Andrena culucciae Annessi, Riccieri & Di Giulio, 2025

Annessi, Matteo, Riccieri, Alessandra & Di Giulio, Andrea, 2025, A new species of Andrena (Hymenoptera, Andrenidae) from northern Sardinia (Italy), Journal of Hymenoptera Research 98, pp. 795-816 : 795-816

Andrena culucciae Annessi, Riccieri & Di Giulio sp. nov

Material examined.

Italy Sardinia, Culuccia Peninsula ( Sassari Province ) Holotype: • 1 ♂; 41.194361°N, 9.288000°E; 18 May 2024; ADG & MA leg.; entomological nets; on Armeria pungens (Link) Hoffmanns. & Link ( Plumbaginaceae ) in herbaceous dune vegetation; MZUR 3 . Paratypes: • 1 ♀; 41.199972°N, 9.292444°E; 17 May 2022; ADG & MA leg.; entomological nets; on Cistus monspeliensis L. ( Cistaceae ) in Mediterranean maquis; GenBank: PX 058890 ; MZUR 3. • 3 ♀; 41.194361°N, 9.288000°E; 18 May 2022; ADG & MA leg.; entomological nets; on Echium plantagineum L. and Jasione montana L. ( Campanulaceae ) in herbaceous dune vegetation; GenBank: PX 058884 ; MZUR 3 . • 1 ♀; 41.203083°N, 9.290833°E; 01 Jun 2023; ADG & MA leg.; entomological nets; on Bunias erucago L. ( Brassicaceae ) in pasture; MZUR 3 . • 2 ♀; 41.194361°N, 9.288000°E; 01 June 2023; ADG & MA leg.; entomological nets; on Armeria pungens (Link) Hoffmanns. & Link ( Plumbaginaceae ) in herbaceous dune vegetation; MZUR 3 . • 37 ♀, 1 ♂; 41.194361°N, 9.288000°E; 18 May 2024; ADG & MA leg.; entomological nets; on Armeria pungens (Link) Hoffmanns. & Link ( Plumbaginaceae ) in herbaceous dune vegetation; GenBank: PX 058885 , PX 058886 , PX 058887 , PX 058888 , PX 058889 , PX 058891 ; MZUR 3 .

Molecular evidence.

The eight COI sequences obtained from our specimens had a total length of 570 bp and were monophyletic, with high support both in the NJ tree (bootstrap = 99) and in the ML tree (UFB = 99; SH-aLRT = 98.4) (Figs 2 , 3 ). The phylogenetic relationships among A. nigrospina , A. pilipes and A. culucciae were clearer in the NJ tree, where A. culucciae forms a clade that is sister to A. pilipes + A. nigrospina (Fig. 2 ). In contrast, the ML tree does not recover A. nigrospina as a monophyletic group, preventing the resolution of relationships among the three taxa, even though A. culucciae emerges as an isolated and well-defined clade denoting genetic differentiation from A. nigrospina and A. pilipes (Fig. 3 ). P-distance values were as follows: A. culucciae vs A. nigrospina = 1.64 %; A. culucciae vs A. pilipes = 1.74 %; A. pilipes vs A. nigrospina = 1.01 %. Relationships among haplotypes in the haplotype network (Fig. 4 ) were coherent with those emerging from the NJ and with the p-distance values. 16 haplotypes were detected: nine belonging to Andrena pilipes , one of which is shared with the subspecies A. pilipes f. iliensis; five belonging to A. nigrospina ; and three belonging to A. culucciae .

Diagnosis.

The new species Andrena culucciae can easily be recognized as a Plastandrena due to its distinctly widened and curved hind tibial spur at the base, the rugose areolate propodeal triangle, the rounded pronotum and coarsely punctate terga. It is structurally very similar to the other taxa within the A. pilipes / nigrospina complex because of its large size, dark body, dense network of raised rugosity on the dorsolateral faces of the propodeum and clypeus with large and dense punctations. Andrena culucciae differs mainly from Andrena pilipes s. s. and A. pilipes f. iliensis in the male sex by a longer genital capsule and broader penis valves at the base (Figs 5 – 7 ), as well as the translucent marginal zones of T 2 - T 5 (Fig. 8 ), which also distinguishes it from A. nigrospina . Females can be distinguished based on the predominant coloration of the setae on the hind legs: in A. culucciae , the setae on the femur are white and the tibial scopa is brown, in A. pilipes f. iliensis both femoral setae and tibial scopa are black, while in A. pilipes and in A. nigrospina both are white (Fig. 9 ). Further morphological comparisons between A. culucciae , A. pilipes and A. pilipes f. iliensis are reported in Table 2 .

Description.

Male (Fig. 10 ). Body length: 12–13 mm. Head. Black, 1.2 times wider than long (Fig. 10 B ). Ocelloccipital distance slightly greater than lateral ocellar diameter. Paraocular areas depressed, both frons and paraocular areas with longitudinal wrinkles (Fig. 10 B ). Clypeus domed, slightly shiny with dense and large punctures, without an impunctate central line (Fig. 10 B ). Labral process trapezoidal, apex emarginate. Mandibles slightly crossing apically with sparse setae along outer margin, bidentate; apical tooth longer than preapical tooth; maxillary palpi with six segments, labial palpi with four segments. Gena moderately broad, about equal in width to compound eye. Vertex and face with whitish and brownish setae (Fig. 10 B ). Antenna dark, A 3 slightly shorter than A 4 (Fig. 10 B ). Mesosoma. Scutum and scutellum irregularly punctate, with punctures larger and sparser medially. Pronotum rounded laterally, without humeral angle. Episternum and lateral propodeal surface reticulate, propodeal triangle strongly carinate with internal surface rugose-areolate. Scutum and scutellum with moderately long whitish setae, episternum and propodeum with brownish setae (Fig. 10 A ). Legs dark, tarsal claw light brown, general pubescence dark brown, lighter on tarsal segments (Fig. 10 A, C ). Wings brownish, venation dark brown and stigma light brown and nervulus slightly antefurcal; tegulae brown with surface rugose (Fig. 10 A ). Metasoma. Terga dark and regularly punctate, punctures separated on average by 2 puncture diameters (Fig. 10 A ). Disc of T 1 with sparser punctation, marginal zones of T 2 - T 5 slightly depressed and translucent (Fig. 10 A ). T 1 - T 4 with very sparse short brown setae, last tergites with longer and darker hairs. Pygidial plate absent. S 7 deeply emarginate apically with lateral lobes hairy. S 8 hairy, slightly emarginate apically (Fig. 10 F ). Genitalia elongate, gonocoxae with clearly produced apical teeth, these diverging slightly; gonostyli with apical spatulate parts elongate and parallel margins (Figs 6 A , 7 A , 10 D, E ). Penis valves broad at the base (Figs 6 A , 7 A , 10 D ), progressively tapering to the apex (Fig. 7 A ). Volsella transverse, with rounded outer margins, and with both cuspis and digitus well developed (Figs 7 A , 11 A ). Digitus curved, subparallel to the cuspis, basoventrally fused with the basivolsella, and with a bulged apex (Figs 7 A , 11 A, C ). Cuspis triangular and spatulate, with a rounded apex and numerous erect setae of different lengths (Fig. 11 C ). Cuneiform tooth-like cuticular structure, obliquely truncate and laterally directed, located in the ventral apical part of the digitus and the dorsal subapical part of the cuspis (Fig. 11 C ). Basivolsella bulged, with numerous elongate setae (approximately 20, Fig. 11 A ).

Female (Fig. 12 ). Body length: 14–16 mm. Head. Black, 1.2 times wider than long (Fig. 12 B ). Ocelloccipital distance slightly greater than lateral ocellar diameter. Fovea uniformly depressed along entire length, with lower margin ending distinctly below antennal insertion (Fig. 12 B ). Frons with longitudinal wrinkles (Fig. 12 B ). Clypeus, gena, maxillary and labial palpi as in male, labral process trapezoidal but without apical emargination. Mandibles slightly crossing apically with sparse setae along outer margin, unidentate. Subgenal coronet present and well-developed. Fovea, vertex and face with brown setae (Fig. 12 B ). Antenna dark, A 3 slightly exceeds A 4 + 5, shorter than A 4 + 5 + 6 (Fig. 12 B ). Mesosoma. Scutum, scutellum, pronotum, episternum, propodeum and propodeal triangle as in male. Scutum and scutellum with moderately long black and dark brown setae, episternum and propodeum with brownish setae (Fig. 12 A ). Propodeal corbicula incomplete, possessing only a dorsal fringe; internal surface mostly glabrous, with very sparse setae. Legs dark, with tarsal claw light brown; fore and middle legs with general pubescence dark brown, lighter on tarsal segments; hind legs with white hairs on femur and tibial scopa predominantly composed of brown hairs (Figs 9 A , 12 A, C ). Wings and tegulae as in male but browner (Fig. 12 A ). Metasoma. Terga entirely dark, punctation similar to that of the male (Fig. 12 A ). Pubescence of T 1 - T 4 as in male, apical fringe of T 5 and hairs flanking pygidial plate dark brown (Fig. 12 A ). Pygidial plate V-shaped with round apex and a distinct raised internal triangle; internal surface rough.

Derivatio nominis.

We named the new species after Culuccia Peninsula ( Sardinia, SS, Italy), where the specimens were collected.

Distribution.

Sardinia ( Italy).

Ecological aspects.

Specimens of Andrena culucciae sp. nov. were mainly observed on Armeria pungens ( Plumbaginaceae ) in the herbaceous vegetation of coastal dunes with coarse sand (Fig. 13 ). However, this new taxon was also recorded on plant species belonging to different families, such as Boraginaceae , Brassicaceae , Campanulaceae and Cistaceae . These observations suggest that A. culucciae sp. nov. is polylectic, like its closest related taxa ( Beil et al. 2008).

Figures

Figure 2. Neighbor Joining Tree based on the COI highlighting the relationship between Andrena pilipes, A. nigrospina and A. culucciae sp. nov. within the context of the Western Palearctic Plastandrena. Numbers at nodes indicate bootstrap values; only values above 70 are represented.

Figure 3. Maximum Likelihood Tree based on the COI highlighting the relationship between Andrena pilipes, A. nigrospina and A. culucciae sp. nov. within the context of the Western Palearctic Plastandrena. Numbers at nodes indicate SH-aLRT / UFB values; only values of SH-aLRT above 80 and of UFB above 95 are reported.

Figure 4. Haplotype network of A. pilipes, A. nigrospina and A. culucciae sp. nov. Colours assigned to each taxon are reported in the legend. Not sampled intermediate haplotypes are indicated by white dots.

Figure 5. Dorsal view of male genitalia A Andrena culucciae sp. nov. B Andrena pilipes f. iliensis C Andrena pilipes s. s. Scale bars: 1 mm.

Figure 6. SEM images of the dorsal view of male genitalia A Andrena culucciae sp. nov. B Andrena pilipes s. s. Scale bars: 0, 5 mm.

Figure 7. Dissected genital capsule of A Andrena culucciae sp. nov. B Andrena pilipes s. s. From top to bottom: gonocoxae and gonostyli, penis valves and volsella. Scale bars: 1 mm.

Figure 8. Dorsal view of male tergita A Andrena culucciae sp. nov. B Andrena pilipes f. iliensis C Andrena pilipes s. s. Scale bars: 1 mm.

Figure 9. Hind legs of female A Andrena culucciae sp. nov. B Andrena pilipes f. iliensis C Andrena pilipes s. s. Scale bars: 1 mm.

Figure 10. Andrena culucciae sp. nov. male A dorsal view B head C lateral view D genitalia dorsal view E genitalia profile F sternite 8. Scale bars: 5 mm (A); 2 mm (B, C); 1 mm (D – F)

Figure 11. SEM images of the lateral view of the volsella of (A, C) Andrena culucciae sp. nov. and (B, D) Andrena pilipes s. s. (A, B) general view; (C, D) details of the apex of the cuspis and the digitus. Scale bars: 0, 2 mm (A, B); 0, 05 mm (C, D).

Figure 12. Andrena culucciae sp. nov. female A dorsal view B head C lateral view. Scale bars: 5 mm (A); 2 mm (B, C)

Figure 13. Herbaceous dune vegetation in the Culuccia Peninsula (Sardinia, Italy), where most of the Andrena culucciae sp. nov. specimens were collected (A) Female of Andrena culucciae sp. nov. on Armeria pungens (B) (Photos by M. Annessi).