Andrena (Micrandrena) spreta pusilla ( Pérez, 1903 ), Perez, 1903

Dardón, María José, Torres, Félix & Ornosa, Concepción, 2014, The subgenus Andrena (Micrandrena) (Hymenoptera: Andrenidae) in the Iberian Peninsula, Zootaxa 3872 (5), pp. 467-497 : 489-490

Andrena (Micrandrena) spreta pusilla ( Pérez, 1903)

Andrena pusilla Pérez 1903:85 (Lectotype examined) Andrena pseudasuniensis Strand 1921:289

Diagnosis. The female has a length between 6 and 7 mm. The clypeus is convex with a microsculpture that is shiny in the middle area. It has strong, defined, and scarce PPs in the lower zone, and is smaller than in the nominal subspecies, E=1–3. In the mesosoma, the entire scutum has a dull microsculpture, with small and fine PBHs, E=1–4. The scutellum is shinier than the scutum, with fine and obvious PPs over smooth integument on the front. The basal area of propodeum has fine ornamentation and a more defined propodeal triangle than in A. spreta spreta . The hind legs have only a white pubescence. The metasomal terga are shiny with a weaker microsculpture than in the other subspecies, which sometimes does not appear. The sterna has PPs that are stronger than in A. spreta spreta .

The male has a length between 5 and 6 mm. The clypeus appears to be very bright, with the base and sides having a microsculpture and PPs like those in the female. The process of labrum is almost quadratic. The face has a whitish pubescence, although occasionally there are some long and abundant black hairs intermingled within it. Some individuals are bright in the middle zone of the scutum and in the front of the scutellum, while the scutum has fine and scarce PPs, E=3–8 ( Stöckhert (1935) suggested that this may not be apparent). The mesepisternum has a dark pubescence in the first generation, while in the second it is whitish-gray. The metasoma is lanceolate, with a microsculpture that is slightly stronger than that of the female; therefore, the PPs become more difficult to distinguish. The marginal zones are more marked than in the female, and in both sexes of the nominate subspecies.

Comment. Andrena spreta Pérez, 1895 , Andrena curtula Pérez, 1903 , Andrena pauxilla Stöckhert, 1935 , and Andrena pusilla Pérez, 1903 , are classified by several authors as a complex group because of the large variability in their characteristics. For this reason is necessary to pursue an exhaustive study with an emphasis on individuals in southern Europe ( Warncke 1967; Gusenleitner 1984; Dylewska 1987; Schmid-Egger & Scheuchl 1997; Gusenleitner & Schwarz 2002).

In the Iberian Peninsula, there are two main complications with A. spreta . The first is related to A. pusilla , which according to Pérez (1903), is a species present in Spain, however the date mentioned is uncertain. Warncke (1967) indicated that this species corresponds to a subspecies of A. spreta , but without providing features to support his remark. Dylewska (1987) and Schmid-Egger and Scheuchl (1997) support it as a valid species, although the characteristics used by these authors to differentiate between species are not categorical. After the study of the lectotype of A. pusilla , similar features are evident with A. spreta , especially the microsculpture of the metasomal terga that is unique in A. spreta .

In agreement with the material examined, A. pusilla has finer and smaller PPs in the clypeus, scutum, scutellum, and metasoma. This characteristic was named by Dylewska (1987) and Schmid-Egger & Scheuchl (1997), and it remains constant and useful for distinguishing A. spreta . However, because this is the only feature that has been found, it is insufficient to determine two different species; therefore, A. pusilla should be considered a subspecies of A. spreta , and should be named A. spreta pusilla . Is possible that A. spreta pusilla is present in this region, although at the moment it is only reported on the record of Pérez.

The second complication is related to A. pauxilla . Dylewska (1987) and Schmid-Egger and Scheuchl (1997) indicate that it is a valid species, while Warncke suggests that it is a subspecies, " A. spreta pauxilla ," in agreement with the data from the specimens identified by this author in the collection of the MNCNM. After comparing the descriptions found in the literature and a review of the individuals studied, it is possible to say that A. pauxilla and A. spreta pauxilla do not have morphological differences, and for this reason it is not possible to define them as separate. Although the specimens recognized as A. spreta pauxilla by K. Warncke have, as a rule, yellow pubescence and PPs in the scutum that are bigger and rough, they are found in intermediate forms. Therefore, A. spreta pauxilla should be considered a synonym of A. spreta , as in A. curtula and A. pauxilla ( Westrich & Dathe 1997) .

This work was done principally with individuals from the Iberian Peninsula, although A. spreta has a wide distribution, therefore, we recommend employing other techniques of identification, using specimens from more regions, to define the taxonomic status of this group.

Specimens examined.

Andrena spreta pusilla Pérez, 1903

Lectotype: France: Nantes, 1 ♀, 1911, Pérez leg., MPARIS. Paralectotype: France: Royan, undated, 1 ♀, OLINZ, No. 508. Other material: Germany: Baden-Württemberg: Karlsruhe, 1 ♀, 23-III-1928, Hohndorf leg., OLINZ. Bavaria: Erlangen, 1 ♀, 10-VII-1932 / 1 ♀, 9-VII-1937 / 1 ♀, 10-V-1938, Stöckhert leg.,OLINZ. Hesse: Darmstadt, 1 ♀, 17-V-1927, Meyer leg., OLINZ; Darmstadt, 1 ♀, 6-V-1930, Meyer leg. Stöckhert det., OLINZ. North Rhine-Westphalia: Krefeld Rh., 1 ♀, 19-VI-1920, Brink leg., OLINZ. Unknown locality:Hausbergen, 1 ♀, 21-IV-1935, Klein, M. leg., OLINZ in Euphorbia L. [ Euphorbiaceae ]; 1 ♂, undated, Stöckhert leg., OLINZ, No. 2776.