Insecticides Abrading or Disrupting Insect Cuticle

Boric acid is an absorber of insect cuticle wax and a stomach poison. Its mode of action on insects has not been clearly established. Two major hypotheses have been proposed  

Silica aerogels kill insects by absorbing waxes from the insect cuticle, resulting in slow desiccation and death by dehydration. 

Pesticidal soaps disrupt the cuticle and break down cell membranes, resulting in rapid death of insects and mites. Because soaps reduce surface tension of water, water readily penetrates insect spiracles, thereby reducing oxygen availability. Therefore, soaps also kill insects by drowning. 

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