Research Article |
Corresponding author: Mahmoud S. Abdel-Dayem ( mseleem@ksu.edu.sa ) Academic editor: Thomas Philips
© 2021 Jiří Háva, Mahmoud S. Abdel-Dayem, Hathal M. Aldhafer.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Háva J, Abdel-Dayem MS, Aldhafer HM (2021) The subfamily Thorictinae (Coleoptera, Dermestidae) from Saudi Arabia. ZooKeys 1029: 155-174. https://doi.org/10.3897/zookeys.1029.63940
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In this study, the Saudi Arabian Thorictinae beetle species, Thorictus riyadhensis Háva & Abdel-Dayem, sp. nov., T. shadensis Háva & Abdel-Dayem, sp. nov., T. sharafi Háva & Abdel-Dayem, sp. nov., T. hanifahensis Háva & Abdel-Dayem, sp. nov. are described, illustrated, and compared with related species. Three other species: T. castaneus Germar, 1834; T. foreli Wasmann, 1894; and T. peyerimhoffi Chobaut, 1904 are excluded from the fauna of Saudi Arabia. A list of Thorictinae species from the Arabian Peninsula is provided.
Beetles, new species, Saudi Arabia, taxonomy, Thaumaphrastini, Thorictini, Thorictus, Thorictodes
Thorictinae Agassiz, 1846, with 189 described species worldwide, is a myrmecophilous subfamily of the family Dermestidae (Coleoptera) (
Thorictinae fauna, in the Arabian Peninsula in general and in Saudi Arabia in particular, is poorly studied due to the lack of adequate dedicated investigation and scant published records for this group. So far, only four species are known from the Arabian Peninsula (
While examining myrmecophilous dermestid specimens from Saudi Arabia, four new species of Thorictus were determined and are described below. The present study follows the revision of Thorictinae from the Afrotropical Region (
The size of beetles’ bodies or body parts can be useful in species recognition; thus, the following measurements were made. Total length (TL): linear distance from anterior margin of pronotum to apex of elytra, pronotal width. (PW): maximum linear transverse distance and elytral width. Elytral width (EW): maximum linear transverse distance. All measurements are given in millimeters. Locality labels are cited in the original version.
The ant species used in the present paper are identified by Dr Mostafa R. Sharaf (Plant Protection Department, College of Food and Agriculture Sciences, King Saud University, Riyadh, Saudi Arabia) and the nomenclature follow the online catalogue (
Specimens of the species described were labeled as follows: “HOLOTYPE” [or “PARATYPE,” respectively] Thorictus ‘species_name’ sp. nov. Jiří Háva & MS Abdel-Dayem det. 2021.”
Male genitalia were not studied. The differential diagnosis of the aedeagi is often problematical and interspecific variation is currently very poorly defined (
JHAC Jiří Háva, Private Entomological Laboratory and Collection, Únětice u Prahy, Prague-West, Czech Republic;
Subfamily Thorictinae Agassiz, 1846
Tribe Thaumaphrastini Anderson, 1949
Genus Thorictodes Reitter, 1875
Saudi Arabia • 1 ex; Riyadh; Nov. 1989; Habib leg.; on ground; J. Háva det.; JHAC • 1 ex; Riyadh, 5 Oct. 1989; in animal dung; J. Háva det.;
Genus Thorictus Germar, 1834
castaneus species group
An endemic species to Saudi Arabia that was originally described from the Eastern Province (
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;
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.
Body measurements (mm): TL 2.5–2.9, PW 1.5–1.9, EW 1.5–1.9.
The new species belong to the 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.
Named according to type locality: Riyadh Province.
The species was erroneously published by
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.
Habitat of Thorictus riyadhensis Háva & 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.
Habitat of Thorictus riyadhensis Háva & 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.
This new Thorictini species is known from Najd Plateau, Central Saudi Arabia, Riyadh Province (Fig.
Holotype.
Saudi Arabia • 1 ex; Riyadh Province, Wadi Hanifah, WHS01 [location near Waseel]; 24.87011°N, 46.456775°E; alt. 707.051 m; 12 Oct. 2015; Abdel-Dayem M et al. leg.; pitfall trap;
Body small, brown covered by long yellow setae on dorsal surfaces and short setae on ventral surfaces. Measurements (mm): TL 2.8, PW 1.6, EW 1.6. 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, 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 very small 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, covered by long yellow setae. First abdominal ventrite with anterior, longitudinal striation. Legs brown, covered by yellow setae.
The new species is similar to T munganasti Reitter, 1908 (Egypt) but differs from it by the abovementioned characteristics.
Named according to type locality: Wadi Hanifah.
This species was found in an area with loam texture, which is dominated by Tamarix senegalensis DC. (Tamaricaceae) and some Acacia gerrardii Benth. (Fabaceae) (Fig.
Thorictus hanifahensis Háva & Abdel-Dayem, sp. nov. is known only from its type locality in central Saudi Arabia, at Wadi Hanifah in the Ad Diriyah Governorate, Riyadh Province (Fig.
Holotype
. Saudi Arabia • 1 ex; Al Bahah, Shada Al Ala Nature Reserve; 19°50.710'N, 41°18.267'E; alt. 1474 m; 5 Jul. 2014; Al Dhafer H, Fadl H, Abadel-Dayem M, El Torkey A, El Gharbawy A leg.; pitfall trap;
Body small, brown covered by short yellow setae on dorsal surfaces and short setae on ventral surfaces. Measurements (mm): TL 2.1, PW 1.1, EW 1.2. Head finely punctate with short yellow setae. Labial palpi entirely brown. Antennae brown, with 11 antennomeres, antennal club compact with three antennomeres. Pronotum as finely punctate as head, covered by short yellow setation. Lateral margin of pronotum not dentate. Pronotum in posterior part near scutellum without bumps. Ventral posterior pronotal angles without long yellow setation. Scutellum not visible from above. Elytra very finely punctate covered by short yellow setation. Each elytron in anterior part near humeri with one very small bump. Epipleuron finely punctate, anterior angles with short yellow setation and small bump. Prosternum finely punctate. Mesosternum finely punctate, mesosternal bulge. Metasternum finely punctate. Visible abdominal ventrites very finely punctate, covered by short yellow setae. First abdominal ventrite with anterior, longitudinal striation. Legs brown, covered by yellow setae.
Thorictus shadensis Háva & Abdel-Dayem, sp. nov. a head lateral eye b ventral setation on pronotum and metepisternum, T abyssinicus John, 1963 c head lateral eye d ventral setation on pronotum and metepisternum, T dilatipennis Reitter, 1881 e head lateral eye (according to
Body measurements (mm): TL 2.1–2.2, PW 1.0–1.1, EW 1.1–1.2.
The new species belongs to the orientalis species group and is very similar to two other species: T abyssinicus John, 1963 (Ethiopia) and T dilatipennis Reitter, 1881 (Egypt, Syria), but differs from them by the abovementioned characteristics.
Named according to type locality: Shada Al Ala Nature Reserve.
The adult beetles were found during April and July at elevations of 1225–1563 m in the Shada Al Ala Nature Reserve. The specimens were collected by pitfall traps in steep slopes covered with vegetation dominated by Acacia thorn woodlands and shrubs of Barbary fig or cactus pear, Opuntia ficus-indica (L.) Mill. (Cactaceae) (Figs
This species is only known from the type locality in the Shada Al Ala Nature Reserve, on the Shada Mountain, in the west of the Sarawat Mountains at Al Mekhwah, Baha Province (Fig.
Holotype. Saudi Arabia • 1 ex; Baha Region, Alqamh Park, Belgershi; 19°48.407'N, 41°42.718'E; alt. 1931 m; 17 May 2010; Dr M.R. Sharaf leg.;
Body small, brown covered by short yellow setae on dorsal surfaces and short setae on ventral surfaces. Measurements (mm): TL 2.1, PW 1.1, EW 1.2. Head finely punctate with short yellow setae. Labial palpi entirely brown. Antennae brown, with 11 antennomeres, antennal club compact with three antennomeres. Pronotum as finely punctate as head, covered by short yellow setation. Lateral margin of pronotum not dentate. Pronotum in posterior part near scutellum without bumps. Ventral posterior pronotal angles without long yellow setation. Scutellum not visible from above. Elytra very finely punctate covered by short yellow setation. Each elytron in anterior part near humeri with one very small bump. Epipleuron finely punctate; anterior angles with short yellow setation. Prosternum finely punctate. Mesosternum finely punctate, mesosternal bulge. Metasternum finely punctate. Visible abdominal ventrites very finely punctate, covered by short yellow setae. First abdominal ventrite with anterior, longitudinal striation. Legs brown, covered by yellow setae.
Body measurements (mm): TL 2.1–2.2, PW 1.0–1.1, EW 1.1–1.2.
This new species is similar to T dohrni John, 1965 (Ethiopia), but differs from it by the abovementioned characteristics.
The specific epithet is a Latinized noun in the genitive case in the masculine form based on the honorific name “Dr Mostafa Sharaf,” who collected the specimens of this species.
This new species inhabits areas at elevations of 1881–2324 m within the African pencil cedar forest, Juniperus procera Hochst. ex Endl. (Cupressaceae) in the Baha Province (Figs
This species is known only from its type locality in the mountains of southwestern Saudi Arabia, at Alqamh Park, Amadan, and Shohba Forest in the Baha Province (Fig.
The study of the insect fauna of Saudi Arabia began with
List of Thorictinae species from the Arabian Peninsula. Indication: recorded (*), not recorded (–), excluded (X).
Kuwait | Saudi Arabia | Yemen | Oman | United Arab Emirates | Qatar | ||
---|---|---|---|---|---|---|---|
Continental Yemen | Soqotra Island | ||||||
Subfamily Thorictinae | |||||||
Tribe Thorictini | |||||||
Thorictus arabicus Háva, 2010 | – | * | – | – | – | – | – |
Thorictus hanifahensis Háva & Abdel-Dayem, sp. nov. | – | * | – | – | – | – | – |
Thorictus omanensis Háva, 2021 | – | – | – | – | * | – | – |
Thorictus riyadhensis Háva & Abdel-Dayem, sp. nov. | – | * | – | – | – | – | – |
Thorictus shadensis Háva & Abdel-Dayem, sp. nov. | – | * | – | – | – | – | – |
Thorictus sharafi Háva & Abdel-Dayem, sp. nov. | – | * | – | – | – | – | – |
Tribe Thaumaphrastini | |||||||
Thorictodes heydeni Reitter, 1875 | – | * | – | – | – | – | – |
Excluded species | |||||||
Thorictus castaneus Germar, 1834 | – | X | – | – | – | – | – |
Thorictus foreli Wasmann, 1894 | – | X | – | – | – | – | – |
Thorictus peyerimhoffi Chobaut, 1904 | – | X | – | – | – | – | – |
The male genitalia are very important for differential diagnoses in insect taxonomy. But interspecific variation in male genitalia within species of Thorictinae leads to problems in the differential diagnosis of the aedeagi (
We reported the ant species captured with the beetle species from the same pitfall trap. The host species of ants were not recognized during this study due to the fact that these specimens were collected accidentally from field surveys. The Thoricuts species are phoretic and obligate myrmecophiles, either generalists or specialists (
We are grateful to Dr Ahmed Soliman, Iftekhar Rasool, and Ahmed Shams Al Ola, Plant Protection Department, College of Food and Agriculture Sciences, King Saud University, Saudi Arabia, for taking the colored photographs. We would like to thank Petr Zahradnik and Andreas Herrmann for their time spent on reviewing our manuscript and their comments helping us improving the article. The authors would like to extend their sincere appreciation to the Deanship of Scientific Research at King Saud University for funding this work [Research group No: RG-1437-009]. The paper was supported by the Ministry of Agriculture of the Czech Republic, institutional support MZE-RO0118.