Spotlighting Darwin wasps (Hymenoptera, Ichneumonidae) in Zambia: a new species and the urgent need for further exploration Meier, Noah Viertler, Alexandra Kapaale, Meekness Katongo, Cyprian Spasojevic, Tamara ZooKeys 2025 2025-04-22 1234 341 367 Meier, Viertler & Spasojevic Meier, Viertler & Spasojevic 2025 Insecta Ichneumonidae Pristomerus Animalia Hymenoptera Arthropoda species roussei sp. nov.   Fig. 2   Material examined.     Holotype.• 1 ♀, ZM  Northern Province, Mbala, Kalambo Falls(above waterfall), sweep net,  1170 m, -8.5961/ 31.2478,  21.viii–2.ix.2023, leg. N. Meier, T. Spasojevic, A. Viertler(  NMBS).    Paratypes.• 1 ♂, ZM  Northern Province, Mbala, Kalambo Falls(above waterfall), sweep net,  1170 m, -8.5961/ 31.2478,  21.viii–2.ix.2023, leg. N. Meier, T. Spasojevic, A. Viertler(  NMBS). •  1 ♂, ZM Mpulungu, Chitili stream, sweep net, -8.6390/ 31.2035,  21.viii–2.ix.2023, leg. N. Meier, T. Spasojevic, A. Viertler, voucher: 20-538 (  NMBS). •  2 ♂, ZM Mpulungu, Kalambo delta, sweep net,  777 m, -8.5964, 31.1844,  21.viii–2.ix.2023, leg. N. Meier, T. Spasojevic, A. Viertler(  LMNH). •  1 ♀, ZM Mpulungu, Mpulungu town, sweep net,  777 m, -8.7621, 31.1138,  21.viii–2.ix.2023, leg. N. Meier, T. Spasojevic, A. Viertler, voucher: 20-537 (  NMBS). •  1 ♀, ZM Mpulungu, Kalambo FallsLodge, sweep net,  786 m, -8.6241/ 31.2011,  21.viii–2.ix.2023, leg. N. Meier, T. Spasojevic, A. Viertler(  LMNH). •  1 ♀, ZM  Northern Western Province,  150 kmW Solwezi, Ntambu,  12°18'S, 25°10'E;  11.11.2005; leg. M. Halada(  LKG).   Figure 2.   Pristomerus roussei sp. nov.Meier, Viertler & Spasojevic. a – fholotype (female) ahabitus, lateral view, with labels bface, frontal view chabitus, dorsal view dhind femur eovipositor tip fmesoscutum and occiput, dorsal view. g – kparatype (male, with the same collection data as the holotype) ghabitus, lateral view hface, frontal view ihabitus, dorsal view jhind femur kmesoscutum and occiput dorsal view. Scale bars: 3 mm.   Diagnosis. Moderate size; pale yellow with black spots on tergites 1–3 antero-dorsally; femora apically white-dotted; pterostigma anteriorly white; occiput without dark spots; face densely and very shallowly punctate; clypeus transverse with dispersed punctures dorsally and almost smooth ventrally; remainder of head coriaceous; malar space shorter than base of mandible; antenna with 30–33 flagellomeres, penultimate flagellomere quadrate; distance between posterior ocelli approx. as wide as one posterior ocellus; mesosoma densely punctate with pronotum and speculum nearly smooth; female femoral tooth distinct but clearly wider than high, followed by a row of minute denticles; ovipositor moderately long, apically weakly sinuous. Male with ocelli enlarged, inner margins of eyes slightly diverging ventrally, femur and femoral tooth stouter with femoral tooth long and acute, area superomedia much more slender than in female.   Differential diagnosis.   Pristomerus roussei sp. nov.is morphologically very close to  Pristomerus masai Rousse & van Noort, 2015, which is suspected to represent a species-complex ( Rousse and van Noort 2015). In the dichotomous key of Rousse and van Noort (2015),  P. rousseiends at couplet # 36. It can be differentiated from  P. masaiby a wider distance between the posterior ocelli, a quadrate penultimate flagellomere (females and males) and the lack of dark marks on the occiput (females).  Pristomerus rousseican be differentiated from  P. wolof Rousse & van Noort, 2015by the more strongly developed femoral tooth (females and males), the quadrate penultimate flagellomere rather than elongate (females and males), and by its more extensive dark metasomal colour (females).   Description.  Female: 4 specimens(measurements of the holotypein brackets).  Colour.Pale yellow. Scape, pedicel, frons, stemmaticum and occiput pale brown; mandibular teeth and flagellum black; mesoscutum apart from notauli and posterior parts orange; wings hyaline, venation brown, pterostigma black, proximal corner translucent; legs orange, femur apically with a white spot, hind tibia basally and apically slightly infuscate, hind tarsus except basal 0.2 of first tarsal segment black; tergites 1–3 on the anterior half black; ovipositor sheath black; ovipositor dark brown, basally and apically testaceous.   Head.Face 2.5 × (2.5 ×) wider than high, densely and very shallowly punctate; inner margins of eyes subparallel, distance between posterior ocelli ~ 1.0 × (1.0 ×) as wide as diameter of one posterior ocellus, distance between posterior ocelli and margin of compound eye 1.1 × (1.1 ×) wider than diameter of one posterior ocellus; clypeus 2.0 × (2.0 ×) wider than high and moderately convex, with dispersed punctures dorsally, almost smooth ventrally; malar space ~ 0.7–0.75 × (0.75 ×) base of mandible; frons, vertex and temple coriaceous; occipital carina joining hypostomal carina distinctly above mandible base; antenna with 31–33 (33) flagellomeres, penultimate flagellomere ~ 1.0 × (1.0 ×) as long as wide.   Mesosoma.Moderately elongate; pronotum nearly smooth posteriorly, with longitudinal striations in its impression and punctures ventrally; mesopleuron and metapleuron with space between punctures less than maximum diameter of punctures, between punctures smooth and shining, mesopleuron with a shallow oblique and transversely strigose furrow below speculum, speculum smooth; mesoscutum densely punctate, between punctures smooth and shiny, notaulus distinct on anterior third of mesoscutum; scutellum densely punctate; propodeum densely punctate, propodeal carination complete, superomedial area ~ 2.3–2.5 × (2.3 ×) as long as its maximum width.   Wings.Fore wing ~ 4.5–4.9 mm( 4.9 mm) with M between 2 rs-m and 2 m-cu ~ 1.25–1.5 × (1.25 ×) as long as 2 rs-m, 2 m-cu with a small bulla covering anterior 0.2–0.4 of 2 m-cu; hind wing with nervellus intercepted at lower 0.7 (0.7), second abscissa of CU not pigmented.   Legs.Tooth on hind femur distinct, clearly wider than high, followed by a row of minute denticles. Hind tibia with dispersed spines between normal setation. Tarsal claws pectinate with two distinct denticles.   Metasoma.Posterior half of tergite 1, tergite 2, and anterior of tergite 3 longitudinally aciculate, following tergites coriaceous; thyridium elongate, elliptic; ovipositor sheath ~ 1.5 × as long as hind tibia, apically weakly to moderately sinuous; ovipositor notch rather weak, its distance from ovipositor tip ~ 1.5 × basal width of first tarsal segment of hind leg.  Male: 4 specimens. Similar to female; stemmaticum with ocelli slightly raised and ocelli enlarged, distance between posterior ocelli approx. as wide as diameter of one posterior ocellus, distance between posterior ocelli and margin of compound eye less than half diameter of one posterior ocellus; inner margins of eyes distinctly diverging ventrally; antenna with 29–31 flagellomeres; mesoscutum laterally almost smooth, impunctate; femur swollen, femoral tooth stronger, long and acute, apically with a distinct row of denticles; dark marks on metasoma sometimes absent or reduced.   Etymology. Dedicated to Pascal Rousse, who contributed greatly to our current understanding of Afrotropical  Pristomerusspecies. 5131809304 2023-08-21 2023-09-02 2023-08-21 sweep net NMBS N. Meier & T. Spasojevic & A. Viertler Zambia 1170 -8.5961 Kalambo Falls 7 31.2478 Mbala 1 1 Northern Province holotype 5131809302 2023-08-21 2023-09-02 2023-08-21 sweep net NMBS N. Meier & T. Spasojevic & A. Viertler Zambia 1170 -8.5961 Kalambo Falls 7 31.2478 Mbala 1 1 Northern Province paratype 5131809303 2023-08-21 2023-09-02 2023-08-21 sweep net NMBS N. Meier & T. Spasojevic & A. Viertler Zambia -8.639 Chitili stream 7 31.2035 Mpulungu 1 1 Northern paratype 5131809301 2023-08-21 2023-09-02 2023-08-21 sweep net LMNH N. Meier & T. Spasojevic & A. Viertler Zambia 777 -8.5964 Kalambo delta 7 31.1844 Mpulungu 2 2 Northern paratype 5131809305 2023-08-21 2023-09-02 2023-08-21 sweep net NMBS N. Meier & T. Spasojevic & A. Viertler Zambia 777 -8.7621 Mpulungu town 7 31.1138 Mpulungu 1 1 Northern paratype 5131809306 2023-08-21 2023-09-02 2023-08-21 sweep net LMNH N. Meier & T. Spasojevic & A. Viertler Zambia 786 -8.6241 Kalambo Falls 7 31.2011 Mpulungu 1 1 Northern paratype 5131809307 2005-11-11 LKG M. Halada Zambia -12.3 Ntambu 1293 25.166666 Solwezi 1 1 Northern Western Province paratype