Conostigmus franzinii Trietsch & Mikó, 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 : 103-108

Conostigmus franzinii Trietsch & Mikó sp. nov.

Figs. 57 , 58 , 59

Diagnosis. This is a widespread and variable species. Conostigmus franzinii can be differentiated from all other species by the combination of the following characters: absence of the axillular carinae; presence of an elongate sternaulus (exceeding 3/4 of the mesopleuron length at the level of the sternaulus); absence of the medioventral conjunctiva of the gonostyle–volsella complex (parossiculi fused); presence of the medioventral ridge of the gono-style–volsella complex; presence of a dense patch of setae on the distoventral edge of the harpe; and presence of distal setae composing a setiferous patch on S9.

Two similar species are C. musettiae and C. bipunctatus , which share the elongated sternaulus, fused parossiculi and the dense patch of setae on the distoventral edge of the harpe. Conostigmus franzinii can be distinguished from C. musettiae by the absence of the axillular carinae (present in C. musettiae ) and the presence of the thick medial patch of setae on S9 (whereas C. musettiae has a single transverse row of distal setae occurring medially with less than 4 setae below it). While C. bipunctatus is similar to C. franzinii in that it is a variable species with a wide Holarctic distribution, C. franzinii can be easily distinguished from C. bipunctatus by male genitalia characters. In C. bipunctatus , the harpe are curved and sickle-shaped and the distoventral margin of harpe is concave in lateral view, whereas in C. franzinii , the harpe are simple, not curved or sickle-shaped, and the distoventral margin of harpe is convex in lateral view. Other differences include that C. franzinii is always macropterous and lacks the paired blue iridescent ovals on the syntergite, whereas C. bipunctatus can be brachypterous and have the paired iridescent ovals present.

C. franzinii bears a strong resemblance to C. minimus in the shape of the harpe, and shares the elongated sternaulus, fused parossiculi and the dense patch of setae on the distoventral edge of the harpe. Conostigmus minimus differs from C. franzinii in gonossiculus spine length (spines of equal length in C. minimus ; one spine more than 2× as long as the others in C. franzinii ), and in the absence of the medioventral ridge of the gonostyle–volsella complex (present in C. franzinii ), as well as the ventral projection of the metapleural carina more than or equal to 2× as long as wide (less than 2× as long as wide in C. franzinii ). The four specimens of C. minimus are much smaller than most C. franzinii specimens, but these differences can still be seen in smaller C. franzinii specimens of the same size as C. minimus specimens (UCRC_ENT 00457072, INHS Insect Collection 287574, INHS Insect Collection 287580), so these differences in male genitalia do not appear to be a function of body size.

Variability. Specimens vary in color from brown to black. The proximodorsal notch of the cupula is always present and V-shaped (acute), though the V-shape is more pronounced in some specimens (PSUC_FEM 50399, INHS Insect Collection 287574) than in others (INHS Insect Collection 287564, UCRC_ENT 00457072). The dorsomedian projection of the gonostyle–volsella complex is present in most specimens, but reduced or seemingly absent in others (PSUC_FEM 50399, UCRC_ENT 00457072). There are also slight variations in coloration, with the neck of the petiole being lighter than the rest of the metasoma in a few specimens (UCRC_ENT 00457072, INHS Insect Collection 287574).

These variations occur across both Nearctic and Palearctic populations. The only consistent difference between Nearctic and Palearctic populations is that in Palearctic specimens, the dorsomedian conjunctiva of the gonostylevolsella complex usually extends about 1/2 of the length relative to the length of the gonostyle–volsella complex, whereas in Nearctic specimens, it usually extends about 1/3 of the length relative to the length of the gonostyle–vol-sella complex.

Description. Color hue pattern in male: cranium and mesosoma except for propleuron dark brown to black; F1– F9 brown; legs, coxae ochre; scape, pedicel, mandibles ochre to brown; propleuron light brown to black. Color intensity pattern in male: propleuron lighter than the rest of the mesosoma on a few specimens (CMNHENT0022719, UCRC_ENT 00457072); flagellomeres darker than scape and pedicel. Color intensity dorsal and ventral to the site of the sternaulus: concolorous. 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: 3.7–4.8. Male scape length vs. F1 length: 1.3–1.7. Male F1 length vs. pedicel length: 2.2–3.3. Male F1 length vs. male F2 length: 1.0–1.3. Longest male flagellomere: F1, F2. Length of setae on male flagellomere vs. male flagellomere width: setae shorter than width of flagellomeres. Sensillar patch of the male flagellomere pattern: F5–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=1.61–1.71. Head height (HH) vs. head length (HL): HH:HL=1.1–1.3. Head width (HW) vs. interorbital space (IOS): HW:IOS=1.6–1.8. Head width (HW) vs. head height (HH): HW:HH=1.2–1.4. Cephalic size (csb): Mean: 340–465 μm. Maximum eye di- ameter vs. minimum eye diameter: 1.3–1.5. POL:OOL: POL equal to or shorter than OOL and ocellar triangle with short base. Male ocular ocellar line (OOL) vs. lateral ocellar line (LOL): OOL:LOL=1.7–2.7. Male ocular ocellar line (OOL) vs. posterior ocellar line (POL): OOL:POL=1.1–1.5. Male ocular ocellar line (OOL): posterior ocellar line (POL): lateral ocellar line (LOL): 1.7–2.7:1.5–2.0:1.0. Head shape (anterior view): circular or triangular. Preoccipital lunula count: present. Preoccipital carina 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. Postocellar carina count: present. 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: absent medially, represented by two grooves laterally of facial pit. Intertorular area count: present. Intertorular carina count: present. Median process on intertorular carina count: present. Median process on intertorular carina shape: blunt. Median process of intertorular carina structure: process does not extend across intertorular area to dorsal margin of clypeus. 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=500–700 μm. Anterior mesoscutal width (AscW) vs. posterior mesoscutal width (PscW): AscW/PscW=0.6–0.8. Mesoscutal length (MscL) vs. anterior mesoscutal width (AscW): MscL/ AscW=1.3–1.7. Mesoscutal length (MscL) vs. mesoscutellar length (MscIL): MscL:MscIL= 0.9–1.0. 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 does not increase more than 2× anteriorly. Notaulus posterior end location: adjacent to transscutal articulation. Posterior region of notaulus orientation: posterior end of notaulus curves and is 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. Mesometapleural sulcus count: present. Ventrolateral invagination of the pronotum count: present. Sternaulus count: present. Sternaulus length: elongate and exceeding 3/4 of mesopleuron length at level of sternaulus. Sternaulus sculpture: smooth. 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: present. Ventral projection of the metapleural carina length: less than 2× as long as wide. Lateral propodeal carina count: present. Lateral propodeal carina shape: inverted “Y” (left and right lateral propodeal are adjacent medially posterior to antecostal sulcus of the first abdominal tergum, and connected to the antecostal sulcus by a median carina representing the median branch of the inverted “Y”). Mesopostscutellum count: absent (scutellum flat). 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: concave. Paired blue iridescent ovoid patches on the syntergite count: absent. Shortest width of petiole neck vs. syntergal translucent patch maximum width: 1.5–2.2. Shortest width of petiole neck vs. synsternal translucent patch maximum width: 2.1–2.3. Syntergal translucent patch maximum width vs. minimum width: 1.5–3.0. Synsternal translucent patch maximum width vs. minimum width: 2.2–3.0. Syntergal translucent patch maximum width orientation: anterolaterally. 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 to the synsternal translucent patch, with a patch of setae lateral or 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 lateral to the synsternal translucent patch posterior margin; 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: convex. Proximolateral corner of male S9 shape: acute. Male S9 distal setal line/setal patch count: distal setae composing setiferous patch or patches. Male S9 distal setal line / setal patch structure: patch of setae occurring medially. 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: notched (inverted V-shape). Proximodorsal notch of cupula width vs length: wider than long. Proximolateral projection of the cupula shape: blunt. Gonocondyle count: present. Gonocondyle shape: acute. Distodorsal margin of cupula shape: straight. Dorsomedian projection of the gonostyle–vol-sella complex count: absent; present. Dorsomedian projection of the gonostyle–volsella complex shape: simple (not bilobed). 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 between 1/3 to 1/2 the length of gonostyle–volsella complex in dorsal view. Dorsomedial margin of gonostyle–volsella complex shape: straight with a median projection. Proximal end of dorsomedian conjunctiva of the gonostyle–volsella complex shape: blunt or straight. 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 absent and parossiculi fused. Medioventral ridge of the gonostyle–volsella complex count (only applicable if medioventral conjunctiva of the gonostyle–volsella complex absent): present. Medioventral ridge of the gonostyle–volsella complex length relative to length of gonostyle–vol-sella complex: ridge extending 2/3 of length of gonostyle–volsella complex in ventral view. Apical parossicular setae count: one. Distal projection of the parossiculus count: present. Distal projection of the penisvalva count: absent.

Gonossiculus spine count: 2. 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: medial. Lateral margin of harpe shape: widest point of harpe is in its proximal 1/3rd. Distal margin of harpe in lateral view: blunt or straight. Lateral setae of harpe count: absent. Lateral setae on harpe density: setae sparse. Dense patch of setae on the distoventral edge of the harpe count: present. Distal setae on harpe length: setae not of equal length, longer setae present on distodorsal and distoventral edges of harpe. Distodorsal setae of sensillar ring of harpe length vs. harpe width in lateral view: setae longer than harpe width. Distodorsal setae of sensillar ring of harpe orientation: distally. Sensillar ring area of harpe orientation: medioventrally. Sensillar ring shape: circular. Distoventral margin of harpe in lateral view: convex.

Distribution. Holarctic.

Etymology. This species is named franzinii in memory of Luca Franzini, a bumble bee researcher and fellow PhD student in the Department of Entomology at Penn State who passed away suddenly during the course of this research.

Material Examined. Holotype male: USA: Illinois: INHS Insect Collection 287553 ( INHS) . Paratypes (24 males): CANADA: 1 male. PSUC _FEM 15835 ( PSUC) . GERMANY: 2 males. PSUC _FEM 26761, 28771 ( PSUC) . SWEDEN: 5 males. IM 1592; NCSU 0043326 , 0052296 , 0055652 , 0055674 ( NCSU) . USA: Alaska: 1 male. PSUC _ FEM 50399 ( PSUC) . USA: California: 4 males. IM 1524 ( PSUC); PSUC _FEM 33990, 34228 , 34231 ( UCFC) . USA: Illinois: 3 males. INHS Insect Collection 287564, 287574, 287580 ( INHS) . USA: New York: 1 male. PSUC _ FEM 9734 ( ROME) . USA: Ohio: 2 males. CMNHENT0022719 ( CLEV); PSUC _FEM 86113 ( OSUC) . USA: Pennsylvania: 2 males. PSUC _FEM 60374, 68186 ( PSUC) . USA: Wyoming: 1 male. UCRC _ ENT 00457072 ( UCRC) . Unknown country: 1 male. INHS Insect Collection 287560 ( INHS) .

Figures

FIGURE 57. Conostigmus franzinii Trietsch and Mikό sp. nov., habitus of holotype male (PSUC_FEM 287553).

FIGURE 58. Conostigmus franzinii Trietsch and Mikό sp. nov., paratype male (PSUC_FEM 15835). A. Lateral view. B. Dorsal view.

FIGURE 59. Conostigmus franzinii Trietsch and Mikό sp. nov., paratype male genitalia A. Ventral view (INHS Insect Collection 287580). B. Lateral view (PSUC_FEM 50399). C. Dorsal view of Palearctic male from Sweden without a pronounced dorsomedian projection of the gonostyle–volsella complex (PSUC_FEM 43326). D. Dorsal view of male with a pronounced dorsomedian projection of the gonostyle–volsella complex (PSUC_FEM 86113).Abbreviations: dorsomedian projection of the gonostyle–volsella complex (dmp); dense patch of setae on the distoventral edge of the harpe (dps); gonossiculus spine (gsn); medioventral ridge of the gonostyle–volsella complex (mgv).