Synergus confertus McCracken & Egbert 1922

Synergus confertus McCracken & Egbert, 1922

(Figure 4 c–d)

Synergus confertus McCracken & Egbert, 1922. Stanford Univ., Pubs., Univ. Ser. Biol. Sci. 3 (1): 55. Type material: CAS (lectotype), paralectotypes in CAS and USNM.

Type material (examined). LECTOTYPE ♀ with the following labels: ‘ L.S.Jr. U., Lot. 554, Sub. 261’ (white label) / ‘ ♀ Type’ (red label) / ‘ confertus ’ (white label, handwritten) / ‘Stanford Univ., Coll. L.A.C.M, Access’d 1964’ (white label) / ‘ Synergus confertus Mc. & Eg. (white label with a black frame, handwritten) / ‘ California Academy of Sciences, Type No. 5815’ (white label) / ‘ Lectotype ♀ Synergus confertus McCracken & Egbert, 1922, IL-V desig-2019’ (red label). PARALECTOTYPES (2♂ & 2♀) deposited in CAS (1♂) and USNM (1♂ & 2♀) with the following labels: ‘ L.S.Jr. U., Lot. 554, Sub. 261’ (white label) / ‘ ♂ Type’ (red label) / ‘ confertus ’ (white label, handwritten) / ‘Stanford Univ., Coll. L.A.C.M, Access’d 1964’ (white label) / ‘ California Academy of Sciences, Type No. 5815’ (white label) / ‘ Paralectotype ♂ Synergus confertus McCracken & Egbert, 1922, IL-V desig-2019’ (red label) (1♂); ‘L.S.Jr.U., Lot. 554, Sub. 261’ (white label) / ‘ ♀ ’ (white label, handwritten) / ‘I. McCracken col.’ (white label) / ‘Paratype’ (yellow label) / ‘Ex. gall of Andricus confertus ’ (white label, handwritten) / ‘ Paratype No. 24999 U.S. N.M.’ (red label) / ‘ Synergus confertus McC + Eg. ’ (white label with a red frame, handwritten) / ‘ Paralectotye ♀ Synergus confertus McCracken & Egbert, 1922, IL-V desig-2019’ (red label) (1♀); ‘ L.S.Jr. U., Lot. 554, Sub. 261 ♀ ’ (white label) / ‘ Paratype’ (yellow label) / ‘ Synergus confertus Egbert’ (white label, handwritten) / ‘ Beut. Coll. rec’d1939’ (white label) / ‘ Paralectotye ♀ Synergus confertus McCracken & Egbert, 1922, IL-V desig-2019’ (red label) (1♀); ‘ L.S.Jr. U., Lot. 554, Sub. 261’ (white label) / ‘ ♂ ’ (white label, handwritten) / ‘ Paratype’ (yellow label) / ‘ Beut. Coll. rec’d1939’ (white label) / ‘USNMENT 00960444’ (white label, QR code) / ‘ Paralectotye ♂ Synergus confertus McCracken & Egbert, 1922, IL-V desig-2019’ (red label) (1♂).

Diagnosis. Synergus confertus is morphologically close to S. walshii Gillette, 1896 (see below), from which differs mainly by having the vertex with some small punctures (without punctures in S. walshii); OOL 1.7 times as long as diameter of lateral ocelli (1.4 in S. walshii); the lateral pronotum dorsally and medially imbricated, weakly wrinkled basally (coriaceous in S. walshii); the scutellar foveae small, ovate (subtriangular, smooth in S. walshii); metasoma about 1.2 times as long as high in lateral view and with a posterodorsal patch of micropunctures somewhat laterally extended (about as long as high in lateral view and posteriorly without punctures or just with a few, not forming a true patch in S. walshii); the hypopygial spine almost 3.0 times as long as wide (about as long as wide in S. walshii); and head yellow, except for a black spot in the ocellar area (dark brown to black in S. walshii) (see the descriptions of both species and the identification key).

Redescription. FEMALE. Length. Body length 1.5–2.0 mm (n = 3).

Color (Fig. 4 c–d). Black to rufous with yellowish areas. Head yellow, except for a dark spot in the ocellar area. Antennae yellow. Mesosoma black, tegulae yellow. Metasoma rufous, dorsally and posteriorly darker. Legs yellow. Wings hyaline, veins pale yellow.

Head. In frontal view, about 1.1 times as wide as high, genae very slightly expanded behind compound eyes. Face faintly pubescent, lower face with striae radiating from clypeus. Clypeus indistinct, ventral margin slightly projected over mandibles. Malar space almost 0.6 times as long as height of compound eye. Anterior tentorial pits visible; pleurostomal and epistomal sulcus absent. Transfacial line about as long as height of compound eye. Toruli situated mid-height of compound eye; distance between torulus and compound eye slightly shorter than diameter of torulus; distance between toruli shorter than diameter of toruli. Frons coriaceous, without punctures; frontal carinae very short and narrow, not reaching lateral ocelli. Head in dorsal view is about 2.1 times as wide as long. Vertex coriaceous, with scattered small piliferous punctures. POL: OOL: LOL = 18: 10: 9 and diameter of lateral ocelli, 6. Occiput coriaceous, without punctures (Fig. 4d).

Antennae. 14-segmented, according to the original description (antennae of all the examined specimens are broken). Scape plus pedicel about 1.3 times as long as F1; pedicel 1.7 times as long as wide; F1 about 1.2 times as long as F2, F2 to F6 subequal and following segments progressively shorter, according to the original description. Last flagellar segment about twice as long as the penultimate, according to the original description.

Mesosoma. About 1.2 times as long as high in lateral view, including nucha, with short and not dense pubescence (Fig. 4c). Ratio of length of pronotum medially/laterally: 0.41. Pronotal plate indistinct. Lateral pronotum (Fig. 4c) imbricated dorsally and medially, wrinkled basally; lateral margins of pronotum rounded, without lateral carina. Mesoscutum (Fig. 4d) about as wide as long, finely coriaceous to imbricated, with weak, discontinuous transversal elements; anterior grooves weakly impressed, extended 1/4 of the mesoscutal length. Notauli incomplete, faint in the anterior 1/3 (sometimes only visible in the distal half of the mesoscutum). Median groove absent. Parapsidal grooves weakly impressed, narrow, reaching tegulae. Scutellum (Fig. 4d) rounded, about as long as wide, wrinkled; circumscutellar carina weak, obscured by wrinkles; scutellar foveae small, ovate, shallow, smooth, not well defined posteriorly and separated by a narrow carina. Mesopleurae (Fig. 4c) regularly and densely striate basally and medially, speculum smooth; little pubescent basally. Metapleural sulcus reaching 3/4 of mesopleural height. Propodeum pubescent and weakly sculptured; propodeal carinae slightly curved and convergent posteriorly. Nucha sulcated dorsally and laterally.

Legs. Tarsal claws with a strong basal tooth.

Wings. Fore wings pubescent with short marginal setae, longer than body length. Radial cell closed and 2.4 times as long as wide; areolet inconspicuous. Rs+M inconspicuous, not reaching the basal vein. Basal cell with sparsely spaced setae.

Metasoma. About as long as head plus mesosoma, about 1.2 times as long as high in lateral view (Fig. 4c). First metasomal segment weakly sulcated dorsally and laterally, with furrows reaching only the half of the segment. Syntergite smooth, anterolateral pubescence composed of a few setae and with a posterodorsal patch of micropunctures somewhat extended laterally; not dorsodistally incised, very slightly pointed. Hypopygial spine about 2.7 times as long as wide and with a few lateral setae; without apical setae.

MALE. Similar to female, except for the following morphological traits: body length 1.5 mm (n = 2). Antennae 15-segmented (according to the original description); F1 about 1.4 times as long as F2; F1 not curved, medially incised, long, expanded basally and apically. Malar space about 0.5 times as long as height of compound eye. Metasoma shorter than head plus metasoma.

Distribution. USA. Stanford University campus, Santa Clara County, state of California (McCracken & Egbert 1922).

Biology. Reared from galls of Andricus confertus McCracken & Egbert, 1922 on Quercus lobata Née (Quercus section) (McCracken & Egbert 1922).

Remarks. Synergus confertus was originally described from 5♂ and 3♀ (McCracken & Egbert 1922: 56). We located and examined 2♂ and 3♀ belonging to the type series: 1♂ and 1♀ deposited in CAS with a ‘Type’ label, and 1♂ and 2♀ deposited in USNM. The authors state that the ‘Type’ was deposited at the Stanford Entomological Museum, later absorbed by CAS; however, in the published ‘Type’ section they do not specify any specimen data details except for the type depository of this species. As a result, and since the descriptors did not designate a holotype, a lectotype has been designated and deposited in CAS.

According to the original description, S. confertus has the last tarsal segments black or darkened; however, this trait is not noticeable in the examined specimens.