The safest way to kill mosquito larvae is to remove their habitat.
Mosquitoes are pests to birds as well as mammals and are vectors of diseases, including malaria and yellow fever. The larval, or immature, stage of the mosquito is aquatic. The larvae live in pools of standing water as large as marshes or as small as puddles. Some chemical larvicides, along with biological or cultural controls such as habitat removal and predator introductions, kill mosquito larvae and have minimal impact on plants and other organisms. Does this Spark an idea?
Mosquito Larvae
Female mosquitoes lay their eggs in standing water. The eggs float on the surface individually or in rafts of over 100 eggs. The larvae hatch in about 48 hours. Larvae remain in the water just below the surface and feed on tiny plant and animal particles. These immature mosquitoes require air to breathe. Some species have breathing tubes that stick out above the water's surface. Other species obtain their air from bubbles around underwater plants.
Habitat Removal
The most effective method for killing mosquito larvae, with minimal impact on plants, is to eliminate their habitat. Small pools of water around the house accumulate after rain. Toys, gardening equipment, birdbaths and wading pools are prime locations for breeding mosquitoes. Removal of these items, and the water inside them, will have little to no effect on surrounding plants and will kill any larvae and eggs already established.
Chemical Larvicides
Habitat removal is not possible for areas such as wetlands, marshes and ponds. These require larger-scale action, but contain other organisms, such as plants, that are sensitive to chemical treatments. Pyriproxyfen and methoprene are chemicals that inhibit insect growth hormones. When added to water, mosquito larvae cannot develop into adults, and will eventually die. Both chemicals pose minimal risk to non-target species, including vascular plants, algae and other organisms.
Other Methods
Biological control is another treatment for mosquito larvae. Bacillus thuringiensis israelensis (Bti) is a naturally occurring bacterium. Bti contains a toxin that, when ingested by the larva, damages the digestive cells and causes its death. When applied correctly, Bti has no harmful effect on the environment, including plants and other non-target species. Vegetable oil or liquid dish detergent applied to the surface of standing water can also kill mosquito larvae without harming plants. These treatments prevent the larvae from contacting the water surface, eventually drowning them. Adding fish to water features, such as backyard ponds, is another non-toxic way to reduce mosquito larvae populations without damaging surrounding plants.
Tags: mosquito larvae, kill mosquito, kill mosquito larvae, other organisms, standing water