Pristiphora melagonia, Liston & Prous, 2020

Liston, Andrew & Prous, Marko, 2020, Recent additions to the list of German sawflies (Hymenoptera, Symphyta), Deutsche Entomologische Zeitschrift 67 (2), pp. 127-139 : 127

Pristiphora melagonia sp. nov. Figures 17-20 , 21-26

Material examined.

Holotype female, pinned. Labels: "Greece: N Peloponnes: Achaia: Achaiko Chorio S 38.1371N, 22.0610E 1150 m alt. 25.IV.2017 leg. SDEI Hym-group GR06 [code for collection event, used for databasing]" [white, printed] " DEI-GISHym80284 (see ethanol coll.)" [white, printed: parts of two extracted legs gummed to label] "tissue sample 2017 genetic data Y[yes] [or] N[no]" [blue, printed: check mark at “yes”] "HOLOTYPE ♀ Pristiphora melagonia det. Liston & Prous, 2020" [red, printed]. Deposited in the DEI.

Paratypes: Germany, Saxony-Anhalt: 1♀ ( DEI-GISHym17900), Rammelburg, GS9 Ra [trap code], Straße zum Strubenberg, Wipperufer vor Brücke / Waldhang, Bärlauchgebiet, Gelbschale [yellow pan], R: 4453597 H: 5718076 [+51.594 +11.331], 14.-21.5.2001, leg. E. Stolle ( DEI). Greece, N Peloponnes, Achaia: 1♀ ( DEI-GISHym80270), Kertezi, +37.980 +21.990, 800-1100 m alt., 28.IV.2017, leg. SDEI Hym-group, GR18 ( DEI). Spain, Aragón: 1♀ ( DEI-GISHym20784), Camarena de la Sierra 2 km S, 1360m alt., 05.05.2014, +40.126 -1.044, leg. Liston Prous Taeger, E021 ( DEI).

Type locality.

Greece: northern Peloponnese, Achaia, south of Achaiko Chorio, +38.137 +22.061, 1150 m alt.

Description

[characters of holotype in brackets]. Female. Body length 5.0-6.0 mm [5.7 mm]. Head mostly black (Figs 21-23 ). Pale are: palpi; clypeus entirely (whitish), to medially more or less dark [holotype]; antennal flagellum ventrally; lower inner orbit partly (brownish) [holotype], to entirely black; outer orbit next to eye narrowly (brownish) (Fig. 23 ), to entirely black [holotype with small, obscurely paler areas]. Thorax mostly black (Figs 17-19 ). Pale (yellowish) are: pronotum except for extreme ventral and posterior margins; tegula; small anterolateral flecks on median metascutal lobe, to completely black [holotype]; anterodorsal fleck on mesepisternum, to whole dorsal half [holotype]; metapleuron; mesepimeron [holotype], to completely dark. Legs pale (yellow) (Fig. 18 ). Dark are: metatarsus, at least on upper-side; apex of metatibia; extreme base of procoxa. Wing membranes hyaline. Venation dark brown; forewing pterostigma uniformly medium brown, to edged dark brown with paler centre; basal 0.25-0.33 of costa whitish. Abdomen yellow (Figs 19 , 20 ). Black are: tergum 1 medially and basally; tergum 2 medially, to completely pale; tergum 3 medially, to completely pale; tergum 8 medio-apically, to completely pale; more or less valvula 3 apically [only tergum 1 of holotype medially black].

Head densely setose; vertex, postocellar area and posterior frontal field shiny between the setae; inner orbits and anterior postocellar area duller, with slight sculpture. Postocellar area about as long as diameter of lateral ocellus. Antenna: Fig. 24 . Flagellomere 1 slightly curved in lateral view; 3.5-4.1 times as long as apical width [holotype 4.1]. Tarsal claws subbifid: inner tooth slightly shorter than outer. Abdominal terga dull, with fine reticulate sculpture (Fig. 20 ). Valvulae 3 in dorsal view (Fig. 25 ): apically subtruncate; about twice as broad as basal width of cercus; setae directed strongly backwards; outermost setae about as long as width of valvulae 3; cercus projecting clearly beyond valvula 3. Valvula 3 in lateral view apically rather acute. Lancet (Fig. 26 ): approximately 23 annulets; slightly upwardly curved distally; annular setae ( “ctenidia”) present on sutures 1 to ca. 17 (counted from base); annular setae about 0.33x as long as width of annulus; cypsellae on basal annulets (ca. 1-8) about 0.33x as long as serrula.

Male: unknown.

Variability.

The Spanish specimen is the palest and the German specimen the darkest, with the two very similarly coloured Greek specimens intermediate.

Genetics.

Mitochondrial CO1 has been sequenced from three specimens, two of which were published by Prous et al. (2017). Sequences of the specimens from Spain and Germany are identical, while the specimen from Greece (holotype) differs by 0.1-0.2%. Three nuclear genes have been sequenced from two specimens, TPI from DEI-GISHym20784 (KY698317, see Prous et al. 2017) and NaK and POL2 from the holotype DEI-GISHym80284. Closest species are P. krausi , P. tetrica and the specimen DEI-GISHym20783 from Spain (possibly an undescribed species, see Prous et al. 2017), with a minimum CO1 distance of 6.7% ( P. tetrica ) and a minimum nuclear DNA distance of 1.5% ( P. krausi ).

Host plant.

The Spanish specimen was swept from Acer monspessulanum . As the known hosts of other species in the Pristiphora depressa group are all Acer species ( Liston et al. 2015, Prous et al. 2017), it is likely that the larva of P. melagonia also feeds on Acer . Hosts other than A. monspessulanum must be used, because this maple species does not occur in the region of Germany where one of the paratypes was collected.

Etymology.

Melagonia , a Latinised noun in the nominative singular, is derived from parts of the Greek words melas (black) and gonia (angle, corner) and refers to the angled black marking on the pronotum.

Diagnosis.

In the key to north-western Palaearctic species of Pristiphora by Prous et al. (2017), P. melagonia runs to the couplet containing P. tetrica and P. depressa , but not clearly to either of these, because the supraclypeal area of P. melagonia can be partly pale or entirely black and the upper head may be marked with pale or entirely black. Externally, P. melagonia is most similar to P. depressa . External differences between these and other described West Palaearctic species are summarised in a key, below. The lancets of P. melagonia (Fig. 26 ) and P. depressa (Fig. 27 ) exhibit several small differences [character state in P. depressa in brackets]: slightly upwardly curved distally [not upwardly curved distally]; annular setae ( “ctenidia”) absent on apical ca. six sutures [annular setae absent on ca. apical 2-3 sutures]; setae on basal annular sutures about 0.33x as long as width of annulus [about 0.2x as long]; cypsellae on basal annulets (ca. 1-8) about 0.33x as long as serrula [about 0.12-0.15x as long].

Figures

Figures 15 - 20. Pristiphora females. 15 - 16. Pristiphora krausi DEI-GISHym 83928; 17. melagonia sp. nov. DEI-GISHym 17900; 18 - 19. melagonia holotype DEI-GISHym 80284); 20. melagonia DEI-GISHym 20784. Scale bars 2 mm.

Figures 21 - 27. Pristiphora females. 21. melagonia sp. nov. DEI-GISHym 80270; 22 - 23. melagonia DEI-GISHym 20784; 24 - 25. melagonia DEI-GISHym 80270; 26. melagonia DEI-GISHym 17900 lancet; 27. Pristiphora depressa DEI-GISHym 17704 lancet.