Mallinus nitidiventris Simon, 1893

Haddad, Charles R., Henrard, Arnaud & Jocque, Rudy, 2019, Revision of the ant-eating spider genus Mallinus Simon, 1893 (Araneae, Zodariidae), ZooKeys 822, pp. 141-158 : 147-150

Mallinus nitidiventris Simon, 1893 Figs 1-4, 5-19, 20-34, 35-46, 47-49, 50-53, 54-57

Mallinus nitidiventris Simon, 1893: 436, figs 409-410 (juv.); Jocqué 1991: 136, figs 334-335 (juv.).

Type material.

Subadult ♂ lectotype and subadult ♀ paralectotype: SOUTH AFRICA: Western Cape: Matjiesfontein, 33°15'S, 20°40'E, MNHN AR 3280 - examined by Jocqué (1991).

Other material examined.

SOUTH AFRICA: Eastern Cape: Aberdeen district, Farm Bokvlei, 32°25.8'S, 23°21.0'E, 14.XII.2007, leg. D.H. Jacobs (pitfall traps, karoo), 2♂ (NCA 2008/4662); Aberdeen district, Farm De Pannen, 32°41.4'S, 23°25.8'E, 14.XII.2007, leg. D.H. Jacobs (pitfall traps), 1 imm. 4♂ (NCA 2011/604); Aberdeen district, Farm Juriesfontein, 32°31.8'S, 23°25.8'E, 11.XII.2007, leg. D.H. Jacobs (pitfall traps), 1♂ (NCA 2008/4665); Aberdeen district, Farm Nuwejaarsfontein, 32°57.0'S, 24°23.4'E, 14.XII.2007, leg. D.H. Jacobs (pitfall traps, karoo), 2 imm. 7♂ 1♀ (NCA 2008/2612). Free State: Luckhoff district, Farm Bankfontein, 30°04.980'S, 24°54.170'E, 22.I.2015, leg. C. Haddad (base of grass tussocks, wetland margin), 1♂ (NCA 2015/1655); Same locality, 30°04.421'S, 24°53.017'E, 6-8.IV.2015, leg. C. Haddad (hand collecting, Nama Karoo veld), 1♂ 1♀ (NCA 2015/1818), 2♂ 1♀ (S.E.M. preparations); Same locality, 30°04.421'S, 24°53.038'E, 26.III.2017, leg. C. Haddad & R. Booysen (hand collecting, Nama Karoo veld), 3 imm. 5♂ (NCA 2017/1447); Same locality, 30°04.974'S, 24°54.297'E, 2-6.IV.2015, leg. University of the Free State students (pitfall traps, Nama Karoo veld), 1♂ (NCA 2015/2398); Same locality, Research camp, 30°04.421'S, 24°53.013'E, 1185 m a.s.l., 24-26.XI.2015, leg. C. Haddad & R. Booysen (night collecting), 1♂ (NCA 2015/2231). Northern Cape: Pofadder, 29°22'S, 19°07'E, 15.X.2006, leg. L. Spangenberg (pitfall traps), 1♀ (MRAC 222264); Tswalu Game Reserve, man-made dam, 27°15'S, 22°27'E, 1176 m a.s.l., 6.II.2005, leg. R. Jocqué (savanna shrubland, by hand), 1♂ (MRAC 216253). Western Cape: Beaufort West district, Farm Eerste Water, 32°41.4'S, 22°57.6'E, 6.XII.2007, leg. D.H. Jacobs (pitfall traps, karoo), 1 imm. (NCA 2008/2610); Prince Albert, Tierberg, 33°13'S, 22°02'E, 23.IX.1989, leg. R. Dean (old lands), 1♂ (NCA 91/1299), 1♀ (NCA 91/1300).

Unconfirmed record.

SOUTH AFRICA: Northern Cape: Goepag Nature Reserve, 29°39.906'S, 17°59.838'E, 14-16.VII.2017, leg. R. Booysen, Z. Mbo & R. Christiaan (pitfall traps, Nama Karoo veld), 1 imm. (NCA 2017/1189).

Female (Bankfontein, NCA 2015/1818). Measurements: CL 1.32, CW 0.89, AL 1.39, AW 1.36, AH 1.65, TL 2.60 (2.13-2.70), SL 0.62, SW 0.63, AME–AME 0.06, AME–ALE 0.03, ALE–ALE 0.25, PME–PME 0.09, PME–PLE 0.09, PLE–PLE 0.31, MOQAW 0.21, MOQPW 0.22, MOQL 0.25.

Length of leg segments: I 0.70 + 0.29 + 0.54 + 0.67 + 0.41 = 2.61; II 0.71 + 0.30 + 0.53 + 0.73 + 0.45 = 2.72; III 0.71 + 0.32 + 0.53 + 0.78 + 0.45 = 2.79; IV 0.92 + 0.32 + 0.68 + 1.00 + 0.48 = 3.40.

Colour: carapace orange-brown, with faint black mottling and striae (Figs 1, 2); chelicerae orange; endites yellow, slightly darker retrolaterally at midpoint; labium orange, cream distally; sternum orange, cream along anterior margin; leg femora orange-brown; patellae yellow proximally, orange brown distally; tibiae and metatarsi light brown proximally, yellow-brown distally; tarsi yellow; palps yellow-brown; abdomen black dorsally, grey ventrally along midline, with large white patches laterally, fused narrowly in ring around anterior of abdomen; spinnerets creamy-yellow. Eyes: AME diameter 1.1 times ALE diameter; AME separated by distance equal to 0.76 times their diameter; AME separated from ALE by 0.4 times AME diameter; clypeus height 4.2 times AME diameter at AME, 4.16 times ALE diameter at ALE; PME and PLE equal in diameter; PME separated by distance equal to 1.15 times their diameter; PME separated from PLE by distance slightly less than 1.21 times PME diameter; CW:PERW = 2.06:1. Legs spineless, covered in short erect setae and incised setae. Abdomen slightly longer than carapace, higher than long or broad, with shiny scutum covering most of dorsum (Figs 1, 2); dorsum sparsely covered in short straight setae, denser on posterior slope and venter. Epigyne as in genus description (Figs 43, 47, 50, 51). Other characters as in genus description.

Male (Bankfontein, NCA 2015/1818). Measurements: CL 1.33, CW 0.88, AL 0.98, AW 0.94, AH 0.98, TL 2.34 (2.23-2.72), SL 0.60, SW 0.59, AME–AME 0.06, AME–ALE 0.03, ALE–ALE 0.25, PME–PME 0.08, PME–PLE 0.08, PLE–PLE 0.29, MOQAW 0.21, MOQPW 0.19, MOQL 0.22.

Length of leg segments: I 0.79 + 0.29 + 0.65 + 0.81 + 0.46 = 3.00; II 0.83 + 0.30 + 0.63 + 0.84 + 0.46 = 3.06; III 0.81 + 0.33 + 0.57 + 0.90 + 0.47 = 3.08; IV 1.03 + 0.33 + 0.75 + 1.15 + 0.53 = 3.79.

Morphology and colouration similar to female (Figs 3, 4), except for the following: AME diameter equals 1.16 times ALE diameter; AME separated by distance 0.67 times their diameter; AME separated from ALE by distance 0.38 times AME diameter; clypeus height 3.85 times AME diameter at AME, 4.0 times ALE diameter at ALE; PME diameter equals 0.89 times PLE diameter; PME separated by distance 1.25 times their diameter; PME separated from PLE by distance 1.25 times PME diameter; CW:PERW = 2.17:1. Abdomen relatively smaller than female (Figs 3, 4), shorter than carapace, as high as long, slightly longer than broad, with conspicuous circumferential folds. Palp as in genus description (Figs 44, 48, 49, 52, 53).

Variation.

Populations from the south-western parts of the species’ range (including the type locality) have a clearly darker carapace and legs, which are wine-red in colour (Figs 54-57). It is plausible that populations in this part of its range may associate with a darker species of model ant, affecting their colouration.

Distribution.

Widespread in the western half of South Africa, known from the Eastern Cape, Western Cape, Northern Cape and Free State Provinces (Fig. 67).

Habitat and biology.

Mallinus nitidiventris is widespread in the semi-arid and arid western half of South Africa, with records in the Nama Karoo and Succulent Karoo biomes, extending into the arid savannas of the southern Kalahari Desert. Specimens collected at Bankfontein in the western Free State Province were all found in Nama Karoo scrubland, either along a hillside or open plains. The substrate at both sites comprised fine Ecca Shale alluvium, siltstone and sandstone gravels that form part of the Ecca Group of the Karoo Supergroup (A. Odendaal and J. Fourie, pers. comm.). Some of the Bankfontein specimens (NCA 2015/1818) were collected during mid-morning (10:00-12:00) foraging in open ground in the vicinity of various ants, including Anoplolepis custodiens F. Smith, 1858, Camponotus spp., Messor sp. and Monomorium sp. Of these, Mallinus nitidiventris most closely resembled Messor sp. in terms of colouration, although workers of this ant were almost double the body length of the spiders. Only one of these five spiders sampled at this specific site was feeding, a female consuming a Monomorium worker ant that measured approximately 2 mm in length, suggesting that this species is myrmecophagous, as are most Zodariinae.