Neomessa steusloffi (Konow, 1892) *, 1990

Liston, Andrew, Prous, Marko & Macek, Jan, 2019, On Bulgarian sawflies, including a new species of Empria (Hymenoptera, Symphyta), Deutsche Entomologische Zeitschrift 66 (1), pp. 85-105 : 95-97

Neomessa steusloffi (Konow, 1892) *

Material.

Varna: 1♂ (DEI-GISHym88743), Tsonevo 5 km S, 100 m, 42.982N, 27.451E, 02.04.2018. 1♀ (DEI-GISHym88749), locality as previous, 03.04.2018 . 6♀ (including DEI-GISHym31831), 4♂ (including DEI-GISHym31830 and 31832), Dolni Chiflik 2 km SE, 50 m, 42.983N, 27.743E, 05.04.2018. 1♀, locality as previous, 13.04.2018 . 1♂, Staro Oryahovo 2 km SW, 120 m, 42.976 N, 27.787E, 09.04.2018. 1♀, locality as previous, 11.04.2018 .

Other material examined.

Germany, Mecklenburg-Vorpommern: 1♂ [lectotype; in very poor condition], Neubrandenburg i. M. (SDEI) . 1♀, near Teschendorf [according to Konow 1897: "in hiesiger Gegend"] (SDEI).

Taxonomic history.

? Fenusa sp. nov. Konow 1885: 298-299. Description of male.

Fenusa steusloffi Konow, 1892: 213. Name proposed by indication on Konow (1885). Syntypes. Type locality: Neubrandenburg i. M. [Germany, Mecklenburg-Vorpommern, Neubrandenburg]. Konow 1897: 180-181, description of female.

Fenusa steusloffii . Dalla Torre 1894: 157. Name for Fenusa steusloffi Konow, 1892. Primary homonym of Fenusa steusloffi Konow, 1892.

Fenusella steusloffi . Enslin 1914: 306. New combination.

Metallus steusloffi . Benson 1959: 90. New combination, invalid lectotype designation [of the female specimen in SDEI collection].

Neomessa steusloffi . Koch 1990: 72-73. New combination, redescription, lectotype designation.

This species (and thus the monotypic genus to which it belongs) does not run unambiguously to a genus in the key to fenusine genera of the world by Smith (1976a), because it has the following combination of characters: winged; tarsal claw with one outer tooth and an acute basal lobe; prepectus absent; genal carina absent; stub of vein 2A+3A of fore wing curved up. With the genal carina scored as absent (this character is difficult to see), N. steusloffi does not run past couplet 17, because the radial cell of the hind wing is open at the apex, but the stub of vein 2A+3A of the fore wing is curved. If the genal carina is scored as present, then in the final key couplet leading to Scolioneura , the character given by Smith "antennal segments 3 and 4 about equal in length" does not fit N. steusloffi , which has antennomere 4 about 0.6 × as long as antennomere 3.

Both Konow (1885) and Koch (1990) have already described a distinctive character in the venation of Neomessa : fore wing vein Rs+M is largely obsolete except for a small stub on Rs, and Rs is strongly bent at this point (Fig. 41 ). All examined specimens show this. Within the Fenusini , this character is apparently unique to Neomessa . Furthermore, fore wing vein M is very straight, whereas it is basally curved in most other genera. The male (Fig. 43 ) is additionally easily distinguishable from other Western Palaearctic fenusines by the colour of the abdomen, which is black with the following yellow: apical terga from T5 or T6 (Fig. 45 ), sterna S8 and S9 and narrow distal margin of S7 (Fig. 44 ), and visible parts of genitalia. Only the male of Parna tenella (Klug, 1816) also has an extensively yellow abdomen; but it differs in only abdominal terga 1 and 2 being mainly black, and in its largely pale legs (legs nearly entirely black in N. steusloffi : Figs 42 , 43 ). We illustrate the penis valve of one of the Bulgarian specimens (Fig. 46 ), because the drawing by Koch (1990) lacks detail.

Based on the combined analyses of mitochondrial COI and nuclear NaK genes (one sequenced male DEI-GISHym88743), the species forms a strongly supported clade with Scolioneura and Fenusella , but the relationships between the three genera are less well resolved (Fig. 47 ).

Biology.

Host plant unknown. All the Bulgarian specimens were swept from the newly opened buds or fresh leaves of one or more unidentified Quercus species, with the exception of the first male, which was swept from low vegetation just outside an area of mixed woodland. According to Konow (1885), the small series of syntype males was collected from flowers of Prunus spinosa . Subsequent authors (e.g. Benson 1959) have therefore suspected P. spinosa to be the host plant. According to our observations, Quercus seems to be a more likely host.

Distribution.

Previously only definitely known from Mecklenburg-Vorpommern, in north-eastern Germany, and now from south-eastern Bulgaria. Muche (1973) published a record of a female identified as this species from Großschönau (Germany, Saxony). However, because he mentioned that this specimen possessed four cubital cells in the fore wing (unlike any specimens which we have seen), it seems likely that it was misidentified.

Figures

Figure 47. Maximum likelihood tree of Blennocampinae and Heterarthrinae based on two genes (COI and NaK). Best-fit model chosen according to Bayesian information criterion was GTR + I + G 4. Numbers beside nodes show SH-aLRT support (%) / ultrafast bootstrap support (%) values. Support values for weakly supported branches (<90) are not shown. Letters " f " and " m " stand for " female " and " male ". Numbers at the end of the tip labels refer to the length of the sequence and the number of ambiguous positions (e. g. polymorphisms). The tree was rooted according to the results of Leppaenen et al. (2012). The scale bar shows the number of estimated substitutions per nucleotide position.

Figures 41 - 46. Neomessa steusloffi. 41, 42 Female habitus, bend on vein Rs arrowed, DEI-GISHym 31831. 43 Male DEI-GISHym 31832 habitus. 44 Male DEI-GISHym 31832 abdomen ventral. 45 Male DEI-GISHym 31830 abdomen dorsal. 46 DEI-GISHym 88743 Penis valve.