Some Martin house manufactures would have us believe that if the Martin was breed in significant quantities this bird would single handedly place the mosquito on the endangered species list. A Purple Martin will consume hundreds if not thousands of mosquitoes per day. Martins are very large swallows and can weigh up to 60 grams. The energy expended in capturing a single large insect like a dragonfly is minimal compared with the energy it would require to capture the hundreds of mosquitoes that would equal the same amount of food as the single dragonfly. Martins and mosquitoes seldom come into contact with each other.
Martins feed quite high in the air and mosquitoes typically stay close to the ground.
Martins, being strong fliers, typically hunt far away from their colony site. This means that all of the mosquitoes on your property where your martin housing is located are virtually untouched by your martins when they are away hunting. Martins are not, however, prodigious consumers of mosquitoes as is so often claimed by companies that manufacture martin housing. An intensive 3-year diet study conducted at PMCA headquarters in Edinboro, PA, failed to find a single mosquito among the 350 diet samples collected from parent martins bringing beakfuls of insects to their young. The samples were collected from martins during all hours of the day, all season long, and in numerous habitats, including mosquito-infested ones.