Cestrus itatiensis, Supeleto & Santos & Aguiar, 2020

Supeleto, Fernanda A., Santos, Bernardo F. & Aguiar, Alexandre P., 2020, A new species and southernmost record of Cestrus Townes (Hymenoptera Ichneumonidae, Cryptinae), Zootaxa 4822 (2), pp. 277-284 : 278-282

Cestrus itatiensis sp. nov.

( Figs 1 , 2 )

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Description. Female HOLOTYPE ( Figs 1 , 2 ). Fore wing 12.55 mm. Head ( Fig. 2A ). Clypeal margin with a minute median tooth; clypeus weakly and area supra-clypeal distinctly coriarious-punctate; supra-antennal area laterally coriarious, centrally transversely rugulose, with a deep centro-logitudinal sulcus. Occipital carina narrow and distinct throughout, reaching hypostomal carina far from base of mandible. Antenna missing beyond f2; f1 about same length as f2.

Mesosoma ( Figs 1 , 2B, 2D ). Distinctly pilose, increasingly so towards propodeum. Mesopleuron distinctly striate, finer centrally. Subalar prominence quite narrow, elongate, not keeled. Sulcus between sternaulus and scrobe absent. Sternaulus complete, deep; posterior corner of mesosternum somewhat swollen, lobular. Median portion of postpectal carina absent. Metapleuron distinctly striate, more densely pilose than mesopleuron. Propodeum the most densely pilose area of mesosoma, except sparse on area in front of anterior transverse carina. Propodeal apophyses inconspicuous; anterior carina complete, distinct, followed by a narrow crenulated sulcus immediately behind; posterior carina complete, distinct, sublaterally slightly raised, forming small, scale-like crests. Area in front of anterior transverse carina laterally shallowly punctate and coriarious, centrally rugulose; area in between transverse carinae obliquely rugose; area behind posterior carina laterally obliquely rugulose-carinate, centrally weakly rugulose. Fore tibia strongly swollen. Fore wing vein 1M+Rs anteriorly straight, posteriorly distinctly curved; crossvein 1cu-a basad of 1M+Rs by 0.40 of its own length; vein 2Cua 0.90 × as long as crossvein 2cu-a; cell 1+2Rs moderately small, 1.15 × as long as pterostigma width, pentagonal, 0.95 as wide as high; crossvein 3r-m nebulous; crossveins 2r-m and 3r-m distinctly convergent, with about same length; vein 3-M about as long as 2-M. Hind wing with 6 hamuli, vein M+Cu apically moderately convex, vein M forming straight angle with vein Cua; vein Cua 1.60 × as long as crossvein cu-a; vein Cub distinctly convex at apical half, forming straight angle with Cua; vein 2-1A reaching 0.80 of distance to posterior wing margin.

Metasoma ( Figs 1 , 2 C–D). Petiole distinctly but shallowly foveolate from base to a little past level of spiracles; postpetiole very weakly convex, colliculate, with sparse weak punctures; dorsolateral carinae stout, distinct from spiracle to apex of tergite; median dorsal carinae absent; petiolar spiracles in dorsal view quite prominent. Gastral sternites with long pilosity, coriarious with coarse punctures. Gastral tergites densely pilose, coriarious-punctate, becoming finer towards T8; T8 somewhat elongate, conical, with a centro-longitudinal positive fold. Apex of dorsal valve with 9 complete teeth plus a few incomplete teeth in between the complete ones, area immediately basad of teeth with distinctly scabrous area. Ovipositor 1.45 length of hind tibia.

Color. Mostly reddish brown (near 140,53,34) with a few blackish and pale-yellow marks. Lateral patterns in Fig. 1 . Mandible blackish except brownish basal spot. Eye margin from level of clypeus to ocelli with narrow paleyellow stripe ( Fig. 2A ). Pronotum anterior margin dorsally widely pale yellow, laterally blackish, apico-ventrally yellow. Mesoscutum on varied areas, propleuron anteriorly, tegula entirely, scutellum lateral spots and apex, mesopleuron ventro-posterior corner, coxae anteriorly and posteriorly, and trochanters mostly, blackish. Femora progressing from yellowish brown (near 140,210,0) on fore leg to reddish brown on hind leg; mid and hind femora ventrally darkest; fore tibia mostly pale yellow, dorsally brown; mid tibia anteriorly pale yellow, otherwise dark brown; hind tibia basal end red brown, remaining dark brown, progressively darker towards apex; fore tarsus progressing from basally light brown to apically dark brown; mid t1–2 whitish, t1 basal 0.1 brown, t3–5 dark brown; hind t1–3 whitish, t4–5 dark brown. Propodeum approximately unicolorous ( Figs 2B, 2D ). Postpetiole and T2–8 progressively dark brown towards apical margin in a somewhat triangular pattern; all tergites with thin border of apical margin pale yellow ( Fig. 2D ); ovipositor laterally flattened, about 3 times taller than narrowest width (near base).

Morphometry. The following measurements are provided in mm, as a Python list (superscript numbers indicate the respective index): Mandible max length 0; mandible min width (apex) 1; mandible max width 2; malar space max width 3; clypeus max height 4; clypeus max width 5; mesoscutum length 6; mesoscutum width 7; notaulus length 8; fore wing max length 9; areolet max length (i.e., anterior to posterior) 10; areolet max width 11; areolet min width 12; pterostigma max width 13; fore wing crossvein 2cu-a length 14; fore wing vein 2Cua length 15; hind wing crossvein cu-a length 16; hind wing vein Cua length 17; hind wing number of hammuli 18; hind tibia length 19; propodeal spiracle max length 20; propodeal spiracle max width 21; petiole, distance from base to spiracle, in lateral view 22; petiole, distance from spiracle to apex, in lateral view 23; T1 (petiole) max length 24; T1 max width, dorsal view 25; T1 min width, dorsal view 26; T2 max length, dorsal view 27; T2 max width, dorsal view 28; T2 min width, dorsal view 29; pre-sheath ovipositor length 30; ovipositor max length 31. These measurements will allow for the calculation of all ratios traditionally used for Cryptinae , as well as many others:

Holotype = [0.712, 0.216, 0.44, 0.30, 0.436, 0.76, 1.90, 1.925, 0.90, 12.55, 0.25, 0.24, 0.144, 0.22, 0.50, 0.46, 0.35, 0.556, 6, 5.5, 0.18, 0.12, 1.24, 1.216, 2.075, 1.125, 0.38, 1.4375, 1.295, 2.275, 2.156, 8.05]

Paratype = [0.656, 0.20, 0.412, 0.27, 0.44, 0.72, 1.50, 1.70, 0.75, 11.375, 0.26, 0.268, 0.18, 0.28, 0.48, 0.448, 0.36, 0.46, 7, 5.17, 0.16, 0.10, 1.22, 1.09, 1.80, 0.975, 0.37, 1.35, 1.11, 1.988, 2.20, 8.20]

Variation. Paratype very similar to holotype except as follows. Body with much lighter overall color (near 186,82,60), putatively because it is a much older specimen; vein 3-M distinctly shorter than 2-M; and hind wing with 7 hamuli. White band of left antenna with 6 articles, including apical 0.60 of f5 (unknown for the holotype).

Male. Unknown.

Comments. Cestrus itatiensis sp. nov. is most similar in color and structure to C. calidus (Cresson) from which it can be readily separated by having the fore wing uniformly hyaline (vs. weakly yellowish with three transverse brownish bands); tergites with apical margin narrowly pale yellow (vs. without apical margin narrowly pale yellow); posterior margin of pronotum, mesopleural suture and mesepimeron reddish brown (vs. black); posterior end of metapleuron without a black spot (vs. with a black spot); scutellum laterally and apically with black marks (vs. without black marks); propodeum entirely reddish brown (vs. with a distinct posterior black spot); pale yellow stripe only along anterior eye margin (vs. along anterior and posterior eye margin); anterior margin of pronotum dorsally widely pale yellow, laterally blackish, apico-ventrally yellow (vs. yellowish); hind t1–3 whitish, t4–5 dark brown (vs. hind t1 yellow, except basal apex brownish, t2–4 yellow, t5 dark brown; sometimes t4 brownish); pterostigma mostly dark brown (vs. brownish yellow (near 232,173,40)); areolet small, APH 0.95–1.15 (vs. moderately large, APH 1.35–1.95).

The overall color pattern is similar to Digonocryptus pontagus Aguiar & Ramos (full picture in Aguiar & Santos 2012:22) which also occurs in the Parque Nacional Serra dos Órgãos, the type locality of the new species. However, in addition to genus-level and several other differences, D. pontagus has a conspicuous pair of long, whitish propodeal apophyses, which are absent in C. itatiensis sp. nov.

Cestrus itatiensis sp. nov. also differs from the closely related Dineotropica lissa Aguiar by having propodeum rugose in between the transverse carinae (vs. polished smooth in D. lissa ); areolet pentagonal, with crossveins 2r-m and 3r-m distinctly convergent anteriorly (vs. subquadrate, with 2r-m and 3r-m nearly parallel); and clypeus margin with a minute median tooth (vs. tooth absent).

The new species also differs from the original description of the only species previously reported from South America, C. miniaceus Brèthes , by its predominantly reddish brown body (vs. black with yellowish areas).

Etymology. The specific epithet derives from the Tupi word itatiaia, meaning pointed cliff or pointed stone ( Navarro 2005). It is a reference to the geomorphology of both regions where the specimens were collected.

Material examined. Holotype ♀ from BRAZIL: RJ, Teresópolis Parque Nacional da Serra dos Órgãos, Altitude 868 m, 22°28’11.8”S, 42°00’05.3”W, XII.2014, Malaise Pt. 6A, Ricardo F. Monteiro expedition ( DCBU). Triangle mount; right antenna beyond f2 and entire left antenna missing; otherwise in good condition . Paratype ♀ from BRAZIL, RJ, Itatiaia, January/1970, Dirings [Ricardo von Diringshofen], UFES51213 ( MZSP). Pinned; left antenna beyond f12 and right antenna beyond f3 missing .

Distribution records. Southeastern Brazil (RJ). This is the southernmost record for Cestrus and the first record of the genus in Brazil ( Fig. 3 ).

Sampling and rarity. The two specimens treated here were the only ones found after over a decade screening many thousands of Cryptinae gathered from numerous collections and derived from the ample collecting efforts described in Aguiar & Santos (2010), Supeleto et al. (2020), and now also including material from 11,700 Malaise trap-days (30 traps x 13 months; partially described in Macedo et al. 2017). Such extensive sampling history strongly suggests that the new taxon is a rare species. It is noteworthy that despite having been collected 44 years apart, the specimens are from close areas (150 km apart), of nearly the same latitude ( Fig. 3 ), both with well-preserved nature areas, and from regions of relatively high altitudes: Holotype at 868 m, and Paratype from about 695 m (average of Itatiaia municipality).

Figures

FIGURE 1. Cestrus itatienis sp. nov., Holotype female, habitus. Scale: ovipositor = 8.05 mm.

FIGURE 2. Cestrus itatiensis sp. nov., Holotype female. A. Head, frontal view. B. Propodeum, dorsal view. C. Apex of ovipositor, left side. D. Dorsal view.

FIGURE 3. Distribution records for Cestrus itatiensis sp. nov.