Combining Onslaught Fastcap Microencapsulated Formula and NyGuard IGR gives pest professionals a one-two punch for mosquito control. Onslaught Fastcap is fast acting, with controlled release giving quick kill and residual control of mosquitoes. NyGuard, an insect growth regulator, will interrupt the reproduction cycle of mosquitoes and other labeled pests. Its photo-stable property ensures extended residual control in sunlight. For best results, apply outdoors with backpack sprayers and blowers.