Observations by christianaah

Madagascar Hissing Cockroach

Scientific and Common Name

The insect pictured above is commonly called the Madagascar hissing cockroach (MHC). It is also called the hissing cockroach or just hisser. This insect belongs to the genus Gromphadorhina which comprises of several hissing cockroaches of different species. Particularly, MHCs belongs to the species portentosa. Hence, its scientific name is Gromphadorhina portentosa (Clark & Moore, 1995)

Habitat and Geographic Range
MHCs are native to only the island of Madagascar which is located off the east coast of Africa (Copeland, 2003). They are terrestrial insects and are largely found in the tropical lowland rainforest region of Madagascar. Unlike other common cockroaches, they do not reside in human dwellings. In the wild, they are usually found in large colonies in leaf litter, underneath rotten logs and detritus on the forest floor (Copeland, 2003). They tend to live in these humid and dark areas as they are nocturnal insects and are in fact afraid of light (Yoder & Grojean, 1997). In captivity, they can be kept in a tightly covered container with paper rolls or egg cartons to allow them hide from light. They also tend to survive a wide range of temperatures but the perfect temperature in which they breed is 75℃-85℃ (Yoder & Grojean, 1997).

Size, Weight and Lifespan
MHCs can grow up to a maximum length of 3 inches (7.5 cm) at maturity (Clark & Moore, 1995). Hissing cockroaches are sexually dimorphic with females and males being shaped differently and females being smaller than males (Copeland, 2003). They can weigh up to 0.8 oz (22.7 g) in weight. They are also able to live up to 5 years in the wild and anywhere ranging from 2 to 5 years in captivity (Copeland, 2003).

Diet
MHCs are both herbivores and detritivores (Clark & Moore, 1994). In the wild, they hunt their meals at night. They feed mainly on fruits, vegetables and decaying plants as they are easy to obtain. In some cases, they might eat tiny insects and animal remains (Clark & Moore, 1994). They play a very big role in the nutrient cycle as they help with recycling a huge chunk of the earth’s dead and decaying plant and animal matter. In captivity, they can eat dog or cat food with small pieces of fruits and vegetables (Clark & Moore, 1994).

Reproduction and Communication
MHCs reach sexual maturity at about 7 months of age (Clark & Moore, 1994). They are able to mate all year round provided the temperature is warm (85℃). When a female is sexually mature and ready to mate, she produces a distinct scent to entice males preferably dominant males (Sreng, 1993). The male stays close to the female, hissing and touching her antennae and body. Then they turn back to back to copulate and engage in this act for approximately 30 minutes. The inseminated eggs are laid in an elongated egg capsule called an ootheca (Sreng, 1993). The female retains the ootheca inside her body for at least 60 days after which offspring called nymphs hatch. These nymphs are about 0.25-0.5 inch in length and they tend to live with their mother until maturation. Female MHCs can produce about 700 offspring during the course of their lifetime (Sreng, 1993).
MHCs are able to communicate through tactile, acoustic and chemical (pheromones) means (Clopton, 1995). The hissing sound produced by MHCs through their spiracles help them communicate amongst themselves. Researchers have found four hisses which serve different social purposes: male-male fight hiss, two kinds of courting and mating hisses and an anti-predatory loud snake-like hiss to threaten predators (Clopton, 1995).

Predation
MHCs have a lot of predators ranging from birds to mammals, amphibians, reptiles and insects such as ants (Clark & Moore, 1994). MHCs have small holes called spiracles which helps with breathing. When they force air out rapidly from these spiracles, it makes a hissing sound comparable to that of a snake with the aim of intimidating potential predators (Copeland, 2003). This is an anti-predatory behaviour which helps prevent them from getting killed by their predators. Another predator of MHCs is a parasite called cockroach mite which attaches itself to MHCs and shares in their food (Clark & Moore, 1994).

Conservation Status
MHC is not listed on the IUCN red list and CITES appendix list of endangered species. Overall, little to no conservation efforts have been done by the government to protect MHCs (Bohannon, 2003). They usually form a cluster in the forest and the forest area which they live on are getting degraded and fragmented (Bohannon, 2003). As a result, conservation biologists have taken it upon themselves to make Madagascar a top priority. Over the past decades, million of dollars have been given to help with conservation projects in Madagascar (Bohannon, 2003).

Did you know?
MHCs have 3 times more protein than chicken or beef of equal mass. MHCs shed their exoskeleton and eat it because of its nutritious content. A small colony of MHCs can eat a large carrot in less than 24 hours (Copeland, 2003). In 2006, Six Flags Great America amusement park announced a promo during a Halloween-themed FrightFest where it would be giving people who eat a live MHC an opportunity to skip lines for all rides. Contestants that were able to break the preceding world record of eating 36 cockroaches in 1 minute were given 4 season passes. This record is hard to break as cockroaches have slight neurotoxin that deadens the mouth, making it hard to swallow (Zimmern, 2012).
 
References
Bohannon, J. (2003). Steve Goodman Profile: Madagascar Tames the Bohemian of Biology. Science, 301(5641), 1835-1837. doi:10.1126/science.301.5641.1835

Clark, D. C., & Moore, A. J. (1994). Social interactions and aggression among male Madagascar hissing cockroaches (Gromphadorhina portentosa) in groups (Dictyoptera: Blaberidae). Journal of insect behavior, 7(2), 199-215.

Clark, D. C., & Moore, A. J. (1995). Social Communication in the Madagascar Hissing Cockroach: Features of Male Courtship Hisses and a Comparison of Courtship and Agonistic Hisses. Behaviour, 132(5), 401-417.

Clopton, R. E. (1995). Leidyana migrator n. sp. (Apicomplexa: Eugregarinida: Leidyanidae) from the Madagascar Hissing Cockroach, Gromphadorhina portentosa (Insecta: Blattodea). Invertebrate Biology, 114(4), 271.

Copeland, M. W. (2003). Cockroach. London: Reaktion.

Sreng, L. (1993). Cockroach mating behaviors, sex pheromones, and abdominal glands (Dictyoptera: Blaberidae). Journal of Insect Behavior, 6(6), 715-735.

Yoder, J. A., & Grojean, N. C. (1997). Group influence on water conservation in the giant Madagascar hissing-cockroach, Gromphadorhina portentosa (Dictyoptera: Blaberidae). Physiological Entomology, 22(1), 79-82.

Zimmern, Andrew (2012). Andrew Zimmern's Field Guide to Exceptionally Weird, Wild, and Wonderful Foods. Feiwel & Friends. p. 30.