Solifugae

Solifugae (solifugids)

sun spiders, red romans, wind scorpions, wind spiders, camel spiders, jerrymanders [English alternative names]; haarskeerders, baardskeerders, rooimanne, jag spinnekoppe ('hunting spiders'), gift-kankers ('poison cancers'), vetvreters ('fat eaters') [Afrikaans]

Life > Eukaryotes > Opisthokonta > Metazoa (animals) > Bilateria > Ecdysozoa > Panarthropoda > Tritocerebra > Arthropoda > Arachnomorpha > Cheliceriformes > Chelicerata > Euchelicerata > Arachnida

This group of arachnids has various common names most of which suggest that they are spiders, which they are not. The only similarity they share with spiders is the fact that they have eight legs. Solifugids have no venom glands and are not a threat to people although they are very aggressive and fast moving and can inflict a painful bite.


Diurnal female Solifuge eating an insect. [image N. Larsen ©]	Diurnal female Solifuge (body length about 15-20 mm). [image N. Larsen ©]

Diurnal femaleSolifugid from De Hoop Nature Reserve (body length about 35 mm). [image N. Larsen ©]	Nocturnal male Solifugid from Vrolikheid Nature Reserve. Animals of this colour probably originated the term 'red roman' (body length about 50 mm). [image N. Larsen ©]

The name of the solifuge originates from the Latin for 'fleeing from the sun' although many species are nocturnal. There are a number of common names in both english and afrikaans for these distinctive creatures, many of which include the term 'spider' or even 'scorpion'. Although it is neither of these, "spider" is prefered to "scorpion". The term 'sun spider' applies to those species active during the day that tend to avoid the heat and dash from shadow to shadow - often of a person - giving the alarming impression that they are giving chase. The term 'red roman' probably originates form the Afrikaans term 'rooiman' (red man) due to the red-brown colour of some species. The popular terms 'haarskeerders' and 'baardskeerders' (Afrikaans words for hair and beard cutters) originate from the strange behaviour of some of these animals where they cut hair from sleeping people or animals (dogs) at night. It appears that female solifuges find hair to be an ideal nest liner. It appears that that their chelicerae are not adapted for cutting hair and until this can be proven it must remain a myth.

Solifuges appear to have 10 legs but in fact, the first pair of appendages are the pedipalps that are very strong and are used for various functions such as drinking, fighting, feeding and mating. The first pair of legs are thin and short and used as tactile organs. The fourth pair of legs are the longest and strongest and carry white structures called racket organs - the purpose of which is not known.

They vary in size and in the arid areas of southern Africa they can reach 70 mm and with legs included, can measure 160 mm. The head is large, supporting large strong chelicerae (jaws). The 11 segmented abdomen is soft and expandable that enables the animal to eat large amounts of food.

The order includes various families including the following South African: Ceromidae (3 genera, 8 species), Daesiidae (4 genera, 59 species), Gylippidae (1 genus, 2 species), Hexisopodidae (2 genera, 6 species), Melanoblossiidae (2 genera, 6 species) and Solpugidae (7 genera, 62 species). Of the 1075 species throughout the world, 153 species or 14% occur in South Africa. Solifuges are divided into two groups - nocturnal and diurnal. The diurnal species are usually more brightly coloured and the nocturnal species are a yellowish brown and some species are much larger. These arachnids are found mostly in the hot arid regions and have a resistance to high temperatures and low humidity.

Solifuges prey on various insects, spiders, scorpions, small retiles, dead birds and even each other. Some species are exclusively termite predators. They run their prey down and once they catch it they eat while the prey is still alive with vigorous ripping and cutting actions of the powerful jaws.

Male solifuges have hook-like flagella on the chelicerae (like backward swept aerials), uniquely shaped for each species, that probably play some part in mating. During mating, the male deposits a spermatophore in the female's vagina. About 20 to 200 eggs are produced and hatch within about four weeks. Solifuges live for about a year and pass through 9 instars before maturity. They are solitary animals living in scraped out sand retreats, often under rocks and logs.

Reference

Dippenaar, A. 1993. Sunspiders - some interesting facts. African Wildlife. 47(3): 120-122.
Dippenaar-Schoeman. A., Gonzalez Reyers. A. X., Harvey. M. S. 2006. A check-list of the Solifugae (sun spiders) of South Africa (Arachnida: Solifugae).African Plant Protection 12:70-92.
Punzo, F.1998. The Biology of Camel-Spiders (Arachnida. Solifugae). Kluwer Acedemic Publishers.301pp.