Compounds of the formula: ##STR1## wherein X is sulfur or oxygen; R.sub.1 is lower alkyl; R.sub.2 is lower alkyl, lower straight chain alkoxy, lower alkylthio, phenyl or the group --NR.sub.3 R.sub.4 where R.sub.3 and R.sub.4 are independently hydrogen or lower alkyl, provided that when X is oxygen, R.sub.2 is not phenyl, are pesticidal, exhibiting activity against pests such as plant fungal diseases and, in many cases, insects.