Metamorphic DevelopmentMetamorphic Development

Metamorphic Development of the Corn Earworm through the Eyes of Sixth

Graders

Presented

By

Amanda Gough, Hannah Kovar, Josef Orsak, Kimberly Wheeler

Snook Secondary School

Snook, TX

Ms. Pamela Romi Donald—Teacher

Mr. Robert Reyes—Principal

Mr. Jim Copeland—Superintendent

Egg, Larva, Pupa, Moth What Else?

This year the sixth graders at Snook I.S.D. studied and worked with corn earworms. The scientific name for the corn earworm is Helicoverpa zea or Heliothis zea. The corn earworm is also known as the tomato fruitworm, the sorghum headworm, vetchworm, and cotton bollworm. You can see corn earworms in four stages egg, larva, pupa, and moths.

These four stages take many days and even weeks to go through. All you need is a bit of patience to raise some corn earworms.

• First stage of corn earworm metamorphosis.

• Are yellow at first then turn a gray shade of color, but turn a pale green color when about to change into the larva.

• Shape can vary from slightly-dome shape to a flattened sphere.

• Usually laid individually, but in groups of 500 to 3,000 eggs per female moth.

• Hatch in about two to ten days depending on the temperature.

• About half the size of a pinhead. The sixth graders at Snook didn’t find

out much about the corn earworm egg but some of my peers did take some pictures of the corn earworm egg.

EGG

Materials Corn Earworm larva

Digital Blue Computer Microscope

Dissecting microscopes

Hand Lens

Paper Towels

Plastic cups with lids

Special Diet

String

Sugar

Two liter bottles

Water

Dentist wick(cotton)

LARVAE

• Second stage of the corn earworm

• Goes through many different colors

• If left in a container with another corn earworm, the bigger worm will eat the smaller one

• Sheds at least five skins, will eat first four if not taken out

• Will grow long and then when ready to turn into the pupa stage it will shrink

• Will start to flip when ready to turn into a pupa

• Will bury itself under food when ready to turn into pupa

• Feeds on many different foods

• Emits a black liquid that will form the

cocoon

Pupa• Third stage of the corn

earworm

• Goes through several different color changes as it matures

• Is a non-feeding immobile stage

• Tissue changes from that of a larva to that of an adult

• When first transformed the pupa is a pearly white color. As it matures it changes to a darker and darker brown

• When it is soon to emerge from the cocoon it turns a dark black

Moth

• The moth is a cream color and has scattered dark spots on its wings.

• The moth will normally lay 500-3000 eggs.

• Moths normally migrate in late May.

• The moth will cost farmers millions of dollars in damage.

Larvae Pupae Moth TOTAL LIFE SPANAracely 22 11 0 33Darius 15 29 1 45Tyree 18 19 1 38Kim W. 14 15 16 45Kerry 17 11 0 28Jenny 16 17 12 45Nathaniel 22 10 13 45Amber J. 14 16 15 45Melanie 15 17 13 45Briana 26 4 15 45Kim H. 15 16 14 45Hannah 21 16 7 44Macy 13 11 20 44Nichole 15 18 9 42Bellamy 14 24 0 38Omar 4 15 22 41Amber B. 25 17 1 43Maranda 17 18 10 45Ashley 14 21 10 45Harley 17 14 9 40Maria 14 22 13 49Sam 20 na na naJosef 16 16 9 41Lionell 17 8 na naAVERAGE 16.7 15.9 11.1 42.3

SUMMARY OF DATA KEPT IN 6TH GRADE JOURNALS IN 2005

Stages of a Corn Earworm Metamorphosis

0 10 20 30 40 50 60

Aracely

Tyree

Kerry

Nathaniel

Melanie

Kim H.

Macy

Bellamy

Amber B.

Ashley

Maria

Josef

AVERAGE

Stu

dent

Res

earc

h S

cien

tist

Number of Days

LarvaePupaeMoth

Percentage of Days Spent in Each Stage of Metamorphosis

38.2%

36.4%

25.4%

Larvae

Pupae

Moth

**This data represents only the Larvae, Pupae & Moth stages of Metamorphosis

Observing the corn earworm is a delicate process but if you are careful you can have a lot of fun. If you are observant enough, you can learn things you never thought were possible.

From the Snook I.S.D. Sixth Graders,

thanks for inviting us to participate.

LIFE CYCLE PICTURES BY 6TH GRADE

Acknowledgements

Dr. Craig WilsonMs. Pamela Donald Teacher

Mr. Jim Copeland Superintendent Snook ISDMr. Robert Reyes Principal Snook Secondary SchoolMr. Selwyn Smith Technology Coordinator Snook ISD

Ms. Laura Oehler Research ScientistParents of

Amanda GoughHannah Kovar Josef Orsak

Kimberly WheelerSnook ISD Sixth Graders