Biology Reference
In-Depth Information
8.2.1 In Vitro Rearing Studies
High- and low-strain bees vary in the age of foraging onset and forag-
ing behavior at least in part because they have dif erent-sized ovaries
(see Chapter 7). I wanted to rear high- and low-strain bees in the labo-
ratory (in vitro) and vary their nutrition in order to make high-strain
workers with smaller ovaries, the size of low-strain bees, and low-strain
workers with larger ovaries. I thought that I would then look at their
foraging behavior. (We never did the experiments.) So Osman Kat -
anoglu developed diets, derived from frozen royal jelly, that contained
dif ering amounts of added sugar, protein, and water and fed dif erent
amounts with dif erent food delivery schedules to larvae from high- and
low- strain bees, commercial wild- type Eu ro pe an bees, and Africanized
bees. h is was similar to an ensemble modeling approach (Chapter 2).
We were exploring the total possible phenotypic space that could be
generated by varying nutritional and genetic parameters.
Tim Linksvayer and Kat anoglu hand-raised about 2,500 individuals.
In addition, workers and queens were reared in their own colonies by
their own nurse bees for comparison. h ey weighed the adults and dis-
sected the ovaries to count the number of ovarioles. h ey also scored the
adults for other characters that dif er between queens and workers: pol-
len baskets, spermathecae, and notched mandibles. h e feeding studies
revealed a strong general relationship between body mass and ovariole
number, and that the phenotypes of queens and workers were not dis-
cretely determined by the developmental programs of the larva. In other
words, we uncovered a cloud of phenotypes that are never seen when
nurse bees rear queens and workers (Figure 8.5). h e other characters
also varied from workerlike to queenlike with all intermediate stages, as
previously shown by Selim Dedej and his colleagues. Workers and queens
raised by nurse bees occupied a much smaller part of the total pheno-
typic space. h e nurse bees constrained the development of the larvae.
8.2.2 Cross- Fostering Experiments
To illustrate the joint operation of the larval and nurse bee modules,
we conducted cross-fostering experiments. h ese are similar to
