Imidacloprid (1-(6-chloro-3-pyridylmethyl)-2-nitroimino-imidazolidine, 4), the 2-nitromethylene analogue (3) and the thiazolidine skeleton are noted for their high insecticidal potential and broad spectrum. 1 - 3) In this class of compound, the 6-chloro-3-pyridylmethyl moiety attached to the saturated heterocyclic skeleton is essential for exhibiting effective activity. In the previous paper, we have shown that the isocyclic diazinyl ring could also enhance the activity when it had an iminyl nitrogen at the γ-position to the methylene bridge and distal chlorine at para. 4 )We describe here the effect of the isoelectronic five-membered heteroaromatic moiety appended to the side-chain on the insecticidal activity.