One Planet News: Is this the stuff of nightmares?

Getting to know Whip Scorpions

By Annette J Beveridge

If I was in the middle of a tropical rainforest and crawling into a cave, I would be very aware that there would be many of these fierce predators around. The fact that they are harmless to humans would not stop me from feeling a bit nervous.

I am not keen on being in enclosed spaces at the best of times.

Whip scorpions are neither spiders nor scorpions, they are arachnids and range in size from 2mm to 70mm. They typically live a few years but may live up to ten years.

With its flattened body, it can manoeuvre in the tightest of gaps and shapeshift its body to hunt in irregular rocky niches.

The pedipalps at the front can extend and grab. They provide a pincer movement enabling them to capture and tear prey apart. They then pour digestive juices over the prey. These are ambush predators or will stalk prey slowly through leaf litter, on bark, rocks or on cave walls. They feed mainly on insects or other arthropods.

Males have longer pedipalps often extending past the first ‘knee’ joint whereas the female pedipalps will not extend this far.

If frightened, some of the species will eject acetic acid in a mist produced from anal glands as a defence - (smells vinegary).

The front legs are longer and thinner than the others and perform a sensory role. This is essential as whip scorpions have weak vision and they may live in a darkened environment.

The other legs are used for walking or running across cave walls.

They are harmless to humans so while they may not look the most friendly, they do have appeal. Having said that, I always think that the more we know about different species - yes, including these mainly solitary cave dwellers, the more fascinating they become.