Molluscicidal and Anti-AChE Activity of Tertiary Mixtures of Pesticides

We studied the toxicity and in vivo inhibition of acetylcholinesterase (AChE) by the organophosphate Nuvan (dichlorvos); Nuvan mixed with a mixed function oxidase inhibitor, piperonyl butoxide (PB); Nuvan with a pyrethroid Decis (deltamethrin); and a tertiary mixture of Nuvan, PB, and Decis in the snail Lymnaea acuminata. Nuvan was highly toxic to the snail and was a strong inhibitor of AChE activity. Both PB and Decis act synergistically with Nuvan when given together in a 1:5 and 1:46 ratio, respectively. When a tertiary mixture of Nuvan, Decis, and PB was given in a 1:46:5 ratio, the toxicity of the mixture was higher in comparision to the binary mixture of Nuvan + PB or Nuvan + Decis.