Beschreibung:
<jats:title>Abstract</jats:title><jats:p>A series of new 1,3, 4‐oxa(thia)diazol‐2(3H)‐ones were synthesized and tested as acaricides. High activities against eggs of Tetranychus urticae (Koch) were found for derivatives bearing an ortho‐halo‐substituted phenyl group in position 3, and a benzyl group para‐substituted by a branched C<jats:sub>3</jats:sub>‐C<jats:sub>6</jats:sub> alkoxy group in position 5 of the hetero‐ring. The best compounds attained the miticidal potency of clofentezine.</jats:p>