Pristomerus Curtis 1836
Creators: name: Rousse, Pascal
name: Villemant, Claire
name: Seyrig, André
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Ichneumonidae
Pristomerus

description: Genus Pristomerus Curtis, 1836 (definition after Townes 1971)
Diagnosis
Body moderately slender, metasoma moderately to strongly compressed. Occipital carina usually complete. Females (often) and males (nearly always) with hind femur swollen and bearing a tooth on lower side. Forewing with areolet open (3rs–m absent), vein Rs&M opposite or a little basal to vein cu–a, and 2rs–m basal to 2m–cu by at least 2rs–m length. Hindwing with vein Cu1 spectral. Tergite 1 moderately slender, glymma hardly distinct. Lower edges of tergite 1 separated and parallel. Epipleura of tergite 2 narrow, separated by a crease and turned under. Thyridium present, transverse or subcircular, located in basal 0.2 of tergite 2. Ovipositor tip most often sinuate. Apex of male gonosquama rounded.
Remarks
Pristomerus is a large genus of 100 species worldwide (Yu et al. 2012). Most species are tropical. Hosts include various small Lepidoptera living in tunnels, leaf rolls, buds and other shelters. This genus is usually well differentiated from the New World genus Xiphosomella Szépligeti by the position of the thyridiae on tergite 2, which in Pristomerus are separated from the anterior margin by at most their own diameter, and most usually further back in Xiphosomella. Additionally, the forewing areolet is always open and the ovipositor tip nearly always sinuate in Pristomerus. As stated by Gauld (2000) this combination of features sometimes fails to unambiguously differentiate from Pristomerus some species in the extreme end of the variation range of Xiphosomella. Subsequently, both genera are susceptible to be eventually merged in absence of clearer autapomorphies.
Key to Pristomerus species of Madagascar
1 Face and inner orbits dark brown, clypeus white (Fig. 10C); area superomedia hardly delimited laterally (male unknown) ....................................................................................... P. melissa sp. nov.
– Face differently colored, white to orange, if medially dark then inner orbits strikingly paler; area superomedia almost always laterally delimited..................................................................2
2 Ground color of face white (e.g., Fig. 6C), sometimes with a more or less large dark mid- longitudinal marking (e.g., Figs 4B, 13B)........................................................................................3
– Ground color of face yellowish to orange (e.g., Figs 5B, 16B).........................................................7
3 Metasomal tergites dark brown with wide white apical margin; female femoral tooth small but distinct (FFT = 1); male with lateral ocellus nearly contiguous with eye (OOL = 0.1) .............. ........................................................................................................................... P. guinness sp. nov.
– Metasoma differently colored; female femoral tooth absent or hardly present as a weak angulation (FFT = 0); male with lateral ocellus more distant from eye (OOL> 0.1) (male of P. ranomafana unknown).................................................................................................................4
4 Mesosoma elongate, more than 2 x as long as wide; ovipositor relatively short (OT <1.5); male with lateral ocellus relatively far from eye (OOL = 0.6) ........................ P. vahaza sp. nov.
– Mesosoma at most 2 x as long as high; ovipositor longer (OT ≥ 1.5); male with lateral ocellus closer to eye (OOL = 0.2) (male of P. ranomafana unknown)..................................5
5 Ovipositor very long (OT> 2.5), pterostigma orange ....................................... P. hansoni sp. nov. – Ovipositor shorter (1.5 <OT <2.3), pterostigma brown...............................................................6
6 Forewing with 2rs–m at least 0.5 x as long as 2m–cu; ovipositor moderately long (OT 1.5–1.8) ..................................................................................................................................... P. caris Fitton
– Forewing with 2rs–m shorter, about 0.3 x as long as 2m–cu; ovipositor longer (OT> 2) (male unknown) ........................................................................................................ P. ranomafana sp. nov.
7 Female femoral tooth absent (FFT = 0); male with ocelli hardly enlarged, distant from eyes (OOL = 1.0)....................................................................................................................................................8
– Female femoral tooth present, though sometimes reduced to a small tubercle (FFT 1 or 2); male, where known, with ocelli enlarged and closer to eye (OOL <1).................................... 9 n. b. Males of P. albescens could key here because their lateral ocelli are distinctly removed from eyes. They can however be distinguished by their transverse head with narrow clypeus (CT = 1.4).
8 Antenna with more than 30 flagellomeres; mesosoma about 2 x as long as wide, body uniformly orange .................................................................................................................... P. kelikely sp. nov.
– Antenna with fewer than 30 flagellomeres; mesosoma stouter, body with dark brown markings ......................................................................................................................... P. moramora sp. nov.
9 Face at least with yellow margins along inner orbits; female femoral tooth small (FFT = 1) ...................................................................................................................................................10
– Face rufo-testaceous; female femoral tooth stronger (FFT = 2)...................................................14
10 Ovipositor relatively short (OT <1.4), its tip straight; head transverse with clypeus narrow (CT <1.5) ............................................................................................................... P. albescens (Morley)
– Ovipositor longer (OT 1.5–2.5), apically sinuate; head not distinctly transverse, clypeus more transverse (CT> 1.5)........................................................................................................................11
11 Antenna with fewer than 25 flagellomeres; mesoscutum granulate with sparse punctures along notaulus; small species (L <3.2) (male unknown) ................................................ P. keyka sp. nov.
– Antenna with more than 25 flagellomeres; mesoscutum moderately to densely punctategranulate; larger species (L> 3.5).................................................................................................12
12 Antenna with more than 36 flagellomeres; pterostigma orange; propodeum with area superomedia hardly defined laterally; large species (L = 5.8) ..................................... P. patator sp. nov.
– Antenna with fewer than 36 flagellomeres; pterostigma brown; propodeum with area superomedia complete; smaller species (L <5.5)....................................................................................13
13 Clypeus strongly transverse (CT> 2.5); malar line short (ML = 0.4), mesonotum orange ............... ................................................................................................................................ P. roberti sp. nov.
– Clypeus narrower (CT <2), malar line longer (ML = 0.7), notaulus and scutellum yellow .............. ......................................................................................................................... P. cunctator Tosquinet
14 Mesonotum densely punctate; face not distinctly transverse; large species (L> 7.0) ...................... ................................................................................................................................ P. veloma sp. nov.
– Mesonotum almost smooth; head distinctly transverse with clypeus narrow (CT = 1.5); smaller species (L <5.0) ........................................................................................................... P. yago sp. nov.
description: Published as part of Rousse, Pascal, Villemant, Claire & Seyrig, André, 2013, Ichneumonid wasps from Madagascar. VI. The genus Pristomerus (Hymenoptera: Ichneumonidae: Cremastinae), pp. 1-38 in European Journal of Taxonomy 49 on pages 4-7, DOI: 10.5852/ejt.2013.49, http://zenodo.org/record/3814375