Ethylene derivatives of formula (I): ##STR00001## where Q is an
unsubstituted or substituted phenyl or heterocyclic group, especially a
4-thiazolyl, 1- or 3-pyrazolyl, 1,3-oxazol-4-yl, phenyl or pyridyl group;
E is a substituent such as a cyano group; A is a substituent such as a
4-pyrazolyl or thiazolyl group; and B is a substituent such as an
alkylcarbonyl group. Agricultural chemicals and agents for preventing the
attachment of aquatic organisms containing one or more such ethylene
derivatives.