Origin of kairomones in the leek moth (Acrolepiopsis assectella,Lep.) frass

Feeding leek moths on an artificial diet has shown that dimethyl and dipropyl disulfides and methyl-propyl disulfide found in frass arise from sulfur compounds specific toAllium. The addition of either propyl or methyl disulfide or their precursors to the diet leads to appearance of the three disulfides in the frass. This implies the transformation of theS-propyl moiety toS-methyl and vice versa by an as yet unknown mechanism.