Abstract: Organic phosphoric acid ester derivatives represented by the formula (I): ##STR1## wherein R and R', which may be the same or different, each represents an alkyl group, and A represents a group of atoms necessary to complete together with the two carbon atoms to which they are attached, a 6-membered heterocyclic group containing an oxygen atom as a heteroatom; a process for preparing the same and insecticidal, miticidal or nematocidal compositions containing the same as an active ingredient are disclosed; the compositions exhibit a high ability to control insect pests, mites, nematodes and unhygienic insects harmful to agricultural and horticultural crops.

Abstract: A composition useful as herbicides, germicides, and acaricides without showing toxicity to men and beasts as well as to fish and shellfishes containing as the active ingredient the compound represented by the general formula ##STR1## wherein R represents a lower alkyl group; R' represents a group shown by the formula ##STR2## (WHEREIN Y represents a halogen atom, an alkyl group, an alkoxy group, a nitro group, a methylthio group, or a trifluoromethyl group and n is an integer of 0 to 3); X represents an oxygen atom or a sulfur atom; and m is an integer of 3 to 6.