In 1997, University of Florida spent 10 years developing a mosquito “diet pill.” Today, larvae fed the hormone-treated algae starve within 72 hours, offering an eco-friendly way to fight disease-carrying pests

Mosquito control often focuses on killing the insects themselves. University of Florida scientist Dov Borovsky spent about a decade developing a different approach: disrupting mosquitoes’ ability to digest food.

The result is what Borovsky described as a mosquito “diet pill.” The treatment uses a hormone involved in mosquito digestion and delivers it through algae. When mosquito larvae eat the treated algae, the hormone interferes with digestion, leaving them unable to properly process their food.

Borovsky said mosquitoes that consume the hormone-treated algae can die within 72 hours. An insect biochemical and molecular biologist at the Florida Medical Entomology Laboratory, part of the University of Florida's Institute of Food and Agricultural Sciences, Borovsky said the approach could help fight malaria and other mosquito-borne diseases.


He said, "We hope this can stop the advance of malaria and other mosquito-borne diseases," adding, "It works on all mosquitoes, all over the world," as quoted by ScienceDaily.

The discovery began with mosquito ovaries

The research started with an unexpected finding. Borovsky extracted and homogenized mosquito ovaries and introduced the material back into mosquitoes. The insects stopped producing eggs.

Researchers initially thought they had found a mosquito birth-control pill. Borovsky pointed out that, "But then we found that the reason they were not producing eggs was because they were not digesting, so then we knew we had a diet pill, not a birth control pill," as quoted by ScienceDaily.

The finding redirected the research toward digestion. Researchers realized the mosquitoes were not producing eggs because they were unable to digest their food. The hormone can now be synthesized, eliminating the need to use 100,000 mosquito ovaries for each batch.

Treated algae carries the hormone

The hormone is inserted into chlorella, an algae found and produced around the world. The treated chlorella can be freeze-dried and stored for long periods before being brought back to life. It can then be placed in water where mosquitoes breed.

Mosquito larvae eat the algae and ingest the hormone. The treatment interferes with their digestion, leaving them unable to properly process their food.

Borovsky said mosquitoes that feed on the hormone-laced algae starve to death within 72 hours. He also said the synthesized hormone and chlorella are inexpensive.

The treatment is designed to fade from the environment

The hormone is not incorporated into the chlorella genome. Instead, it sits outside the genome and becomes undetectable after the algae undergoes its third division.

Borovsky said the chlorella stops producing the hormone within three weeks. The temporary effect is intentional. If the hormone remained present indefinitely, mosquitoes could potentially develop resistance to it.

He said, "This is a natural bullet that we can use in the environment because the hormone doesn't stay in the environment," adding, "The chlorella stops producing the hormone within three weeks," as quoted by ScienceDaily.

A potential tool against mosquito-borne diseases

Borovsky sees the treatment as a possible way to control mosquitoes that spread diseases such as malaria.

The approach differs from DDT and some other pesticides mentioned in the research. Rather than broadly altering the environment, the treatment targets the food consumed by mosquito larvae.

Years of skepticism preceded wider acceptance

The idea was not immediately accepted. Borovsky said attitudes toward the research changed after years of work.

Borovsky recalled a meeting in Vancouver where a colleague harshly criticized the research because he did not believe it.

The project eventually progressed from extracting the hormone from mosquito ovaries to producing it synthetically.

The approach could also be used against agricultural pests

Borovsky said the next step is to develop similar diet pills for agricultural pests. He said, "A pest that doesn't molt but still feeds is still a problem," adding that, "By putting the diet pill into the crop or into the plant, the insect feeds and then dies before it takes its next meal," as quoted by ScienceDaily.

His proposed approach would put the diet pill into a crop or plant. The pest would consume it while feeding and die before taking its next meal.