Hercules Beetle Fact File
The Hercules beetle is one of the largest beetles on Earth. Males can measure up to 180mm (7in) long. Females are much smaller and average 61.8mm (2.4in) long.
Males are most noticeable due to the large horns which protrude from their body. There is a thoracic horn which comes out from the thorax and a cephalic horn which emerges from the head. These resemble a large claw and are used for grabbing opponents in battle. Females lack these horns.
As an insect they have six legs.
Their abdomen is covered by the elytra which are hardened front wings. In males these change color based on the humidity in their environment. In low humidity it is a yellow or olive green and in high humidity it will change to black. The head of a male is black.
Females are dark brown across their entire body.
An average male Hercules beetle will weigh 34g (1.2oz) while the females weigh 16.3g (0.6oz).
The Hercules beetle is a herbivore. Adults feed on fallen fruit. The skin is pierced with their horn and they then chew the soft tissue in to a pulp.
Young feed on rotting wood.
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Hercules beetles can be found through Central and South America. They range from Mexico south to Brazil and Peru. In addition to the mainland they can be found on offshore islands such as the Lesser Antilles and Trinidad and Tobago.
They make their home in montane and tropical rainforests.
Larvae are mostly found in rotting trees while the adults hide among fallen logs and leaves.
Breeding typically occurs during the rainy season from July to December.
Females release a pheromone to let males within her area know she is ready to mate.
Several males will gather to attempt to mate with the female. These males engage in violent contests in an attempt to gain mating rights. The males will face one another and attempt to grab their opponent between the two horns. Once they have the other male grasped between the horns they will lift them over their head and throw them to the ground.
This occurs several times till one will retreat in defeat.
In the wild these battles may take place in a tree branch and this makes it easier for the male to be successful as when they throw their opponent off it will take them time to get back up the tree.
Males may breed with several females throughout the breeding season.
Hercules beetle have a life cycle which involves a complete metamorphosis. The females will initially lay 100 eggs in to a rotting log or the ground. These eggs will incubate for 28 days.
Eggs hatch as a larvae. This is colored white with a black face patch and white dots. This will undergo 3 instars across a 12-18 month period. Large larva can grow to be as long as a human hand and these may weigh up to 140g (4.9oz).
Following this they will form a pupa where they complete their development for 32 days.
After they emerge from the pupa they resemble an adult beetle and will not grow any larger. All growth occurs during the larval and pupal stages.
Sexual maturity is reached between 15-22 months old.
Adults are primarily active at night with a peak in activity before dawn.
They are capable of flight with the wings being stored under the elytra.
Hercules beetles are able to create a ‘huffing’ sound which is generated by rapidly vibrating the abdomen against the elytra.
Predators and Threats
Humans threaten their survival through habitat destruction.
They are able to lift items which weigh 100 times as much as they do.
Hercules beetles are highly desired for the pet trade.
By Novita Estiti from Tokyo, Japan – Hercules beetle larva: July 24, 2010, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=25402137
Muséum de Toulouse / CC BY-SA (https://creativecommons.org/licenses/by-sa/4.0)
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