Tag: ARANEIDAE

Orb-Weaver Spiders. They are known for making a wagon wheel-like web. They are usually nocturnal animals, but some of the species are active throughout the day. Orb-weaver spiders have 8 eyes of about the same size and located in two rows. The first pair of legs of most of the spiders in this family is the longest of all their legs, and the third pair of legs the shortest. Their legs arrangement is as follows: 1, 2, 4, 3. They are medically insignificant to humans.

NEOSCONA SP.

NEOSCONA SP.

by anikekirsten
Adult female Neoscona sp.

Taxon:

  • Class: Arachnida
  • Order: Araneae
  • Infra-Order: Araneamorph (true spiders)
  • Family: Araneidae
  • Genus: Neoscona
  • Species: Neoscona sp.

Female

Around 5mm in body length. Leg span of approximately 8mm diagonally.

Cephalothorax:
Carapace cream coloured and plain save for cephalic region raised and with faint white setae. Chelicerae same colour as carapace. Pedipalps same colour as legs, plain. Faint striations from fovea.

Abdomen:
Abdomen same colour as carapace, hairy, shield shaped with two shoulders anterior dorsal and 6 black dimples between shoulders down dorsal middle with faint markings posterior dorsal.

Legs:
Legs cream coloured, slightly darker than body, faintly mottled with light spines, darker distally. 1, 4, 2, 3.

Male

Unknown.

Adult female Neoscona sp.
Adult female Neoscona sp.

ABOUT THE GENUS

These spiders are commonly found all over South Africa and are called the hairy field spider or barn spider. They come in a huge variety of colours, shapes, and patterns, even among the same species. They are medium-sized spiders, often confused with the Araneus genus (field spider) or the Paraneus genus (the spikey field spiders). They will hid in a retreat off to the side of their web and emerge once prey is caught in the strands. Some species have been observed consuming their webs in the morning only to reconstruct them come the evening.

NEOSCONA SUBFUSCA

NEOSCONA SUBFUSCA

by anikekirsten
Adult female N. subfusca

Taxon:

  • Class: Arachnida
  • Order: Araneae
  • Infra-Order: Araneamorph (true spiders)
  • Family: Araneidae
  • Genus: Neoscona
  • Species: N. subfusca

Female

Around 5mm in body length. Leg span of approximately 9mm diagonally.

Cephalothorax:
Carapace white with a slightly darker cephalic region that is slightly raised, and dark lines along the anterior margins. Sternum yellowish white with dark border and faint dark patch in center, shield shaped. Chelicera yellowish fading to dark ends. Pedipalps pale and hairy.

Abdomen:
Rounded triangular shape, whitish in colour. Dark wavy V marking on dorsum from apex down to posterior with thin darker lines inside and faint yellowish wave lines from the edges of the marking to the sides of the abdomen, white wing-like pattern anterior. Venter yellowish with dark Y shape marking centre that leads to dark spinnerets. Epigyne dark.

Legs:
Legs yellowish white with thin bands around joints. 1, 4, 2, 3.

Male

Unknown.

Adult female N. subfusca
Adult female N. subfusca

ABOUT THE GENUS

These small to medium-sized spiders are among the most frequently encountered orb-weavers in South Africa, making large webs around human habitats as well as in gardens. They are near-cosmopolitan is range and are commonly known as the hairy field spider. These spiders will construct their web in the evenings and devour them in the mornings where they will retreat to a nearby hide. They come in various colours and patterns, but are still often difficult to identify to species level without a microscope. This species, in particular, has many variations and is recorded as being found in every province.

TRICHONEPHILA SENEGALENSIS

TRICHONEPHILA SENEGALENSIS

by anikekirsten
Dead sub-adult female T. senegalensis

Taxon:

  • Class: Arachnida
  • Order: Araneae
  • Infra-Order: Araneamorph (true spiders)
  • Family: Araneidae
  • Genus: Trichonephila
  • Species: T. senegalensis

Female

Around 20mm in body length. Leg span of approximately 70mm diagonally. Sub-adult female.

Cephalothorax:
Carapace oval with square-like cephalic region, silvery and furry, faint lines radiating from fovea, two eye-like dots on raised cephalic region near fovea, indents in between trochanter, black semi-circle poster centre. Ocular region black, chelicera black and thick and long. Sternum long triangle shape and orange. Pedipalps unmodified, orange with black tarsus.

Abdomen:
Abdomen long, rounded square shaped, sloped in dorsal middle. Dorsal black with white half-square border anterior and along sides, with 4 bars of white across centre toward posterior.

Legs:
Long legs with black plumose setae near ends of tibia in legs 1 and 2. Legs 1 and 2 with brown femur and orange tibia. Legs 3 and 4 with orange femur and brown tibia. Tibia of leg 4 fully covered in black plumose setae, and metatarsus partially so. Spines of femur, tibia, and metatarsus of all legs. Patella, metatarsus, and tarsus black. Leg formation 1, 2, 4, 3.

Male

Around 8mm in body length. Leg span of approximately 20mm diagonally.

Cephalothorax:
Carapace shape as in female but orangish-brown with two dark lines down centre. Cephalic region black. Pedipalp tarsi light orange-brown fading to black at tips, and bulbous. Sternum triangular and yellow.

Abdomen:
Abdomen long and thin, slightly tapered. Dorsal yellowish with dark marking down centre, marking outlined by yellow border. Ventral black with yellow splotchy lines down each side.

Legs:
Legs much like female but faded and the bands indistinct, more brownish than orange. Leg formation 1, 2, 4, 3.

Adult male T. senegalensis
Dead sub-adult female T. senegalensis

ABOUT THE GENUS

Spiders of the genus Trichonephila are known as Golden Orb-Weaver spiders because of their yellow silk that looks golden in sunlight. They, like the Argiope orb-weaver spiders, spin large and wide webs of sticky silk and are generally web-bound for their whole lives. They are iconic for their long bodies and legs that feature tufts of feather-like hair on the tibia.

These spiders are also rare to come by, often preferring to stay very far from human activity and are usually found in areas with plenty of large shrubs, bushes, and trees. They aren’t readily found in arid areas, having a preference for wet and humid regions.

CYRTOPHORA CITRICOLA

CYRTOPHORA CITRICOLA

by anikekirsten
Adult female C. citricola

Taxon:

  • Class: Arachnida
  • Order: Araneae
  • Infra-Order: Araneamorph (true spiders)
  • Family: Araneidae
  • Genus: Cyrtophora
  • Species: C. citricola

Female

Around 25mm in body length. Leg span of approximately 35mm diagonally.

Cephalothorax:
Carapace silvery and “furry”. Pedipalps unmodified, light brownish yellow with faint bands.

Abdomen:
Abdomen brown and mottled, square-like oval shape, tapering slightly, with 2 pairs of shoulders and two “humps” on posterior tip. Dorsal centre with thick dark marking with undefined pattern of brown and white, bordered by white. Dark spinnerets ventrally with mottled marking around epigynum.

Legs:
Greyish brown with dark spines. Femurs more grey. Bands prominent on tibia and metatarsus. Tarsus dark.

Male

Around 3mm in body length. Leg span of approximately 5mm diagonally. Possibly sub-adult and not fully mature yet.

Cephalothorax:
Carapace dark with slightly lighter, greyish band down centre. Pedipalps short with tarsi dark, large, and oval.

Abdomen:
Abdomen square-like oval with slight dip in middle of posterior tip. Dorsal brown with an irregular band of white down the sides and a thicker irregular band of white down the middle. Ventral light with dark band down centre.

Legs:
Legs light brown, faintly banded.

Adult female C. citricola
C. citricola Egg Sacs

ABOUT THE GENUS

C. citricola, the tropical tent-web spider, is a special and interesting spider due to the different (often wildy different) variations of the abdominal colouration and pattern the species has.

From black & white colours, to an almost uniform olive-brown colour, and the grey & black in between. Even a grey & red colouration! Not to mention its variances in the opaqueness of the pattern and abdomen shape 3.

C. citricola are one of the few spiders that are colonial. They group together in an area and build their webs close together, like a small colony. They’re not “communal”, however, so each spider has their own web. Uloborids are similar in this behaviour.

The tent structure of C. citricola’s web could very well be giving these spiders a huge advantage because their webs can withstand the weather better in wide, open spaces where other web-dwelling spiders struggle to thrive 1.

Like Argiope and Pholcid spiders, when C. citricola detects a threat through vibrations on her web, she’ll “bounce” herself on the web which makes her difficult to see. And if the threat persists, she’ll scurry into the “tent” of her web. This is rather effective, though it might not look it.

Her web is impressively strong for even an orb-weaver. Almost as strong as a funnel nursery-web spider’s web.

ARGIOPE LOBATA

ARGIOPE LOBATA

by anikekirsten
Adult female A. lobata

Taxon:

  • Class: Arachnida
  • Order: Araneae
  • Infra-Order: Araneamorph (true spiders)
  • Family: Araneidae
  • Genus: Argiope
  • Species: A. lobata

Female

Around 25mm in body length. Leg span of approximately 60mm diagonally.

Cephalothorax:
Carapace silvery white with black half-moon marking near pedicel (small tube connecting the cephalothorax to the abdomen). Large chelicerae with small fangs. Pedipalps with black setae.

Abdomen:
Abdomen oval with sharp black-tipped ridges on sides. Dorsal abdomen with 3 rows of 2 indents in middle, silvery white with yellow stripes across in line with ridges. Spinnerets under abdomen, raised hump. Epigynum with appendage. Abdomen underside black with yellow outline along ridges, yellow splotch pattern in parallel down centre toward spinnerets.

Legs:
First two leg pairs longer than hind two. 3rd pair shortest. All legs pale and covered with black bands down segments fading into black on metatarsus and tartsus. Black setae on legs, most on metatarsus and tarsus.

Male

About 6mm in body length. Leg span of approximately 11mm diagonally.

Cephalothorax:
Cephalothorax larger than abdomen. Two thick dark brown stripes parallel down silvery carapace. Large brown pedipalps.

Abdomen:
Narrow and long brownish silvery abdomen. Two dark brown stripes down centre dorsal abdomen. Yellow spots on black ventral abdomen.

Legs:
First two pairs of legs longer. 3rd pair shorter than others. Sparse long hairs on legs. Cream legs with dark brown joint segments and spots on femurs.

Adult female A. lobata
Adult male A. lobata
Adult male A. lobata

ABOUT THE GENUS

Argiope is a genus known for large and yellow orb-weavers with a silvery carapace. They often weave zig-zags (called stabilimentum) in the form of a cross on their immense webs and this helps alert larger animals that there is a web so that they don’t walk or fly into it easily and destroy it 4. Not always successful, but it helps.

When threatened, Argiope spiders will also shake their web, and it looks like the spider is bouncing. This, too, confuses predators and makes the spider either difficult to see or appear as something else to them 5.

Most male spiders are considerably smaller than the females and tend to be a brownish or orange instead of the bright colours of the females. A male’s abdomen also does not look like that of a female Argiope spider.

Argiope spiders are also known to engage in sexual cannibalism, which is where the female will eat the male after mating.

One of the reasons to keep A. lobata and any orb-weaver in your garden is simply that their webs trap mosquitoes very well, along with flies and moths.