The Effect of Different Colored Light on the Growth of Caterpillars

Sabrina Alexis
<strong>The</strong> <strong>Effect</strong> <strong>of</strong> <strong>Different</strong>
<strong>Colored</strong> <strong>Light</strong>
on the Growth <strong>of</strong>
Caterpillars
Introduction
Our problem statement was “Does different
colored lighting affect the growth <strong>of</strong> caterpillars?” We decided to study this
problem because we thought it would be interesting to see if the caterpillars
would grow faster in the green light because they live in and eat green leaves.
Our hypothesis was “If we placed two groups <strong>of</strong> caterpillars, one in the green light and one in white light,
the caterpillars will grow faster in the green light than the caterpillars in the white light”. We chose that as
our hypothesis because in life caterpillars are surrounded by leaves and trees which are green.
We used the Vanessa cardui because our caterpillars they grow very quickly and can give us quick
results. Also, the caterpillars were adapting fairly well due to their location in the lab. <strong>The</strong>y used their
nutrients efficiently because they were growing rather quickly. In addition our caterpillars were not very
colorful.
Materials and Methods
For this project we tested if different colored lights affect the growth rate <strong>of</strong> the
caterpillars. We used 2 florescent lamps so the caterpillars were not receiving any heat.
One <strong>of</strong> the lamps had a green light bulb (the experimental group) and the other lamp had a
normal light bulb (the control group). Also, we used black pieces <strong>of</strong> construction paper,
painters tape, the caterpillar kit, small plastic cups, a big container caterpillar food, and an
empty gas chamber. We used the gas chamber to put the caterpillars inside so none <strong>of</strong> the
outside light would affect the results <strong>of</strong> the caterpillar weren’t affected. Since the windows
on the gas chamber were clear we had to place the pieces <strong>of</strong> black construction paper over
the window. First we placed 7.2 ounces <strong>of</strong> food in 30 little containers. <strong>The</strong>n we split them
up into 2 groups <strong>of</strong> 15 then we placed them in the big containers and positioned it in the gas
chambers and turned on the lights. We did this experiment because we wanted to find out if
different colored lighting affected the growth <strong>of</strong> caterpillars. Each day we recorded if the
caterpillars were superior in the green light or in the white light. We also had to see if the
caterpillars were dead. <strong>The</strong> data we analyzed quantitatively was whether there was a
difference in the number <strong>of</strong> days from start to pupation between treatment and control.

Sabrina Alexis
Results
<strong>The</strong> description data that we collected shows that the green light in the experimental group
actually slowed down the process (Table 1). In the control group, when 4 had pupated, only
1 had pupated in the experimental group. And also, that one had died the experimental
group.
Table 1. Description <strong>of</strong> Control and Treatment Caterpillars
Control Group
DATE PHYSICAL APPEARANCE EXTRA INFORMATION
6/21/12 Delicate, small, and black N/A
6/22/12 Still small and looked delicate,
black
Some looked dead and we were not
able to find some
6/25/12 Not much <strong>of</strong> a difference Some were visible
6/26/12 Bigger, and fatter 1 on side and rest were on the
ground
6/27/12 Bigger, and fatter N/A
6/28/12 Look bigger and very fat N/A
6/29/12 Fat and long, control is bigger Some buried under food
than treatment
7/2/12 Very big and plump Climbing up the wall
7/3/12 Fatter than usual N/A
7/5/12 N/A Some are on ro<strong>of</strong> getting ready for
metamorphosis
7/6/12 As big as they can be 7 on side, 2 on ro<strong>of</strong>, and 6 on the
ground
7/9/12
7/10/12
7/11/12
7/12/12
7/13/12

Sabrina Alexis
7/14/12
DATE PHYSICAL APPEARANCE EXTRA INFORMATION
6/21/12 Delicate, small, and black N/A
6/22/12 Still small and looked delicate,
black
Some looked dead and we were not
able to find some
6/25/12 Not much <strong>of</strong> a difference Some were visible
6/26/12 Normal, very fat N/A
6/27/12 N/A N/A
6/28/12 N/A N/A
6/29/12 Small, long Not as big as control
7/2/12 Climbing on wall Starting pupa stage
7/3/12 Not that fat N/A
7/5/12 Fat 7 are on the side 2 are on the ro<strong>of</strong>,
and 6 are on the ground
7/6/12 On the ro<strong>of</strong> making webs 9 on the side, 3 on the ground
7/9/112 N/A 10 are in webs one caterpillar dead
7/10/12 2 pupated Pupation stage has started
7/11/12 10 pupated N/A
7/12/12 12 pupated N/A
7/13/12 13 pupated N/A
7/14/12 All pupated N/A
Discussion
In our experiment we tested to see if the green light affected the growth <strong>of</strong> the caterpillars
because all their lives they ate green leaves. Since everything they ate was green we
thought that the color light would affect the rate <strong>of</strong> their development. However, the time
from start <strong>of</strong> the experiment to pupation was not significantly different between treatment
and control groups.