Study area

The study area comprises the whole of the Maghreb (Morocco, Algeria, Tunisia and Libya) and the region of Ghardaïa (Algeria) in particular. This Saharan region is characterized by a hot, arid climate with a mild winter. As an example, the annual recorded precipitations and mean temperatures during 2017 were 33.79 mm, 22.5 °C for Ghardaïa and 65.28 mm, 22.8 °C for El Menia (Algeria).

Due to the aridity and the scarcity of precipitation in this region, two wetlands are of note: Kef Doukhane, located at 600 km to the south of the capital Algiers, at 390 to 430 m a.s.l. It is a channel in a riverbed of about 22 km length, supplied by treated wastewater from the treatment plant of El Atteuf. It passes different rocky and sandy structures and is characterized by vegetation on the banks, hosting several species of birds, reptiles and other animals (Fig. 1). The other is Sebkhet El Melah Lake, located in the centre of Algeria (30.4166°–30.5333°N and 2.9000°–2.9333°E). This Ramsar wetland (Fig. 2) was described by Alioua et al. (2016).

Abbreviations

CRB: Collection Robert Bosmans

CYA: Collection Youcef Alioua

MNHN: National Museum of Natural History, Paris

Sampling. Material was collected in Morocco, Algeria and Tunisia from 1984 to 2018. Between 2016 and 2018, individuals of L. chloris were collected by the first author directly from vegetation around the fresh water basin of Sebkhet El Melah and the Wadi Kef Doukhane. The specimens were preserved in 70% ethanol. A stereomicroscope (Nikon SMA 1270) was used for specimens' examination and a Moticam camera mounted on a Realux microscope and Olympus SZX7 stereomicroscope to take photographs of the spiders. The individuals of L. lineata were collected by the second author directly or with a sweep net, between 1984 and 1990 in Algeria, during 1999 in Morocco and in 1985 and 2003 in Tunisia.

Determination. L. chloris and L. lineata were determined according to the paper of Grasshoff (1970).

Distinguishing both species

Males can be readily recognised by the structure of their palpal organs. In Larinia chloris, the median apophysis ends in two short, pointed processes (Figs 7, 8), which are much longer in L. lineata (Fig. 9). Females of Larinia chloris are distinguished from L. lineata by the epigyne being 1.5 times as wide as long in Larinia chloris (Fig. 10), and as wide as long in L. lineata (Fig. 11). The epigynal scape is often broken off, as in Fig. 10, which does not facilitate identification. Characters useful for separating the two species occurring in the Maghreb are adequately described by Grasshoff (1973), Tikader (1982), Levy (1986) and Kunt et al. (2012).

Fig. 6-9.

Male palps of Larinia species. 6-8. Larinia chloris from Ghardaïa (Algeria): 6. retrolateral view; 7. ventral view; 8. prolateral view; 9. Larinia lineata from France (Gaymard & Lecigne 2018, Oger 2019), prolateral view. Arrows show the differences in the median apophyses between males of both species. Scale line = 0.5 mm

Fig. 10-11.

Ventral views of epigynes. 10. Larinia chloris, from Ghardaïa; 11. Larinia lineata, from France (scape broken off) (Gaymard & Lecigne 2018, Oger 2019). Scale line = 0.2 mm

Fig. 12.

Map of known and new records of Larinia chloris (Circles: previous records, after Cambridge 1876, Pavesi 1895, Simon 1904, 1906, 1908, Caporiacco 1936, Denis 1947, Grasshoff 1970, Tikader 1982, Levy 1986, Dippenaar-Schoeman et al. 2005, Gajbe 2007, Foord et al. 2011, Kunt et al. 2012, Biswas & Raychaudhuri 2012, Dippenaar-Schoeman et al. 2018, Soliman et al. 2018, Bosmans et al. 2019; square: type locality, after Audouin 1826; hexagon: disputable occurrence, after Simon 1882 and Grasshoff 1970; triangles: new records)

Comments

Larinia chloris was captured on low vegetation in Sebkhet El Melah and on leaves of Nicotiana glauca Graham, 1826 in Kef Doukhane. It is very rare at the first locality but common on vegetation along the river at the second one. According to Levy (1986), the species is found at humid sites in Israel. Kunt et al. (2012) collected it at a similar locality near the Firat River (Turkey), and Denis (1947) around the Shiata Lake (Libya). Our observations are in accordance with these previously published data, since both our localities are humid. Apparently, L. chloris prefers humid and hot areas with dense vegetation providing web support. The new record in Algeria is the most western point of L. chloris' known distribution (Fig. 12).

Larinia lineata, on the other hand, was captured at several localities in the more northern parts of Algeria, Morocco and Tunisia (Fig. 13), from the coast to the steppe region. It prefers various habitats in small wetlands along rivulets, springs and even irrigated gardens.

Fig. 13.

Map of known and new records of Larinia lineata in the Maghreb (circles: previous records, after Pavesi 1880, Simon 1899, 1909, 1929, Grasshoff 1970, Jocqué 1977; square: type locality, after Lucas 1846; triangles: new records)