Salsa fuliginata

Salsa fuliginata, commonly known as the sooty orbweaver, is a orb-weaver spider of Araneidae in the genus Salsa. The species is found throughout southeastern Australia and New Zealand.

Spiderling stage
According to Dondale, spiderlings of Salsa fuliginata have a black and yellowish-brown carapace. Spiderlings also feature a black pattern that is extended around the tip and over the ventral side on their smooth abdomen. The end of the dark part of the ventral side of the abdomen contains some white spots; the spiderlings also have a much lighter colour on their legs compared to when they are an adult. When the spiderlings grow to a total length of about 2.5mm, Salsa fuliginata females will have a squared shape at the anterior of the carapace and the posterior of the abdomen will be slightly angled. The carapaces of females are brownish at this size similar to males and both sexes' pattern on their abdomen bear a resemblance of an adult Salsa fuliginata. Immature males of this size have rather swollen palpi.

Adult stage
The carapace of S. fuliginata males is usually dark brown-orange in colour and have a lustrous coat and flat yellow setae throughout the carapace. The chelicerae of male S. fuliginata are orange-brown with three promarginal teeth and three retromarginal teeth, where the median promarginal teeth and basal retromarginal teeth are the largest. The basal of femora, trochanters and coxae are all brownish-yellow; other than these three areas, the whole leg is brown in colour. Males have a leg formula of I > II > III > IV, where the longest leg is the first leg and the shortest leg is the fourth leg. The ventral portion of the cephalothorax or the sternum is brown in colour and dorsum has a beige colour to it and males also have an olive-grey irregular large folium. The lateral portion of the folium is dark brown with some black spots. Underside of abdomen is dark brown followed by two white patches along the abdomen right behind the epigastric furrow. Salsa fuliginata male has a slightly curved and short paracymbium; conductor lobe is sturdy and attach to conductor from basal of embolus; median apophysis has a flat tip, has a C-shape and also lengthened, it is also basally pronounced with a reduced basal process. Terminal apophysis have overall rectangular shape with a projection at the tip which looks like a thumb; conductor is weakly sclerotised and flat; embolus of the male is straight, lengthen and also pronounced. According to Framenau and Pedro, males of Salsa fuliginata are mostly alike compared to Salsa recherchensis (Main, 1954) in the morpohology of their genitals.

Nonetheless, median apophysis in S. fuliginata is much elongated and narrow compared to S. recherchensis; The obvious spine-like prong on the terminal apophysis found in S. recherchensis is also absent in S. fuliginata. Based on the research of Dondale and Framenau & Pedro, adult males' total length are measured to be 3.2-5.5 mm based on 18 male adult specimens.

Sexual dimorphism exists in Salsa fuliginata, where the females are generally larger than the male like most spiders. Characteristics of female carapace and chelicerae are similar to male's with only one difference where three retromarginal teeth are of similar size in females. Legs of female are brownish-orange and mottled in light brown; leg formula for females are the same as males, where leg lengths have the formula, I > II > IV > III. Salsa fuliginata females have a dark brown labium; dark brown sternum with filled with grey setae; maxillae are brownish to dark brown; dorsal part and lateral part of abdomen are olive-grey a darker folium pattern. Ventral part of abdomen is similar to males where it is dark grey-olive with elongated ovoid pale bands paired with pale band behind epigastric furrow. Atrium of female Salsa fuliginata are shaped like a heart; spermatheca of the females are also spherical and huge in size. At the epigyne of S. fuliginata females, the atrium is not apparent due to the rotation of the epigyne relative to the abdomen. S. fuliginata females have total lengths ranging from 4.5-11.0 mm based on 30 specimens from two research studies (Dondale and Framenau & Pedro ).

Variation in colour patterns is vast in Salsa fuliginata, particularly in the folium, the colour shades also vary from brownish red to dark brown and light beige to orangey.

Natural global range
Salsa fuliginata is native to Australia and believed to be introduced into New Zealand over 22 years ago. Salsa fuliginata can be found in the southeast region of Australia, mainly New South Wales, Victoria, Tasmania and South Australia. It is found throughout New Zealand.

New Zealand range
Since Salsa fuliginata was introduced to New Zealand, it has been distributed all around the country. Based on a citizen science site, iNaturalist NZ, Salsa fuliginata was first observed in New Zealand in November 2008 by the observer under the username of "stevenwallace". The observed spider was located in Makarau, New Zealand. Salsa fuliginata can be found in both the North Island and South Island. By referring to distribution records from Framenau and Pedro, S. fuliginata is found mainly in Christchurch, Auckland, Wellington and also near Lake Taupō in the North Island.

Habitat
Salsa fuliginata doesn't have a specific preferred habitat. This species is observed in open spaces with low-lying vegetation and in various types of forests. The collected specimens of Salsa fuliginata have been found in environments such as dry sclerophyll forests, open forests, bushes, shrubs, gardens, and swamps.

Life cycle/phenology
There is not much known about the life cycle of Salsa fuliginata, but it is assumed that it has an identical life cycle with other spiders with are four main stages: eggs, spiderlings, juveniles and adults. Because Australia and New Zealand are temperate countries, the spiders' mating and egg laying happens during spring and may continue over summer. After males and females mate, they split up where males will look for another mate and females will capture organisms in order to keep her developing eggs healthy. After a few weeks, female spiders hang their egg sacs near their web or even in their web after laying it. The eggs inside the egg sacs take about two to four weeks to hatch. After spiderlings developed completely in the egg sacs, they pierce through the strong membrane of the egg sacs but it usually happens after an average of two moults happen inside the egg sacs due to the struggle to break through the strong membrane of the silken cover. Once the spiderlings go through their early moults and are independent, they usually disperse swiftly through ballooning. The spiderlings will then become juveniles after several moults until they reach their mature adult form, generally up to eight moults and some have molted nine times, which then go through the life cycle again. In temperate regions like New Zealand and Australia, most spiders live only one year or at most two years, but these life cycles are only assumed for Salsa fuliginata since the life cycles of spiders has been investigated in only a minimal number of spider species. Based on Framenau & Pedro, Salsa fuliginata mature adults are common and mostly collected ranging from October and January. However, mature males of Salsa fuliginata reduced in the latter months especially September and February, which may indicate male's life expectancy which are usually low. However, for females they have relatively higher life expectancy, which in Framenau & Pedro's research showed that there are more female Salsa fuliginata specimens than males

Diet and foraging
Individuals of Salsa fuliginata are carnivores like most spiders; they feed on small insects like flies, moths, beetles and other small insects. These preys are usually captured in webs. For instance, according to Geier & Briese light-brown apple moth or Epiphyas postvittana, was observed being preyed on by Salsa fuliginata.

Predators, parasites, and diseases
According to Keziah D'Souza, a masters student in University of Auckland, one of the species that prey on Salsa fulignata is Pison spinolae, which is more commonly known as the mason wasp. Pison spinolae is native to Australia and in 1880, it was introduced to New Zealand and can be found widely throughout New Zealand. Other predators of S. fuliginata could be parasitoid wasps or spider-hunting wasps; some wasps are able to lay eggs into egg sacs and their grubs can feed on the spiders' eggs when they hatch.

Other information
Before Salsa fuliginata was in the genus Salsa, it was placed in the genus Cyclosa by Dondale in 1966 even though it shows more resemblance to the genus Araneus at that time compared to Cyclosa. It was obvious that Salsa fuliginata did not belong in the genus, Cyclosa based on two articles from Levi, H.W. and required further revision based on molecular data. As a result, the species was then placed in the genus Salsa after further revision.