Thorictus riyadhensis Hava & Abdel-Dayem, 2021

Hava, Jiri, Abdel-Dayem, Mahmoud S. & Aldhafer, Hathal M., 2021, The subfamily Thorictinae (Coleoptera, Dermestidae) from Saudi Arabia, ZooKeys 1029, pp. 155-174 : 155

Thorictus riyadhensis Hava & Abdel-Dayem sp. nov. Figs 3 , 4

Material examined.

Holotype. Saudi Arabia • 1 ex; Riyadh Province, Wadi Hanifah , WHS04 [location near Waseel]; 24.86682°N, 46.45959°E; alt. 694.942 m; 29 Apr. 2015; Abdel-Dayem M et al. leg.; pitfall trap; KSMA . Paratypes. Saudi Arabia • 1 ex; Riyadh Province, Az Zulfi, Rawdat Al Sabalh ; 26°22.040'N, 44°59.137'E; alt. 670 m; 31 Jan. 2016; Abdel-Dayem M et al. leg.; pitfall trap; KSMA • 1 ex; Riyadh Province, Rhodet Khorim; 25°25.943'N, 47°13.863'E; alt. 572 m; 28 Apr. 2012; pitfall trap, Calotropis procera ; KSMA • 1 ex; same collection data as preceding; 9 Jun. 2012; pitfall trap, Acacia gerrardii ; KSMA • 1 ex; same collection data as preceding; 26 May 2012; pitfall trap, Acacia gerrardii ; JHAC • 1 ex; same collection data as preceding; 26 May 2012; PT, Lycium shawii ; KSMA • 1 ex; same collection data as preceding; 10 Dec. 2011; pitfall trap; KSMA .

Description of holotype.

Body small, brown covered by long, yellow setae on dorsal surfaces and short setae on ventral surfaces. Measurements (mm): TL 2.9, PW 1.9, EW 1.9. Head finely punctate with long yellow setae. Labial palpi entirely brown. Antennae brown, with 11 antennomeres; antennal club compact, with three antennomeres. Pronotum as finely punctate as head and covered by long yellow setation. Lateral margin of pronotum not dentate. Pronotum in posterior part near scutellum without bumps. Ventral posterior pronotal angles with long yellow setation. Scutellum not visible from above. Elytra very finely punctate covered by long yellow setation. Each elytron in anterior part near humeri with one large bump. Epipleuron finely punctate, anterior angles with long yellow setation. Prosternum finely punctate. Mesosternum finely punctate, mesosternal bulge. Metasternum finely punctate. Visible abdominal ventrites very finely punctate and covered by long yellow setae. First abdominal ventrite without anterior, longitudinal striation. Legs brown, covered by yellow setae.

Variability.

Body measurements (mm): TL 2.5-2.9, PW 1.5-1.9, EW 1.5-1.9.

Differential diagnosis.

The new species belong to the Thorictus castaneus species group, from Saudi Arabia. There is currently only one known species, Thorictus arabicus Háva, 2010 but the new species differs from it in the abovementioned characteristics.

Etymology.

Named according to type locality: Riyadh Province.

Remarks.

The species was erroneously published by Abdel-Dayem et al. (2017) as Thorictus foreli Wasmann, 1894. Thorictus foreli is a North African species, occurring in Algeria, Morocco, and Tunisia ( Háva 2015a), so it is excluded from the fauna of Saudi Arabia.

Ecological notes.

The holotype was found in Wadi Hanifah at an area with loam soil covered by Carthamus oxyacantha M. Bieb. ( Asteraceae ) and Zilla spinosa (L.) Prantl ( Brassicaceae ) (Fig. 5 ). The ant species Camponotus thoracicus (Fabricius 1804), Cataglyphis holgerseni (Collingwood & Agosti, 1996), Cataglyphis lividus ( André, 1881), Lepisiota simplex (Forel, 1892), and Monomorium abeillei ( André, 1881) were collected with the holotype in the same pitfall trap. The paratype was found in loam area covered with Calotropis procera (Aiton) W.T. Aiton ( Apocynaceae ) and Pulicaria undulata (L.) C. A. Mey. ( Asteraceae ) at Rawdat Al Sabalh (Fig. 6 ). While at Rhodet Khorim, the paratypes were collected from a sandy area using pitfall traps under canopies of Acacia gerrardii Benth. ( Fabaceae ), Calotropis procera (Aiton) W.T. Aiton, and Lycium shawii Roem. & Schult. ( Solanaceae ) (Fig. 7 ). Ant species of Camponotus sericeus (Fabricius, 1798), Camponotus xerxes Forel, 1904, Cataglyphis fisheri Sharaf & Aldawood, 2015, Cataglyphis lividus ( André, 1881), Cataglyphis niger ( André, 1881), Cataglyphis viaticoides ( André, 1881), Lepisiota dammama Collingwood & Agosti, 1996, Lepisiota simplex (Forel, 1892), Tetramorium chefketi Forel, 1911, Tetramorium sericeiventre Emery, 1877, and Trichomyrmex mayri (Forel, 1902) were caught with the paratypes from the same pitfall traps. Thorictus riyadhensis was collected during December and January, and from April to June.

Geographical distribution.

This new Thorictini species is known from Najd Plateau, Central Saudi Arabia, Riyadh Province (Fig. 1 ), at Wadi Hanifah (Ad Diriyah), Rawdat Al Sabalh (Az Zulfi), and Rhodet Khorim (Ramah).

Figures

Figure 1. Map of Saudi Arabian provinces and distribution of Thorictinae species.

Figure 3. Habitus dorsal aspect of Thorictus riyadhensis sp. nov. Hava & Abdel-Dayem a specimen from Wadi Hanifah b specimen from Rhodet Khorim.

Figure 4. Thorictus riyadhensis Hava & Abdel-Dayem, sp. nov. a head lateral eye b ventral setation on pronotum and metepisternum; Thorictus arabicus Hava, 2010 c head lateral eye d ventral setation on pronotum and metepisternum.

Figure 5. Habitat of Thorictus riyadhensis Hava & Abdel-Dayem, sp. nov. holotype in Wadi Hanifah, Ad Diriyah, Riyadh Province, at an elevation of 695 m. Carthamus oxyacantha M. Bieb. (Asteraceae) in the bottom right corner, and Zilla spinosa (L.) Prantl (Brassicaceae) in the foreground.

Figure 6. Habitat of Thorictus riyadhensis Hava & Abdel-Dayem, sp. nov. paratype in Rawdat Al Sabalh, Az Zulfi, Riyadh Province, at 670 m elevation. Calotropis procera (Aiton) W. T. Aiton (Apocynaceae) in background, and Pulicaria undulata (L.) C. A. Mey. (Asteraceae) in the foreground and among the shrubs.

Figure 7. Habitat of Thorictus riyadhensis Hava & Abdel-Dayem, sp. nov. paratype in Rhodet Khorim, Ramah, Riyadh Province, at an elevation of 572 m. Trees of Acacia gerrardii Benth. (Fabaceae) in the background, shrubs of Calotropis procera (Aiton) W. T. Aiton (Apocynaceae) and Ziziphus nummularia (Burm. f) Wight & Arn. (Rhamnaceae), shrub of Lycium shawii Roem. & Schult. (Solanaceae) in the left corner of the bottom, and Rhazya stricta Decne. (Apocynaceae) in the foreground and middle.