Sr. Catherine Duffy asked about how to tell the quality of a colony from the
brood pattern.  Lloyd Spear remarks that "if 5% or more of the cells are
empty, the queen should be replaced."

A few years back I observed that some of my colonies were not building their
populations in April and May as I had expected, but that they had what had
always been called "an excellent brood pattern."   I did 25 to 30 brood
survival tests in some of my two queen colonies the way Dr. Bromenshenk used
to do in conducting his research.

He chose a comb that contained mostly eggs and identifies 5 rows of 24 cells
by marking the corner cells with colored pins.  He noted on a log sheet the
contents of each of the center 100 cells i.e., eggs, one or more day old
larvae, pollen, nectar, or empty.  Then he came back 14 days later and
uncapped the cells he had identified.  He again noted on a log sheet the
contents of the cells.  All eggs should now have developed into black eyed
workers.  The percent of cells that previously had eggs and that now have
black eyed workers is the percent of brood survival.

I found in my tests that brood survivability ranged from 35 to 95 percent
even with 5 to 10 empty cells.  Consequently, I don't hold with the "good
brood pattern" idea any longer.  I have observed many variables between
colonies with very similar brood patterns.  I'm not sure that the empty
cells can be used as a measuring device because bees regularly place pollen
cells among the brood and it is hard to remember where those  cells were,
and which ones were empty, unless one does a formal documentation of cell
contents.  Some colonies put most of the pollen to the sides of the brood
rearing area and just below the top bars, others scatter pollen more
throughout the brood rearing area, and some even put whole combs of pollen
above the brood nest (clearly an aberrant behavior).

When Lloyd suggests the 5% figure, I wonder if that includes natural
mortality of eggs, larvae, and genetic deficiencies.  Somewhere I read that
only 90 to 95 percent of eggs hatch, and only 85 to 95 percent of larvae
become pupae, and some percent of pupae don't make it.  So what is the
average survivability of a disease and mite free colony with ideal pollen
and honey resources?  I wish I had access to a good bee library so that I
could search the literature for the answer.

I wonder what Jerry can add to these ideas with his latest research.

James C. Bach
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