In my OB hive I noticed today that the workers are opening the capped brood exposing under developed brood (bees that have not turned brown yet) They have eyes and heads and such but they are still white. They are not chalky white, they just look like they died before finishing development. What are some causes of this so I can make adjustments to keep this hive alive?
I have heard of bees doing this if they detect mites in the cell or other problems. The other thing is if the brood had gotten chilled they would be removing the effected brood. Just a couple of guesses that may help.
I have seen bees do this also. I asked them why. They have refused to answer. The humans I have talked to said bees that aren't right may give off a scent that is not right and the bees tear in ad take it away. Whatever the way the bees know something is not right and deal with it.
Sincerely,
Brendhan
Varroa hygenic bees will open varroa infected pupa and discard them. This time of year it's usually drone brood they do this too, but will do it with worker brood as well. I count this behavior as desirable when I notice it happening.
Many times in the spring, the queen gets frisky on warm days and starts laying more eggs than what the workers can take care of if the weather turns to a cooler spell. In this situation the brood will chill because not enough nurse bees to keep it warm as the weather cools. This will happen at the edges of the brood cluster. The girls will then uncap the brood and either eat it for added protein or discard it. As the weather warms again and more young bees hatch out, the population of nurse bees rise so more brood can be properly cared for. Then the brood will no longer be chilling and you'll see this behavior go away.
I doubt if you have serious problems and am betting what you are seeing is normal behavior in the spring.
As RayMarler infers, it is often an indicator of chilled brood that died from cold in the cells, hygenic behavior towards mites, 86ing excess drones prior to hatch (this is usually, also, of a slow down in honey flow), illustrative of cannabalism during a dearth, or a die off a brood due to bad food (tainted honey or pollen).
In the spring is more likely the result of an over active queen and an enlargement of the brood chamber past the capacity of the hive to tend for all of the brood, therefore it gets chilled or some of it is sacrificed and drone or pest infected pupae are the primarly targets.
In the case of an ebb in flow or dearth when cannabalism can rear its head, the haste of the opening (wax crumbs) looks very much like honey comb that has been robbed out.
A few minutes inspecting and assessing the "picture" of the frame and bee conduct plus food stores will usually give a pretty good indication of what the exact situation is.
Seems like all the possibilities are covered. Mites, disease, chilled, cannibalism, etc.