Gromphadorhina portentosa

Geographic Range

Gromphadorhina portentosa , the Madagascar hissing cockroach, occurs only on the the island of Madagascar.

• Biogeographic Regions
• ethiopian ethiopian
  • native native

• Other Geographic Terms
• island endemic island endemic

Habitat

Gromphadorhina portentosa is primarily found in the tropical lowland rainforests of Madagascar. They tend to live in the dry litter on the forest floor.

• Habitat Regions
• tropical tropical
• terrestrial terrestrial

• Terrestrial Biomes
• rainforest rainforest

Physical Description

Like most insects, Gromphadorhina portentosa has a head, thorax, abdomen, and 6 legs. Unlike many cockroach species, they do not possess wings. Their exoskeleton is dark, from mahogany brown to black, and very thick, hard, and waxy. They have pads and hooks on their feet that allow them to climb smooth surfaces. Males possess a pair of large bumps or tubercles behind their head, these structures are much smaller in females. These horns are known as pronatal humps. Gromphadorhina portentosa is one of the largest species of the cockroaches in the world, adults are 5.1 to 10.2 cm long, with males growing larger than females.

• Other Physical Features
• ectothermic ectothermic
• heterothermic heterothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• male larger
• sexes shaped differently

Development

Madagascar hissing cockroachs have an incomplete or partial metamorphosis. They hatch from eggs as nymphs, which are quite similar to adults in general structure, but lack reproductive organs. Nymphs molt their exoskeleton six times as they grow to adulthood, a process that usually takes 6-7 months.

• Development - Life Cycle
• metamorphosis metamorphosis

Reproduction

Male Madagascar hissing cockroaches produces acoustic sounds or hissing during courtship interactions with females. Males typically produce two types of signals, a calling sound and a courtship sound. The calling sound is a long distance song that is used to attract females while the courtship sound is used more during close range interaction.

Adult male hissing cockroaches defend mating territories from other males, and attempt to monopolize mating with all the females in their territory. Males interact by hissing, and in bouts of pushing and shoving. Cockroach mating can occur year around, but only when the climate is warm.

• Mating System
• polygynous polygynous
• polygynandrous (promiscuous) polygynandrous (promiscuous)

Male hissing cockroaches are attracted and stimulated by the odor of the female. The males have specialized sense organs on their antennae for this. The amount of sex attractant secreted is higher in virgin females, although the output can be sporadic. It decreases with age. When the male is attracted to the female by this scent, he begins to hiss and touch her antennae. The pair then attaches to one another and turn rear to rear and remain in this position for 30 minutes. The females carry the ootheca, a long yellowish egg case, internally and they release the young nymphs after the eggs have hatched. Typically 15 - 40 cockroach nymphs will emerge.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• year-round breeding year-round breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• fertilization fertilization
  • internal internal
• ovoviviparous ovoviviparous

Female Madagascar hissing cockroaches provision their eggs, then carry them after fertilization until they hatch.

• Parental Investment
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • protecting
    • female

Lifespan/Longevity

Madagascar hissing cockroaches can live up to five years.

Behavior

Male Madagascar hissing cockroaches establish territories that are defended from other adult males. Aggressive hissing and posturing behavior is used to warn intruders away. The male that is larger and hisses more usually wins. The dominant males stand on their "toes," which is called stilting. Stilting is a way for males to "show off." The males use their pronatal humps when fighting other males to defend territories. Fighting between males does not appear to injure the males. Females and nymphs are more social and do not fight with one another or with males. The cockroaches are nocturnal and they avoid light.

• Key Behaviors
• terricolous
• nocturnal nocturnal
• motile motile
• sedentary sedentary
• territorial territorial
• social social

Home Range

Territory sizes are rather small. A male may sit on a rock for months and defend it from other males, only leaving to occasionally obtain food and water. Females do not defend a territory like this.

Communication and Perception

The Madagascar hissing cockroach is unique in its ability to make a "hissing" sound. These cockroaches hiss through the breathing spiracles located on their abdomens. This hissing sound is used to communicate with its own species and others. Four hisses with different social purposes and amplitude patterns have been identified: a male combat hiss, two types of courting and mating hisses, and an alarm hiss (a loud snake-like hissing that startles predators).

• Communication Channels
• tactile tactile
• acoustic acoustic
• chemical chemical

• Other Communication Modes
• pheromones pheromones

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

Madagascar hissing cockroaches are detritivores. Their most frequent food is decaying plant material, including fallen fruit, because it is so readily available. They also eat smaller insects and animal carcasses.

• Primary Diet
• detritivore detritivore

• Animal Foods
• carrion carrion
• insects

• Plant Foods
• leaves
• seeds, grains, and nuts
• fruit
• lichens

• Other Foods
• fungus
• detritus detritus
• dung

Predation

Hissing cockroaches probably have many types of predators, but there are few documented relationships. Arachnids, ants, tenrecs, and some ground-feeding birds are likely predators. As previously mentioned, an anti-predatory strategy is an alarm hiss - producing a loud snake-like noise that may startle potential predators.

Ecosystem Roles

Gromphadorhina portentosa plays a role in the rainforests of Madagascar by recycling a large amount of decaying plant and animal matter.

The mite Androlaelaps schaeferi , formerly Gromphadorholaelaps schaeferi , is a common parasite of this cockroach. These mites form small clumps of four to six individuals at the base of the leg of their cockroach host. While it was originally thought that this mite was sanguinivorous (blood-sucking), recent studies showed that the mite simply "shares" in a cockroach's food items.

• Ecosystem Impact
• biodegradation biodegradation

Economic Importance for Humans: Positive

This species is part of the nutrient cycling process in Malagasy forests. These forests are important as sources of timber, for water quality, and sources of other natural products.

Hissing cockroaches are also sold commercially in the pet trade.

• Positive Impacts
• pet trade pet trade

Economic Importance for Humans: Negative

There are no known adverse effects of Gromphadorina portentosa on humans.

Conservation Status

Because the Madagascar hissing cockroach is only found in Madagascar, little conservation efforts have been done. This is due to political turmoil. Since the Malagasy people were forced out by the French colonizers in the 1960’s, the country has gone from dictatorship to dictatorship. It is difficult for field biologists to research the area due to the sparse network of passable roads. In the recent years, Liberation and international aid have made it easier for biologists to study Madagascar focusing on the hissing cockroach. The Madagascar hissing cockroaches huddle together in the forest. These pockets of natural forest are dying by degradation and fragmentation and because of this Madagascar has become a top priority for conservation biologists. Hundreds of millions of dollars have been contributed over the past three decades to help conservation efforts in Madagascar.

Additional Links

Encyclopedia of Life

Contributors

Ashley Jessee (author), Radford University, Karen Powers (editor, instructor), Radford University.

References

Bohannon, J. 2003. Madagascar Tames the Bohemian of Biology. Science , 301/5641: 1835-1837.

Clark, D., A. Moore. 1995. Genetic Aspects of Communication During Male Competition in the Madagascar Hissing Cockroach: Honest Signalling of Size. Heredity , 75: 198-205.

Clark, D., A. Moore. 1995. Social Communication in the Madagascar Hissing Cockroach: Features of Male Courtship Hisses and a Comparison of Courtship and Agonistic Hisses. Behavior , 132: 5-6.

Clark, D., A. Moore. 1994. Social Interactions and Aggression Among Male Madagascar Hissing Cockroaches (Gromphadorhina portentosa) in Groups (Dictyoptera: Blaberidae). Journal of Insect Behavior , 7/2: 199-215.

Clopton, R. 1995. Hissing Cockroach, Gromphadorhina portentosa. Invertebrate Biology , 114/4: 271-278.

Copeland, M. 2003. Cockroach . London: Reaktion Books.

Fraser, J., M. Nelson. 1984. Communication in the Courtship of the Madagascan Hissing Cockroach: Normal Courtship. Animal Behavior , 32: 194-203.

Gordon, D. 1996. The Complete Cockroach . Berkeley, California, USA: Ten Speed Press.

Guthrie, D., A. Tindall. 1968. The Biology of the Cockroach . London: Edward Arnold Publishers Ltd..

Matthews, R., J. Matthews. 1978. Insect Behavior . New York: John Wiley & Sons.

Milius, S. 2002. Meeting Danielle the Tarantula. Science News , 161/6: 90-92.

Miller, J. 1977. Society for the Science and the Public. Science News , 112/21: 344.

Mulder, P. 2008. "L-278: Madagascar Hissing Cockroaches: Information and Care" (On-line). OSU Ag in the Classroom. Accessed December 17, 2008 at http://agweb.okstate.edu/fourh/aitc/lessons/extras/cockroach.pdf .

Nelson, M., J. Fraser. 1980. Sound Production in the Cockroach, Gromphadorhina portentosa: Evidence for Communication by Hissing. Behavioral Ecology and Sociobiology , 6/4: 305-314.

Roeder, K. 1963. Nerve Cells and Insect Behavior . Cambridge, Massachusetts: Harvard University Press.

Ryan, J., G. Creighton, L. Emmons. 1993. Activity Patterns of Two Species Nesomys in a Madagascar Rain Forest. Journal of Tropical Ecology , 9: 101-107.

Sreng, L. 2005. Cockroach Mating Behaviors, Sex Pheromones, and Abdominal Glands (Dictyoptera: Blaberidae). Journal of Insect Behavior , 6/6: 715-735.

Yoder, J., J. Barcelona. 1995. Food and water resources used by the Madagascan hissing-cockroach mite, Gromphadorholaelaps schaeferi. Experimental and Applied Acarology , 19/5: 259-273.

Yoder, J., N. Grojean. 1997. Group Influence on Water Conservation in the Giant Madagascard Hissing-Cockroach, Gromphdorhina portentosa (Dictyoptera: Blaberidae). Blackwell Science , 22: 79-82.