Giant fijian long-horned beetle
The giant Fijian long-horned beetle (Xixuthrus heros) is native to the island of Viti Levu in Fiji, and is one of the largest living insect species, with specimens around 15 cm long, excluding legs, antennae, or jaws. It is closely related to the Taveuni beetle, which is only marginally smaller. These beetles have powerful jaws, and should be handled with care when alive—when threatened, they produce a loud and fearsome hissing noise by squeezing air out from under their elytra. The rainforest habitat on its home island has suffered severe fragmentation by deforestation and habitat degradation by invasive species such as the small Indian mongoose, with other threats being cyclones that could devastate its remaining habitat, light pollution and human consumption of its larvae. Consequently, the beetle is regarded as rare and endangered.
Xixuthrus heros is distributed in the lowland rainforests of south-east Viti Levu, with Colo-i-Suva Forest Reserve being the stronghold; natives in some nearby villages continue to consume the larvae when they split decaying wood, which is then burnt for fuel, placing additional pressures on the population. Adult beetles have been recorded in the past flying to lights in the nursing college near Suva. A scientific study in 2001/2002 determined that there are, in fact, two distinct species which had been identified as heros, one of them true heros, the other being X. ganglbaueri.
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TerrestrialTerrestrial animals are animals that live predominantly or entirely on land (e.g., cats, ants, snails), as compared with aquatic animals, which liv...
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OviparousOviparous animals are female animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive...
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starts withThe habitat of X. heros is the decaying wood of large trees, typically those with a minimum diameter of 80 cm. Such substantial trees are rare in the region, with estimates indicating their presence at less than four per square kilometer. This habitat is under threat from activities like logging, land clearance for agriculture, and vulnerability to cyclone damage. Notably, Xixuthrus larvae have been associated with the creation of intriguing galleries within the buabua tree (Fagraea gracilipes, Loganiaceae).
The life cycle of X. heros is yet to be fully understood. Observations and historical collections suggest that these beetles are more prevalent during the months of May to September. Both male and female X. heros are primarily nocturnal and demonstrate embark on long-distance flights in their quest for mates and suitable host trees. Additionally, there is evidence suggesting that certain cerambycid beetles, including X. heros, employ sex pheromones as attractants.
