Super Mosquitoes.. Advanced Species That Defy Insecticides

Weather of Arabia - It seems that the world will need to develop insecticides, after a team of researchers from Ghana and several Asian countries concluded that mosquitoes that transmit dengue fever and other diseases have developed "frightening resistance" to insecticides in parts of Asia.

In the study, published in the journal Science Advances , researchers collected mosquitoes in several countries and found that most species from Cambodia and Vietnam had a mutation associated with resistance to a commonly used insecticide. The mutation (named L982W) has been observed previously in mosquitoes, but not at such a high rate.

The team of researchers said a series of mutations made some mosquitoes immune to the effects of pyrethroid-based chemicals commonly used in insecticides, and in some cases increased insect resistance a thousand times.

The study showed that insecticides that normally kill nearly 100% of mosquitoes now only kill about 7% of the insects. Even a 10-fold dose only kills 30% of the highly resistant mutant mosquitoes."

The L982W mutation has not yet been identified outside Southeast Asia, but it is likely that the insect was spread through international trade.

Insecticide-resistant mosquitoes are a growing public health concern, with dengue cases increasing 30-fold in the past 50 years, the authors wrote in the study.

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The CDC estimates that about 400 million people contract dengue fever each year, and about 21,000 die. With no vaccine or affordable medicine available, insecticides are the only way to manage dengue epidemics, according to the authors.

The scientists recommended that more chemicals be developed to control mosquitoes so that people could replace them with insecticides and reduce the chance of a mutation.

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