Community-Wide Efforts to Reduce Backyard Mosquitoes

Stephanie Richards, PhD, Medical Entomologist

Where do mosquitoes lay their eggs?

Different mosquito species lay their eggs in different locations where standing water is present (e.g., woodland pools, ditches, storm drains, artificial containers). The mosquitoes (Aedes aegypti and Aedes albopictus) responsible for the spread of chikungunya, dengue and Zika viruses lay their eggs primarily in artificial containers near human residences and can be considered “backyard mosquitoes”. The public can help prevent the spread of these mosquito-borne viruses and reduce the annoyance of these mosquito populations by removing the sources of standing water where these mosquitoes lay their eggs.

Can knowledge of mosquito biology help us control mosquitoes?

Aedes species of mosquitoes that lay their eggs in containers deposit the eggs above the waterline or directly in the standing water. After a rain event, the eggs are flooded with water and hatch into larvae. The larvae go through four stages (called instars), getting progressively larger before transforming into pupae. It takes about seven days (depending on environmental conditions) from egg hatch to adult emergence.

Knowledge of mosquito biology is important, because if homeowners dump or treat water-holding containers around their homes at least once a week, they can significantly reduce the number of Aedes albopictus and Aedes aegypti that become blood-feeding adults.

What are some examples of water-holding containers?

Here are some examples of water-holding containers commonly found in back yards:

  • plant pot receptacles

  • tarps

  • birdbaths

  • buckets

  • toys

  • tires

  • boats

  • corrugated pipes

  • trash cans and/or lids

  • rain barrels

Most containers can be dumped regularly to control mosquitoes. Rain barrels can be covered with 1.2 mm mesh small enough to prevent mosquitoes from passing through to lay their eggs.

How can communities help control mosquitoes?

Homeowner associations may consider discussing mosquitoes and the reduction of water-holding containers at neighborhood meetings. It is possible that some homeowners are not aware that they are producing mosquitoes, hence, information about where mosquitoes lay their eggs would be useful. If there is neighborhood interest, homeowner associations may consider organizing weekly and/or monthly campaigns to reduce water-holding containers before mosquito season begins (March through April, depending on the geographic location) and during mosquito season. The first time a neighborhood assesses sources of mosquito egg-laying sites would likely take the most effort; however, once most mosquito sources are removed, follow-up assessments should get easier and easier. For example, if someone in your neighborhood has an abundance of plant pots with water-holding receptacles, removing these receptacles early in the season would likely solve the problem at that mosquito “hot spot” for the entire season, provided no new receptacles are introduced. Another neighbor may have some junk piles (holding water) in the back yard that could be cleaned up (with permission from the homeowner) with community assistance.

One idea would be to pass out flyers in the neighborhood with information about how to control mosquitoes that lay their eggs in containers. Here is an example of a flyer provided by the Centers for the Disease Control and Prevention. The informational flyer distributed to homeowners could also be customized to include contact information for local mosquito control programs (public and/or private) that could provide additional assistance, if needed. A homeowner association may also consider asking a local university partner or other community-based group for help in assessing and eliminating backyard mosquitoes.

Homeowners would need to grant permission to “source reduction crews” that could go house-to-house controlling mosquitoes by identifying and dumping water-holding containers. This “source reduction” approach is a non-insecticide method of control.

Homeowners and communities have the ability to make a big impact on reducing backyard mosquito species, such as Aedes aegypti and Aedes albopictus. With knowledge of mosquito biology and perseverance of homeowners in continually reducing water-holding containers, people can help reduce backyard mosquito populations.