As if last season’s pest concerns weren’t enough to fill us with impending trepidation, researchers from the London School of Hygiene and Tropical Medicine have given us something more to consider.
In studies published Wednesday in the journal PLOS ONE, Dr. James Logan and others at the institute report that mosquitoes might not be as adverse to the widely used repellant, DEET, as we might believe. Studying Aedes aegypti mosquitoes-daytime biters that transmit deadly diseases-found changes in the way the insects responded to the repellant.
They discovered that three hours following a slight exposure to DEET, the mosquitoes were not as sensitive to the chemical and couldn’t identify it as readily. Linking the ineffectiveness of the odor to the fall in the sensitivity of the smell receptors on the insects’ antennae after an earlier exposure, Dr. Logan said, “Mosquitoes are very good at evolving very, very quickly.”
He further stated, “Our study shows that the effects of this exposure last up to three hours. We will be doing further research to see how long the effect lasts. This doesn’t mean that we should stop using repellants. On the contrary, DEET is a very good repellant and is still recommended for use in high risk areas. However, we are keeping a close eye on how mosquitoes can overcome the repellant and ways in which we can combat this.”
Still DEET alternatives have been sought for use in the past; the most common example being citronella oil and candles. In today’s market, plant-based repellants-like Off Botanicals or Garden’s Alive Sting Free-are being used more and more by consumers concerned with the environmental and health issues associated with the use of DEET. These eco-friendly repellants are usually made either with lemon eucalyptus oil, soybean oil or geraniol (geranium oil).
Source: Kelly Fitzgerald (2013, February 21). “Mosquito Repellant DEET Is Becoming Less Effective.” Medical News Today http://www.medicalnewstoday.com/articles/256731.php.
Important Phone Numbers
National Pesticide Information Center (NPIC) – 1-800-858-7378
Natural Insect Repellent Websites
Burt’s Bees Herbal Insect Repellent
The Daily Green – Off-the-shelf and Homemade Natural Insect Repellents
About.com Chemistry – Natural Insect Repellent Recipe
Earth Easy – Natural Pest Control
Web MD – Natural Bug Repellents
For more info: DEET Fact Sheet