Socca pustulosa

Socca pustulosa is a Orb-weaver spider species in the family Araneidae (Clerck, 1757), and it was first described by a French scientist Charles Athanase Walckenaer in 1841 from Tasmania, Australia, but later on when Walckenaer examined the specimen collected from New Zealand and renamed it as a different species- Epeira verrucosa. Until 1917, Dalmas reviewed the Australian pustulosa and New Zealand verrucosa and realized they were the same species. Although S. pustulosa has been accepted for some time in the genus of Eriophora (E. pustulosa), the evidence supporting its placement within this genus were not fully convincing. Therefore, an alternative view was proposed in 2022- a new genus established to accommodate pustulosa along with 11 other spider species from Australia; the diagnostic test based on haplotype analysis and systematic morphology study by arachnologists and found the anatomical features of male pedipalp terminal apophysis differs from other orb-web species.

Taxonomy and naming
Scientific name: Socca pustulosa (Walckenaer,1841)

Common name: Garden Orb-weaver Spider.

Description
Socca pustulosa is a perfect example of a symmetry orb-weaving spider, with its intricately glittering orbweb representing the pinnacle of spider evolution. Their abdominal characteristics are the most distinguishing features: roughly triangular shape with two noticeable humps towards the front and five-pointed knobs on the dorsal posterior abdomen. More interestingly, most are covered with a leaf-shaped pattern and various colouration on the abdominal surface, from reddish-brown to yellow or even green, while some have duller colours like greys, whites, or pure black. Mouthpart is another clue to be recognised as Chelicerae, with four teeth on promargin and three on retromaringin, functioning as holding prey when sucking up the fluids from insects.

In general, female spiders tend to be larger than males of the same species, and this is also true for Socca pustulosa; the females of S. pustulosa are almost twice as large as males, with a body length of about 11 mm, while males are weighing about 6mm. In addition, the precise identification of S. pustulosa relied on the reproductive organ, which is the unique trip-partite terminal apophysis amongst the Socca genera; the terminal appendix is an elongated, sometimes threadlike apophysis located between two firmly sclerotised basal and apical lobes. In terms of the female genitalia, the epigyne plate appears roughly square-shaped in ventral view and has a broad atrium. The scape, which bears relatively long setae, is elongated and typically extends beyond the posterior margin of the epigyne plate.

Natural global range
The species of Socca pustulosa is native to Australia and occupies vast territorial areas from Southern Australia- Tasmania and crosses the sea from Victoria, New South Wales, and Queensland. In addition, the species exists throughout New Zealand and is also recorded on many other Pacific islands.

New Zealand range
Presumably, S. pustulosa migrated to New Zealand from Australia by ballooning on silk, which means using small silk strands as "balloons" and being carried by the breeze. Today, this spider species can be found throughout New Zealand and is probably the most abundant of all spider species in the country. Its distribution includes the South Island, North Island, Chatham Islands, Campbell Island, and Bounty Islands.

Habitat preferences
Socca pustulosa tends to stay in any open vegetation habitat exposed to the sun, occupying a wide range of shrublands, forests, and even gardens. Nevertheless, they rarely penetrate deep into dense native forests. Instead, their prey will determine their habitat preferences and whether have enough structures to help them disperse and support their webs, which is the critical factor to hunt, including tree branches, twigs, weeds, fences, and bushes. In contrast, landscape alteration and fragmentation are caused by anthropogenic effects, deforestation, and urbanisation, which have provided many suitable habitats for them.

Life cycle/phenology
The life cycle of S. pustulosa begins with eggsacs, mature females S. pustulosa tend to lay eggsacs during late summer or early autumn. Surprisingly, the number of pink eggs in a single eggsac can reach several hundred, which the females wrap up in olive green silky cocoons. Some survey review that female spiders would lay another eggsac upon the first one and repeat; they rest on it occasionally, presumably that is for protection reasons. After approximately seventeen days, these juvenile orbweb spiders hatch from eggs and grow up quickly; moreover, the spiderlings are exceptionally capable of performing every step required to spin webs without guidance from parents because most of them disperse by ballooning by natural forces. After the S. pustulosa spidering molting (shed their juvenile skin) a couple of times and fully grown sexually mature, most of them enter adulthood in the summertime and start looking for mates. However, when male species reach this stage, they seem to lose interest in web building and preying, instead, they look for mating. The process of reproduction is to produce sperm in the abdomen and then transferred it to the pedipalp, while sperms are injected into the female's epigyne during copulation. Once the injection process finish, the male leaves quickly so as not to be eaten as food by the female. The peak mating season is summer, particularly during warm and humid evenings, and the period will last until the winter months if the weather is still mild. Finally, a new generation of mature females lay egg sacs, and the lifecycle will restart again.

Diet and foraging
Like any other orbweb spider, Socca pustulosa uses its typical spider webs to prey on flying insects; small insects like flies, moths, beetles, wasps, and mosquitoes become their primary food source. Nearly all orbweb spiders are nocturnal; therefore, web-constructing usually takes place at night, but sometimes they may also be found spinning their web in the middle of the day if the weather is dull or overcast. The intricate orbweb is their efficient predation tool, silk is produced by spiders through specialized glands called spinnerets, which are situated at the end of their abdomen. To begin with, females S. pustolosa spend some time exploring their surroundings, laying a dragline as they travel back and forth, that not only expands their boundary threads from suspension but also might leave for later web forming. After a strong top bridge line linking two trees or bushes, the next step is to spin several anchor points attached to each side, using one of the loose threads pulled down vertically to form a Y-shape as the central structure, with more silk reinforcing the central hub from which spiral outwards; noticeably that this first radiational orbweb is not sticky but act as a framework. Following the first layer, the spider exchanges silk production into sticky silk form, starting a spiral at the outer edge of the web by crossing between the non-sticky wave that radiates from the centre hub to its edge, more specifically called dry scaffold threads; thus, a new glinting enduring orbweb is ready for the hunt. At this stage, the spiders rest in a head-downwards position and enter into stationary prey mode; when detecting the vibration from any ‘food’ mistakenly enters their territory, they can quickly swing down and prey.

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Predators, Parasites, and Diseases
While S. pustulosa are predominantly predators, other creatures can frequently prey on them. In New Zealand, there are many parasitoid wasps targeting spiders and insects. Unlike parasites, parasitoids ultimately cause the death of their host. For instance, Pison spinolae, widely recognised as the mason wasp, belong to the solitary member of the Crabronidae family and is distributed across the entire New Zealand region; it commonly prey on orb-weaving spiders. The mason wasps use venom through their stinger to inject into spiders which paralyses them. Then, using their strong legs to drag their prey back to the burrow, the spider is placed in the mud-walled chamber and rendered immobile. The hatched grub eventually consumes the spider alive as nutrients until nothing remains.

Another well-known spider-hunting wasp is the spider wasp (family Pompilidae); for example, Priocnemis monachus (large black wasp), the female P. monachus hunt during daytime, swiftly stinging their chosen spider prey upon discovery, effectively paralyzing them. The incapacitated spider is subsequently dragged to a burrow and lays an egg on top of the spider's abdomen. Once the egg hatches, a larva emerges and gradually consumes the paralyzed spider while it remains alive until entirely devoured.

Other Information
The naming of Socca was not a random choice, but the Socca arachnologists team called it "a happy coincidence". Dr Pedro Castanheira and his co-author, Dr Volker Framenau, from Brazil and Germany, respectively, and their love for soccer prompted them to name the spiders after their favourite hobby. Moreover, as fate would have it, their research paper coincided with the World Cup, adding excitement to their discovery. Back to 2022, the researchers dedicated their time to uncovering the secrets of these spiders, they also made sure to follow the thrilling events of the World Cup 2022. This unique discovery added enthusiasm to both the scientific community and the exciting atmosphere of the World Cup.