Permethrin insecticide
Permethrin (“per-meth-rin”), on the other hand, is a synthetic, man-made insecticide, whose chemical structure is based on natural pyrethrum. The so-called pyrethroid insecticides were developed to match or exceed the effectiveness of natural pyrethrum but be more stable in sunlight. Pyrethroid insecticides are used in agriculture because of their stability in sunlight.
This is the product he used.