Synergus, Hartig, 1840

Lobato-Vila, Irene, Equihua-Martínez, Armando, Estrada-Venegas, Edith G., Cibrián-Tovar, David, Barrera-Ruíz, Uriel M. & Pujade-Villar, Juli, 2020, Synergus Hartig species group (Hymenoptera: Cynipidae: Synergini) with partially smooth mesopleurae from the New World, Zootaxa 4822 (1), pp. 1-38 : 33-35

Key to Synergus species with partially smooth mesopleurae from the New World

1 Lateral frontal carinae present (see Lobato-Vila & Pujade-Villar 2017: Figs 2a , c–d; 6b–c). Sometimes very short, running just a little from the posterior margin of toruli and eclipsed by antennae, rarely appearing as multiple striae running from lower face and toruli to ocelli (like in S. striatifrons , see Lobato-Vila & Pujade-Villar 2017: Fig. 7a, c–d), but always visible. Syntergite with or without punctures; if present, they can form either a posterodorsal patch or a band............................ 2

- Lateral frontal carinae absent (like Fig. 3 a–b). Syntergite with or without punctures, but if present, they form at most a posterodorsal patch, never a band.......................................................................... 14

2 Syntergite posteriorly without punctures or just with some micropunctures sometimes forming a posterodorsal patch (except in males of S. stelluli , which have a narrow band, but in this case the radial cell of fore wings is 2.1 times as long as wide and vertex has some wrinkles in the ocellar area................................................................ 3

- Syntergite posteriorly with a more or less extended band of punctures, occupying from 1/5 to the half of the syntergite length ................................................................................................... 9

3 Mesoscutum with strong, widely spaced discontinuous carinae. Lateral pronotum strongly carinated. Notauli complete and well impressed in their whole length, sometimes interrupted by carinae. Pedicel as long as wide. Reared from tuberous galls. USA (see Lobato-Vila et al. 2019: Figs 36–37).................................................... S. mendax Walsh

- Mesoscutum finely coriaceous or coriaceous, coriaceous to imbricated or just with weak, discontinuous and usually dense transversal elements not forming true carinae (like Figs 1b ; 4d ). Lateral pronotum finely coriaceous, coriaceous or imbricated, sometimes with some carinae in the basal half. Notauli incomplete and usually shallow, faint anteriorly (except in S. castanopsidis , which are complete but less impressed anteriorly, but in this case the mesoscutum never has strong carinae). Pedicel longer than wide. Reared from different morphotypes of galls, except from tuberous ones. USA and/or Mexico................ 4

4 Radial cell of fore wings very short, 2.1 times as long as wide. Vertex slightly wrinkled in the ocellar area. POL as long as OOL. Malar space 0.5 times as long as height of compound eye. Scutellar foveae inconspicuous. USA (see Burnett 1976: Figs A–I)..................................................................................... S. stelluli Burnett

- Radial cell of fore wings longer, at least 2.3 times as long as wide. Vertex coriaceous, with or without small piliferous punctures, but always without wrinkles (like Figs 1b ; 4d ). POL longer than OOL (except in females of S. striatifrons , which is subequal, but in this case frons is covered with striae projecting from toruli and lower face). Malar space 0.6 times as long as height of compound eye or longer. Scutellar foveae sometimes small, shallow and/or not well defined posteriorly, but always visible. USA or Mexico....................................................................................... 5

5 Frons covered with multiple fine striae projecting from lower face and toruli to ocelli. Malar space 0.8 times as long as height of compound eye. Head in anterior view more or less quadrate, the transfacial line long, 1.3 times as long as height of compound eye. POL about as long as OOL in females. Circumscutellar carina projected and upturned. Reared from galls of different Amphibolips species from Mexico (see Lobato-Vila & Pujade-Villar 2017: Fig. 7)...................................................................................................... S. striatifrons Pujade-Villar & Lobato-Vila

- Frons coriaceous, without striae. Malar space shorter. Head in anterior view round or trapezoid, the transfacial line as long as height of compound eye or just slightly longer. Females with POL longer than OOL. Circumscutellar carina weak, neither projected nor upturned. Reared from non-tuberous galls of Andricus , Dryocosmus or Neuroterus from USA............. 6

6 Notauli complete, reaching the posterior margin of pronotum. Median groove of the mesoscutum appearing as a short basal sulcus. Scutellar foveae large, subquadrate, weakly sculptured bottom. Female syntergite dorsodistally incised. Reared from galls of Dryocosmus castanopsidis (see Pujade-Villar & Melika 2005: Fig. 1 )........... S. castanopsidis (Beutenmüller)

- Notauli incomplete, faint in the anterior third of the mesoscutum or before reaching the pronotal margin. Median groove of the mesoscutum absent. Scutellar foveae small, ovate or subtriangular, smooth bottom. Female syntergite not dorsodistally incised. Reared from Andricus (non-tuberous galls) or from Neuroterus galls............................................. 7

7 Transfacial line slightly longer than height of compound eye. Mesoscutum finely coriaceous to reticulated, without transversal elements ( Fig. 1b ). Mesopleurae basally and medially with spaced striae. Body mainly brownish yellow to yellow ( Fig. 1 a–b). Reared from galls of Neuroterus ....................................................... S. agrifoliae Ashmead

- Transfacial line as long as height of compound eye. Mesoscutum coriaceous or imbricated, with weak, discontinuous transversal elements (like Fig. 4d ). Mesopleurae basally and medially with dense striae. Body mainly black, dark brown or rufous, with some yellowish areas (like Fig. 4 c–d). Reared from non-tuberous Andricus galls................................... 8

8 Head yellow, except for a black spot in the ocellar area; vertex with some small punctures; OOL 1.7 times as long as diameter of lateral ocelli ( Fig. 4d ). Lateral pronotum dorsally and medially imbricated, weakly wrinkled basally ( Fig. 4c ). Scutellar foveae small, ovate ( Fig. 4d ). Metasoma about 1.2 times as long as high in lateral view ( Fig. 4c ), the syntergite with a posterodorsal patch of micropunctures somewhat laterally extended. Hypopygial spine almost 3.0 times as long as wide....................................................................................... S. confertus McCracken & Egbert

- Head dark brown to black; vertex without punctures; OOL 1.4 times as long as diameter of lateral ocelli. Lateral pronotum coriaceous. Scutellar foveae subtriangular, smooth bottom. Metasoma about as long as high in lateral view, the syntergite posteriorly without punctures or just with a few, not forming a true patch. Hypopygial spine about as long as wide (see Lobato-Vila et al. 2020b: Figs 53–54)................................................................. S. walshii Gillette

9 Head and body mainly black, except for a yellow or brownish to chestnut halo surrounding the oral fovea (except in males of S. punctatus , which have the head yellow with a black spot in the ocellar area) (see Lobato-Vila & Pujade-Villar 2017: Fig. 8a–b). Frons and vertex coriaceous or reticulated, without punctures. OOL about as long as diameter of lateral ocelli. Circumscutellar carina inconspicuous or absent. Mexico and USA........................................................... 10

- Head and body never almost completely black, at most yellowish brown with some dark areas, brownish black or rufous ( Figs 4 a–b, e–f; 5a–b, e–f). Frons and vertex finely coriaceous to coriaceous, with some small punctures. OOL longer than diameter of lateral ocelli. Circumscutellar carina weak, but always visible. USA.......................................... 11

10 In females, head black except for a well delimited yellow halo around the oral fovea; in males, head yellow except for a black spot in the ocellar area. F1 1.4 times as long as F 2 in males. Notauli incomplete, faint in the anterior third of the mesoscutum. Syntergite with a complete band of micropunctures occupying the distal half of the syntergite length. USA (see Lobato-Vila & Pujade-Villar 2017: Figs 6; 8a)........................................................... S. punctatus Gillette

- Head black, except for a not well defined brownish to chestnut halo around the oral fovea in both sexes. F1 slightly longer than F 2 in males. Notauli complete and visible in their whole length, less impressed anteriorly. Syntergite with an incomplete band of micropunctures occupying about 1/3 of its length. Mexico (see Lobato-Vila & Pujade-Villar 2017: Figs 2 ; 3 ; 8b)............................................................................ S. gilletti Pujade-Villar & Lobato-Vila

11 Notauli complete, reaching the posterior margin of pronotum, but narrower and less impressed anteriorly ( Figs 4b ; 5f ).... 12

- Notauli incomplete, faint in the anterior half or third of the mesoscutum, not reaching the posterior margin of pronotum ( Figs 4f ; 5b )............................................................................................. 13

12 POL about as long as OOL. F1 1.5 times as long as F2. Lateral pronotum strongly imbricated to weakly carinated, especially basally ( Fig. 5 e–f)................................................................ S. succinipedis (Ashmead)

- POL about 1.8 times as long as OOL. F1 and F2 subequal. Lateral pronotum completely coriaceous ( Fig. 4 a–b)....................................................................................... S. campanula Osten-Sacken

13 Scutellar foveae large, subquadrangular. In females, syntergite of the metasoma weakly dorsodistally incised and last flagellar segment more than 4.0 times as long as wide. Males almost completely yellow, with the malar space about 0.7 times as long as height of compound eye and POL 1.7 times as long as OOL ( Fig. 4 e–f)................. S. flavens McCracken & Egbert

- Scutellar foveae ovate to subtriangular. In females, syntergite of the metasoma not dorsodistally incised and last flagellar segment about 3.0 times as long as wide. Males mainly black, with the malar space about 0.5 times as long as height of compound eye and POL 2.2 times as long as OOL ( Fig. 5 a–b)............................... S. pacificus McCracken & Egbert

14 Head strongly transverse in dorsal view, more than 2.5 times as wide as long (see Nieves-Aldrey & Medianero 2011: Fig. 3C ). Malar space about as long as height of compound eye (see Nieves-Aldrey & Medianero 2011: Fig. 1B ). Panama.......................................................................... S. laticephalus Nieves-Aldrey & Medianero

- Head in dorsal view about 2.0 times as wide as long. Malar space at most 0.8 times as long as height of compound eye. USA, Mexico and/or Panama................................................................................ 15

15 In females, body mainly black, head black except for a brownish orange surface under compound eyes and around the oral fovea ( Fig. 2a, c ); in males, lower face, genae and antennae (except the last segments), yellowish orange ( Fig. 2b, d ). OOL almost 3.0 times as long as diameter of lateral ocelli. Radial cell about 2.7 times as long as wide in females, with R1 vein weakly pigmented and Rs vein strongly projected beyond the end of the radial cell along the wing margin in both males and females ( Fig. 2f ). Mexico............................................ S. aurofacies Lobato-Vila & Pujade-Villar , sp. nov.

- In both sexes, body mainly yellow, yellowish brown, brown or black and yellow, with head at least with lower face and genae yellow or yellowish brown (like Figs 4 g–h; 5c–d). OOL about 2.0 or less times as long as diameter of lateral ocelli. Radial cell about 2.4 times as long as wide in females, with R1 vein either weakly pigmented or not, and Rs not so strongly projected in both sexes. USA, Mexico and/or Panama................................................................. 16

16 Body yellow to yellowish brown or brown. Scutellar foveae large, subquadrate to ovate. Circumscutellar carinae weak, not well defined ( Fig. 5 c–d). USA and Mexico................................................. S. pomiformis (Ashmead)

- Body brown or black with yellowish areas. Scutellar foveae absent, inconspicuous or small and shallow. Circumscutellar carina well defined, sometimes upturned and projected. USA, Mexico and/or Panama................................... 17

17 Mesoscutum alutaceous to finely coriaceous, with weak, discontinuous transversal elements not forming true carinae. Notauli complete, reaching the posterior margin of pronotum, narrow. Scutellar foveae small, circular, separated by a wide septum ( Fig. 4 g–h). Syntergite punctuation absent. USA......................................... S. laeviventris (Osten-Sacken)

- Mesoscutum alutaceous to coriaceous or weakly imbricated, never with transversal elements. Notauli incomplete, faint in the anterior third or before reaching the pronotal margin (except in S. longimalaris , which are complete, but in this case the malar space is 0.8 times as long as height of compound eye and the transfacial line, 1.3 times as long as height of compound eye). Scutellar foveae shallowly impressed and almost inconspicuous or absent. Syntergite punctuation composed at most by some micropunctures either forming or not a posterodorsal patch. USA, Mexico and/or Panama........................... 18

18 Malar space 0.6 times as long as height of compound eye. USA, Mexico and/or Panama............................ 19

- Malar space longer, 0.8 times as long as height of compound eye. Mexico....................................... 20

19 Scape long, longer than F 1 in females and about as long as F 1 in males. F1 as long as F 2 in females and just slightly longer in males. Transfacial line about as long as height of compound eye. Mexico (see Lobato-Vila & Pujade-Villar 2017: Fig. 5 )................................................................... S. longiscapus Pujade-Villar & Lobato-Vila

- Scape shorter than F1 and F1 1.3 times as long as F 2 in both sexes. Transfacial line about 1.3 times as long as height of compound eye. USA, Mexico and Panama (see Lobato-Vila et al. 2020b: Figs 9–12)............... S. citriformis (Ashmead)

20 POL as long as OOL. OOL 2.2 times as long as diameter of lateral ocelli. F1 1.5 times as long as F2. Notauli complete. Scutellum alutaceous to finely coriaceous or reticulated. Syntergite of the metasoma with a few weak posterodorsal micropunctures forming a small patch, following segments and hypopygium, which is completely covered by the syntergite, not punctate (see Lobato-Vila & Pujade-Villar 2017: Fig. 4 ).............................. S. longimalaris Pujade-Villar & Lobato-Vila

- POL 1.5 times as long as OOL. OOL 1.5 times as long as diameter of lateral ocelli. F1 1.3 times as long as F2. Notauli almost complete, faint before reaching the pronotal margin. Scutellum anteriorly coriaceous, posteriorly imbricated. Syntergite of the metasoma with a conspicuous posterodorsal patch of micropunctures, following segments and hypopygium, which is visible and projected (not covered by the syntergite), punctate (see Lobato-Vila & Pujade-Villar 2017: Fig. 1 )...................................................................................... S. cibriani Pujade-Villar & Lobato-Vila

Figures

FIGURE 1. Synergus agrifoliae: a) female lateral habitus; b) female dorsal view.

FIGURE 2. Synergus aurofacies, sp. nov.: a) female habitus; b) male habitus; c) female face; d) male face; e) first antennal segments of the male; f) female forewing; g) host gall.

FIGURE 3. Synergus aurofacies, sp. nov.: a) female head in frontal view; b) female head in dorsal view; c) mesosoma in lateral view (the black arrow points out the speculum); d) mesosoma in dorsal view; e) tarsal claws; f) female antenna; g) propodeum; h) metasoma in lateral view.

FIGURE 4. Synergus campanula: a) lateral habitus; b) dorsal view. Synergus confertus: c) lateral habitus; d) dorsal view. Synergus flavens: e) lateral habitus; f) dorsal view. Synergus laeviventris: g) lateral habitus; h) dorsal view.

FIGURE 5. Synergus profusus (synonym of S. pacificus): a) lateral habitus; b) dorsal view. Synergus pomiformis: c) lateral habitus; d) dorsal view. Synergus succinipedis: e) lateral habitus; f) dorsal view.