Abstract: | The insecticidal properties of two fibre-reactive organophosphorus esters, O-ethyl-S-n-propyl-O-(4- (2-(3- vinylsulphonylpropionyl) oxyethyl)-thiophenyl) phosphorothionothiolate and O-ethyl-S-n-propyl-O-(4-(2-(3-vinylsulphonylpropionyl) oxyethyl)-thiophenyl)phosphorothiolate, have been determined against a number of keratin-digesting insects. Both compounds were effective against the more common textile pests at relatively low application levels; however, considerably higher levels were required to control the feeding damage due to Hoffmannophila pseudospretella. Generally, the insecticidal activity of the phosphorothiolate was greater than the activity of the phosphorothionothiolate; however, this was offset by the greater susceptibility of the phosphorothiolate to hydrolysis during application from a dyebath. The application of these compounds during dyeing and other textile processes was examined. |