The Effects of Feeding greater Quantities of Food to Caterpillars
while they become Adults
By: Nicole Cinquino, Andrea Remiro, Justin Carasa, Santiago Londono, Christopher
Contreras, and Alexander Rodriguez
June 21,2012
HHMI Research in Ecology 2012
Introduction
The problem statement for the experiment is how does the different amount of food given
to each group affect its growth and development? My group chose this problem statement,
because we wanted to see if the amount of food affects how much time the caterpillars transform
into butterflies. Our hypothesis is, the group that is given the most food will transform faster,
than the control group. I support this hypothesis, because I have noticed that mostly every living
thing increases in size if they receive enough nutrition, my cat has gotten fatter with more
nutrients and vitamins. The species of butterflies we used were The Painted Ladies (Vanessa
cardui). We chose this species of butterflies, because they grow quickly.
The species of butterflies called The Painted Ladies is also known as Vanessa cardui.
They have broad wings, and their wing span is from 4 to 5 centimeters in size. These butterflies
have a specific wing pattern. The Painted Lady has a pointed white bar on their forewing, the
hindwing has five small black dots. When the Painted Lady is a adult butterfly it is orange with
rose-like overtones. The lifespan of these butterflies depend on the climate, and only adult
Painted Lady butterflies can survive through a mild winter. These butterflies consume more than
100,000 different species of plants, some include groundsel, burdock, and thistles. For
reproduction the female Painted Ladies lay their eggs on plants that they think their babies will
eat. The baby caterpillars that hatch eat constantly and molt several times.
Materials
To be able to perform this experiment based on caterpillars, food, and growth we needed
specific equipment. First, we used twenty two small plastic cups to keep the caterpillars in,
eleven cups for the control group and the same for the treatment group. Then, food was placed in
the cups so the caterpillars can eat. Next, we placed the caterpillars with a small brush in the
cups. Each cup was weighed with the food, the control group with eleven cups was 9.1 g and the
treatment was 13.6 g. We wanted to see if the development and growth of the caterpillar was
affected by the amount of food placed in the plastic cups. After this is done place the cups with
the caterpillars into a container to keep them safe. Everyday we had to record the temperature,
the size of the caterpillar, any significant change, and to see if the caterpillar is turning to a
chrysalis. The thermometer was placed inside the container holding the caterpillars to measure
the temperature which they are in. We used a wax pencil to label the cups, so we can identify
each of the caterpillars, and mark the containers. We set up the control and treatment this way,
because we wanted to see if the amount of food would contribute to the caterpillars growth. We
took daily observations on how the caterpillars look to see if the caterpillars are getting closer to
adulthood.
Results
Many unusual things happened while the caterpillars were getting ready to form their
chrysalis. I want to address a few major points. For example, T6 is still forming a chrysalis,
which is very strange since the others are in chrysalis. Our results showed that it took around two
weeks for the caterpillars to form their chrysalis. The painted Lady butterflies take small
amounts of time to form a chrysalis. Some caterpillars from the control and treatment group
made their chrysalis first. Those were the bigger and fatter caterpillars, that made the caterpillars
form their chrysalis faster than the rest of the other species. The last chrysalis to be made from
the control and the treatment was T5. Since June 25, all the caterpillars started getting fatter and
growing. The first caterpillar to start forming the chrysalis was T11.
Discussion
As shown in the results section the mean of the control group was 18.1 and for the
treatment it was 18.875, so there is not a very significant difference between the two results. The
variance for the control group was 0.1 and for the treatment it is 0.982143, again the two values
are close. This shows that the amount of food does not affect the rate of which the caterpillars
form into chrysalis. This occurred with the small group, but if I had a larger sample group, then
would get different results. Our experiment had many problems, such as mixing up the results,
there was confusion in the healthiness of our caterpillars. Also, some caterpillars in each of the
groups died. I think this was caused by the amount of food given to each group of caterpillars.
Some days we even forgot to record our data with the caterpillars, which was a big error. When
we pick the cups containing the caterpillars, it could probably cause them to stop eating.
Conclusion
This experiment could be duplicated by a research group, because they could give the
caterpillars different amounts of foods. Our hypothesis was rejected, because it does not matter
how much food is given to the caterpillars before they pupate. We will change the experiment
the next time we perform it, by putting the containers containing the caterpillars outside. We
would do this because it would be better for the caterpillars to be in warmer weather than the
weather in the building.
Date
Table 1. Control Group Days to pupation and daily appearance
Time Temp. Other Differences
Shape
(am)
(C)
June 21
June 22
June 23
June 24
June 25
June 26
June 27
June 28
June 29
9:45
8:09
N/A
N/A
8:09
8:09
8:17
8:14
8:20
23
21
N/A
N/A
21
21
21
21
21
June 30
July 1
July 2
July 3
July 4
July 5
July 6
N/A
N/A
8:21
8:09
N/A
8:20
8:12
N/A
N/A
21
21
N/A
21
21
July 7
July 8
July 9
N/A
N/A
8:21
N/A
N/A
21
July 10
July 11
July 12
July 13
July 14
July 15
July 16
July 17
8:19
8:26
8:15
8:24
N/A
N/A
N/A
N/A
21
21
21
21
N/A
N/A
N/A
N/A
No change
No change
N/A
N/A
No change
No change
C2 is dead. No significant change
No change
C3 and C9 forming webs C7
molting skin
N/A
N/A
Darker than usual
White stripes
N/A
Yellow stripes
All are hanging from top except
C5,C10,C6
N/A
N/A
C8, C11, C3, C1, and C4 in
chrysalis
C9, C10, and C7 in chrysalis
No change
A caterpillars chrysalis breaking
No change
N/A
N/A
No change
No change
Size
No change
No change
N/A
N/A
Got Fatter
Got Fatter
No change
No change
Grew Fatter
No change
No change
N/A
N/A
Grew Bigger
Grew Bigger
No change
No change
Grew Bigger
N/A
N/A
All are spiky
No change
N/A
Wide
N/A
N/A
Larger
C5 very small
N/A
Longer
Wider
N/A
N/A
No change
N/A
N/A
Wide
No change
No change
No change
No change
N/A
N/A
No change
No change
No change
No change
No change
No change
N/A
N/A
No change
No change
Table 2. Treatment Group Days to pupation and daily appearance
Date
Time
(am)
Temp.
(C)
Other Differences
Shape
June 21
June 22
June 23
June 24
June 25
June 26
June 27
June 28
June 29
June 30
July 1
July 2
July 3
July 4
July 5
9:45
8:09
N/A
N/A
8:09
8:09
8:17
8:14
8:20
N/A
N/A
8:21
8:09
N/A
8:20
23
21
N/A
N/A
21
21
21
21
21
N/A
N/A
21
21
N/A
21
No change
No change
N/A
N/A
No change
No change
No significant change
T11 forming chrysalis
T4 Dead
N/A
N/A
All forming webs
All have webs
N/A
All starting to form chrysalis
July 6
July 7
July 8
July 9
July 10
July 11
July 12
July 13
July 14
July 15
July 16
July 17
8:12
N/A
N/A
8:19
8:19
8:26
8:15
8:24
N/A
N/A
N/A
N/A
21
N/A
N/A
21
21
21
21
21
N/A
N/A
N/A
N/A
All hanging from top. T6 dead
N/A
N/A
T1, and T11 in chrysalis
T10, T8, T3, and T2 in chrysalis
No change
No change
T5 in chrysalis
N/A
N/A
No change
No change
No change
No change
N/A
N/A
Fatter
Fatter
No change
No change
No change
N/A
N/A
Spiky
No change
N/A
Growing
thicker
No change
N/A
N/A
No change
No change
No change
No change
No change
N/A
N/A
No change
No change
Size
N/A
N/A
Bigger
Bigger
Bigger
Growing more
Bigger
N/A
N/A
Bigger
Fatter
N/A
Bigger
No change
N/A
N/A
No change
No change
No change
No change
No change
N/A
N/A
No change
No change
References
http://animaldiversity.ummz.umich.edu/site/accounts/information/Vanessa_cardui.
html