Conostigmus pulchellus Whittaker, 1930

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 : 74-79

Conostigmus pulchellus Whittaker, 1930

Figs. 41 , 42

Species Comments and History. Whittaker (1930) described this species from three male specimens collected in Hollyburn, British Columbia, Canada, deposited in the NHMUK. Dessart (1997a) expected to synonymize this species with C. abdominalis , but after examining the types and comparing them with additional male and female specimens collected in the United States and Canada, he was surprised to find that C. pulchellus and C. abdominalis did constitute different species. Dessart (1997a) noted that while C. pulchellus and C. abdominalis were nearly indistinguishable in somatic characters, there were differences in the male genitalia. Dessart (1997a) also described the females of C. pulchellus for the first time.

Whittaker’s holotype and two paratype specimens are present at the NHMUK, as well as a third specimen from Whittaker that Dessart identified as C. pulchellus . This third specimen does not have type status but was also collected by Whittaker in “Hn.”, which matches the type locality, Hollyburn. One paratype (NHMUKENT010812165) bears a label from Dessart identifying it as “ C. abdominalis , (BOH 1832), syn. nov.”, but Dessart presumably thought the species were synonymous when he left his label on the specimen in 1975, as he expresses surprise in his 1997a publication that they were not synonymous species. Dessart does not mention this particular paratype specimen in his 1997a publication. The genitalia would need to be dissected to confirm the species identification, but we consider it C. pulchellus and include it in the material examined below.

Variability. The main variation observed in this species is in the coloration. Females have lighter reddish or yellow coloration along the notauli and median mesoscutal sulcus, as well as on the axilla, axillula and the anterior mesosoma, though some specimens have lighter coloration (PSUC_FEM 34271, PSUC_FEM 34085) than others (PSUC_FEM 50386, PSUC_FEM 84526). Males are brown to black in color and typically lack the lighter yellow or reddish coloration observed in females, but there is one male specimen (PSUC_FEM 64329) that exhibits the female coloration pattern.

Differences between males and females. The most striking difference between male and female specimens is in the coloration of the mesosoma, viewed dorsally. Females have lighter reddish or yellow coloration on the axilla, axillula and the anterior mesosoma along the notauli and the median mesoscutal sulcus. There is one male specimen (PSUC_FEM 64329) that has the same coloration pattern found in females, but the majority of male specimens have uniform mesosomal coloration. Other than coloration, genitalia differences and sexual dimorphism in the antennae, there are no differences in the morphology of the males and females.

Diagnosis. This species can be distinguished from other Conostigmus species by the following combination of characters: facial sulcus present; sternaulus present and elongate, exceeding 1/2 of the mesopleuron length at the level of the sternaulus; harpe longer than the gonostipes in lateral view; harpe shape spatulate; harpe twisted and oriented dorsally or dorsomedially; and 4 apical parossicular setae. This species is similar to C. longiharpes but can be distinguished by the facial sulcus, which is present in C. pulchellus and absent in C. longiharpes . This species is also similar to C. rosemaryae , but differs in that C. rosemaryae has the dorsomedian projection of the gonostyle–volsella complex present (absent in C. pulchellus ), and has harpe that are not spatulate or spoon-shaped and are shorter than the gonostipes in lateral view.

The most similar species to C. pulchellus is C. abdominalis in that they share the presence of a facial sulcus, elongate sternauli and elongated spatulate harpe. The major differences between the males of these two species are in the genitalia. Conostigmus pulchellus has 4 or more apical parossicular setae (1–3 in C. abdominalis ), and the harpe are twisted and oriented dorsally or dorsomedially (harpe are not twisted and are oriented medially in C. abdominalis ). The main difference between females of C. abdominalis and C. pulchellus is in the coloration; whereas the females of C. abdominalis have similar coloration to the males, the females of C. pulchellus have lighter reddish or yellow coloration on the axilla, axillula and the anterior mesosoma along the notauli and median mesoscutal sulcus.

Dessart (1997a) compared the females of C. pulchellus and C. abdominalis and noticed minor differences in pubescence (European C. abdominalis more densely pubescent), the shape of the head (head of C. pulchellus less triangular, more domed and rounded) and body (mesopleuron more rounded in C. abdominalis ), the sculpturing of the mesosoma (mesopleuro-metapleural furrow more strongly foveolate in C. abdominalis , pleural characters less defined in C. pulchellus ), and antennal ratios. Dessart (1997a) pointed out that all of these characters could be due to intraspecific variation, and expressed doubt whether the colored females associated with C. pulchellus belonged to that species.

However, we found one male specimen of C. pulchellus (PSUC_FEM 64329) that bears the same lighter yellow or reddish coloration on the anterior mesosoma, axilla and axillula that is present in the females associated with the species. The presence of this male exhibiting the female coloration pattern, coupled with the fact that no male or female specimens with this unique coloration have been found in the Palearctic, suggests that these females do belong to C. pulchellus and not another species.

Description. Body length: 2.5–3.4 mm. Color hue pattern in male: cranium, mesosoma, metasoma brown to black; F1–F9 brown to dark brown; scape, pedicel ochre to brown; legs ochre to brown; cranium, metasoma brown to black; mesosoma brown to black except propleuron, anterior mesosoma between the notauli and median mesoscutal sulcus, axilla, axillula; F1–F9 brown to dark brown; propleuron, anterior mesosoma between the notauli and median mesoscutal sulcus, axilla, axillula reddish to yellow on one specimen (PSUC_FEM 64329). Color intensity pattern in male: flagellomeres and pedicel darker than scape; mandible lighter than cranium; anterior mesosoma between the notauli and median mesoscutal sulcus, axilla, axillula lighter than rest of mesosoma on one specimen (PSUC_FEM 64329). Color hue pattern female: cranium, mesosoma, metasoma brown to black; F1–F9 brown to dark brown; scape, pedicel ochre to brown; legs ochre to brown; propleuron, anterior mesosoma between the notauli and median mesoscutal sulcus, axilla, axillula reddish to yellow. Color intensity pattern female: scape and pedicel lighter than flagellomeres; anterior mesosoma between the notauli and median mesoscutal sulcus, axilla, axillula lighter than rest of mesosoma. 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: present on head. Rugose region on upper face count: present.

Antennae: Male scape length vs. pedicel length: 4.1–5.5. Male scape length vs. F1 length: 0.8–1.2. Male F1 length vs. pedicel length: 4.7–5.3. Male F1 length vs. male F2 length: 1.2–1.5. Longest male flagellomere: F1. Female scape length vs. pedicel length: 3.4–4.0. Female scape length vs. F1 length: 2.0–2.2. Female F1 length vs. F2 length: 1.6–2.0. Female F1 length vs. pedicel length: 1.6–1.9. Longest female 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: 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=1.4–2.1. Head height (HH) vs. head length (HL): HH:HL=1.1–1.3. Head width (HW) vs. interorbital space (IOS): HW:IOS=1.6–2.0. Head width (HW) vs. head height (HH): HW:HH=1.2–1.5. Cephalic size (csb): Mean: 450–760 μm. Maximum eye diameter vs. minimum eye diameter: 1.1–1.3. 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=1.8–2.0. Male ocular ocellar line (OOL) vs. posterior ocellar line (POL): OOL:POL=0.8–1.0. Male ocular ocellar line (OOL): posterior ocellar line (POL): lateral ocellar line (LOL): 1.8–2.0:1.8–2.3:1.0. Female ocular ocellar line (OOL) vs. lateral ocellar line (LOL): OOL 1.8–2.0× as long as LOL. Female ocular ocellar line (OOL): posterior ocellar line (POL): lateral ocellar line (LOL): 1.8–2.0:1.8–2.3:1.0. 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 ends at 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 sulcus present. Facial sulcus count: present. 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: present. Median process on intertorular carina shape: acute. 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=750–1200 μm. Anterior mesoscutal width (AscW) vs. posterior mesoscutal width (PscW): AscW/PscW=0.7–0.8. Mesoscutal length (MscL) vs. anterior mesoscutal width (AscW): MscL/ AscW=1.3–1.9. Mesoscutal length (MscL) vs. mesoscutellar length (MscIL): MscL:MscIL= 0.8–1.2. 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 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: present. Axillular carinae shape: the left and right carinae are separated posteromedially. 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 1/2 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: absent. 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: straight.

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: 1.9–2.7. Shortest width of petiole neck vs. synsternal translucent patch maximum width: 2.1–2.7. Syntergal translucent patch maximum width vs. minimum width: 1.4–2.0. Synsternal translucent patch maximum width vs. minimum width: 1.1–2.0. 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: straight; convex. 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: wider than long. Proximolateral projection of the cupula shape: acute. Gonocondyle count: present. Gonocondyle shape: blunt. Distodorsal margin of cupula shape: straight. 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: U-shaped. 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 present and parossiculi independent or fused proximally. Apical parossicular setae count: 4 or more. Distal projection of the parossiculus count: present. Distal projection of the penisvalva count: absent. Gonossiculus spine count: 3. Gonossiculus spine length: one spine not more than 2× as long as the other(s) (spines of similar lengths). Harpe length: harpe longer than gonostipes in lateral view. Harpe shape: simple and not bilobed; spatulate or spoon-shaped. Harpe orientation: dorsomedial. Lateral margin of harpe shape: widest point of harpe is in its distal 1/3rd. Distal margin of harpe in lateral view: blunt or rounded. Lateral setae of harpe count: present. Lateral setae of harpe orientation: oriented distolaterally. 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 longer than harpe width. Distodorsal setae of sensillar ring of harpe orientation: distodorsally. Sensillar ring area of harpe orientation: distodorsally. Sensillar ring shape: circular; elongate. Distoventral margin of harpe in lateral view: convex.

Distribution. Nearctic.

Material Examined. Holotype male: CANADA: NHMUKENT010812088 ( NHMUK) . Paratypes (2 males): CANADA : 2 males. NHMUKENT10812165, 10812175 ( NHMUK) .

Non-type material (10 females, 9 males): CANADA: 1 male. NHMUKENT10812160 ( NHMUK) . USA: Alaska: 1 male. PSUC _FEM 50073 ( PSUC) . USA: Idaho: 2 males. PSUC _FEM 34075, 34140 ( TAMU) . USA: Kentucky: 2 males. PSUC _ FEM 148623 ( NCSU); PSUC _FEM 76971 ( PSUC) . USA: Maryland: 1 female. PSUC _FEM 34085 ( TAMU) . USA: Michigan: 1 female. PSUC _FEM 34095 ( TAMU) . USA: New York: 1 female. PSUC _FEM 50386 ( WIRC) . USA: Ohio: 1 male, 5 females. CMNHENT0022692, 0022698, 0022766, 0022769 ( CLEV); PSUC _ FEM 7369 , 27264 ( OSUC) . USA: Pennsylvania: 1 male. PSUC _FEM 64329 ( PSUC) . USA: Texas: 1 female. PSUC _ FEM 34271 ( TAMU) . USA: West Virginia: 1 male. PSUC _ FEM 148451 ( PSUC) . USA: Wisconsin: 1 female. PSUC _FEM 84526 ( WIRC) .

Figures

FIGURE 41. Conostigmus pulchellus Whittaker, 1930 in dorsal view. A. Holotype male (NHMUKENT010812088). B. Male with female coloration (PSUC_FEM 64329). C. Female (CMNHENT0022766).

FIGURE 42. Conostigmus pulchellus Whittaker, 1930 male genitalia. A. Ventral view (PSUC_FEM 7369). B. Dorsal view (PSUC_FEM 76971). Abbreviation: apical parossicular setae (prs).