I just discovered that Diazinon is still available to holders of private applicators permits, although I intend to try Advion (having a little difficulty finding Advion) before returning to Diazinon.
Also, I heard that some of the local rice farmers, who farm crawfish as a secondary crop, used fipronil in their rice fields and had no crawfish crop as a result. Since I have no first-hand knowledge of this, it should be regarded as unreliable.