Biology Reference
In-Depth Information
sucrose and also were more likely to exhibit a PER when pollen was
touched to their antennae.
5.4.3 Sensitivity to Brood
High-strain bees are more sensitive to brood stimuli. Tanya Pankiw
showed in common-garden experiments that high-strain bees re-
sponded more than low-strain bees when the pollen-foraging stimuli of
stored pollen and larvae were changed. h ey increased their pollen-
loading bias and foraged earlier in life when there were more larvae and
less stored pollen. However, those studies confounded stimuli because
both stimuli were changed simultaneously.
Jennifer Tsuruda held the amount of stored pollen constant in hives
and looked at the ef ects of brood by having some colonies with a i xed
amount of larvae and others completely broodless. Colonies contained
cohorts of high- and low-strain workers, again a common-garden ex-
periment. High-strain bees were more sensitive to the brood stimulus;
the pollen-foraging bias increased when brood was present in the hive.
High- and low-strain bees still dif ered in their pollen-foraging biases
in the hives without brood, showing that pollen foraging is not a re-
sponse only to brood stimuli, and that dif erences between highs and
lows are not based only on responses to brood.
5.4.4 Sensitivity to Light
High-strain bees are more responsive to low levels of light. Within the
high and low strains, light sensitivity correlates positively with sensi-
tivity to sucrose. h e same relationships are found with wild-type bees.
Pollen foragers are more responsive to light and sucrose than are nectar
foragers.
5.5 Associative Learning
High-strain bees perform better on tactile associative learning tests
than do bees from the low strain. Pollen-foraging wild-type bees per-
form better than nectar foragers. h e trials of conditioned stimulus
