Method for detecting sensitivity to acetylcholine esterase in insects

A method for detecting acetylcholine esterase sensitivity to insecticides in insects, comprising:

• homogenizing a single insect in a neutral to acid pH phosphate buffer and forming an insect homogenisate,
• providing a solution of acetylcholine iodide in a neutral to acid pH phosphate-buffered water-miscible organic solvent,
• providing a solution of 5,5-dithio-bis-(2-nitrobenzoic acid) in the phosphate buffer,
• providing a solution of propoxur in the phosphate buffer,
• introducing the insect homogenisate into at least one first well and at least one second well of an assay plate, then introducing the acetylcholine iodide and 5,5-dithio-bis-(2-nitrobenzoic acid) solutions into the at least one first well and 5,5-dithio-bis-(2-nitrobenzoic acid), acetylcholine iodide and propoxur solutions into the at least one second well,
• detecting a difference in yellow coloration between samples in the first and second cells, and
• correlating the yellow coloration difference observed in the first and second cells with acetylcholine esterase sensitivity to insecticide in the single insect.