Insect Olympians
Background
Insects are the most ubiquitous organism on planet earth having terrestrial, aquatic and marine representatives. Insects have been around for over 250 million years (before dinosaurs) and account for almost 75% of all the animals species on earth. They are one of the most successful groups of organisms, and have many fascinating abilities including lifting objects 52 times their own weight.Approximately 290,000 different species of beetles have been identified. This not only makes them the largest group in the animal kingdom, but it's more than all of the species in the plant and fungi kingdom. In this lab you will investigate the strength of Papillus disjunctus , commonly known as the bess beetle, betsy bug or patent leather beetle.
Objectives
- To use metric measurements to find length and mass
- To calculate the pulling power of a bess beetle
Materials
- Bess beetle
- roll of pennies
- string
- Balance or scale
- petrie dish
- masking tape
- paper towel
Hypothesis
How many pennies do you think a bess beetle can pull?
Procedures
1. During this lab you will be working with a living organism. You are to show your beetle respect and any beetles harmed or killed during this experiment will result in a failing grade.Bess beetles have pincers and can pinch, however seldom do. When handling your beetle, gently hold it on either side of it's abdomen with your thum and forefinger.
2. During the lab, talk in quiet voices and try not to make any sudden movements tht may startle your beetle.
3. Weigh a petrie dish on your triple beam balance to the nearest tenth of a gram.
4. Place your beetle on its back in the petrie dish weigh the dish and the beetle to the nearest tenth of a gram.
5. Calculate the mass of your beetle by subtracting the mass of the dish from the mass of the beetle and the dish, and place your calculation in the appropriate section in Data and Observations.
6. Place your beetle on it's back on your lab desk and mesure it's length from tip to tip to the nearest tenth of a centimeter. Place this calculation in your data section.
7. Weigh a penny to the nearest tenth of a gram and record your measurement in the data section.
8. Hypothesize how many pennies your beetle will be able to pull in the petrie dish sleigh you will construct for it. Write your answer in the space provided for your hypothesis.
9. Use your piece of string and slip the lasso over the head and body of your beetle until it fits snugly around the middle of the body between the thorax and abdomen. Tape the free end of your string to the inside rim of your petrie dish.
10. Use the masking tape to secure your paper towel to the lab desk to prevent it from sliding.
11. Place your beetle on the cloth allowing the petrie dish to slide on the smooth lab desk.
12. When the beetle begins to pull or move the sled by walking, slowly add pennies to the sled one at a time until you find the maximum weight your beetle can pull (when it's no longer able to walk). It may be necessary to reposition the beetle to prevent the sled from touching the paper. Do not prod or push your beetle while it is pulling the sleigh.
13. After you have reached the maximum pennies your beetle can pull, remove the ahrness from the beetle and return him to your teacher for inspection. Count the total number of pennies pulled, weigh them, and place them in the appropriate place in you Questiosn and Conclusions section.
Data and Observations
What is the length of your beetle? _____cm What is the class average length for bess beetles? _____cm What is the mass of your beetle? _____g What is the class average mass for bess beetles? _____g What is the mass of a penny? _____g What is the class average mass for pennies? _____g
Hypothesis
Conclusions and Questions
1. How did your actual results compare with your expected results (hypothesis)?
2. How much weight was your beetle able to pull? weight of pennies _ weight of = weight and petrie dish petrie dish pulled ___________ - ___________ = ____________ 3. Calculate your beetle's pulling power by figuring out how many times it's weight the beetle was able to pull? Total weight pulled / beetle's weight = pulling power ____________ / ___________ = ____________ 4. If you had the strenth of a bess beetle, how much weight could you pull? Your weight X pulling power = weight you could pull ____________ X _____________ = _________________
Teacher Tips:
Bess beetles can be collected underneath or between the bark and wood of fallen hardwood trees in the eastern United States. A sign of their presence in a fallen snag are tunnels about 1 cm wide burrowed into the wood. Adulls and larvae are capable of stridulation ( a whistling noise) and students should be informed so that they are not startled.Beetles can be maintained for about a month in some of the wood they wre found in and then released where they were found.