Conostigmus duncani Trietsch, 2020

Trietsch, Carolyn, Mikó, István, Ezray, Briana & Deans, Andrew R., 2020, A Taxonomic Revision of Nearctic Conostigmus (Hymenoptera: Ceraphronoidea: Megaspilidae), Zootaxa 4792 (1), pp. 1-155 : 99-103

Conostigmus duncani Trietsch sp. nov.

Figs. 54 , 55 , 56

Diagnosis. This Nearctic species is distinguished by the following combination of characters: head width less than 1.3× wider than the mesosoma; facial pit present; sternaulus absent; mesopostscutellum present; transverse striations on the ventral metapleural area absent; proximodorsal notch of the cupula present and U-shaped, longer than wide; proximal end of the dorsomedian conjunctiva of the gonostyle–volsella complex shape acute; and dorsomedian projection of the gonostyle–volsella complex absent.

The female of this species is unknown.

This species can appear Dendrocerus -like in that it lacks a sternaulus, the ocellar triangle can appear obtuse (POL longer than LOL, ocellar triangle with a wide base), and the metapleural sulcus can appear arched in some specimens (including PSUC_FEM 50388). However, it is not a Dendrocerus species because of the presence of the facial pit, independent parossiculi (parossiculi and gonostipes not fused), medioventral conjunctiva of the gono-style–volsella complex, and cylindrical male antennae. This species differs from C. lepus and C. triangularis , two other Dendrocerus -like species, in that it lacks the transverse striations on the ventral metapleural area (present in both C. lepus and C. triangularis ).

Another similar species is C. orcasensis , which also possesses the mesopostscutellum and lacks a sternaulus. However, these species can be distinguished by the male genitalia. The proximal end of the dorsomedian conjunctiva of the gonostyle–volsella complex shape is acute in C. duncani and blunt in C. orcasensis . The proximodorsal notch of the cupula is present and U-shaped in both species, but it is longer than wide in C. duncani and wider than long in C. orcasensis . Conostigmus duncani also has 1 apical parossicular seta, whereas C. orcasensis has 2–3.

Variability. The metapleural sulcus can appear straight (PSUC_FEM 50384) or arched (PSUC_FEM 50388). Though some specimens have an ocellar triangle with a short base and POL equal to or shorter than OOL (PSUC_ FEM 50259), other specimens have an ocellar triangle with a wide base and POL longer than OOL (PSUC_FEM 50388, PSUC_FEM 50380). Both the arched metapleural sulcus and the ocellar triangle with a wide base can give some specimens a Dendrocerus -like appearance.

Description. Body length: 1.7 mm, 1.925 mm. Color hue pattern in male: cranium, mesosoma except propleuron, metasoma reddish brown to dark brown; propleuron yellow to light brown; legs, basal half of scape and apical half of pedicel ochre to light brown; apical half of scape, flagellomeres and basal half of pedicel brown. Color intensity pattern in male: anterior half of metasoma lighter than posterior half of metasoma; propleuron lighter than the rest of the mesosoma. Color intensity pattern of syntergite: petiole neck and anterior region of syntergite concolorus with the posterior region of the syntergite. Foveolate sculpture on body count: absent. Rugose sculpturing count: absent. Rugose region on upper face count: absent.

Antennae: Male scape length vs. pedicel length: 4.0–4.7. Male scape length vs. F1 length: 1.1–1.2. Male F1 length vs. pedicel length: 3.3–4.2. Male F1 length vs. male F2 length: 1.1–1.3. Longest male flagellomere: F1. Length of setae on male flagellomere vs. male flagellomere width: setae shorter than width of flagellomeres. Sensillar patch of the male flagellomere pattern: F6–F9.

Head: Head width, dorsal view: equal to or only slightly wider than mesosoma (less than 1.3× wider than mesosoma). Head height (HH, lateral view) vs. eye height (EHf, anterior view): HH:EHf=1.3–1.6. Head height (HH) vs. head length (HL): HH:HL=1.2–1.3. Head width (HW) vs. interorbital space (IOS): HW:IOS=1.5–1.8. Head width (HW) vs. head height (HH): HW:HH=1.2–1.5. Cephalic size (csb): Mean: 480–550 μm. Maximum eye diameter vs. minimum eye diameter: 1.2–1.4. POL:OOL: POL equal to or shorter than OOL and ocellar triangle with short base OR POL longer than OOL and ocellar triangle with wide base. Male ocular ocellar line (OOL) vs. lateral ocellar line (LOL): OOL:LOL=1.2–1.8. Male ocular ocellar line (OOL) vs. posterior ocellar line (POL): OOL:POL=0.9–1.5. Male ocular ocellar line (OOL): posterior ocellar line (POL): lateral ocellar line (LOL): 1.2–1.8:1.1–1.4:1.0. Head shape (anterior view): circular or triangular. Preoccipital lunula count: absent. Occipital carina structure: occipital carina complete. Occipital carina sculpture: crenulate. Preoccipital furrow count: present. Preoccipital furrow anterior end: preoccipital furrow ends inside ocellar triangle, but ends posterior to the anterior ocellus. Preoccipital furrow sculpture: crenulate. Dorsal margin of occipital carina vs. dorsal margin of lateral ocellus in lateral view: occipital carina ventral to lateral ocellus in lateral view. Transverse scutes on upper face count: absent. Transverse frontal carina count: absent. Randomly sized areolae around setal pits on upper face count: absent. Setal pit on vertex size: smaller than diameter of scutes. Ventromedian setiferous patch and ventrolateral setiferous patch count: absent. White, thick setae on upper face count: absent. Antennal scrobe count: absent. Facial structure count: facial pit present. Facial pit count: present. Facial sulcus count: absent. Median facial keel count: absent. Supraclypeal depression count: present. Supraclypeal depression structure: present medially, inverted U-shaped. Intertorular area count: present. Intertorular carina count: present. Median process on intertorular carina count: absent. Median region of intertorular area shape: convex. Ventral margin of antennal rim vs. dorsal margin of clypeus: not adjacent. Torulo–clypeal carina count: present. Subtorular carina count: absent. Mandibular tooth count: 2. Mandibular lancea count: absent.

Mesosoma: Weber length: WL=800 μm, 850 μm. Anterior mesoscutal width (AscW) vs. posterior mesoscu- tal width (PscW): AscW/PscW=0.6–0.8. Mesoscutal length (MscL) vs. anterior mesoscutal width (AscW): MscL/ AscW=1.5–1.9. Mesoscutal length (MscL) vs. mesoscutellar length (MscIL): MscL:MscIL= 0.9–1.1. Wing count: present. Fore wing size: wings present and macropterous with apex extending past petiole. Pronotum median length: less than longest median anatomical line of the mesoscutum. Notaulus count: present. Crenulae of notaulus width: width of the crenulae increases more than 2× anteriorly. Notaulus posterior end location: adjacent to transscutal articulation. Posterior region of notaulus orientation: posterior end of notaulus does not curve and is not adjacent to median mesoscutal sulcus. Median mesoscutal sulcus count: present. Median mesoscutal sulcus posterior end: adjacent to transscutal articulation. Scutoscutellar sulcus vs. transscutal articulation location: adjacent. Axillular carinae count: absent. Speculum ventral limit: not extending ventrally of pleural pit line. Metapleural sulcus shape: straight or arched. Mesometapleural sulcus count: present. Ventrolateral invagination of the pronotum count: present. Sternaulus count: absent. Sternaulus length: sternaulus absent. Epicnemial carina count: complete. Epicnemium posterior margin shape: anterior discrimenal pit present; epicnemial carina curved. Transverse striations on the ventral metapleural area count: absent. Scutes on posterior region of mesoscutum and dorsal region of mesoscutellum convexity: flat. Ventral projection of the metapleural carina count: absent. Mesopostscutellum count: present (posterior margin of scutellum appears raised). Anteromedian projection of the metanoto–propodeo–metapecto–mesopectal complex count: absent. Posterior margin of nucha in dorsal view shape: concave.

Metasoma: Transverse carina on petiole shape: straight. Paired blue iridescent ovoid patches on the syntergite count: absent. Shortest width of petiole neck vs. syntergal translucent patch maximum width: 1.7–2.5. Shortest width of petiole neck vs. synsternal translucent patch maximum width: 1.5–2.3. Syntergal translucent patch maximum width vs. minimum width: 1.1–2.0. Synsternal translucent patch maximum width vs. minimum width: 1.5–2.3. Syntergal translucent patch maximum width orientation: anteromedially. Synsternal translucent patch maximum width orientation: anterolaterally. Synsternal setiferous patch shape: linear, with a patch of setae lateral or posterior to the synsternal translucent patch. Synsternal setiferous patch structure: comprised of a single or double row of setae anterior and lateral to the synsternal translucent patch, with a patch of setae posterior to the synsternal translucent patch. Synsternal setiferous patch anterior end: synsternal setiferous patch begins anterior to the synsternal translucent patch anterior margin. Synsternal setiferous patch posterior end: synsternal setiferous patch ends posterior to the synsternal translucent patch posterior margin. Synsternal setiferous patch length vs. synsternal translucent patch maximum width: synsternal setiferous patch at least 2× as long as the maximum width of the synsternal translucent patch. S1 length vs. shortest width: S1 wider than long.

Male Genitalia: Distal margin of male S9 shape: straight. Proximolateral corner of male S9 shape: blunt. Male S9 distal setal line/setal patch count: distal setae composing transverse setiferous line or lines. Male S9 distal setal line / setal patch structure: single or double transverse row of distal setae. Distomedian hairless area interrupting transverse row of setae or patch on male S9 count: absent with distal setiferous patch/line continuous medially. Submedial projections on proximal margin of S9 count: absent. Cupula length vs. gonostyle–volsella complex length: cupula less than 1/2 the length of gonostyle–volsella complex in lateral view. Proximodorsal notch of cupula count: present. Proximodorsal notch of cupula shape: arched (inverted U-shape). Proximodorsal notch of cupula width vs length: longer than wide. Proximolateral projection of the cupula shape: blunt. Gonocondyle count: present. Gonocondyle shape: acute. Distodorsal margin of cupula shape: concave. Distoventral submedian corner of the cupula count: absent. Dorsomedian projection of the gonostyle–volsella complex count: absent. Dorsomedian conjunctiva of the gonostyle–volsella complex count: present. Dorsomedian conjunctiva of the gonostyle–volsella complex length relative to length of gonostyle–volsella complex: dorsomedian conjunctiva extending more than or equal to 2/3 of length of gonostyle–volsella complex in dorsal view. Dorsomedial margin of gonostyle–volsella complex shape: V-shaped. Proximal end of dorsomedian conjunctiva of the gonostyle–volsella complex shape: acute or V-shaped. Parossiculus count or parossiculus and gonostipes fusion: present and parossiculi not fused with the gonostipes. Medioventral conjunctiva of the gonostyle–volsella complex count or fusion of parossiculi: medioventral conjunctiva present and parossiculi independent or fused proximally. Apical parossicular setae count: one. Distal projection of the parossiculus count: absent. Distal projection of the penisvalva count: absent. Gonossiculus spine count: 3. Gonossiculus spine length: one spine more than 2× as long as the other(s). Harpe length: harpe shorter than gonostipes in lateral view. Harpe shape: simple and not bilobed. Harpe orientation: dorsomedial. Distal margin of harpe in lateral view: blunt or straight. Lateral setae of harpe count: present. Lateral setae of harpe orientation: oriented distally. Lateral setae on harpe density: setae sparse. Dense patch of setae on the distoventral edge of the harpe count: absent. Distal setae on harpe length: setae of equal length across distal end of harpe. Distodorsal setae of sensillar ring of harpe length vs. harpe width in lateral view: setae as long as or shorter than harpe width. Distodorsal setae of sensillar ring of harpe orientation: distomedially. Sensillar ring area of harpe orientation: distomedially. Sensillar ring shape: circular. Distoventral margin of harpe in lateral view: convex.

Distribution. Nearctic.

Etymology. This species is named duncani in honor of the first author’s partner, Stephen D. Duncan, for his love and support during the course of this research.

Material Examined. Holotype male: USA: Wisconsin: PSUC _FEM 50384 ( WIRC) . Paratypes (3 males): USA: Wisconsin : 3 males. PSUC _FEM 50388 ( PSUC); PSUC _FEM 50259, 50380 ( WIRC) .

Figures

FIGURE 54. Conostigmus duncani Trietsch sp. nov., male holotype (PSUC_FEM 50384).

FIGURE 55. Conostigmus duncani Trietsch sp. nov. A. Lateral view of paratype (PSUC_FEM 50388). B. Dorsal view of holotype (PSUC_FEM 50384).

FIGURE 56. Conostigmus duncani Trietsch sp. nov., paratype male genitalia (PSUC_FEM 50380) A. Ventral view. B. Lateral view. C. Dorsal view. Abbreviations: apical parossicular setae (prs); proximodorsal notch of cupula (pdn; in this case, longer than wide).