IMAGE I: TAKEN BY SAM COUCH AT WONDERLAB (2017) FEMALE MADAGASCAR HISSING COCKROACH GIVING LIVE BIRTH IN THE HISSER EXHIBIT.
For the first time I got to see the birth of dozens of baby cockroaches! Before this awesome sight though, a lot of work goes into creating it.
While there is no designated breeding season for Madagascar Hissing cockroaches, they do need temperatures warm to reproduce. As they come from Madagascar Africa, warmth is not usually a problem, competition is.
Mating begins with finding a mate. The males and females of this species do this in different ways. Females lay down what are called pheromones which are smelly scents that are unique to each female. The males hiss and fight each other to attract females, much like the name suggests. They fight using bumps near their heads called pronotal horns. When the stronger, fiercer roach wins, he will sometimes probe the females antennae with his own and then back up rear end to rear end against the female.
Once fertilized, female roaches produce what is called an ootheca, an egg sack in which the nymphs (baby roaches) grow and develop. This ootheca is seen only when the female is forming it. She will extend it from her body to allow the air to dry the egg sac. To see what this looks like, visit Extended Ootheca. Once it is formed, she will pull it back into her body where the eggs will sit for 60 days. To see what how this looks inside the female visit Female internal anatomy.
Once the eggs are ready to hatch, they will hatch inside her abdomen and she will then give live birth pushing out about 20-60 nymphs! They are completely white except their black eyespots. This combination of having eggsac as part of reproduction and also giving live birth is called ovoviviparity. Many animals including some sharks can do this!
They are white because they have not developed a protein called chitin. This protein gives the exoskeleton its sturdiness. (More information is soon to come in another post). These nymphs will go through 6 molts within 6-7 months. On the 7th molt they are considered an adult cockroach and will live for about 2-5 more years.
SAM COUCH Writing to you here. I am the animal exhibits manager at WonderLab Museum of Science, Health and Technology. I found my way here from Indiana University where I got a B.S in Biology and a certificate in animal behavior with a concentration of marine science. I have done coral health assessments in the Dominican Republic and studied tropical biology in the Cayman Islands but the most important things you should know about me are that I think coral are one of the coolest animals on the planet (that we know of) but if I could be any animal in the world for a day I would want to be Cuvier’s beaked whale. In 2014 they were logged for the deepest dive, so if I were a beaked whale, I could see first hand where no human can dive!