MOSHI, TANZANIA - New insecticides to control mosquitoes - being tested in Tanzania - promise to overcome the biggest threat to malaria control in Africa: resistance to pyrethroid insecticides. Dr Richard Oxborough from the London School of Hygiene & Tropical Medicine explained to Sarah Maxwell how his group's research evaluating new insecticides for mosquito nets and spraying inside houses, at the Kilimanjaro Christian Medical Centre in Moshi, Tanzania, is bringing hope for sustainable control of pyrethroid-resistant malaria-transmitting mosquitoes. The development of new insecticides for malaria vector control will help continue the decline of malaria in the region when combined with other malaria-control measures including new drugs, a vaccine and better diagnostic tests.