Synergus dorsalis ( Provancher, 1889 )

Lobato-Vila, Irene & Pujade-Villar, Juli, 2021, The genus Synergus Hartig (Hymenoptera: Cynipidae: Synergini) in the New World: a complete taxonomic revision with a key to species, Zootaxa 4906 (1), pp. 1-121 : 43-46

Synergus dorsalis ( Provancher, 1889)

( Figure 15 )

Ceroptres dorsalis Provancher, 1889 . Addit. Corr. Faune Entomol. Canada Hym., p. 398. Type material: ULQC.

Synergus splendidus Fullaway, 1911 . Ann. Entomol. Soc. Am. 4: 369 syn. nov. Type material: presumably lost.

Synergus dubiosus Fullaway, 1911 . Ann. Entomol. Soc. Am. 4: 372 (synonymized with S. splendidus by McCracken & Egbert 1922). Type material: presumably lost.

Synergus dorsalis: Weld in Muesebeck et al. (1951) . U. S. Dep. Agr., Agr. Monog. (2): 611 [not Synergus dorsalis Cameron, 1883 ]

Type material of Ceroptres dorsalis Provancher, 1889 (examined). LECTOTYPE (♀) with the following labels: ‘1595’ (yellow label) / ‘56’ (white label) / ‘12’ (orange label) / ‘ Ceroptres dorsalis Prov. ’ (white label with a red frame, handwritten) / ‘ Lectotype 252, Ceroptres dorsalis Provancher, Coneaw ? 44’ (red label) / ‘ Lectotype Ceroptres dorsalis Provancher, Grahan & Rohwer ’15, Barron ’71, 1595’ (red label).

Other material examined (17♂ & 35♀). Material determined as Synergus dorsalis deposited in USNM with the following labels: ‘#1621 L. H. Weld’ (white label) / ‘Ex. gall Callirhytis pomiformis ’ (white label) / ‘ Synergus dorsalis (Prov) (= splendidus Full ) det. Weld 1937’ (white label with a black frame, handwritten) (6♂ & 6♀). Material determined as Synergus splendidus deposited in USNM with the following labels: ‘L.S.Jr.U., Lot. 554, Sub. 161’ (white label) / ‘I. McCracken Col.’ (white label) / ‘♂’ (white label) / ‘Ex. gall of Callirhytis pomiformis ’ (white label, handwritten) / ‘ Synergus splendidus Full., I. McC’ (white label with a red frame, handwritten) (2♂); ‘L.S.Jr. U., Lot. 554, Sub. 161’ (white label) / ‘I. McCracken Col.’ (white label) / ‘ ♀ ’ (white label) (2♀); ‘22’ (white label, handwritten) / ‘Sacramento Co., Cal.’ (white label) / ‘Through C. V. Riley’ (white label) / ‘ Synergus splendidus Full. det. Weld’ (white label with a black frame, handwritten) (3♂ & 12♀); ‘22’ (white label, handwritten) / ‘Marin Co., Cal.’ (white label) / ‘Through C. V. Riley’ (white label) (2♀); ‘Sacramento Co., Cal.’ (white label) / ‘Through C. V. Riley’ (white label) / ‘On Quercus wisliceni , 22’ (white label with a black frame, handwritten) (1♂ & 1♀); ‘Sept’ (white label) / ‘Sacramento Co., Cal.’ (white label) / ‘Through C. V. Riley’ (white label) / ‘ Quercus wisliceni No. 22’ (white label with a black frame, handwritten) (1♀); ‘ T Pergande Coll.’ (white label) (2♂ & 1♀); ‘Collection Ashmead’ (white label) / ‘California’ (white label, handwritten) (2♂ & 4♀); ‘Cal.’ (white label, handwritten) / ‘ T Pergande Coll.’ (white label) (1♂ & 2♀); ‘ 2847, Feb·17· 86’ (white label, handwritten) / ‘Through C. V.Riley’ (white label) (2♀); ’22 Sept. 85’ (white label, handwritten) / ‘Sacramento Co., Cal.’ (white label) / ‘Through C. V.Riley’ (white label) / ‘ Quercus wisliceni ’ (white label, handwritten) (2♀); ‘Alpine, Cal., 1916’(white label) / ‘1621’ (white label, handwritten) / ‘ Synergus splendidus Full. ’ (white label with a black frame, handwritten) (1♀); ‘Azusa, Cal.’ (grey label) / ‘4/20/17’ (white label, handwritten) / ‘1621’ (white label, handwritten) / ‘ Synergus splendidus Full. ’ (white label with a black frame, handwritten) (1♀).

Diagnosis. Synergus dorsalis belongs to a group of species characterized by having the mesopleuron entirely sculptured, including the speculum; hyaline wings and radial cell of fore wing at most 2.5 times as long as wide; POL longer than OOL; F1 as long as F2 and female antenna with 14 segments, rarely 15; mesoscutum with transversal carinae, interspaces sculptured; and notauli complete, reaching the posterior margin of pronotum. Synergus dorsalis differs from the rest of species sharing these traits ( S. villosus , S. ficigerae , S. ochreus , S. duricorius , S. beutenmulleri , S. linnei , sp. nov., S. erinacei , S. nigroornatus , S. oneratus and S. rutulus ) by having females ranging from 4.5 to 5.0 mm in length (at most 4.0 mm in the rest of species); female antenna with 15 segments ( Fig. 15e ) (usually 14 in the rest of species; if 15, then the syntergum has a narrow band of micropunctures posteriorly); tarsal claws with an inconspicuous to absent basal lobe ( Fig. 15g ) (tarsal claws with a distinct basal lobe in the rest of species, as in Figs 6e ; 22e ); first metasomal segment with striae reaching dorsally only the half of its length ( Fig. 15a, c ) (completely sulcate dorsally and laterally in the rest of species, as in Figs 6h, j ; 22h, j ); and syntergum posteriorly without micropunctures (with a posterior band in the rest of the species).

Redescription

FEMALE. Length. Body length 4.5–5.0 mm (n = 36).

Color ( Fig. 15 ). Yellow to dark yellow and black. Face and gena yellow to dark yellow; vertex around the ocellar triangle and occiput around the occipital foramen, black. Antenna yellow to dark yellow, the tips somewhat darker. Mesoscutum almost completely black with lateral margin yellow to dark yellow, or only black medially between notauli, the rest being yellow to dark yellow; pronotum except a dorsomedial black spot, mesopleuron, mesopleural triangle and tegulae, yellow to dark yellow; mesoscutellum completely black or only dorsomedially black, laterally and posteriorly yellow; propodeum black, sometimes yellow laterally. Metasoma yellow to dark yellow, first metasomal segment dark or black, the second somewhat tinged with black dorsally. Legs yellow to dark yellow. Wings hyaline, veins dark yellow.

Head. In frontal view trapezoid, about 1.2 times as wide as high, gena not broadened behind eye ( Fig. 15d ). Face faintly pubescent, lower face with striae radiating from clypeus. Clypeus indistinct, ventral margin straight, not projected over mandibles. Malar space about 0.5 times as long as height of eye. Anterior tentorial pits visible; pleurostomal and epistomal sulcus absent. Transfacial line about as long as height of eye. Toruli situated slightly under mid-height of eye; distance between torulus and eye shorter than diameter of torulus; distance between toruli shorter than diameter of toruli. Frons ( Fig. 15d ) coriaceous, without punctures nor wrinkles; frontal carinae well marked, not branched and reaching lateral ocelli. Head in dorsal view is about 2.0 times as wide as long. Vertex ( Fig. 15d ) coriaceous, with some small piliferous punctures. POL: OOL: LOL = 2.7: 2.0: 1.3 and diameter of lateral ocelli, 1.7. Occiput coriaceous, without punctures nor wrinkles.

Antenna ( Fig. 15e ). 15-segmented; filiform, not broadened apically; pubescence dense and short. Scape plus pedicel about as long as F1; pedicel just slightly longer than wide; F1 as long as F2, F2 just slightly longer than F3; the following segments progressively shorter. Last flagellar segment almost 3.0 times as long as wide and about 1.2 times as long as F12.

Mesosoma. About 1.3 times as long as high in lateral view, including nucha, with short and not dense pubescence ( Fig. 15a ). Ratio of length of pronotum medially/laterally: 0.31. Pronotal plate indistinct. Lateral pronotum weakly carinated; lateral carina absent, lateral margins of pronotum rounded seen from above. Mesoscutum ( Fig. 15c ) about 1.1 times as wide as long, with dense but weak discontinuous carinae, interspaces coriaceous; anterior parallel lines weakly impressed, reaching 1/3 of the mesoscutum. Notauli complete and visible in their whole length, somewhat interrupted by carinae anteriorly, slightly convergent posteriorly. Median mesoscutal line absent. Parapsidal lines shallowly impressed, reaching tegulae. Mesoscutellum ( Fig. 15c ) rounded, about as long as wide, wrinkled, interspaces coriaceous; circumscutellar carina weak but visible, not upturned nor projected; scutellar foveae ovate to subtriangular, shallow, weakly impressed, not well defined posteriorly and separated by a narrow carina. Mesopleuron ( Fig. 15b ) with regular and dense striae, interspaces smooth. Metapleural sulcus reaching about 3/4 of mesopleural height. Propodeum pubescent and weakly sculptured; propodeal carinae straight and slightly convergent posteriorly. Nucha sulcate dorsally and laterally.

Legs. Tarsal claws with an inconspicuous basal lobe ( Fig. 15g ).

Wings. Fore wing pubescent with short marginal setae, about as long as body length. Radial cell closed, about 2.5 times as long as wide; areolet visible, small, basal vein not well pigmented ( Fig. 15f ). Rs+M slightly visible, not reaching the basal vein. Basal cell with sparsely spaced setae.

Metasoma. Slightly longer than head plus mesosoma and 1.4 times as long as high in lateral view ( Fig. 15a ). First metasomal segment sulcate dorsally and laterally but sulci incomplete, not reaching the anterior margin of the segment ( Fig. 15a, c ). Syntergum smooth, anterolateral pubescence composed of a few setae and posteriorly without micropunctures; strongly dorsodistally incised, not pointed; the following segments, including the hypopygium, minutely punctate. Hypopygial spine about as long as wide and with a few lateral setae; without apical setae.

MALE. Similar to female, except for the following: body length 2.5–3.0 mm (n = 17). Antenna 15-segmented. Metasoma shorter than head plus mesosoma.

Distribution. USA: California ( Provancher 1889; Fullaway 1911; McCracken & Egbert 1922; authors).

Biology. Both the gall and the host tree from which S. dorsalis was reared are unknown ( Provancher 1889). Synergus splendidus was reared from undetermined galls on Q. lobata ( Fullaway 1911) , and posteriorly obtained from galls of Amphibolips quercuspomiformis (Bassett 1881) (= C. rossi Kieffer, 1903 , = C. maculipennis Kieffer, 1904 , = Andricus yosemite Beutenmüller, 1911 ) on Q. agrifolia by McCracken & Egbert (1922). Synergus dubiosus was originally reared from galls of A. quercuspomiformis on Q. agrifolia ( Fullaway 1911) . Some of the specimens determined as S. dorsalis deposited in USNM were reared from galls of A. quercuspomiformis , whereas others determined as S. splendidus (= S. dubiosus ) were obtained from unspecified galls on Q. wislizeni , according to their labels.

Remarks. Synergus dorsalis was described from an unstated number of females and males ( Provancher 1889: 398). We located and examined a single female belonging to the type series (lectotype) deposited in ULQC.

Synergus splendidus was described presumably from a single female ( Fullaway 1911: 370). According to Mc-Cracken & Egbert (1922), the type of S. splendidus was deposited in the Stanford Entomological Museum, later absorbed by CAS, but it was found neither in its main type collection nor in the paratype collection of this institution ( R. Zuparko pers. comm.). Its current location is unknown, so it is presumably lost .

Synergus dubiosus , synonymized with S. splendidus by McCracken & Egbert (1922), was described from an unstated number of females and males ( Fullaway 1911: 372). The type material of this species was probably deposited in the Stanford Entomological Museum as was S. splendidus and the rest of Fullaway’s types, but as with S. splendidus , its current location is unknown.

Weld determined some specimens deposited in the USNM general entomological collection as Synergus dorsalis . One of these specimens has a label reading ‘ Synergus dorsalis (Prov) (= splendidus Full ) det. Weld 1937’. These specimens, as well as those of S. splendidus , are identical to the lectotype of S. dorsalis , so we are confident that all of them belong to the same species. We assume that Weld examined both the types of S. dorsalis and S. splendidus and then proposed (but not formally published) the synonymy of these species. Then, based on Weld’s labels and since both the original description of S. splendidus and the specimens determined as S. dorsalis and S. splendidus deposited in USNM fit with the lectotype of S. dorsalis , we propose here S. splendidus Fullaway, 1911 as a synonym of S. dorsalis ( Provancher, 1889) . Furthermore, both the specimens determined as S. dorsalis by Weld, those determined as S. splendidus by McCracken & Egbert (1922) and the type material of S. dubiosus were obtained from galls of A. quercuspomiformis .

McCracken & Egbert (1922) synonymized S. dubiosus with S. splendidus despite the fact that in the original description of S. dubiosus it was stated that females have 14-segmented antenna instead of 15 as is present in S. splendidus . Since we have neither found the type material of S. splendidus nor of S. dubiosus , we cannot confirm or refute this synonymy.

When Weld (1951) transferred Ceroptres dorsalis Provancher, 1889 to Synergus , this species became a secondary homonym of Synergus dorsalis Cameron, 1883 . According to Ritchie & Shorthouse (1987), a new name for S. dorsalis ( Provancher, 1889) is unnecessary: S. dorsalis ( Provancher, 1889) is not a primary homonym of S. dorsalis Cameron, 1883 since it was originally described as a Ceroptres , and it is not a secondary homonym of this species because S. dorsalis Cameron, 1883 became a junior synonym of ‘ Andricus guatemalensis ’ ( Cameron, 1883) (incertae sedis after Pujade-Villar et al. 2011a). Hence, these species are no longer congeneric: Synergus dorsalis Cameron now belongs to Andricus (after Ritchie & Shorthouse 1987), whereas S. dorsalis (Provancher) is an actual Synergus (after Weld 1951).

Figures

FIGURE 6. Synergus beutenmulleri Lobato-Vila & Pujade-Villar, sp. nov. (female): a) head in frontal view; b) head in dorsal view; c) antenna; d) propodeum; e) tarsal claw; f) radial cell of the fore wing; g) mesosoma in lateral view; h) metasoma in lateral view; i) mesosoma in dorsal view; j) metasoma in dorsal view.

FIGURE 15. Synergus dorsalis (lectotype): a) lateral habitus; b) mesopleuron; c) mesosoma in dorsal view; d) head in anterodorsal view; e) antenna; f) radial cell of the fore wing; g) tarsal claw.

FIGURE 22. Synergus linnei Lobato-Vila & Pujade-Villar, sp. nov. (female): a) head in frontal view; b) head in dorsal view; c) antenna; d) propodeum; e) tarsal claw; f) radial cell of the fore wing; g) mesosoma in lateral view; h) metasoma in lateral view; i) mesosoma in dorsal view; j) metasoma in dorsal view.