I always knew that one day I’d be writing about these guys. Hercules beetles are too big, too weird looking, and too interesting to ignore for long. Though two years is a pretty long time — that’s right, this week was the two year anniversary of this blog. So congratulations to me, and thank you to all my readers who have kept me going!
Hercules beetles are part of the rhinoceros beetle family, which is named for the large horns that the male beetles have. They are found in Central and South America, from southern Mexico to Bolivia. Hercules beetles live in rainforests, mostly sticking to the understory of the forest. They prefer areas with lots of moisture, fallen fruit, and large decaying logs.
As one of the largest species of insects in the world, I don’t think I’d like to meet a hercules beetle. For the most part I’m not too afraid of insects, but giant 17cm long beetles with huge horns are a little too much for me. The horns of hercules beetles look pretty much like a giant claw, and serve basically that function. The beetles’ shells change in colour, depending on moisture levels in the air. When humidity is low, the shells are yellow or olive green, but they turn black as humidity rises.
During the breeding season male hercules beetles have a chance to strut their stuff and really use those horns of theirs. Females send out an “I’m ready” call via chemical pheromones. This attracts nearby males, who then compete for the honour of mating with her ladyship. The competition takes the form of a kind of wrestling match, where the beetles try and grasp one another in their massive horns and then slam their opponent into the ground. This goes on until one beetle retreats. Hercules beetles are aptly named, for they can perform amazing feats of strength. They can lift over 80 times their body weight, the equivalent of a 80kg human lifting a 68 metric ton truck.
The adults of the species aren’t the only ones that are impressively huge. Hercules beetle larvae can reach sizes of more than 15 cm and weigh up to 140 grams. The eggs are laid in decaying logs, but due to the massive size of the larvae the fallen trees must be fairly large. After 12-18 months the larvae pupate, and three months later they emerge as adult beetles.
As you might imagine, hercules beetles are quite intimidating for any potential predators. Not only are they huge, with super thick armoured plating, but the males also have those giant horns to protect themselves. I certainly wouldn’t want to try eating a hercules beetle. The beetles also have one further anti-predator technique: they can vibrate their abdomen against their forewings to create a huffing sound that warns predators away.
Though I can’t say I’m generally much of a beetle fan, I have to admit that the hercules beetle is pretty amazing. Still, I don’t think I’d ever want to see one outside of a captive environment. They’re just too big for me.
Cover image by Arpingstone, Public domain, via Wikimedia Commons