Eucera gennargentui Nobile, Catania & Bella, 2021

Catania, Roberto, Nobile, Vittorio & Bella, Salvatore, 2021, The species of Eucera Scopoli, subgenus Tetralonia Spinola from Sardinia (Italy) with new records and E. gennargentui sp. nov. (Hymenoptera, Apidae), Journal of Hymenoptera Research 88, pp. 1-16 : 1

Eucera gennargentui Nobile, Catania & Bella sp. nov.

Material examined.

10 ♀, 1 ♂: Holotype: • 1 ♀; Italy, Sardinia, Fonni (Nuoro province), Gennargentu Massif , Bruncu Spina , 1540 m a.s.l.; 6-8.VIII.2020; S. Bella and R. Catania leg.; Di 3A . Paratypes: • 9 ♀, 1 ♂; paratypes identical data to previous; Di 3A, RC, VN, SB .

Description.

Female (Fig. 3 ). Body length: 10 mm. Body with black integument with fine and evident punctation, grey setae. Head. Head with wrinkled punctation, finer at the edges and with white setae; clypeus black, with the lower half light yellow; this spot, extending upwards, and in the middle part, ends with a triangulated tip; labrum and mandibles black, antennae dorsally black, ventrally orange, with scape and first two flagellar articles black. Mesosoma. Mesothorax with greyish setae, median part of the metathorax with dense and large punctation. Black legs with greyish setae and the last four tarsi brown; the hind legs are equipped with a uniformly yellow-rust-coloured pollen-collection system. Slightly darkened wings, with black veins and dark brown tegulae. Metasoma. Dark brown, almost black, with dense and fine punctation. T1 with long and sparse white setae, T2-4 with basal bands of white felt, T5 with white felt on the sides and dark brown in the middle, and T6 almost completely covered with dark-brown felt. Dark-brown sternites with thick punctation and long golden-yellow fringes.

Male (Figs 4 - 5 ). Body length: 9 mm. General appearance similar to the female, with yellow clypeus and labrum, antennae are more than half of the body length long and reddish, except for a black streak on the whole dorsal part; black scape; mandibles are black, but reddish in the distal half. Mesosoma. With long silky whitish setae. Black legs with whitish setae. The hind femur, in the lower median part, has a small pointed tubercle equipped with a tuft of brownish bristles. Metasoma. As in the female, is dark brown, but all segments are covered with white felt, and T6 on the sides has 2 prominent teeth, one on each side. The last sternites are provided with a long and deep longitudinal median sulcus. Genitalia and hidden sterna. S6 without anterolateral marginal projections; posterolateral carina curved laterally at each side. S7 with medial process rounded and attached at the posterior lobes of lateral processes; the posterior lobes of lateral processes are relatively short with straight superior margins; anterior lobes of lateral processes wide with straight superior margins and rounded lateral-inferior margins. S8 with a wide concavity between rounded apical lobes; apicomedian ventral process well defined and saddle shape, with a large depressed area at the base. Genital capsule with the apex of the gonostylus remarkably arched, and inward-facing triangular protuberance placed slightly over the central part of the gonostylus.

Difference with the closest related taxa.

The new species Eucera gennargentui , is similar to E. alticincta (Lepeletier, 1841), including the nominate subspecies and E. alticincta bindai .

In the female of E. gennargentui , the long fringes of the sternites are yellow-gold, whereas in the closest related species E. alticincta alticincta , they are white; the scopa is yellow-rust in the new species, whitish externally and brown internally in E. alticincta alticincta .

In the male of the new species, the long silky hairs of the mesosoma are whitish, while they are brownish-yellow in E. alticincta alticincta . Genitalia of E. gennargentui is very similar to that of E. alticincta alticincta , however, in the gonostylus the inward-facing triangular protuberance, that in E. alticincta is located in the middle part, in the new species is placed slightly over half of the gonostylus, slightly closer to the apex. Further differences can be noted in the morphology of the hidden sterna, especially for the medial and lateral processes in S7, and for apical lobes and apicomedian ventral process in S8.

In both sexes of the new species, the integument and wings are considerably darker than E. alticincta alticincta , and the body length of both sexes of E. gennargentui is greater than that of the related species.

Further morphological and bio-ecological comparisons between E. alticincta alticincta , E. alticincta bindai , and E. gennargentui are reported in Tables 2 and 3 .

Derivatio nominis.

We named the new species after Gennargentu Massif, where the specimens were found.

Distribution.

Sardinia (Italy).

Flower choices.

Specimens of the new taxon were observed on Carlina macrocephala Moris subsp. macrocephala , Tanacetum audibertii (Req.) DC. (Sardo-Corsican endemisms), and Helichrysum saxatile Moris subsp. saxatile (Sardinian endemism) ( Asteraceae ) (Fig. 6 ).

Bio-ecological aspects.

A total of 22 specimens (half captured and half marked) were observed in the sampling site: 20 females and 2 males. Specimens of E. gennargentui were observed in activity in a restricted area of about 300 m2, from 10:30 to 15:00; in particular, the females visited the flowers from 10:30 to 14:30, and the two males were observed from 13:30 to 15:00 on Carlina macrocephala subsp. macrocephala . The female specimens visited the same flowers at intervals of about ten minutes, with a preference for the flowers of Carlina macrocephala subsp. macrocephala .

To know better the flights period of E. gennargentui , further surveys in the same site were conducted during mid-July 2021, however no specimens were found. This confirms the relationship between the new species and its main host plant, in fact Carlina macrocephala subsp. macrocephala was at the beginning of its flowering.

Figures

Figure 3. Eucera gennargentui sp. nov., female (A-E) A head, anterior view B habitus, lateral view C dorsal view D mesosoma, dorsal view E metasoma, dorsal view. (Photos by R. Catania).

Figure 4. Eucera gennargentui sp. nov., male (A-E) A head, anterior view B habitus, lateral view C dorsal view D mesosoma, dorsal view E metasoma, dorsal view. (Photos by R. Catania).

Figure 5. Eucera gennargentui sp. nov., genitalia and hidden sterna (A-F) A S 6 ventral view B S 7 ventral view C S 8 ventral view D genitalia, dorsal view E genitalia, lateral view F vision of gonostylus and posterodorsal projection of gonocoxa (Photos by R. Catania).

Figure 6. Female of Eucera gennargentui sp. nov. Sardinia, Gennargentu Massif, locality of Bruncu Spina (Photos by P. Niolu - R. Catania).