Effects of magnetic fields on mosquitoes

Phylogenetically diverse organisms, including some insects, are able to det ect and respond to magnetic fields comparable to the Earth's magnetic held. Because of their tremendous importance to public health, mosquitoes were t ested for the presence of remanent ferromagnetic material indicative of a b iological compass and also tested for behavioral responses to magnetic fiel ds. Using a superconducting quantum interferometry device, we found that si gnificant remanence was probably due to attraction of ferromagnetic dust on to the surface of live or dead mosquitoes. Most mosquitoes placed in a 1.0- gauss, uniform magnetic field moved until they were oriented parallel to th e field. Two of 3 species of mosquitoes tested took fewer blood meals in a rotating magnetic field than in the Earth's normal magnetic field.