Nonnus spurius Wahl & Bennett, 2020

Wahl, David B. & Bennett, Andrew M. R., 2020, First record of Nesomesochorinae (Hymenoptera: Ichneumonidae) from America north of Mexico with descriptions of two new species of Nonnus Cresson, Zootaxa 4779 (1) : -

Nonnus spurius Wahl & Bennett , sp. nov.

( Figs. 6–8 , 11 , 16 )

Diagnosis. Nonnus spurius can be distinguished from other North and Central American species of Nonnus by the combination of the following characters: eyes strongly convergent ventrally; female flagellar band symmetrical, not extending further on dorsal surface than on ventral surface; female body uniformly black/fuscous; female mesopleuron weakly granulate with distinct punctures separated by 0.5–1.0× their diameter; ovipositor 2.2–2.4× as long as length of hind femur, straight with apical 0.3 slightly decurved; male supra-antennal area lacking median lamellar projections; male mesosoma black/fuscous, metasoma with T1, most of T2, and T5+ dark brown and T3–4 light to deep brownish-red.

Description. Female. Structure. 1. Supraclypeal area centrally granulosopunctate, punctures shallow and separated by 0.2–0.3× their diameter; supraclypeal width just below antennal sockets: width just above clypeal suture = 1.0: 0.7; eyes strongly convergent ventrally. 2. Supra-antennal area without projections; antenna with 38–42 flagellomeres. 3. Mesosoma elongate ( Figs. 6–8 ), about 1.7× as long as deep. 4. Lateral face of pronotum with posterodorsal area centrally weakly to moderately granulate with small scattered shallow punctures, dorsal and posterior margins crenulate. 5. Mesopleuron centrally granulate, punctures 15–21 μm in diameter and separated by 0.5–1.0× their diameter. 6. Mesoscutum with lateral lobe granulate with shallow punctures separated by 0.3–1.0× their diameter; median lobe defined by shallow notauli extending to slightly beyond mesoscutal midpoint. 7. Ventral division of metapleuron weakly granulate, punctures about 15 μm in diameter and separated by 1.0–2.0× their di- ameter. 8. Propodeum granulate and impunctate; carinae absent except for PTC and sections of median longitudinal carinae between PTC and propodeal apex; area anterad PTC with numerous strong rugulae, longitudinal near PTC then becoming transverse, extending about 0.8 distance to anterior propodeal margin and laterally extending almost to pleural carina. 9. MS1 slender, usually with weak dorsal convexity on petiole ( Fig. 6 ). 10. Thyridium ovoid, granulate and of lighter color than surrounding tergite, and connected to base of T2 by narrow ridge ( Fig. 11 ). 11. Ovipositor 2.2–2.4× as long as length as hind femur, straight with apical 0.3 slightly decurved. Color. Head black to fuscous, with apical 0.5 of mandible dark brown; antenna dark brown to fuscous except for white dorsal surfaces of flagellomeres 1–4 (becoming progressively reduced until flagellomere 4 with only narrow short strip or rarely with strip absent) and white band on flagellomeres 10–17 (comprising 6–8 flagellomeres for any one individual; note band is symmetrical, not extending further on dorsal surface than on ventral). Mesosoma black/fuscous. Fore leg with coxa and trochanter dark brown except for brownish-white ventral trochanteral surface; remainder of leg brown. Middle and hind legs dark brown except for white hind tarsomeres 2-3, and occasional apical 0.2–0.4 of hind tarsomere 1. Wings with membrane with weak brown tint, and veins brown to dark brown. Metasoma dark brown except for narrow whitish-brown apex of T2, and white apical 0.3 of ovipositor sheath. Measurements. Body 10.0– 14.3 mm (11.0 mm); fore wing 7.0– 8.8 mm (7.4 mm).

Male. Structure. 1. Supraclypeal area smooth and punctate, punctures deep and separated by 0.2–0.3× their diameter; supraclypeal width just below antennal sockets: width just above clypeal suture = 1.0: 0.7; eyes strongly convergent ventrally. 2. Supra-antennal area without paired median lamellar projections below median ocellus; antenna with 45–47 flagellomeres. 3. Mesosoma elongate, about 1.7× as long as deep. 4. Lateral face of pronotum with posterodorsal area centrally smooth to weakly granulate with small scattered punctures dorsally and posteriorly, dorsal and posterior margins crenulate. 5. Mesopleuron centrally smooth, punctures 15–21 μm in diameter and separated by 1.0–2.0× their diameter (variation: punctures 9–15 μm in diameter and separated by 2.0–3.0× their diameter). 6. Mesoscutum with lateral lobe granulate with shallow punctures separated by 0.3–1.0× their diameter; median lobe defined by shallow notauli extending to slightly beyond mesoscutal midpoint. 7. Ventral division of

10. N. atratus Cresson , holotype female; ANSP.

metapleuron smooth, punctures about 15 μm in diameter and separated by 2.0–3.0× their diameter (variation: punc- tures about 9 μm in diameter and separated by 2.0–3.0× their diameter). 8. Propodeum smooth to weakly granulate, lateral margins usually with weak punctures separated by 0.3–0.5× their diameter; carinae absent except for PTC and sections of median longitudinal carinae between PTC and propodeal apex; area anterad PTC with numerous strong rugulae, longitudinal near PTC then becoming transverse, extending about 0.8 distance to anterior propodeal margin and laterally not extending almost to pleural carina (variation: rugulae sometimes absent except along midline). 9. MS1 slender, without weak dorsal convexity on petiole. 10. Thyridium present as elongate ovoid, granulate and of lighter color than surrounding tergite; connected to base of T2 by narrow ridge (as in Fig. 11 ). Color. Head black to fuscous, with apical 0.5 of mandible dark brown, clypeus rarely with 0.3 of apical margin dark brown; antenna dark brown to fuscous except for white (completely or partially) flagellomeres 15–20 (comprising 4–6 flagellomeres for any one individual). Mesosoma black/fuscous, occasionally with following brown: anterior margin of pronotum, extreme posteroventral corner of mesopleuron, tegula, extreme posterior margin of mesonotum, raised areas of metanotum, and extreme posterior margin of propodeum. Fore leg with coxa and trochanter dark brown, remainder of leg brown to yellowish-brown. Middle leg: coxa, trochanter, and trochantellus dark brown; femur and tibia dark brown to brown; basal 0.3–0.5 of tarsomere 1 sometimes yellowish-brown to brownish-white, remainder of tarsus dark brown. Hind leg: coxa, trochanter, and trochantellus dark brown; femur and tibia brown, tibia shading to dark brown on apical 0.2; tarsus with tarsomere 1 ranging from completely dark brown to having apical 0.3–0.6 yellowish-white; tarsomeres 2–3 yellowish-white; tarsomere 4 dark brown or yellowish-white; tarsomere 5 dark brown. Wings with membrane with weak brown tint, and veins brown to dark brown. Metasoma with MS1 dark brown; T2 dark brown except rarely with brownish-red apex and posterolateral corners; T3–4 light to deep brownish-red, rarely concolorous with T5–8; remainder of metasoma dark brown (including gonoforceps) except for narrow white posterior margins of T7–8. Measurements. Body 12.5–13.5 mm; fore wing 7.8–9.0 mm.

Material. Holotype F: MEXICO, Oaxaca: Vista Hermosa (17° 37’ 59.0”N, 96° 20’ 31.6”W), 1450 m, 20.x.1962,

H. & M. Townes ( EMUS). Condition of holotype: intact. Paratypes. MEXICO, Chiapas: 1F, San Cristobal de las

Casas , 7200 ft., 17.x.1962, B.V. Petersen ( EMUS) ; 1M, Durango: 3 mi. east of El Salto , 8500 ft., 4.vii.1964, W.R.M. Mason ( CNCI) ; Oaxaca: 1F, Vista Hermosa (17° 37’ 59.0”N, 96° 20’ 31.6”W), 1450 m, 17.x.1962, H. & M. Townes ( EMUS) ; 2FF2MM, same data as preceding except 19.x.1962 ( CNCI, EMUS) ; 2MM, same data as preceding except 20.x.1962 ( EMUS) . USA, Arizona: 1M, Cochise Co., 5 mi. west of Portal, Southwestern Research Station , 5400 ft., 13.ix.1965 ( EMUS) . Other specimens: MEXICO, Chiapas: 1M, San Cristobal de las Casas , 7200 ft., 17.x.1962, B.V. Petersen ( EMUS) .

Comments. Nonnus spurius is strikingly similar to Nonnus atratus Cresson, 1874 , which was described from a female specimen collected in Orizaba, Mexico by Adrien Louis Jean de. Sumichrast sometime between 1855 and 1873 (details on Sumichrast from Papavero & Ibáñez-Bernal, 2001). The resemblance is quite close with regard to color and general surface sculpture ( Fig. 11 vs. Fig. 12 ). Several characters, however, lead us to believe it is a separate species: 1) it is 30–40% larger than N. spurius , with a body length of 17.3 mm and a wing length of 9.8 mm., 2) the thyridium is linear and relatively smaller than in spurius , depressed, has a small posterior pit, and is not connected by a ridge to the anterior margin of T2 (compare Fig. 12 to Fig. 11 ), 3) the MS1 is arched and more elongate (compare Fig. 10 to Fig. 6 ), and 4) vein 2/Cu of the hind wing is straight versus slightly apically curved in N. spurius .

Nonnus niger (Brullé) is another black species, originally described from Brazil, with a putative range from Brazil to Panama ( Townes & Townes, 1966). Krieger (1903) discussed the black Nonnus specimens in his personal collection. Apparently working solely from published descriptions, he assigned his two male specimens (from Peru and Bolivia) to Nonnus albitarsis (Brullé) , now a junior synonym of N. niger ( Townes & Townes, 1966) . The six females, which he considered to ‘broadly agree’ with N. niger (“mit Atractodes niger Brullé in Bezug auf diese Merkmale im Grossen und Ganzen überein”) were from Bolivia, Brazil, Panama, and Peru. Unfortunately, we were not able to borrow the Brullé types from the Museum d’Histoire Naturelle. We did, however, have specimens compared by Henry Townes to the Brullé types. While acknowledging that ‘compared with type’ (CWT) specimens can have considerable drawbacks, the Townes N. niger CWT specimen ( Brazil: Santa Catarina, Nova Teutonia) is decidedly a different species than N. spurius : the angulation of the gena in dorsal view is quite different ( Fig. 14 vs. Fig. 16 ); mesopleural sculpture is strongly granulate with punctures about 10 μm in diameter and separated by 0.5–1.0× their diameter; propodeal rugosity is weak and confined to the central median region; size is noticeably larger (fore wing 13 mm long). It should be noted that N. atratus is quite different from N. niger as well: the angulation of the gena in dorsal view is subtly different ( Fig. 13 vs. Fig. 14 ); the mesopleural punctation of N. atratus is weakly granulate with punctures about 20 μm in diameter and separated by about their diameter; the propodeal rugosity in N. atratus is extensive and extends from the PTC to the propodeal anterior margin, and nearly to the lateral margins; the thyridium is not depressed, lacks a posterior pit, and is connected by a ridge to the anterior margin of T2.

A female collected 3 miles [4.8 km] east of El Salto is readily assignable to N. spurius . The associated male has the metasoma completely dark brown. While this is probably natural variation, we prefer to exclude this male from the paratypes.

The range of N. spurius is mostly concurrent with N. barnesae : ranging from the Isthmus of Tehuantepec north through the Sierra Madre Orientale to Arizona ( Fig. 17 ).

See the “Comments” section for the N. barnesae species description regarding the location of Vista Hermosa.

Etymology. The specific name derives from the Latin spurius , false or bastard, referring to the deceitful resemblance to N. atratus .

Figures

FIGURE 17. Distributions of Nonnus barnesae Wahl & Bennett and N. spurius Wahl & Bennett.

FIGURES 5–6. Nonnus spp., lateral habitus. 5. N. barnesae Wahl & Bennett, paratype male (USA: Arizona); AEI photo vouch- er specimen #1069. 6. N. spurius Wahl & Bennett, holotype female; AEI photo voucher specimen #1074.

FIGURES 7–8. Nonnus spurius Wahl & Bennett, lateral habitus. 7. Paratype male (Mexico: Durango); AEI photo voucher specimen #1073. 8. Paratype male (USA: Arizona); AEI photo voucher specimen #1068.

FIGURES 11–12. 5. Nonnus spp., lateral view of second metasomal tergite. 11. N. spurius Wahl & Bennett, holotype female; AEI photo voucher specimen #1074. 12. N. atratus Cresson, holotype female; ANSP.

FIGURES 13-16. Nonnus spp., dorsal outlines of heads. 13. N. atratus Cresson, 14. N. niger Brullé. 15. N. barnesae Wahl & Bennett. 16. N. spurius Wahl & Bennett.

FIGURES 9–10. Nonnus spp., lateral habitus. 9. N. antennatus Cresson, holotype female; ANSP.