Madagascar Hissing Cockroach Competition for Survival with Tug-of-war

Target Audience

2^nd or 3^rd Grade

Estimated Time

3-5 hours classroom (may be divided)

Overview

This lesson uses Madagascar Hissing Cockroaches (MHC) in displays of competition and strength to demonstrate how certain characteristics provide advantages in surviving, finding mates, and reproducing.

Students will handle and observe MHC behaviors. Students will develop a hypothesis and put the cockroaches to a test of competitive strength. Students will discuss which traits may provide the insects a benefit and how those benefits may be valuable to their survival and reproduction.

Background and Introduction to Study Insect

The Madagascar hissing cockroach originates from the island county of the Republic of Madagascar. MHCs are rather large insects, which gives them a “wow” factor the first time they are encountered. However, despite their size and the striking noise they produce, these insects are very safe. They don’t bite. They don’t sting. And unlike some other cockroaches, they don’t appear to pose any threat to human health.

In the US, the MHC can easily be obtained in the pet trade market, including via the internet (see Madagascar Hissing Cockroach Suppliers at the end of this lesson) or local pet stores. Many local pet stores will carry them. A local store can often help equip buyers with the items needed to create a good habitat for your new pets. Also, they can answer questions a buyer might have.

The cost to start a new colony of MHCs is minimal. Unless you plan to use this lesson in the near future, there’s no need to jump in with a large colony. Just start with at least 4 males and 4 females (Wagler and Moseley, 2005). In a short period of time, with the right care, there will be plenty. Although not usually needed with this species, please note that some states may require a permit to keep certain insects, so it’s important to check with local agencies.

MHCs range in size from about 2 to 4 inches long. They weigh between 1/4 and 7/8 of an ounce (Mulder, 2017). They are wingless and covered by a hard, dark exoskeleton. They are somewhat swift movers (though not as fast as many of their cousins). Also, unlike some cockroaches, MHCs cannot fly.

Males can be differentiated from females primarily by two large bumps (sometimes confused with eyes) on the top (dorsal) part of the body, near the front (pronotum). These bumps are also found on females, but they are much less robust, and are more gradual in their slope (Heyborne et al., 2012; Mulder, 2017).

Don’t be frightened if a cockroach turns white. This is actually normal. Cockroaches, like other insects, go through metamorphosis. The type of metamorphosis a cockroach undergoes is called gradual metamorphosis. As the insect gets larger, it needs to have a way for the growing insides to fit in that hard exterior shell, so it drops the old one and a new one forms. During the short time after it sheds the old exoskeleton, the insect will appear white. It’s best not to handle them until their exoskeleton has hardened to avoid harming them (Mulder, 2017).

 

 

MHCs are fairly tame, other than an occasional one who might try to run away. Usually, and especially after repeated exposure, they can be easily held. This makes them great for showing. They are also quite resilient too, able to survive drops from children with no ill effects.

As noted, MHCs are able to produce a loud “hissing” sound. But unlike a cat, this isn’t from their mouth, and when they do it, there’s no reason to fear. MHC do this by forcing air rapidly through modified breathing holes on their abdomen. There are three times when the MHC will use its hiss: during times of aggression and fighting, during mating to attract a female, and when it is being disturbed (Mulder, 2017).

Another interesting behavior of MHCs is the development of social hierarchies (Wagler and Moseley, 2005). Often, one male will take control of and dominate an area. Females and nymphs can be in this area, but if other males come near, he will defend his territory. They will try to push others off objects and occasionally even chase them around the terrarium.

Learning Objectives

Students will learn some basic insect biology and information about the MHC. They will observe and record MHC behaviors.

Students will investigate and understand how variations in characteristics among individuals of MHC may pro-vide advantages.

Students will demonstrate their understanding of the benefits of individual characteristics among members of a species and how that relates to survival and reproduction.

National Science Standards

3-LS4-2 “Biological Evolution: Unity and Diversity.”

Science and engineering practices

Constructing Explanations and Designing Solutions

Solutions

Constructing explanations and designing solutions in 3–5 builds on K–2 experiences and progresses to the use of evidence in constructing explanations that specify variables that describe and predict phenomena and in designing multiple solutions to design problems.

SL.3.4	Report on a topic or text, tell a story, or recount an experience with appropriate facts and relevant, descriptive details, speaking clearly at an understandable pace. (3-LS4-2)

It also follows the 5E instructional model.

Instructions for Teacher Lesson Plan

Materials

A population of Madagascar Hissing Cockroaches (purchase from one of the online sites listed at the end of this lesson or at a local pet supplier)

Small containers with lids (with holes in the lids)

String

Three colors of painter’s tape

Duct tape

Scale (for measuring weight)

Ruler

Scissors

Habitat and Care Requirements for MHC

MHCs are generally easy to rear. Expect an individual MHC to live about 3-5 years, but again, with proper care, an ongoing colony can be sustained long term. A 10-20 gallon terrarium should suffice depending on how large one wants to grow the colony. MHCs are excellent climbers, even able to scale glass. In order to keep any from escaping, it is recommended that petroleum jelly be placed around the top two inches of the container if it doesn’t have a good roof covering (LLL Reptile).

Inside the terrarium, there are a few items that should be included. First, like most other cockroaches, MHCs are negatively phototrophic – they don’t like light. It’s important to give them an area where they can shelter. A simple egg crate works well. Another good item to include is a sizable piece of cork bark. This gives them something to crawl on, as well as shelter in and around. Rocks, woodchips and other items may be included.

For the base material, soil is fine to use, as long as it’s purchased from a pet supply store. Using soil from the environment could put the cockroaches at risk of exposure to chemicals or other materials that may be in the soil. Aspen wood shavings (commonly used for small rodents) can also be used, but avoid using cedar as it contains terpenes which may harm the MHCs (McLeod, 2017; Wagler and Moseley, 2005). The substrate should be changed out approximately every two months to avoid buildup of fecal material and odors.

Being from a tropical/subtropical climate, MHCs like warmth and humidity. The ideal temperature range for them is between 72° and 76° F (Wagler and Moseley, 2005). If they are kept in cooler environments, it might be necessary to use a heating pad. If the temperature falls below 70°, MHCs will become lethargic and no longer breed. Above 80°, they become noticeably more active. Ideal breeding temperatures are between 80° and 85° F. They do well in a broad range of humidity. However, if it gets too humid, mold and fungus can develop. If the humidity drops too low, it can become more difficult for them to grow and molt.

In their native environment, MHCs function as recyclers, generally feeding on decomposing plant matter and fruit that has fallen. They are omnivorous, so it makes feeding them easy. They’ll eat apples, bananas and many other fruits, as well as carrots and sweet potatoes (LLL Reptile). They don’t necessarily need grade A quality either. It’s fine to give them old apples or bananas once they’ve become too ripe. They will also eat lettuce and some other leafy greens, but organic food sources are recommended to avoid accidental pesticide exposures. Finally, it’s also a good idea to provide them with some dog or cat food as a source of protein. They have chewing mouthparts, so there’s no need to grind up or mash the food.

The cockroaches will likely also need a source of water. While they may be able to get this from the humidity and/or foods supplied, including a small damp sponge will ensure they have an adequate water supply. However, be sure not to place a tray of water in with the cockroaches, as they may drown.

Methods: Step by Step Instructions for Lesson

Engagement

Step 1. If possible to coordinate with Physical Education, begin by having tug-of-war events. Separate the students into different teams. Try many different mixes, including having more people on one side. If PE is not an option, then incorporate math. Draw math problems on the board and ask students which side would win. For example:

230+90+110 versus 170+10+190

(If time allows, both PE and math could be used.)

Step 2. Ask students what they know about how strength might impact survival and competition among animals in general, and then specifically insects. If recent social studies discussions apply, such as battles or territory expansion, they can be incorporated as well. Ask students how they relate. What did the people have that allowed them to expand? Discuss the tug-of-war and math problems. What makes the difference to what side wins? Ask what role strength plays.

Exploration

Step 3. Introduce students to the MHCs using this video.

Step 4. Have the students observe and comment on the behavior of MHCs. Take some MHCs out of their habitat and allow the students to handle the cockroaches. Encourage participation. Ask the students what they would like to know/learn about the strength and behaviors of these cockroaches.

Most likely some cockroaches will hiss. Ask the students why they might exhibit this behavior. Note to the students the behavior of males being territorial if it is not pointed out by a student. Hopefully, you will have the chance to observe this. If it is not demonstrated by your colony, videos of this behavior can be found on Youtube. Discuss this and other observed behaviors. Ask the students what makes a MHC strong. Have them note any visible characteristics.

Step 5. Feed a small amount of food to the cockroaches (so that only a couple are able to eat). Banana works well as they generally recognize it and come to it quickly. (This will work better if you have withheld food from them for a couple days. Also be sure the population is in a warm environment so they are active.)

Explanation

Step 6. Have the students record what they observe during the feeding. Ask questions and discuss. Do certain cockroaches get the food over others? Is there competition? Do some cockroaches stay back and venture to the food area later? With limited resources, what characteristics do some of the cockroaches have that might allow them to get more of the resources?

Step 7. Introduce the idea of competing for resources. What advantages do those that are able to secure more resources have? Discuss the impact on survival, finding mates and reproduction.

NOTE: If you would like to break the lesson in to multiple sessions, this is a good point for a break. This is also a good time to give the crossword puzzle learning assessment. (See below. The word list can be covered when copies are made to increase difficulty.)

Elaboration

Step 8. Break the students into pairs or small groups. Give each group 3 MHCs of the same sex in a small container. Try to vary the size. (For the purpose of survival of the species, both males and females are needed. Therefore, the test will look separately at males against males and females against only other females. As noted, in it is common for MHC males to engage in competition.)

Step 9. Ask the students how they might be able to assess the strength of one MHC over another. (Remind them of the tug-of-war and/or math problems if necessary.)

Step 10. Once there is agreement that a tug-of-war would work, ask the students what attributes might make one cockroach win. Suggestions include length, weight, size of “feet” (tarsus). Have the students develop a hypothesis about which attribute will predict the winner of their test. For example: “Cockroaches that weigh more will defeat a lighter cockroach.” Have the students write down their hypothesis.

Step 11. Have the students place a different piece of colored painter’s tape on each of their cockroaches to help identify each individual. The tape should be placed near the head.

Step 12. Have the students measure and record the attribute they have chosen to test for each cockroach. (See example below for data collection entry.)

Step 13. Tug-of-war. Have the students do the following:

Step 13A. Use a piece of the painter’s tape as a center line and place about a 12-inch strip on the surface where the tug-of-war will occur.

Step 13B. Cut a piece of string approximately 6 inches long. Using the duct tape, attach one end of the string to the abdomen of one MHC and the other end to the abdomen of another MHC.

Step 13C. Place the cockroaches on the surface facing away from each other. Be sure that they are equally distant from the tape.

Step 13D. Release the cockroaches. Some guidance may be necessary to keep them pulling opposite the tape line. The winner is the cockroach to pull the other over the line first. Record the winner. Repeat the test three times.

Step 14. Have the students remove the string from cockroach 2 and attach it to cockroach 3. Repeat steps 13C and 13D.

Step 15. Have the students remove the string from cockroach 1 and attach cockroach 2 again (so that 2 is versus 3). Repeat steps 13C and 13D.

Step 16. Have the students discuss their results. Facilitate the discussion toward how being larger, or weighing more provides the insect a competitive advantage. Ask how that relates to survival and reproduction. (See discussion questions below.)

Evaluation

Step 17. Have students present their data to the class and discuss how the characteristic they selected for their hypothesis may help individual MHCs to survive, find mates and reproduce.

Step 18. To further assess what the students have learned, have each student select an insect of their choosing. Instruct them that they need to research and prepare a small poster board to present to the class. The presentation should offer a basic description of the insect. It should also discuss what characteristics provide the insect with an advantage over members of the same species, and how those characteristics benefit it with regard to survival, finding a mate and reproducing. For example, a student might suggest that crickets with louder chirps could better attract mates if they were farther away. Inform the students of the components of the rubric (see below).

Step 19. Give the students time to research and prepare their poster board.

Step 20. Have the students present their research and poster board to the class.

Step 21. After the presentations, discuss with the students what they have learned.

Possible Discussion Questions

What factors did you test?

Why did you choose those factors?

Which cockroaches won?

Did you notice if bigger differences had any impact on the tug-of-war? What were they?

What traits seem to make the most difference? (This will require the whole class discussing their results.)

How might these traits impact their survival in the natural environment?

Learning Assessment

Suggested Rubric (100 Points Possible)

Crossword Puzzle = 10 points

Participation and Data Collection= 40 points

 

References

Heyborne, W. H., Fast, M., & Goodding, D. D. (2012). The Madagascar Hissing Cockroach: A New Model for Learning Insect Anatomy. The American Biology Teacher, 74(3), 185-189. doi:10.1525/abt.2012.74.3.11

LLL Reptile. “Madagascar Hissing Cockroach.” LLL Reptile. www.lllreptile.com/articles/197-madagascar-hissing-cockroach/.

McLeod, Lianne. “Cockroaches, Pets! Yes, Madagascar Hissing Cockroaches Are Docile Pets.” The Spruce Pets, 18 Sept. 2017, www.thesprucepets.com/madagascar-hissing-cockroach-1236891.

 

Mulder, P. (2017, March). Madagascar Hissing Cockroaches: Information and Care. Retrieved September 22, 2018, from http://factsheets.okstate.edu/documents/l-278-madagascar-hissing-cockroaches-information-and-care/

Wagler, R., & Moseley, C. (2005). Cockroaches in the Classroom. Science Scope, 28(6), 34-37. Retrieved from http://www.jstor.org/stable/43181581

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