Killing mosquitoes becomes more difficult after they reach adulthood.
Mosquitoes are the bane of every evening outdoors. Various methods have been used through the years to control their numbers, but nothing has succeeded in completely eradicating the pest. Mosquitoes lay their eggs and spend their first life cycle in water. Their ability to lay eggs and reproduce in less than a teaspoon of water has allowed them to proliferate even in dry regions. The key to controlling mosquito numbers is to kill their larvae. A science fair project on various methods of killing mosquito larvae is a compelling and practical project that will convey an understanding of the scientific method while creating a memorable demonstration.
Soap
Many people believe that adding a small amount of dish soap to standing water will cause adult mosquitoes to become stuck in the water once they land to lay their eggs. Some homeowners add a few teaspoons of dish soap to spare tires and rain barrels to prevent them from serving as breeding grounds for mosquitoes. Perform a test: Put two identical containers of water outside in an area you know to be populated with mosquitoes. Put plain water in one container and a mixture of water and dish soap in the other. After a few days, use tweezers to count the number of dead mosquito adults in each container. Repeat the experiment and create a chart indicating the differences between the two containers.
Vegetable Oil
Vegetable oil is thought to suffocate mosquito larvae rather than trap the adults. The idea is that the oil will float on the surface of the water, creating a thin film of thicker liquid that traps the larvae beneath the surface. The larvae are deprived of oxygen and drown. Place two containers outside in an area you know to be populated by mosquitoes. Leave them both for a few days, checking back periodically to see if there is larvae present in the water. The larvae will appear as small and squiggling, with a worm-like body. Place a few tablespoons of vegetable oil in one container and leave the other one alone. Check back after a few hours and then a day to see how the larvae have fared.
Commercial Mosquito Dunks
Mosquito dunks are small chunks of chemical or organic larvicides that are sold to be placed in containers or gutters that are expected to have standing water. Often, they contain the eggs of larvae-eating nematodes or other small, harmless insects. Create a controlled experiment by placing two containers of water outside, one with mosquito dunks used as instructed on the package and the other containing plain water. Observe the differences between the two, such as the number of larvae alive, the number dead and the number of adults found floating on the surface. Chart how effective the mosquito dunks are over a period of days.
Salinity
An interesting science fair project would be to test the amount of salt that mosquito larvae can tolerate in water. Collect larvae from a standing container you have placed outside in an area populated with mosquitoes. Place them in a small container with a known amount of water, such as 1 gallon. Photograph the number of larvae you begin with using a digital camera and a white background behind the container to contrast against the gray-black larvae. Add salt incrementally by removing some of the water and dissolving table salt in it in a separate container and then adding it back to the container. Photograph the larvae at each stage. Identify at what point all die and chart the salinity tolerance of mosquito larvae.
Tags: mosquito larvae, dish soap, outside area, area know, area know populated, containers water