Crystallized forms of common insecticide more effective

New York University chemists funded by the U.S. National Science Foundation have developed crystal forms of the widely used insecticide imidacloprid. The team published the findings in the Journal of the American Chemical Society. The new forms of the insecticide are more effective at insect control and are more sustainable.

Imidacloprid has a variety of applications, including protecting pets, crops and preventing the spread of insect-borne diseases. But extensive use of the compound has been indicated as a potential contributor to bee colony declines because of its toxicity. Smaller amounts of the rapid-acting crystal versions of imidacloprid could reduce harm to bees.

Researchers created the new crystal forms by melting and cooling commercial versions of the compound. The most active form of imidacloprid has potential for commercial use because of its stability.

"By using modified forms of imidacloprid, we may have a sustainable strategy for improving the insecticide's ability to control mosquito disease vectors while lessening the quantity needed," said Bart Kahr, a chemist at New York University who led the research. "That provides a pathway to minimize exposure and harm to other organisms, as well as delay the onset of the development of resistance by mosquitoes, an urgency where malaria is endemic."