Female mosquitoes were found to regulate their own population density at breeding sites using community cues

When female mosquitoes are feeding, they don’t seem to mind the crowds, because lots of carbon dioxide usually means there is food. However, they were thought to be more solitary when laying eggs. New research has found the opposite for the deadly Aedes aegypti.

Although they avoid large crowds, female mosquitoes appear to follow other females and congregate in small groups when laying eggs. This new discovery, published in Communication biologyleads scientists to rethink the possibilities of fighting mosquitoes.

“What we found is that mosquitoes work together to control their density,” said FIU biologist Matthew DeGennaro, co-author of the study and director of FIU’s Biomolecular Sciences Institute. . “If there are too many, there could be a resource problem. But grouping together is probably beneficial for the survival of their young.”

Researchers say female mosquitoes use a balance of odors to decide where to lay their eggs. Some smells encourage them to lay eggs, while others make them want to avoid laying eggs. Through a series of laboratory tests, DeGennaro and his team observed female Aedes aegypti mosquitoes avoiding areas with high amounts of carbon dioxide, likely because high CO₂ means a large crowd. When egg-laying females detected smaller groups of females with eggs or young mosquitoes, again relying on their sense of smell, they would settle down.

“It’s like female mosquitoes are going to an exclusive pool party,” said FIU biologist Andre Luis Costa-da-Silva, lead author of the study. “They don’t want too many or too few guests.”

Aedes aegypti mosquitoes love urban habitats and can lay eggs in tiny containers that litter our neighborhoods. This makes it difficult to find breeding sites. This new understanding of how mosquitoes decide where to lay their eggs could also lead to entirely new ways of controlling mosquito populations to reduce the spread of the diseases they carry.

“We discovered a new behavior. Now we’re exploring how we can use it to control the choices mosquitoes make,” DeGennaro said. “We don’t want mosquitoes having their baby shower anywhere.”