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with only 3 percent of low-strain bees. Only bees with seven or more
ovarioles had them activated. In queenless colonies, 75 percent of high-
strain and 42 percent of low-strain bees had activated ovaries. Forty-
i ve bees had vitellogenic ovaries with eggs, the highest state, suggest-
ing that these bees were active laying workers. Of the 45, 36 came from
the high strain. h is showed that the high-strain workers were at higher
states of reproductive activation.
Because of Csondes's discovery of the dif erent ovariole numbers in
high- and low-strain workers, we now had a way to validate our hypoth-
esis with wild-type bees. If our hypothesis is correct, then wild-type bees
with more ovarioles should have ovaries in higher activated states (be
more reproductively developed) and demonstrate a stronger bias toward
collecting pollen. We took combs from four unrelated wild-type colonies
that contained naturally mated queens. Because of the polyandrous mat-
ing of queens, each colony should contain a large number of subfamilies
derived from the many mates of the queens and be genetically very di-
verse. Emerging adult workers were marked with paint, and the workers
from the four sources were mixed together and put back in each of the
four hives from which the mixture was derived. Marked bees were col-
lected at the entrances over several days at er they initiated foraging. Pollen
loads were weighed, nectar loads were measured, and the concentration of
the nectar collected was determined using a handheld refractometer. Our
hypothesis of the relationship between ovary size and foraging behavior
was coni rmed. Bees with more ovarioles behaved like the high-strain
bees: they foraged earlier in life and were more likely to collect pollen,
and when they collected nectar, they accepted nectar with a lower con-
centration of sugar (see Section 5.12).
7.4 How Vitellogenin Af ects Onset of Foraging
and Foraging Behavior
We hypothesized that vitellogenin (Vg) was pacing the onset of forag-
ing, perhaps through its suppression of juvenile hormone (JH) and
probably other mechanisms. It has long been known that topical appli-
cation of JH or analogs, chemical compounds with similar structure
