Figure 6.  These are plugs of beebread that I pulled from a brood frame.  Note the layering of the different species of pollen.  If a colony suffers from a pesticide kill, any traces of the responsible pesticide residue may only be in the topmost layer of pollen.  If the state agent who takes the beebread sample scoops all the way to the midrib, he may dilute the offending pesticide by a factor of 10 or more.