AbstractQuwenling is a mosquito repellent product made in China from lemon eucalyptus. It was tested in the laboratory against.Anopheles gambiaein comparison with two commercial products containing 20–22% deet. The numbers of mosquitoes coming to bite in 30 s with successive increments of dosage of each product applied to human skin or to a cotton sleeve were compared with the numbers of bites with untreated controls. The ED50, ED90and ED100values indicated that Quwenling was somewhat less potent than the deet products. The performance of the three products against British wild mosquitoes did not differ significantl