AW Arachnid Book: Spiders (Araneae) - Photos & Descriptions

Sun Apr 19, 2015 9:57 pm

Flower Crab Spider Thomisus sp.
Family Thomisidae

A Banded-Eyed drone Fly on a daisy caught my eye.... I had to look closely to see that a superbly camouflaged Crab Spider had it in its clutches!

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Garden in Johannesburg

AW Arachnid Book: Spiders (Araneae) - Photos & Descriptions

Sun Apr 19, 2015 10:00 pm

Flower Crab Spider Thomisus sp.
Family Thomisidae

An even smaller Crab Spider; these are really hard to spot.
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The same spider but closer.
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AW Arachnid Book: Spiders (Araneae) - Photos & Descriptions

Sun Apr 19, 2015 10:01 pm

Flower Crab Spider Thomisus sp.
Family Thomisidae

Image © steamtrainfan
Garden in Pretoria

Sparassidae (Huntsman Spiders)

Sun Apr 19, 2015 10:05 pm

Sparassidae (Huntsman Spiders)

Sparassidae spiders (huntsman spiders) are often confused with the family Theraphosidae (Baboon spiders). The latter are more bulky and very hairy without the typical ventral markings. Sparassids can be confused with spiders of the Ctenidae and Pisauridae families. Sparassids are commonly known as huntsman spiders and large wandering crab spiders. Afrikaans names are grootdwaalkrapspinnekop and jagspinnekop.

The family Sparassidae is a large family comprising 83 genera of which 34 are known from the Afrotropical cal Region. From South Africa 9 genera represented by 56 species are known of which 40 are endemics.

Body size
6-40 mm with leg span up to 100 mm (males slightly smaller and more slender).

Diagnostic characters
Colour: cream, fawn to dark brown or grey, often with darker stripes and mottled patterns while some species of Olios and Pseudomicrommata are green.
Carapace: round to ovall, narrower in eye area, fovea present.
Eyes: 8 in 2 rows (4:4) with the posterior eye row evenly spaced, equal in size while the size of eyes in anterior row varies between genera, with the median eyes usually largest.
Abdomen: hairy, round to oval, often with dark, median heart mark.
Legs: long, positioned side-ways and held at right-angle to body, the tarsi with dense claw tufts.

Web and retreat
Web: absent; retreat: some genera live in silk-lined burrows while other make silken retreats to reside in when not active.

Habitat
The sparassids are found in diverse habitats ranging from desert to coastal and montane
forest. Some genera like Pseudomicrommata
common in grassland and savanna while some species of Palystes are found in and around houses.

Behaviour
Most of the sparassids are large noctural spiders wandering around in search of prey. When disturbed they raise their front legs in warning. Palystes, is large spiders frequently entering houses, usually one or two days before it starts to rain, hence their common name "rain spiders". They are often noticed at night on the walls of rooms where they prey on insects attracted to the light source.

Genera native to southern Africa:
Arandisa: One species (monotypic), Arandisa deserticola, a Namibian endemic. 10.8mm.
Carparachne: Two species, endemic to dunes of the southern Namib Desert in Namibia.
Eusparassus (Rock huntsman spider): Presently the only species in the genus is Eusparassus palystiformis, known from southern Africa.
Leucorchestris (white lady spiders): a psammophilous genus occurring on sand dunes in arid areas, Namibia, Angola and the Northern Cape, South Africa.
Microrchestris: a Namibian endemic genus with two small-sized species (10-12mm long).
Olios: 27 species recorded from southern Africa; smaller spiders (Body length is 10-14 mm), either light brown and live under rocks (rupicolus) or green and live on trees (arboreal). The rock-dwelling species produce a flattish sac retreat and egg sac attached to the underside of a rock or stone.
Orchestrella: a Namibian endemic genus with two species (10-18 mm long).
Palystella: a Namibian endemic genus with four species (11-18 mm long).
Palystes (rain spiders): Occur mainly on plants where they hunt predominantly insects but they also eat geckos. Large spiders, come indoors. Females of the two common species, Palystes castaneus and Palystes superciliosus, construct an egg case in a bush that is made of dead leaves and twigs drawn together with silk and with a white silk covering.
Panaretella (forest huntsman spiders): a genus of small spiders endemic to the forests from Grahamstown to northern Kwazulu-Natal. Five species. The retreat is two leaves spun together with silk. Body length 12-18 mm. They vary from a yellowish to a light reddish brown colour with a distinctive black mark on either side anterior of the spinnerets.
Parapalystes: Five species, endemic to southern Africa.
Pseudomicrommata: a monotypic genus with only one species, Pseudomicrommata longipes. Found in areas with Eragrostis grass where it constructs its large nest. Easily recognised by the medial dorsal band running the length of its body.

Genera naturalised in southern Africa:
Heteropoda: Heteropoda venatoria (Brown huntsman spider), a species with a pantropical distribution, has been introduced to Mozambique and South Africa.

Links: Biodiversity Explorer; Atlas of the Spiders of South Africa

Sparassidae, Genus Olios

Sun Apr 19, 2015 10:07 pm

Genus Olios

27 species recorded from southern Africa.
Smaller spiders (Body length is 10-14 mm), either light brown and live under rocks (rupicolus) or green and live on trees (arboreal). The rock-dwelling species produce a flattish sac retreat and egg sac attached to the underside of a rock or stone.

Biology
As adults, huntsman spiders do not build webs, but hunt and forage for food: their diet consists primarily of insects and other invertebrates, and occasionally small skinks and geckos. They live in the crevices of tree bark, but will frequently wander into homes and vehicles.

AW Arachnid Book: Spiders (Araneae) - Photos & Descriptions

Sun Apr 19, 2015 10:08 pm

Huntsman Spider Possibly Olios sp.
Family Sparassidae

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Kgalagadi Transfrontier Park

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Huntsman spider with moth prey

Sparassidae, Genus Palystes (Rain Spiders)

Sun Apr 19, 2015 10:12 pm

Genus Palystes (Rain Spiders)

Palystes is derived from either the Latin "palaestes" or Greek "palaistes" meaning wrestler. These are the large spiders, often referred to as "tarantulas", that cause havoc by entering buildings during summer or before rain.
These spiders were previously listed as potentially dangerous. After tests where they were induced into biting guinea-pigs it was established that although the guinea-pigs had died within 3 minutes, it had been from shock and not the effects of any venom. For humans, the venom is in fact no worse than a bee sting although the spider's aggressive display, with its 2 front pairs of banded legs raised in warning, is enough to shrink the stoutest of hearts. They occur usually in vegetation but sometimes occur in the home.
Palystes occurs mainly on plants where it hunts various insects but is also regularly found in the home where they are fond of hunting geckos (usually the Marbled leaf-toed gecko, Afrogecko porphyreus in the Western Cape or the Cape dwarf gecko, Lygodactylus capensis in the eastern parts of southern Africa) and are sometimes called lizard-eating spiders. They usually appear in the home just before the onset of rain and the males are regularly seen in August to December, probably looking for females and also females busy foraging.
Palystes is also regularly seen in more unfortunate circumstances where it is being dragged around by a wasp or often the wasp is missing and all one finds is what seems to be a dead spider on the pathway. What has in fact happened is that the spider has been stung and immobilized by a female wasp of the family Pompilidae. These wasps hunt only spiders that they sting and paralyse and then stock each of their nests with a paralyzed spider, lay an egg on it and then seal the nest. The wasp eggs then hatch and the larvae have live fresh food on which to feed. All peripheral tissue is eaten first and lastly the vital parts so the meal stays fresh long enough for the larva to mature and then pupate.

Distribution
Twenty eight Palystes species occur in central, eastern and southern Africa with 13 resident in South Africa.

Descriptions
Palystes body length is 15-36 mm with a leg span of up to 110 mm.
Dorsally (top) it is covered in tan to dark tan velvety covering of setae (hairs). The abdomen and legs might be interspersed with slightly longer setae (hairs).
The diagnostic features are a white moustachial stripe below the anterior (front) eyes and extending down the chelicerae (fangs) as well as banding on the ventral (underside) of the legs.
Another identifying feature of Palystes castaneus and P. superciliosus, is the egg sac made by the female. It is a roundish bag made of silk with leaves and twigs woven into it and is about 60-100mm in size. The construction of this nursery and the laying of eggs takes about 3-5 hours. The eggs hatch inside and are protected within the bag of silk and leaves. During this time the female guards her brood aggressively. Many a gardener has been bitten by a protective Palystes mother. After about 21 days, the spiderlings chew their way out of the sac to join the world. These egg sacs are a common sight from about November to April. Mating takes place in early summer and the spider will produce about 3 egg cases in her 2 year life.

Biology
As adults, huntsman spiders do not build webs, but hunt and forage for food: their diet consists primarily of insects and other invertebrates, and occasionally small skinks and geckos. They live in the crevices of tree bark, but will frequently wander into homes and vehicles.

Biodiversity Explorer

AW Arachnid Book: Spiders (Araneae) - Photos & Descriptions

Sun Apr 19, 2015 10:16 pm

Common Rain Spider Palystes superciliosus, formerly Palystes natalius (Reënspinnekop)
Family Sparassidae

Image © BluTuna

Description
Body length is 25-30 mm with a leg span of up to 100 mm. Dorsally (top) it is covered in tan to dark tan velvety covering of setae (hairs). The abdomen and legs might be interspersed with slightly longer setae (hairs).
The diagnostic features are a white moustachial stripe below the anterior (front) eyes and extending down the chelicerae (fangs) as well as banding on the ventral (underside) of the legs.
It has slightly darker markings dorsally and the sternum is of the same colour as the spider with a single dark traverse bar between the second coxa.
It has eight eyes in two rows.

Distribution
Palystes superciliosus is the most common and widespread species of the genus. It is distribution ranges from Kwazulu-Natal then westwards to Mpumalanga, North West, Limpopo, Gauteng and south through the Free State to the Eastern and Western Cape.

Habitat
Its favoured habitat is scrubland and savannah woodland and it is also typically found in houses.
They are nocturnal wandering hunters, and do not build webs. Although they normally live in vegetation, they often come indoors at night to hunt insects attracted to our lights which can cause quite a stir because of their impressive size.

Behaviour
These large rain spiders are free-living plant dwellers, often actively wandering at night in search of prey. The common name is derived from the fact that they frequently enter buildings a day or two before rain. When disturbed they raise their front legs in warning, displaying their strong fangs. They are often seen on walls at night, preying on insects attracted by the light. They prey on a variety of insects. They have also been observed feeding on other arachnids as well as small reptiles such as gecko.

Reproduction
Palystes superciliosus produces the well known "bag of leaves" egg cocoon. It is a roundish bag made of silk with leaves and twigs woven into it and is about 60-100 mm in size. The construction of this nursery and the laying of eggs takes about 3-5 hours. The eggs hatch inside and are protected within the bag of silk and leaves. During this time the female guards her brood aggressively. Many a gardener has been bitten by a protective Palystes mother. After about 21 days, the spiderlings chew their way out of the sac to join the world. These egg sacs are a common sight from about November to April. Mating takes place in early summer and the spider will produce about 3 egg cases in her 2 year life.

Venom
While they can bite, their venom is harmless to people and their domesticated animals.

Links: Biodiversity Explorer; Wikipedia; ARC-Plant Protection Research Institute Plant Protection Research Institute Plant Protection Research Institute Fact sheet series (PDF)

AW Arachnid Book: Spiders (Araneae) - Photos & Descriptions

Sun Apr 19, 2015 10:19 pm

Huntsman Spider Palystes sp.
Family Sparassidae

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Tsendze Camp, Kruger National Park

Palystes: Large spiders with a distinct white line in front of the eyes which are in two rows of four.

Biology
As adults, huntsman spiders do not build webs, but hunt and forage for food: their diet consists primarily of insects and other invertebrates, and occasionally small skinks and geckos. They live in the crevices of tree bark, but will frequently wander into homes and vehicles.

Selenopidae (Wall Crab Spiders, Flatties)

Sun Apr 19, 2015 10:21 pm

Selenopidae (Wall Crab Spiders, Flatties)

A small family represented by 4 genera and about 200 species. They are well represented in the Afrotropical Region. From South Africa 2 genera and 68 species are known.

Life style
Wanderers (plant and ground dwellers): free-running.

Body size
6-23 mm.

Diagnostic characters
Colour: They are cryptically coloured in cream to yellow or grey with mottled grey, brown or black markings and the legs are usually banded or mottled which may be distinct or indistinct. As with many spiders, their coloration varies and with the Selenopidae, the colouration can vary from one habitat to another, some resembling the lichen of their rock habitat or colour of the tree they occur on.
Carapace: flattened and subcircular.
Eyes: 8 in 2 rows (6:2) with the anterior row containing 6 eyes wide near edge of carapace, posterior row with 2 fairly large eyes, one on each side. In Selenops the four median form almost a straight row and with Anyphops they form a recurved row.
Abdomen: flattened, round to oval in shape and densely clothed with setae
Legs: spread outwards (latrigrade). 2 claws with claw tufts and scopula and legs directed sideways with anterior legs provided with strong, paired setae on tibiae and metatarsi I and II.

Web and retreat
Web: absent; retreat: hide beneath debris when not active.

Habitat
They have a very wide habitat range and have been collected from all the different biomes. They are synantropic and commonly found in houses on the walls.

Behaviour
Selenopids normally appear sedentary and will stay motionless for long periods but they are able to move with great agility in a smooth flowing motion, their latrigrade legs enabling them to move rapidly in any direction. When moving normally their movement resembles that of the Sparassidae. With their very flattened bodies they are able to move into narrow crevices. They dart with astonishing speed sideways for cover when disturbed. With their mottled bodies they blend in with their surroundings whether on the soil surface, rocks or tree trunks. They are commonly found in agro-ecosystems especially in orchards like avocado and macadamia. Selenopids are among the most common spiders encountered in houses in Southern Africa, living on the walls. They are attracted by light in the evening and prey on the insects that gather around the light. When disturbed they disappear under wall hangings or in crevices. The egg sacs are about 15 cm in diameter. The disc-shaped, satin smooth egg cocoons are attached to the under surface of stones and in houses are easily seen when attached to dark wooden beams. Local people use it as a vibrating element in music instruments.
These spiders are useful in controlling insect pests such as mosquitoes, moths and cockroaches. Research has shown that Selenops radiatus can be an effective controlling agent of the potato tuber moth in potato sheds in South Africa.

Genera indigenous to southern Africa
Anyphops occurs from Cape Town to Somaliland in north Africa and Madagascar with 56 species in South Africa. Anyphops can be separated from all other genera by the ventral leg spination of Ti and Mt I and II, coupled with the collection locality. Specimens have either 4, 5, 6 or 7 paired ventral tibial spines and are found in Africa or Madagascar. If the tibial-metatarsal spination is 4–3 the spider is found in Africa and not Madagascar. Median eyes strongly recurved.
Selenops has a subtropical distribution occurring in central and south America, Asia, Africa, Mediterranean region of southern Europe. There are 12 species known from South Africa. All members of this genus can be distinguished from other genera by the ventral spination on the tibiae and metatarsi of legs I and II, where there are 3 pairs of spines on the tibiae, and 2 pairs of spines on the metatarsi. Eyes: 6 eyes in anterior row, either in a straight line or slightly recurved. Selenops radiatus, the type of the genus, is the most widespread species.

Links: Astri Leroy, John Leroy: Spiders of Southern Africa