The Effects of Insecticide on Ladybugs
The purpose of this experiment was to determine the effect of insecticide on ladybugs.
I became interested in this idea because I know that ladybugs are beneficial insects. They live around insect pests, which leads to accidental spraying of the ladybugs. Farmers need the ladybugs to help keep down pest population, and need to avoid killing them accidentally.
The information gained from this experiment can warn farmers to be extra-careful when using insecticide.
My hypothesis is that the organic insecticide will kill the ladybugs faster than Sevin.
I base my hypothesis on the fact that my parents and I have used soap and water to kill potato bugs, and that is like an insecticide. The natural insecticides usually work better.
The constants in this study were: the same amount of insecticide, the same type of ladybug, and the same size of ladybug.
The manipulated variable was: the type of insecticide.
The responding variable was: the percentage of the ladybugs that die from each insecticide.
To measure the responding variable I will observe the ladybugs after spraying them with insecticide, counting how many die.
||Marking pens to label boxes
||Sheets of plastic
||Pencil to poke holes in boxes
||Pair of yellow kitchen gloves
||Gallon container of distilled water
||Types of insecticide
||Roll of scotch tape
1. Purchase 2 different types of insecticide, and 1 gallon of distilled water.
2. Purchase about 100 ladybugs.
3. Gather 3 shoeboxes.
4. Divide each shoebox into 3 different compartments with slats of cardboard and tape.
5. Poke air holes in sides of all the shoebox compartments.
6.With a marking pen, label each shoebox: " Sevin", " Organic", and " Control."
7. Clean sprayer.
8. Fill sprayer with Sevin insecticide, mixed according to instructions on container.
9. Place about 5 ladybugs inside the first compartment in the " Sevin" box.
10. Uncover the shoebox.
11. Spray this group with Sevin insecticide.
12. Record time.
13. Observe ladybugs for a few seconds.
14. Repeat steps 9-13, 2 more times for this test substance.
15. Repeat steps 9-13 3 times with organic insecticide.
16. Repeat steps 9- 13 3 times with distilled water (as a control.)
The original purpose of this experiment was to determine which insecticide worked best, Sevin, or the Organic.
The results of the experiment were Sevin killed nearly all of the ladybugs, while the Organic destroyed only about 3. Therefore Sevin worked much faster than the Organic. Most natural remedies for killing bugs don’t work nearly as well as I thought at first.
My hypothesis was that the organic insecticide would kill beetles more effectively.
The results indicate that this hypothesis is incorrect. Sevin worked best by far.
Because of the results of this experiment, I wonder if farmers would see that although Sevin is not a very strong insecticide, it works well, ( at least on ladybugs.) I could use this information to show farmers that when spraying, be very careful to spray the insects you are aiming for, and not the ladybugs, too. Ladybugs are not hard to kill, especially if you are using Sevin.
If I were to conduct this project again I would start gathering up my supplies sooner, reconsider my hypothesis, and use more ladybugs in each test group. On this experiment I only used 5 ladybugs for each trial which is too few for a valid test.
Ladybugs are beneficial insects. They are helpful to people, eating aphids, and helping to save many crops. When people spray plants to rid them of harmful insects, they are also killing the ladybugs. It doesn’t take a very strong insecticide to kill the ladybugs. Farmers, and anyone else, who sprays their gardens, need to watch for ladybugs and other beneficial insects.
Insecticide is very harmful to insects, humans, or even animals that get hold of it by accident. Insecticide is a poison. It was created to kill insects.
There are many different types of insecticide. One type was DDT. DDT was an insecticide introduced in the 1940’s to battle a variety of insects. Insects stored the DDT in their fatty tissue. DDT was banned from the United States in 1972, due to damage to the environment.
Other insecticides, called stomach poisons, kill insects when eaten.
Systemic insecticides are sprayed or injected, into plants and even animals.
Contact poisons kill insects when touched.
Organic insecticides are natural insecticides. They consist of carbon, hydrogen and oxygen atoms. Three main types of organic insecticides are chlorinated hydrocarbon, organic phosphate, and carbamate insecticides. Organic insecticides are usually most often used.
Organic phosphate insecticides are very poisonous to humans, but don’t leave harmful chemicals in food.
Parathion, an insecticide, provides excellent protection against plant lice.
Botanical insecticides are insecticides made from plants. Rotenone is a poisonous substance discovered in derris and cube plants. It can be used to kill fish that are not wanted when cleaning lakes out.
Inorganic insecticides are quickly being replaced to reduce danger of contamination. They are mostly made from minerals.
Microbial insecticides infect insects with diseases.
Soybean oil is used to kill insects. It will not burn plants in cold weather.
Mosquito dunks are another product that kills mosquito larvae in still water.
Carbamate insecticides don’t leave harmful chemicals in food, but some can harm warm-blooded animals.
Nicotine makes a strong insecticide against aphids.
As you can see, there are many different kinds of insecticide.
LadybugsLadybugs help us keep down pest population. Since they are around insect pests all the time, they are often sprayed by accident.
A ladybug’s maximum length is .5 in. Ladybugs have had their name since the Middle Ages. Ladybugs were looked at as a gift from the Virgin Mary because of their eating habits.
Even when they are only larvae, ladybugs eat aphids and other pests.
In the late 19th century, California farmers released ladybugs on their crops in order to save the plants from destruction by the cottony-cushion scale insect.
Ladybugs are often red or orange. They are usually spotted with black, white, or yellow.
Adult two-spotted ladybugs often hibernate in houses during the winter season. Ladybugs hibernate together in sheltered places, piled in huge masses.
Ladybugs are very helpful, and shouldn’t be getting sprayed by farmers, even if it is by accident.
Insecticide is very harmful to insects, humans, or even animals that get hold of it by accident.
Insecticide is a poison. Ladybugs help us keep down pest population. Since they are around insect pests all the time, they are often sprayed by accident. Farmers need to make sure they do not spray ladybugs, that they spray the harmful pests.
Coble, Harold. “ Insecticide,” World Book Encyclopedia, 1995.
Doris, Ellen. Insects. Danbury, Connecticut: Grolier Educational, 1996. pp.60-61
“ Insect,” WorldBook Encyclopedia, 1991.
“ Ladybird Beetle,” Encarta, 1998.
“ The Natural Gardening Company.” [ Online] Available http:// www.naturalgardening.com/cgi-bin/S-Mart
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