The disclosure relates to a composition comprising an insecticide compound (as shown herein) and an organic acid or a salt thereof, wherein the ratio between the compound according to formula (I) and the organic acid is about 300:1 to about 10:1. The organic acid may be selected from the group consisting of citric acid, phthalic acid, malic acid, tartaric acid, maleic acid, malonic acid, lactic acid and succinic acid. The compound contains a sulfoximine and a 6-haloalkylpyridin-3-yl. The sulfoximine is optionally also bound to a carbon to form a 5 membered thiolane (tetrahydrothiophene). The composition comprising this compound and the organic acid or salt thereof exhibits increased stability and may optionally include another insecticide. Methods of controlling insects using the composition are also disclosed.
