A compound of formula: ##STR1## wherein one of R.sup.1 and R.sup.2 represents a group of formula: W(CF.sub.2).sub.m - where W represents an atom of hydrogen, fluorine or chlorine and m has the value one or two, and the other of R.sup.1 and R.sup.2 represents an atom of fluorine, chlorine or bromine or a group of formula: ##STR2## where each of X, Y and Z independently represents an atom of hydrogen, fluorine or chlorine, and R.sup.3 represents an atom of hydrogen, or the cyano or ethynyl group. The compounds are useful against insect or acarine pests.
一种化合物的公式:##STR1## 其中R.sup.1和R.sup.2中的一个代表公式:W(CF.sub.2).sub.m -,其中W代表氢、
氟或
氯的原子,m的值为一或二,而R.sup.1和R.sup.2中的另一个代表
氟、
氯或
溴的原子或公式:##STR2## 其中X、Y和Z中的每一个独立代表氢、
氟或
氯的原子,而R.sup.3代表氢原子,或
氰基或
乙炔基。这些化合物对昆虫或螨虫有用。