Research report: Taxonomic and distributional updates on the Arabian species of the genus Palpita Hübner, 1808 ( Lepidoptera , Crambidae , Spilomelinae )

The findings, published in the Biodiversity Data Journal, add a third Arabian species to the genus Palpita, one of the most species-rich groups of crambid moths in the world, and significantly extend the known range of a species that was described only a few years ago from the mountains of Oman. The genus Palpita currently comprises 166 valid species, placing it among the three most diverse genera in the moth subfamily Spilomelinae. Externally, they are characterised by a white ground colour, cellular spots on the wings and subterminal fasciae.

Internally, the genus is defined by a suite of anatomical features in the genitalia, including saccular processes in the male, deciduous cornuti in the vesica and paired signa in the female bursa copulatrix. In the Afrotropical zone, the genus is represented by 21 species, 20 of which have been known exclusively from that zone to date. The Afrotropical zone reaches its northern boundary in the southern Arabian Peninsula, encompassing the Dhofar province of southern Oman, Yemen and the Sarawat mountain chain in southern Saudi Arabia.

Although the Arabian fauna is predominantly Afrotropical in character, it is also influenced by Palaearctic and Oriental elements, a pattern well documented for butterflies and noctuid moths. The new study draws on material collected in the Raydah Reserve in the Asir mountains of Saudi Arabia during research projects of the King Saud University Museum of Arthropods in 2014 and 2015, in the Fayfa mountains of Jizan province between 2022 and 2025, in the surroundings of Taif in 2022 and in Oman's Dhofar province in 2026. All specimens were captured at night using light traps equipped with ultraviolet tubes and UV power-LEDs covering a wave spectrum of 365 to 385 nanometres.

Adults were photographed after relaxation using high-resolution digital imaging systems, with image stacking performed to produce sharp composite photographs. Genitalia were examined using slide-mounting techniques following standard protocols, prepared under stereomicroscopes and photographed with dedicated cameras. One part of the material represents a species new to science, which the authors have named Palpita digitalis.

The species epithet refers to one of the differential character states in the male genitalia, namely the digitiform cornuti in the vesica. The holotype and a paratype were collected in the Raydah Reserve at an elevation of 2,387 metres in April 2014. The adults and male genitalia are described and illustrated in the paper; the female genitalia remain unknown.

At present, the species is known only from the type material from south-western Saudi Arabia, where it was collected exclusively in the Junipera zone of the Afromontane escarpment in the Asir mountains. Palpita digitalis is closest both in external and in internal morphology to the Afrotropical species Palpita irroratalis and Palpita tsisabiensis and to the Oriental species Palpita argoleuca. Externally, these species share a complete bareness from any black maculation in the fore- and hind-wing.

In the male genitalia, they share the shape of the uncus, composed of a neck and a beak-shaped apex, and the number and shape of the saccular processes, with one simple dorso-distal process forming a right-angled structure with the rest of the sacculus. The new species is distinguished from its relatives by a saccular process that is posteriorly narrowed and bare from any appendix, and by a juxta bare from invagination. One further species sharing the wing maculation, Palpita candicantis, is distinguished by the presence of two widely separated distal saccular processes.

The other part of the material was attributed to Palpita subflavalis, which is reported as new to the fauna of Saudi Arabia. The species had been known exclusively from the southern Arabian Peninsula, specifically from the type locality in Oman's Dhofar province. The new records from the Raydah Reserve in the Asir mountains, from Shada Al Ala in Al Baha province, from Al Shafa near Taif, from Balhurashi in Al Baha, from the Fayfa mountains in Jizan and from Wadi Lajab in Al Reeth significantly extend the presently known distribution range of the species to the southern Sarawat mountain chain in Saudi Arabia.

The species was also recorded again in Oman, at Dhalkut in Dhofar province, in January 2026. The re-description of Palpita subflavalis based on the new material revises the attribution of character states in the original description, namely in external characters of the head profile and in characters of the male and female genitalia. The head profile has been re-figured at an enhanced resolution level compared with the figure in the original description.

The male genitalia show variation in the size of the valva and in the length of the arms of the distal sacculus, while the female genitalia exhibit variation in the size of the dilated posterior ductus bursae and in the length of the anterior ductus bursae. There are no intersexual differences, neither in wing maculation nor in wing shape. The data do not allow attribution of the variability to geographic separation between the samples from Dhofar and Saudi Arabia, and the authors therefore refrain from drawing taxonomic consequences at subspecific level.

With a wingspan of 20.1 to 25.0 millimetres, it bears a yellowish-brown subcostal stripe on the fore-wing ranging from the base to the apex, and a hind-wing terminal line marked as a series of yellowish-brown interneural spots. In the male genitalia, the diagnostic character states include one distal bifid saccular process, whose arms form a right angle and differ significantly in length, and a vesical sclerotisation marked as three cornuti, one of them very short and the other two deciduous and acuminate. Further diagnostic character states revealed by the analysis of the present material are the presence of a dorso-medial invagination in the sacculus and the trapezoid shape of the laterally projected juxta.

In the female genitalia, the species is differentiated from the Palpita vitrealis species group by the presence of tiny, thorn-shaped signa, in the strongly dilated and strongly sclerotised posterior ductus bursae and by the strongly sclerotised, trapezoid-shaped antrum. The paper also provides a determination key to the presently known Arabian species of Palpita and to their closest Afrotropical and Oriental relatives, enabling researchers to separate Palpita candicantis, Palpita subflavalis, Palpita digitalis, Palpita argoleuca, Palpita tsisabiensis and Palpita irroratalis on the basis of characters in the male genitalia. The life history, premature stages, host plant selection and abundance of the Arabian species Palpita digitalis and Palpita subflavalis remain unknown and are subject to further research.

Subject of Research: Taxonomic and distributional updates on the Arabian species of the genus Palpita Hübner, 1808 (Lepidoptera, Crambidae, Spilomelinae)

Article Title: Taxonomic and distributional updates on the Arabian species of the genus Palpita Hübner, 1808 ( Lepidoptera , Crambidae , Spilomelinae )

Article References: Seizmair, M., Ishag, A., & Al Dhafer, H. (2026). Taxonomic and distributional updates on the Arabian species of the genus Palpita Hübner, 1808 (Lepidoptera, Crambidae, Spilomelinae). Biodiversity Data Journal, 14, Article e199345. https://doi.org/10.3897/bdj.14.e199345

Image Credits: AI Generated

DOI: 10.3897/BDJ.14.e199345

Keywords: Taxonomic, distributional, updates, Arabian, species, genus, Palpita, bner, Lepidoptera, Crambidae, Spilomelinae, scientific research