The present invention relates to N-acylimino compound of formula (I): wherein X is О or S, in particular Ο Υ is a single bond, O, S or NR5 Het is a 5 or 6 membered carbon-bound or nitrogen-bound heterocyclic ring, W1, W2, W3, W4 represents a carbon chain group connected to N and C=N, and thus forming a saturated, unsaturated, or partially unsaturated 5 or 6 membered nitrogen containing heterocycle, wherein W1, W2, W3 and W4 each individually represent CRvVRw R1, may be hydrogen, halogen, etc. R3 may be hydrogen, CN, С1-С6-alkyl, etc. R4 may be of hydrogen, C1-C6-alkyl, С2-С6-alkenyl, С2-С6-alkinyl, С3-C8-cycloalkyl, Q-phenyl, Q-O-phenyl, Q-S-phenyl, where the phenyl ring is optionally substituted with one or more, e.g. 1, 2, 3, 4 or 5 identical or different substituents R10, and the moieties Q-Het#, Q-O-Het# and Q-S-Het# where Het# represents a heterocyclic radical and where Q and Q are С1-С6-alkandiyl, С2-С6-alkandiyl, or C2-C6-alkyndiyl, and where Q may also be a single bond R3 and R4 together may also may also a bivalent radical, selected from the group consisting of С2-C5-alkandiyl, C2-C5-alkendiyl, Q"-C1-C4-alkandiyl and Q"-C2-C4-alkendiyl, where Q" is О or S. The invention also relates to the use of the N-acylimino heterocyclic compounds, their stereoisomers, their tautomers and their salts, for combating invertebrate pests. Furthermore the invention relates also to methods of combating invertebrate pests, which comprises applying such compounds. (I)Даний винахід стосується N-ациліміносполуки формули (І): , де X являє собою О або S, зокрема О Υ означає одинарний звязок, О, S або NR5 Het означає 5- або 6-членне приєднане через атом вуглецю або через атом азоту гетероциклічне кільце, W1-W2-W3-W4 являє собою групу вуглецевого ланцюга, звязаного з N і C=N, таким чином утворюючи насичений, ненасичений або частково ненасичений 5- або 6-членний азотовмісний гетероцикл, де W1, W2, W3 і W4 кожний окремо являє собою CRvRw R1, R2 можуть являти собою водень, галоген тощо
