The Uropygi are known by many names, including whipscorpions, vinegaroons, whiptail scorpions, grampus, and others. These arachnids are relatives of the well-known tarantulas, scorpions, and true spiders and the not-so-well-known tail-less whipscorpions, ticks, mites, and solifugids. There are about 70-130 species world wide and they are native to the tropical and semi-tropical regions of our planet, inhabiting North, South and Central America, Asia, and the East Indies.

These invertebrates resemble scorpions but differ from them in the size of their pedipalps and their tail. They range in size from the very minute (one and a half inches or less) to the quite large (four inches or more), the largest being the giant vinegaroon Mastigoproctus giganteus. They are not especially colourful arachnids, being dull brown to black in colour. Their first pair of walking legs are long and thin and are used as feelers. They have a long whip-like tail at the end of the abdomen (hence the name) and at the base of the tail there are two slits that are used to spray formic acid in self-defence.

The North American species sprays an acid and a solvent that attacks the exoskeleton of other invertebrates. This acid smells of vinegar and it is this feature which brought about the commonly used name vinegaroon. Other tropical species spray a mixture which smells of formic acid or chlorine. The spray is not dangerous to humans, unless it enters the eyes or mouth, but it is quite effective in repelling mice, birds and other small predators.

Apart from this defensive mechanism, they are actually quite harmless, although they can pinch would-be predators. Whipscorpions are nocturnal and secretive creatures, which by day hide under stones, rotting wood, in deep self-dug burrows and in homes in dark corners. In captivity and in the wild they dig burrows in the soil to a depth of six inches or more. Such burrows are essential for whipscorpions, as they must have access to these to moult. Most of the time whipscorpions will only moult in the safety of a deep, humid burrow and if the conditions are not correct, (for example: too dry, not enough substrate to burrow in, etc.) they may go long periods of time between moults; even up to two to three years.

Captive Care

I’ll be the first to admit that whipscorpions are not exactly mainstream pets, but if you give them a try you’ll find that they can make a great, calm addition to your collection that may live a decade, or more, in captivity.

For your enclosure you can use a glass tank, a small plastic animal enclosure such as a “Pet Pal” or “Critter Keeper”, or a plastic sweater box. I recommend glass tanks, as these last a long time and give the whipscorpions enough room. Of course, if you have a small nymph or juvenile, you certainly would not want to give it a huge ten-gallon tank, so make the enclosure size appropriate to the size of your creature.

For substrate I would highly recommend sterile peat moss. This is relatively inexpensive and can be purchased in quantities amounts at department stores or garden centres. I do not recommend play sand, soil collected from the outdoors or gravel as these do not allow your whipscorpions to dig properly. They may also contain harmful additives. Since these are burrowing creatures, a substrate depth of five inches or more will be required. A number of good hiding places should be provided on the surface and can include items such as slabs of cork bark, driftwood, plants and other decorative items. It is recommended that you obtain these from a pet store or other similar establishment but if you do collect your own tank décor from a desert or forest, any items to be used in the terrarium should be soaked in a saline solution for twenty-four hours, taken out and rinsed in warm water very thoroughly, then placed out in the sun for a day to dry. The items should be sterile after this process. Generally it is safer, and much easier, just to buy your hides and decorative items and a wide range of suitable products are now widely available.

A small, wide, shallow water dish can be provided but exercise caution, as I have heard of instances where whipscorpions drown themselves in their dishes, even when they appear to be shallow enough for them to right themselves and escape. In view of this I think it’s safer to just mist the sides of the enclosure every other day, enabling the whipscorpion to drink. Humidity should be kept at seventy-five to eighty-five percent and can be maintained by a light misting of the tank one to two times per week. Be careful not to let the habitat become overly damp, as this can become a breeding ground for infections which could kill the whipscorpion. One of the main problems is a fungus that deteriorates the exoskeleton.

The temperature of the whipscorpion‘s enclosure should be kept at seventy-five to eighty-five degrees Fahrenheit, with an optional five-degree temperature drop at night.

For food I recommend store bought crickets as these are inexpensive and you can be sure they are free from harmful pesticides that may kill your whipscorpion. Do not feed wild caught insects unless you can be one-hundred percent sure they are free from sprays. Alternatives to crickets are mealworms, moths, and other small insects. Some people trim the jumping legs of the crickets before they are fed to their whipscorpion, but this seems cruel to the crickets, even if it does help the whipscorpion catch the prey more easily. This practice is not necessary in my opinion. Whipscorpions will also take large, freshly-killed prey items which may be a more suitable and humane alternative.

Mating

The whipscorpion mating process is similar to that of the true scorpions, i.e. the male and female come together and perform a courtship dance. In this process the male grasps the female‘s pedipalps and the pair “dance” claw in claw. The male then releases a spermatophore which he inserts into the females genital opening, the gonopore, with his pedipalps. The pair then separate, leaving the female to care for the future brood. Inside the female the sperm develops and soon she lays a membranous sac which she carries just below her abdomen. The sac contains twenty-five to thirty-five eggs (depending on the species).

The female will stay in some kind of shelter, like a burrow, while she carries the egg-sac. In thirty to sixty days (depending on the species) the eggs within the sac will hatch and all the nymphs will emerge and clamber onto the mothers back. The young nymphs are white and helpless and they remain on their mother until their first molt. After this they will proceed to venture off the mothers back one by one until they eventually become totally independent. After this the female soon dies due to starvation. This is because she has not eaten during the entire period in which she carried the sac and the nymphs. There have been cases of the female surviving but it is not for long, and is very uncommon.

Whipscorpions have been bred in captivity, but they are not one of the more popular invertebrates to breed. If you want to go about this process, first of all make sure you have a male and female. They can be a challenge to sex, but if you have a few to compare then it can be relatively easy. The best way to sex whipscorpions is to look at the pedipalps (pincers). A male‘s pedipalps will be very heavy, pronounced, and strong and will also protrude quite a bit more than the females. The female will have smaller and weaker pedipalps.

Make sure the male and female are both well-fed prior to them mating, introduce the male to the female’s enclosure and let nature take its course. Watch carefully to make sure no fights occur as this could result in the injury, or death, of either mate. When the process is over, separate them and in a short time, if the mating was a success, the female will lay her sac. The nymphs should hatch in one to two months (depending on the species). Let the them stay on the female’s back until they are ready come off. They should start venturing away from the mother soon after their first moult. Try feeding the mother immediately after they are all off (she may survive if she eats straightaway) but do bear in mind that this is not nature’s way and she will, in all probability, die. Separate the youngsters into their own individual containers (deli. cups and small plastic animal enclosures work well) and give them enough substrate to make a small burrow in. Basically just give them the same care as the adults, only on a smaller scale. They can be fed on small insects, such as a pinhead crickets, with the head crushed or the jumping legs removed so they are easier to catch.

In closing, whip-scorpions are very interesting arachnids. If you do give them a go, I believe you will grow to like them, as they continue to be one of the most fascinating animals of the invertebrate world.