Effect of Bird's Eye chili(i.e. capsicum frutescen) on Gryllus assimilis (the common black cricket)Featured science projectScience project video

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Complexity level:
5
Project cost ($):
20
Time required:
1 day to prepare for this science project, 1 hour for observation
Material availability:
Easily found
Safety concerns:

Avoid letting the chili juice come into contact with your eyes or other sensitive parts of your skin. Wear safety goggles as as precaution. Ensure that you use gloves when handling the chili.

Abstract

This science project was conducted to determine if Bird's Eye chili can be used as a form of deterrent against Gryllus assimilis (the common black cricket). The experiment was done by spraying various concentrations of Bird's Eye chili extract on crickets.

Hypothesis

Bird's Eye chili extract will repel and even kill crickets.

Background

Natural pesticides

We normally use chemical pesticides in our homes and gardens to kill or deter pests and insects. This is because insects such as mosquitoes are not only a nuisance, they also spread diseases. Other pests like termites can damage our property and caterpillars eat away at the leaves of our plants. Other insects like the cricket make very annoying noises.
Chemical pesticides are very effective but they can also be very harmful to our health.

Young children are especially vulnerable of the side effects of chemical pesticides. When we use a can of pesticide spray, often, a small percentage of its fumes is inhaled. Pesticides used in farms to protect the crops seep into the soil and contaminate our ground water resources.

Natural pesticides are a much safer way to keep pests and insects away without harming our environment. Since natural pesticides are made of natural substances, they will not harm us. Examples of how natural pesticides are used include the use of borax acid to repel termites and cockroaches. Lemon juice, bay leaves and cucumber peel help to keep ants away. Pepper spray can repel and kill crickets.

The Bird's Eye chili

The Bird's Eye chili fruit comes in a few varieties an can be either  red, yellow, purple or black in color. Once upon a time, it was listed in the Guiness Book of World Records as the hottest chili in the world, but today, even hotteer species of chilis have been identified, such as the Habanero chili (Capsicum chinense) which is rated 100,000–350,000 on the Scoville scale. The Bird's Eye chili is a popular condiment use din Indonesian, Malaysian, Thai, Filipino and south-east Asian Chinese cuisine.
 

Scientific Terms

Natural pesticides, capsicum frutescen, ground water

Materials

The materials required for this science project are:

-    4 empty aquarium tanks with a cover each
-    A plastic container
-    40 crickets
-    A food grinder
-    4 spray dispensers
-    100 grams of Bird's Eye chili
-    400ml of distilled water
-    4 beakers
-    1 measuring cylinder
-    A black marker pen

Procedure

1.    For this experiment, the independent variable is the concentration of the Bird's Eye chili extract– 100%, 75%, 50% and 25%. The dependent variable is the number of crickets that remain alive in the tank. This is determined by observing and counting the number of crickets which survive the experiment. The constants (control variables) are the size of the tank, the species of crickets and the volume of Bird's Eye chili extract that is used on each tank of crickets.

2.    40 crickets are caught and kept in a plastic container. 100grams of Bird's Eye chili is purchased from the supermarket.

3.    The tanks, beakers and spray dispensers are labeled as “100%”, “75%”, “50%” and “25%” according to the concentration of the Bird's Eye chili extract used.

4.    Grind 100grams of Bird's Eye chili and add 250ml of distilled water whilst grinding. The juice is extracted and poured in a measuring cylinder. Pour 100ml of the ground Bird's Eye chili extract into the beaker labeled “100%”,. Into the beaker labeled “75%”,75ml Bird's Eye chili juice is mixed with an additional 25ml of water. The beaker marked “50%” will contain 50ml of Bird's Eye chili juice mixed with an additional 50ml of water. The beaker marked “25%” will contain 25ml of Bird's Eye chili juice mixed with an additional 75ml of water.

5.    The Bird's Eye chili juice is poured into the respective spray dispensers.

6.    10 crickets are placed in each of the 4 tanks. The Bird's Eye chili juice is sprayed into the 4 tanks. The respective concentrations of Bird's Eye chili are sprayed 5 times in each tank. The number of crickets that remain alive every 30 minutes for the next 2 hours are counted and the results are recorded in the table given below.
 

Observation

It is observed that the highest  concentration of Bird's Eye chili juice, i.e. 100%, killed all the crickets in the shortest amount of time.
 

Bird's bird's eye chilli science projectEye chili juice concentration Number of crickets that remain alive. after:
  0 minutes 30 minutes 60 minutes 90 minutes 120 minutes
25% 10 10 9 9 9
50% 10 8 7 5 5
75% 10 6 2 1 0
100% 10 3 0 0 0

The graph below represents the results of our science project:

 

Conclusion

The hypothesis that Bird's Eye chili extract will repel and kill crickets is proven to be correct.

Crickets are insects that belong to the same family as grasshoppers. They make a loud, high pitched chirping noise that is comforting for some but can be irritating to others. One of the safest methods to repel crickets is to use pepper spray. However, care must be taken to avoid contact with the eyes or plants. Pepper can cause pain and irritation if it comes into contact with the eyes .
 

Also consider

What would happen if the experiment were to be repeated using different type of peppers like capsicum, red chilies or green chilies?

The experiment can also be done using different types of insects like the grasshopper or praying mantis.
 

References

Natural pesticide alternatives - http://www.essortment.com/all/pesticidesalter_rfhc.htm

Natural pesticides - http://www.livingwithbugs.com/natural_pesticides.html

Home made cricket repellant - http://www.ehow.com/way_5811611_homemade-cricket-repellent.html
 

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