AceCap Insecticide Systemic Tree Implants, 1/4-inch Implant Diameter (10 Pack) Acecap Systemic Insecticide Implants, contains environmentally acceptable acephate Each implant is 1/4-inch diameter, ideal for smaller caliper and indoor plants (for trees 1.5 to 3 inches in diameter) Apply in 1-inch spacing around the tree, use a 1/4-inch diameter drill bit to drill 1-inch deep from the cambium surface Testing proves that Acecap implants prevent and control Emerald Ash Borer Do not use on fruit, nut, or syrup trees that will be consumed or sold - Use on ornamental trees