FUNGUS AMONG US!by

Madisyn

7th Grade Science ProjectMarch 24, 2011

Question

My Question is“ Can an entomopathogenic Fungus Control Insect Pests?”

HypothesisMy hypothesis Is “I think the fungus will control insect pests.”

VariablesConstants Same temperature Same seeds planted Same insects Same fungus Same amount of

water Same light regime Same soil

Variables

Independent Variable

The independent variablein my experiment is the treatment with the fungus, Beauveria bassiana.

VariablesDependent Variable

The dependent variable in my experiment is the insects,Heliothis virescens cottonbollworm.

Materials 120 Heliothis virescens (larvae or

worms) Beauveria bassiana (fungus in liquid

solution) 1750 soybean seeds 2 pair forceps 7 pans 1 bag Vermiculite 1 camera 21 cups water 1 pencil 1 notebook 1 pair gloves

Procedure1. Gather the materials.2. Lay down the vermiculite in the pan.3. Planted the soybeans.4. Put another layer of vermiculite over the

soybeans.5. Watered the seeds with three cups of

water.6. Made a greenhouse using a tarp to cover

the light and heat source.

Procedure continued7. Watered plants every other day using

one and a half cups of water.8. Allow plants to grow to a height of six

inches before introducing the treatment.9. Allowed larvae to grow to the third instar

or stage.10. Open rearing cups to expose the larvae.11. Used a dropper to squirt the liquid fungus

solution on the larvae.

Procedure continued12. Placed the treated larvae on the three pans

of plants. Three replications of treated larvae.

13. Using a different pair of forceps I removed 60 untreated larvae from rearing cups and placed the insects on the plants. Three replications of the untreated larvae.

14. I moved treated plants to a room with a light source and heat, then I took the untreated plants to a different room with a light source and heat.

Procedure continued15. I continued to water plants every other

day.16. I observed plants daily to see if the

insects had eaten the plants.17. I also observed to see if the insects had

been affected by the treatment or if they were feeding normally.

18. I recorded observations such as how many had died from the fungus.

Procedure continued19. I recorded how many plants were eaten.20. I took pictures of all the stages of the

insects as they continued to grow untreated.

21. Took pictures of plants as they were being eaten.

22. I removed dead treated larvae from plants and placed them in the rearing cups. The fungus continued to grow on the dead larvae.

Procedure continued23. I recorded data from the experiment for

twelve days.24. I recorded how many plants were eaten.25. I put the untreated larvae back in the

cups after they had eaten all the plants so they could pupate and develop into adults.

26. The experiment was held at 72 degrees F.27. The light/dark regime was 16 hours light

and 8 hours dark.

Data TableRep1

Rep2

Rep3

Rep1

Rep2

Rep3 Control

PLT eaten

Lar died

PLT eaten

Lar died

PLT eaten

Lar died

PLT eaten

Lar died

PLT eaten

Lar died

PLT eaten

Lar died

PLT eaten

Lar died

trt trt trt untrt untrt untrt untrtd 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0d 2 4 6 12 3 15 4 10 0 13 0 15 0 0 0

d 3 4 4 11 5 12 6 15 0 16 0 17 0 0 0

d 4 7 3 6 5 8 2 18 0 18 0 18 0 0 0

d 5 4 6 8 2 9 5 19 0 18 0 20 0 0 0

d 6 2 1 3 5 6 3 21 0 20 0 20 0 0 0

d 7 0 0 0 0 0 0 22 0 23 0 21 0 0 0

d 8 0 0 0 0 0 0 27 0 25 0 23 0 0 0

d 9 0 0 0 0 0 0 25 0 25 0 25 0 0 0

d 10 0 0 0 0 0 0 28 0 27 0 26 0 0 0

d 11 0 0 0 0 0 0 30 0 29 0 30 0 0 0

d 12 0 0 0 0 0 0 32 0 31 0 30 0 0 0

Data Table AveragesTreated Treated Untrt Untrt Control Control

Avg-plt eaten

Avg-Lar died

Avg-plt eaten

Avg-Lar died

Avg-plt eaten

Avg-Lar died

day 1 0 0 0 0 0 0day 2 10 4 13 0 0 0day 3 9 5 16 0 0 0day 4 7 3 18 0 0 0day 5 7 4 19 0 0 0day 6 4 3 20 0 0 0day 7 0 0 22 0 0 0day 8 0 0 25 0 0 0day 9 0 0 25 0 0 0day 10 0 0 27 0 0 0day 11 0 0 30 0 0 0day 12 0 0 31 0 0 0

Graph

ResultsThe insects treated with Beauveria

bassiana all died after six days while the untreated insects stayed alive throughout the entire experiment. Plants fed on by untreated larvae all died while the plants fed on by treated larvae had a little damage but they still lived and thrived throughout the experiment.

ConclusionMy question is “ Can a fungus control insect pests?” My hypothesis is I think a fungus can control insect pests. I thought this would be my answer because a fungus that naturally occurs in the soil already works on insects, so if you did this in an experiment it would work just the same with any kind of insect or plant. I accept my hypothesis because the fungus did kill the insects that were treated with it and therefore allowed the plants to grow uninterrupted.

Conclusion continuedBeauveria bassiana is a naturally occurring fungus in soils throughout the world. Beauveria is a fungus which causes a disease known as the white muscadine disease in insects. When spores of this fungus come in contact with the skin of leaf feeding insects, they grow inside the insect and eventually kill it. Beauveria covers the insect body with a layer of white mold, hence the name white muscadine disease.http://www.hort.uconn.edu/ipm/general/htms/bassiana.htm

Conclusion continuedHeliothis virescens is an insect pest of soybeans, cotton, tobacco, and numerous vegetables and occurs mostly in the Southern U.S. and the Caribbean. It feeds on the leaves of plants and can destroy entire crops if not kept under control. Heliothis feeds constantly in the larval or worm stage on leaves of cotton, tobacco, and vegetables which makes it a good insect to be controlled with Beauveria.http://entomology.ifas.ufl.edu/creatures/field/tobacco_budworm.htm

Conclusion continuedI believe that my results were accurate. I believe this because I wrote down what happened to my plants everyday. I would write down how many of the treated insects had died that day, how many leaves the treated and untreated insects ate that day. I also recorded the height of the plants when they were still growing, that was before I put the insects on the plants. I would take pictures of all the plants with and without the insects. I made sure that they all had the right amount of water and light.

Conclusion continued If I were to repeat this experiment I would take this fungus which is a biological pesticide and compare it to a chemical pesticide. This chemical pesticide would probably kill the insects, but would also do harm to the environment as well as humans. So therefore I would want to see if the fungus kills the insects as well as the chemical might. I would like to be able to recommend to farmers the biological pesticide rather than the chemical pesticide which is harmful to the environment.

Conclusion continuedIn summary, I can conclude that a biological pesticide (Beauveria bassiana) can control insect pests. My data can prove that my hypothesis is correct. When the insects (Heliothis virescens, the cotton bollworm) in my experiment were treated with this entomopathogenic fungus they ate the plants for a few days, but were killed after six days and the plants could recover from the feeding and grow well. The cotton bollworms that were not treated continued to feed and at the end of 12 days killed all the plants, none of the insects died.

Conclusion continued