Prasinocyma Warren, 1897

Hausmann, Axel, Sciarretta, Andrea & Parisi, Francesco, 2016, The Geometrinae of Ethiopia II: Tribus Hemistolini, genus Prasinocyma (Lepidoptera: Geometridae, Geometrinae), Zootaxa 4065 (1), pp. 1-63 : 9-11

Genus Prasinocyma Warren, 1897

Type species: Thalassodes vermicularia Guenée, 1858 ( South Africa: Northern Cape: Namaqualand) by original designation.

Prasinocyma is an enigmatic, taxonomically difficult genus, megadiverse in Africa, with 98 known species, most of them described before 1930. Eight species are described from Ethiopia, three from Saudi Arabia, one each from Sudan and Somalia, 11 from Kenya and 15 from Uganda. However, most species of the last mentioned country are from Ruwenzori Region in the south-west, close to the Congo basin. The genus still lacks a comprehensive revision. The more recent descriptions are all done as single descriptions in the framework of national treatments. In many cases the description is based on just one sex and not rarely it remains unclear which males match with which female.

DNA barcoding brings together a lot of data, males can easily be matched with females and the genetic distances of populations from different regions of Africa are showing deep 'barcode gaps' and thus are reflecting quite well their interspecific relationships. So far we have gathered more than 400 barcodes for African members of the genus Prasinocyma belonging to 140 BINs (cf. Fig. A) with 20 additional lineages clearly referring to further Prasinocyma species but without BIN assignment (fragment lengths <500 bp). The accumulation curve of African Prasinocyma species (Fig. A) suggests saturation far beyond 200 species—perhaps even beyond 300. This means that species assessment in this genus is still at the very beginnings for the whole of the continent.

For verifying the identifications we have dissected more than 150 individuals (mainly males) of Ethiopian members of this genus, studies on original descriptions, type examinations in collection Herbulot (ZSM) and in the NHM (London).

In this work we raise the number of known Prasinocyma species for the fauna of Ethiopia from eight to 40, two of these species show subspecific divergences within the territory of Ethiopia. One further, undescribed species is analysed and presented here but set back for a later formal description due to the poor conservation status of the singleton.

FIGURE A. Accumulation curve for DNA barcode clusters (source: BOLD database, http://www.boldsystems.org/ accessed 3.12.2014) of African members of the genus Prasinocyma .

The genus was poorly defined by Prout (1930), just indicating presence of frenulum in male and its absence in female, the 'lack of specialized structures', third segment of female palpi 'more or less elongate', and hindwing termen rounded or slightly angled at M3. Presence of coremata at base of valvae and elongate shape of valva with concave ventral margin shared with genus Thalassodes , but the latter with the following important differential characters (cf. Holloway 1996): socii present, long and narrow, sternum A8 unmodified or slightly only, typically also angled hindwing termen and pale transverse lines. Most species show pale ‘strigulae’ ( Janse 1935) densely irrorated over the green ground colour.

Prout (1930) based the order (sequence) of species on the presence/absence of discal dots and dots at the inner termen, but such criteria are not reliable for a solid and reliable classification. In this paper, we list the species in more natural species-groups according to relationships as they are revealed by a combined analysis of genitalia and DNA barcodes. These allow to arrange the 40 Ethiopian species in the following groups: (a) the immaculata species-group with eleven species (b) the nereis species-group with eighteen species (c) the aetheraea speciesgroup with five species (d) the bifimbriata species-group with six species. For all groups we found synapomorphies, mainly in male genitalia (see species-group descriptions). Generally the male genitalia of Prasinocyma bear valuable differential features at species level, common features are the lacking or vestigial, short socii, almost all species show a membranous, subterminal, ventral lobe at the valva, sacculus and/or harpe usually sclerotized, sternum A8 often bilobous or with paired projections.

In the descriptions of wing coloration of Prasinocyma species we just differenciated between “bluish green” and “leaf green”, such as between “pale (bluish/leaf) green” and “deep (bluish/leaf) green”. Any further differenciation is not helpful in our opinion.