A common type of bacteria that naturally infects mosquitoes may actually protect them from certain mosquito pesticides, one study found.
Wolbachia – a bacterium that occurs naturally and spreads between insects – has been used more widely in recent years as a means of controlling mosquito populations.
Scientists from the University of Reading, INBIOTEC-CONICET, and the National University of San Juan in Argentina studied the effects of Wolbachia on a common species of mosquito and found that those who carry the bacteria are less susceptible to common pesticides.
Dr. Alejandra Perotti, Associate Professor of Invertebrate Biology at the University of Reading and co-author of the study, said, "This shows the importance of studying the interaction of bacteria in mosquitoes and pesticides, especially at a time when new plans are being formulated what methods to use, where to apply and what ways to aim. "
Mosquitoes transmit various diseases such as dengue fever, malaria, zika and yellow fever to humans through their bites, killing more than a million people worldwide each year.
In the new study published in Scientific reportsThe researchers examined Culex quinquefasciatus – also known as the southern house mosquito – which had been raised under environmentally controlled conditions in a laboratory in Argentina (INBIOTECT insectarium) for several years.
This is one of the most common species in countries with hotter climates. The mosquito species transmits various diseases, a variety of viruses such as the West Nile Virus (WNV), the San Luis Encephalitis Virus (SLEV) and the Venezuelan Equine Encephalitis Virus, as well as a variety of parasites (roundworms) in Central and Eastern Europe South America, Africa and Asia.
The team found that the mosquito larvae, naturally infected with an Argentine strain of Wolbachia, were less susceptible to three bacterial pesticides (Bacillus thuringiensis israelensis, Bacillus wiedmannii biovar thuringiensis, and Lysinibacillus sphaericus), two of which are commercially available and used in many countries to control mosquito populations.