There is disclosed a spray apparatus for holding contents comprising diatomaceous earth and a compressed propellant for propelling the diatomaceous earth. There is also disclosed use of diatomaceous earth to control a population of bedbugs, wherein the diatomaceous earth comprises remains of pennate diatoms. There is also disclosed a method of controlling a population of insects, the method comprising causing a compressed propellant to propel diatomaceous earth on a surface. Method of manufacturing a spray apparatus and methods of preparing diatomaceous earth for use in controlling a population of insects are also disclosed.
