Abstract: A compound of formula: ##STR1## wherein W represents one or more substituents selected from halo, alkyl, alkoxy, alkoxyalkyl, haloalkyl and haloalkoxy or W represents a bidentate group linking adjacent carbon atoms selected from alkylene and alkylenedioxy; Y is a group of formula ##STR2## wherein X is a group of formula --(CF.sub.2).sub.n R.sup.3, where R.sup.3 is selected from hydrogen, chloro and fluoro, and n is one or two, R.sup.1 is selected from hydrogen, chloro, fluoro and hydroxy and R.sup.2 is selected from methyl, cyano, ethynyl and hydrogen; Q is selected from carbon bearing a hydrogen atom and nitrogen; and Z represents one or more substituents selected from fluoro, benzyl, phenoxy, chlorophenoxy, fluorophenoxy and bromophenoxy, or any isomer thereof. Processes for preparing these compounds and intermediates for use therein, insecticidal compositions containing these compounds and the use thereof are also disclosed.

Abstract: A method is described for the control of nematodes and soil-borne insects in agricultural crops which comprises applying to the situs of infestation a composition containing as active ingredient a compound of the formulaR--Z--(CH.sub.2).sub.n --Qwherein R is an alkyl radical of one or two carbon atoms carrying one-to-four fluorine substituents and one-to-three chlorine or bromine substituents represented as CF.sub.p X.sub.(3-p) -- or CF.sub.r X.sub.(3-r) --CF.sub.s X.sub.(2-s) --; Z is --(CH.sub.2 --CHX)-- or --(CH.dbd.CH)--; X is chlorine or bromine; Q is methyl, isopropyl, tert-butyl, or C.sub.3 -C.sub.6 cycloalkyl; n is 5 to 12 as required to yield in the compound a chain of 10 to 16 carbon atoms; p is 1 or 2; r is 2 or 3; s is 0 or 1 or 2. A process for preparation of active ingredient compounds is described, and utility of compositions against nematodes and soil-borne insects is exemplified.