I've sprayed Diazinon in the past. What are you looking to do??? If you need to apply a curative you can't beat Dylox.
Carbamate 2 gallons per acre plus wetting agent will knock them down. You need to apply it with lots of water 5 gallon per k or more. Carbamate will kill everything including earth worms. it has the broadest label of all pesticides. It is also one of the more environmentally unfriendly chemicals. Stay with Merit if it doesn't work Bayer will give you Dylox for free. But you have got to sign up on there program on the web.
Your merit should have been applied, not now. If doing now use Dylox. Dylox is the only chemical known to have an easier penetration of a thatch layer
