A pesticide for cockroaches and larvae which is based on purified naturally occurring plant substances. Phenethyl propionate; methyl salicylate, pulegone; carvacrol; thymol; thyme oil; citronellal; a three-blend of eugenol, α-terpineol and cinnamic alcohol; a four-blend of benzyl alcohol, phenethyl alcohol, phenetyl propionate and α-terpineol; and a five-blend of thymol, tanethole, α-terpineol, eugenol and citronellal have been used as the pesticide. The pesticide affects the octopamine receptor site in the cockroach. The five-blend has been used as a pesticide for Asian armyworms and green peach aphid nymphs. Methods of use of the pesticides are disclosed.