[gmb04]

I have a 41.7% pesticide that I want to make a 1000 ppm stock solution can we use the MV=MV (understanding that it is not Molarity we are working with but %) to calculate this?

(41.7%) (V) = (0.1%) (1000 mL)

We need it to be 1000 ppm of the active ingredient which is 41.7% in the pesticide. It is a liquid.

[AWK]

ppm is also a mass/mass concnetration - percent times 10000 (10⁴).
Hence you have a problem of dilution (hint - for diluted solution density of solution is practically equal to density of water)