEET or PMD.
“These findings are extremely important for consumers because they need to be aware that there are mosquito repellent products available that are ineffective,” said Stacy Rodriguez, one of the researchers involved in the study. “While the labels of many products make strong claims, some products simply don’t work.”
Rodriguez and her colleagues stress the importance of seeking out the most effective repellents to avoid mosquito bites.
“At a time where vector-borne disease like Zika is a real threat, the most egregious danger to the consumer is the false comfort that some repellents give them protection against Aedes aegypti when they actually offer none,” explains Rodriguez.