Usia martini François, 1969

Gibbs, David, 2011, 2960, Zootaxa 2960, pp. 1-77 : 18-19

Usia martini François, 1969

Diagnosis. Quite distinct from any known Usia or Parageron such that it cannot be placed with any other species without creating a clearly polyphyletic group. Thus it is necessary to propose a species group to accommodate this single aberrant taxon.

Differs from all other Usiini in by the combination of

1. smooth, non-scrobiculate cuticle

2. all hair punctures simple

3. frons densely dusted

4. mesonotum densely olive-grey dusted with brown paramedian and ante-humeral vittae

5. abdominal dust largely obscuring ground colour

6. sternites often with narrow yellow margins

7. dorsal surface of labrum bare

8. very narrow mouth margin

9. entirely dark tergites (no yellow margins)

10. very narrow anal lobe

11. dusky mesonotal hairs

Characters 1–6 are typical of Parageron but characters 7–10 are typical of Usia while character 11 approaches the condition typical of Micrusia .

The male genitalia are difficult to interpret, while the shape of the epandrium and gonostyli suggest affinity with Usia bicolor , the highly polished epandrium with medial and lateral dust spots is quite unlike any other species. The epiphallic complex is also unique but the epiphallus appears to have vestiges of apical spines typical of Parageron and also reminiscent of some Micrusia .

The female genitalia have a relatively simple furca and transparent vaginal plate as often found in Usia , including Micrusia . However, the apical sternite is much closer to many Parageron . The furca has a medial fold at which point the tip of the furca is hinged, a character quite unique in the Usiini .

History and affiliations. This rare Iberian endemic does not fit well with any other known species and is included in this part of the revision because it is keyed out in the key to the genera above. First described from two females found in the Sierra Nevada ( François 1969), there have been only three further records. From François’ labels it is clear that he initially considered this species to belong in the then subgenus Parageron . However, when describing the species he tentatively suggested that it belonged in Paramonov’s versicolor –group, i.e. all the black haired species. Evenhuis (1990) did not have access to this species when redefining the genera of Usiinae and Evenhuis & Greathead (1999), who also did not see this species, placed it in Usia sensu stricto. Examination of the type, paratype and two other females suggested that it was a very unusual species, external morphology and, especially, the genitalia did not fit with any other known species. It was not until the DuMerle collection in MNHN was studied that male specimens were seen. Dissection of males confirmed its unique character and suggest that this species is somewhat intermediate between Usia and Parageron . It seems possible that it represents a relict taxon closest to the common ancestor of both these genera.