Bumblebee’s Learning Behavior

Bumblebee’s Learning Behavior

Aim:

To investigate the learning behaviors of bumblebee’s pollinating behaviors by sugar-trapping bumblebees and by recording the time bumblebees visiting the flowers.

Introduction:

Pollinators are animals that move pollen between flowers to bring about fertilization in nature. Major insect pollinators include bees, pollen wasps; ants; flies; lepidopterans; and flower beetles. Bumblebee is an important pollinator and it has distinctive foraging behaviors. Bumblebee is a member of the genus Bombus, part of Apidae, one of the bee families. Bumblebees tend to visit and forage flowers of the same plants; and different bumblebee workers prefer working on different flowers through their majoring and learning behaviors. Once the bumblebees understand how to handle their targeted flowers, they start to specialize them.

Hypothesis

The hypothesis is that bumblebees will memorize their targeted plant and forage the same plant every time.  

Method and Material  

• Observe the flowers, especially azalea
• Number each flower and measure sugar concentration in flower nectar by a refractometer
• Observe and record bumblebee pollination behaviors
• Record the time bumblebees “come in” and “leaving” the flower patch
• Catch bumblebees and put them into diethyl ether bottle for several minutes to anesthetize them. Once they become inactive, mark individual on the thorax
• Collect bumblebees and other generalist pollinators of the observing flower
• Add sugar water with a syringe into dozens of flower to sugar-trap bumblebees. If the bumblebees are attracted to the flower, record the time “come in” and “leaving” the flowers.

Raw Data

Table1: table showing the flower number, stage of flower and sugar concentration (±0.1%) of azalea flower nectar

Table 2: table showing the arriving time (±0.1min), leaving time (±0.1min), duration of a visit (±0.2min), interval between visit (±0.2min), and number of flower visited of bumblebees in our observing flower patch

[pic 1]

Processed data

Table3: table showing the stage of flower, number of flowers and average sugar concentration (±0.1%) of azalea flower nectar

Graph: Graphs 1 to 5 showing the daily working activity of bumblebees of PBY, PYR,YYY,YYB and PGY, moving bewteen their colnoy(0) and flower (1) during the time period of 7 a.m. to 9 a.m.

[pic 2]

[pic 3]

[pic 4]

[pic 5]

[pic 6]

Observation and Discussion  

In our assigned pot, there were quite a lot of azalea flowers and most of them were young. We had found the nectar gland the most inside of the flower, at the wall of a plant ovary. However, there were water dews on many of the flowers, which may dilute the sugar concentration of our flower nectar. According to our data in table 3, the average sugar concentration that we had measured was 24.2%. Real sugar concentration would expect to be a little higher than this value due to the water drew dilution. The average sugar concentration of flower stage bud, young and old was 20%, 28.6%, and 17.5% respectively. This was because that bud flower was not mature enough to produce the most nectar; and the nectar in old flowers may already been extracted by pollinators. As a result, young flowers have the highest sugar concentration of nectar.