Diketopiperazine compounds designated N-methylepiamauromine, epiamauromine and cycloechinulin have been isolated from the sclerotia of the fungi Aspergillus ochraceus. The compounds are effective for controlling Coleopteran and Lepidopteran insects. The compounds have the structures: ##STR1## wherein: R is a hydrogen atom or a methyl group, such that the compound formed when R is a hydrogen atom is designated epiamauromine and the compound formed when R is a methyl group is designated N-methylepiamauromine; and cycloechinulin has the structure: ##STR2##
