Our scorpion expedition was set up to be both an educational and adventure outing.
The event took place on the Oori Reserve, Winsome Valley (near Lanseria) with
Jonathan Leeming, a recognised expert on Southern African scorpions and spiders.
He also covered the prevalent species in the area of the field trip and where and how to look for these animals hiding places.
I must admit that I was rather sceptical when we set out as to whether or not we would be able to find any specimens – after being on herping trips where we had to work hard for one or two interesting finds, and it being well into our autumn.
We proceeded to a rocky outcrop on the reserve, and began our search. It wasn’t long – possibly 20 minutes – into the walk that we got our first find.
We were given instruction on how to safely handle these creatures, and how to recognise behaviour indicators that the animal is becoming stressed.
The techniques proved useful and accurate, and we handled a number of species without harm to the handler, or the handled!
We encountered a few specimens of 2 scorpion species foundin this area, namely Opistathalmus glabifrons (mild venom) and Hadogenes gunningi (one of the least venomous scorpions).
A burrowing species endemic to Southern Africa with over 59 species in the genus.
They have robust pincers and a relatively thin tail. Their burrows may be out in the open, or under debri, or under rocks.
Their burrows are usually easy to find with the abundance of bleached millipede rings at the entrance – remains of one of their favourite food items.
The general rule of thumb on how to tell how venomous a scorpion is, is the comparative size and thickness of the tail and the pincers – a scorpion with a
thin tail and “heavy duty” pincers is less venomous than a scorpion with a thick tail and small pincers (eg Parabuthus transvaalicus).
Opistathalmus are sit and wait predators, and will spend hours at the entrance of their burrows. When a prey item walks past, they rush out and grab it.
They will normally only sting if the prey item is large, otherwise they use their impressive pincers to crush prey.
Commonly known as the Rock Scorpion , these guys are often found in rock crevices and are quite flat in profile to make use of these
inaccessible hiding places. Hadogenes can be quite large, but their venom is so weak as to be practically harmless to humans.
Due to their specific habitat requirements they are under threat from development and habitat destruction.
The Hadogenes feed on insects, spiders, other scorpions, millipedes, and due to their size, can even take small vertebrates.
This is a medically important scorpion, in that the venom is of sufficient strength to be possibly fatal to humans, particularly children and the elderly.
They can not only sting, but have the capability of “spitting” their venom a short distance.
They live in rock areas, under surface debri such as loose rocks,logs, leaf litter, and around human habitation such as in firewood
piles, garden refuse, etc.
We saw a number of other interesting creatures such as a baby baboon spider who was defending the entrance to his burrow as if he was ten times his actual size, wasp larvae feeding on spider remains, an African Bush Locust, showing a good example of aposematic colouration, and various Solifugae.
All in all, a great day out in the bush!