 |
|
|
|
||
 |
 |
|
|
|
||||
|
About this Daily Classroom Special Critter Corner is maintained by Judith Jones, teacher at East Chapel Hill High School (NC) and Teachers Network web mentor. To the Critter Corner Directory. Introduction
Scientific Name Gromphadorhina portentosa General Physical Description These wonderful roaches are large (adults are two to three inches long and about one inch wide) and wingless. They have brown segmented abdomens and a darker brown thorax. Females have two short antennae that point downward. Males have two longer antennae that point upwards. Males also have obvious humps on the thorax that look like blunt horns. Madagascan cockroaches are called sexually dimorphic because the male and female look different. Fortunately, these roaches do not produce any obvious odor. General Physical Description These wonderful roaches are large (adults are two to three inches long and about one inch wide) and wingless. They have brown segmented abdomens and a darker brown thorax. Females have two short antennae that point downward. Males have two longer antennae that point upwards. Males also have obvious humps on the thorax that look like blunt horns. Madagascan cockroaches are called sexually dimorphic because the male and female look different. Fortunately, these roaches do not produce any obvious odor. Behavior Madagascan cockroaches cannot fly and are very slow and usually quiet. They hiss to communicate. When they are first picked up, they will make a loud hissing sound. They do this by pushing air through a pair of openings in the abdomen. There are as many as five different hisses that are used to defend territory, warn of danger, and in courtship behaviors. The Madagascan cockroaches do not bite and are nocturnal - active at night. If you want them to be more active during the day, you can use a light on a timer to reverse their "photocycle" giving them 12 hours of light and 12 hours of dark - a dark room or a closet. Reproduction This is an unusual species of cockroach. The females appear to bear live young rather than deposit eggs. Actually, the young do develop in eggs which open within the female so that the young emerge live. Gestation is about 60-70 days and each female can have 20-40 young or nymphs. Each nymph is about 1/4 of an inch long. I did not notice my nymphs until they were about 1/2 inch long probably because the female raises her body over them for a while to protect them. The young will molt or shed six times until they are adult size at about five to ten months depending on the temperature. I have already found several molts and my young are about 3/4 inch long - in late July. The young eat their shed exoskeletons. What great recyclers! Native Habitat and Role in the Environment These roaches are originally from Madagascar, an island off the eastern coast of Africa. It is a valuable scavenger that lives on or near rotten logs. Biological supply companies raise their own roaches so if you order them, you will be assured that you are not endangering the species in their native environment. From my experience, they are not hard to raise and breed! Classroom Habitat You can use anything from a small aquarium to a plastic shoebox. You will need a few holes for air and a secure lid. I found that I needed to change my lid when the extremely small babies were born. I put some very fine filter paper over the top so that the babies were secure but oxygen could get in. You can use wood chips, gravel, pine shavings, or a corn cob product found at pet stores. I use old egg cartons to provide hiding and climbing places. Cardboard toilet paper rolls would work well, also. If you have only a few roaches, you only need to change the substrate once every four months or so! Food and Feeding Schedule Madagascan roaches can eat dry dog, cat, or rodent food. It is nice to supplement this with small bits of fresh vegetables and fruits. Don't let the food get moldy. For water, you can use a small piece of sponge in a small dish. I use a plastic petri dish lid. Keep the sponge moist and the cockroaches will have plenty of water and they won't drown! Keep food and water available at all times. Handling Tips Pick the cockroach up carefully around the thorax - the hard section between the abdomen and the head. Lift gently, because the sticky pads on its feet have hooks that grip tightly onto the surface. Teach students to be careful but these insects are really not very fragile. The cockroach can crawl safely over hands and arms. It will not bite! Be very careful not to let them escape. We would not want these roaches to become household pests in the United States! In fact, if you live in Florida, you cannot have them shipped to you. A Critter Corner fan writes... "Just a little hint, if you put these roaches in an aquarium, use dirt for the substrate. Put some rock in the bottom, followed by a little activated carbon, followed by an inch and a half to two inches of dirt, and plant some oats (found in stores for cats) in the dirt! This will last you through at least six months, even a year! Another hint is to put a giant Asian millipede in the aquarium. This will eat all of the same left over food, doesn't take over in the aquarium, and is really cool! Take care, and great page!!!" |
In the fall of 1996, I ordered from the Carolina Biological Supply
Company in Burlington, North Carolina, six Madagascan Giant Hissing
Cockroaches. I kept three and gave three to a colleague. My students
have enjoyed watching and handling these large mellow roaches. Much
to my surprise, I looked in the aquarium in late June, 1997, and there
were at least three dozen baby roaches! These interesting animals
are very easy to take care of and quite a conversation piece!
