Vinyl phosphoric esters of the following formula are effective in the control of insects and acarids: ##STR1## wherein R.sub.1 is lower alkoxy;R.sub.2 is selected from lower alkoxy and lower thioalkyl;R.sub.3 is selected from lower alkyl, phenyl, and halophenyl;R.sub.4 is selected from hydrogen, lower alkyl, halogen, and lower thioalkyl;V is selected from hydrogen, halogen, lower alkyl, lower alkoxy, lower haloalkyl, amino, mono and dialkyl substituted amino, lower alkoxy carbonyl, lower thioalkyl, lower alkyl sulfonyl, nitro, and phenyl;W is oxygen or sulfur;Y is halogen;m is 0-2; andn is 0-2.