Stenomacrus luteus, Varga, 2024

Varga, Oleksandr, 2024, Review of the genus Stenomacrus Förster, 1869 (Hymenoptera: Ichneumonidae: Orthocentrinae) from Kenya and Burundi: a first step to understanding the diversity of the genus in the Afrotropics, European Journal of Taxonomy 958, pp. 177-202 : 188-190

Stenomacrus luteus sp. nov.

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Fig. 5

Diagnosis

Stenomacrus luteus sp. nov. is characterized by the combination of the following: face smooth ( Fig. 5B ); mesosoma yellow ventrally ( Fig. 5A ); antenna with 18 flagellomeres, first flagellomere 3.3 × as long as wide; temples 0.4 × the maximum diameter of eye in dorsal view, strongly narrowed ( Fig. 5D ); propodeum smooth, weakly wrinkled subapically, with only area apicalis partly delimited by carinae ( Fig. 5E ); fore wing with vein 2 rs-m about 0.8 × the distance between 2 rs-m and 2 m-cu; vein 3rs-m absent ( Fig. 5F ); first tergite 1.4 × as long as its apical width, longitudinally wrinkled, with latero-median longitudinal carinae hardly visible among wrinkles; second tergite 1.1 × as long as its apical width, sculptured on basal 0.3 ( Fig. 5G ); ovipositor sheath about 0.6 × as long as hind tibia ( Fig. 5A ).

Stenomacrus luteus sp. nov. differs from all known Afrotropical species in having a largely yellow mesosoma in combination with a smooth face and relatively short antenna.

Etymology

The new species is named after the relatively pale yellowish body colouration.

Type material

Holotype

KENYA • ♀; Eastern Prov. , Mt Kulal Forest ; 2.65400º N, 36.93660º E; 1810 m a.s.l.; 1 Nov. 2015 – 01 Apr. 2016; R. Copeland leg.; Malaise trap in disturbed forest; ICIPE.

Paratype

KENYA • 1 ♀; same data as for holotype; ICIPE .

Description

Female

Body length 2.5 mm. Fore wing 1.9 mm.

Head smooth and sparsely pubescent. Antenna with 18 flagellomeres, first flagellomere 3.3 × as long as wide. Face about 0.6 × as long as wide, smooth, sparsely pubescent; inner orbits parallel. Malar space 2.1 × basal width of mandible; subocular sulcus distinct. Clypeus 0.7 × as long as wide, smooth. Mandible bidentate, strongly bent outwards; lower tooth small and hardly visible. Temples 0.4 × maximum diameter of eye in dorsal view, strongly narrowed. Frons and vertex smooth; length of ocellar-ocular distance about as long as maximum diameter of lateral ocellus; occipital carina absent.

Propleuron sparsely pubescent. Pronotum smooth; epomia absent. Mesoscutum densely pubescent anteriorly; notauli absent. Scutellum sparsely pubescent, with carinae present only on basal 0.1. Mesopleuron smooth; epicnemial carina present laterally. Metapleuron smooth; pleural and submetapleural carinae present. Propodeum smooth, weakly wrinkled apically, with only area apicalis partly delimited by carinae.

Legs relatively stout; hind femur 3.5 × as long as wide, third tarsomere of hind tarsus about as long as fifth tarsomere; tarsal claws simple.

Fore wing with vein 2 rs-m about 0.8 × distance between 2 rs-m and 2 m-cu; vein 3rs-m absent; vein 1cu-a opposite M & Rs; hind wing with nervellus not intercepted, reclivous.

Metasoma with first tergite 1.4 × as long as apical width, smooth, longitudinally wrinkled, with latero-median longitudinal carinae hardly visible among wrinkles; lateral oblique grooves distinct and deep. Second tergite 1.1 × as long as apical width, sculptured on basal 0.3, with weak basolateral grooves; thyridium round. Remaining part of metasoma smooth, laterally compressed. Ovipositor sheath about 0.6 × as long as hind tibia, apical part widened and pubescent.

Body generally brown dorsally and yellow ventrally: antenna, face narrowly below antennal sockets, mandible (except apices), mesosoma ventally, and legs yellow.

Male

Unknown.

Distribution

So far only known from Kenya.

Figures

Fig. 5. Stenomacrus luteus sp. nov., holotype, ♀ (ICIPE). A. Lateral view of habitus. B. Frontal view of face. C. Lateral view of head and mesosoma. D. Dorsal view of head and mesoscutum. E. Dorsal view of propodeum. F. Wings. G. Dorsal view of metasomal tergites 1–3. Scale bars: A = 0.5 mm; B–G = 0.1 mm.