The corn earworm is known as the tomato fruit worm or cotton bollworm. Pictures 1 & 2 are from
The Life of a Corn Earworm The life of a corn earworm starts with an egg.
The female adult moth smells the silk of a corn. Moths can smell corn silk from miles away.
The moth flies toward the corn to lay her eggs. When the eggs hatch, they will find food and shelter inside the corn ear.
Depending on the temperature, the eggs should hatch in 2 to 6 days after being laid.
The larvae follow the silk channel to the tip of the developing ear where they feed on kernels and grow.
Observations The worms come in a variety of colors: green, tan, brown, pink, maroon, or nearly black. Pictures 1 and 3 from
Look what the worms did. A cup of frass! (Worm excrement) Picture Number 2 from
We tested the following foods in our experiment: corn, tomatoes, potatoes, strawberries, and apples. Experiment #1 What do earworms eat?
Colton Taylor was watching what his worm ate.
Dexter is spying out the worm. Which food is best?
Rhetts worm likes the tomato.
Megans worm is trying out the potato.
Jakes worm keeps crawling away.
These worms are trying out the corn, potato, tomato, strawberry, and apple.
Conclusions The worms liked the corn, apple, and tomato the best. Photo from:
As the worms grew, we measured them. This one measured about 31mm.
The worms went from an egg to a pupa in about 21 days. Picture from
Worm Measurements 3/29/054/4/054/7/054/11/054/12/05 Very small, gray largerPinkish larger Red stripe forms larger 1mm15mm26mm30mm Lots of frass. 31mm
Experiment Number Two. Would worms eat anything outside?
We tried to see if the corn earworm would eat bluebonnets.
Do Corn Earworms like grass?
Do corn earworms like hackberry trees?
Are wildflowers a part of their diet?
Are weeds on the menu for pink corn earworms?
Results of Foods Outside BluebonnetsGrassHackberry Trees WildflowersWeeds NoNO NoneNO
Observations The students noticed that the worms at this stage wanted to fall off and burrow. They had a hard time keeping the worm on the plant.
To the PUPA! ! ! ! ! It took 21 days for our corn earworms to start metamorphosis.
The Transformation from Worm to Pupae
The larva will go through five moltings before pupating.
The larva burrows under its own castings to pupate. It creates a shell around its body.
Views of the pupae with the Intel microscope.
The Pupa Magnified 10X 60 X 200X
Egg 2-5 days Larvae days Pupa days Adult Moth 8-15 days Life Cycle
Is the moth a male or female? Hold the moth and gently squeeze the abdomen. The females will have a brownish small part pop out. They are usually less active and have shorter, fatter abdomens than the males. Females are usually darker. Drawing from
Laramie is using the microscope to find the sex of the moth.
Which pupa is male or female? Which pupa is male or female?
The moth emerging from the pupa must struggle to spread its wings.
The moths continue to emerge.
The corn earworm moth has a wing span of 1 ½ inches. It is buff colored with irregular spots and markings on the wings.
The front wings have a dark, comma shaped spot that is more prominent on the males.
A new generation of moths lays eggs on fresh corn silk, and the cycle begins again.