I wonder if you could put a container with oil in it under the exit to the observation hive? That way when the larve try to exit and go to the soil to start a new life cycle they would just drown in oil. Just a theory here never had to deal with them past seeing them in Bud's hives. But the idea comes from talking with Alan Buckly about adding cardboard soaked in mineral oil to the bottom board of the hive. From what he said the bees will run them into the grooves in the cardboard where they sufficate in the oil. Like I say probably wrong in this idea so you want to hear from some guys that have had to deal with the problem before.
By the way great video and lighting was good too don't know anybody that could have done it better unless you have a movie studio. So good i'm sure i'm gonna have nightmares tonight about them nasty little critters. Hope you find a way to get rid of them from what I hear they are sent here by the devil himself to punish all beekeepers.