Powdered poisons, packed into cartridges, are fired from a shotgun in one method of controlling insects in trees. Twelve-gauge cartridges arg available containing arsenate of lead for control of leaf-eating insects, nicotine dust for sucking insects, or sulphur dusts for preventing infection by leaf diseases. The paper “projectile” bursts on contact with the air after it leaves the muzzle, the insecticide scattering widely and settling on the leaves. By calculating wind drift a single tree can be covered with one cartridge, and in an orchard a cloud of dust can be sent drifting along a row of trees by aiming the gun carefully.