Blaberus giganteus
The Central American
Giant Cockroach, Blaberus giganteus, is considered one of the largest cockroaches in the world, with males being able to reach lengths of 7.5 cm and females 10 cm. This cockroach belongs to the family Blaberidae. As typical for all roaches, individuals undergo hemimetabolous metamorphosis, which means the change from juvenile to adult is gradual.
It is endemic to Central America and northern South America, and can be found naturally occurring in the rainforests. Habitat preferences include areas of high moisture and little light, such as caves, tree hollows, cracks in rocks, etc. Their lifespan can be up to 20 months depending on habitat conditions and diet. The majority of its diet is decaying plant material, but Blaberus giganteus is an omnivore and a scavenger. Other food choices can include bat guano, fruit, seeds, dead insects, and other dead animals.
Two chemical signals play important roles in the sexual behaviour of B. giganteus. The sex pheromone is released by the female and used in attracting mates that are long distances away. The male will produce an aphrodisiac sex hormone from its tergal glands that will encourage female mounting. Females choose the males with which they will mate, so this sexual selection becomes a major pressure and driving force behind evolution. Carbohydrate intake has been found to be related to male sex pheromone expression, dominance status, and attractiveness more so than protein.
Males have been shown to have a preference for a high carbohydrate diet versus one focused on protein. This would suggest they are actively increasing their carbohydrate consumption to maximize their reproductive fitness and attractiveness to potential female mates. After mating, the female B. giganteus will be pregnant for life and stores the fertilized eggs in her ootheca, where they are incubated for roughly 60 days. When the eggs are about to hatch, the female will expel the ootheca so the nymphs can break free and feed on their first meal, which consists of the ootheca. After eating their fill, the young nymphs will burrow into soil or somewhere dark and remain there until they have molted numerous times and reached maturity.