What You Need to Know
Mosquito eggs, larvae, and pupae need water to continue development. Many mosquito breeding sites such as old pails, scrap tires, even some ditches with standing water can be controlled by emptying or removing the standing water source. When this is not possible, placing a larvicide into the water, or into an area where the water collects and stands after a rain, can control mosquitoes before they emerge. Liquid larvicide labels will tell you "how much" to apply (usually per area). These may be just poured onto the site, although misting or spreading the larvicide over the water surface with a mister or sprayer may enhance the application.
Dry, such as granular, larvicide labels will tell you "how many pounds" to apply per area. These materials can be hand tossed or spread with a small broadcast seeder type unit or for large areas, a motorized backpack will help. Larger briquette type products will tell how many briquettes to place per so many square foot of area.
Larvicide can last from a few hours to many days, depending on the product. Reading and following the label instructions as to when to apply the product and to see how long it lasts is very important.