Feron gigas ( Kinsey, 1922 ) Cuesta-Porta & Melika & Nicholls & Stone & Pujade-Villar, 2023

Cuesta-Porta, Victor, Melika, George, Nicholls, James A., Stone, Graham N. & Pujade-Villar, Juli, 2023, Re-establishment of the Nearctic oak cynipid gall wasp genus Feron Kinsey, 1937 (Hymenoptera: Cynipidae: Cynipini), including the description of six new species, Zootaxa 5366 (1), pp. 1-174 : 74-79

Feron gigas ( Kinsey, 1922) , comb. nov.

Figs 203–215

Andricus gigas Kinsey, 1922: 282 , female, male, gall.

Dryocosmus gigas (Kinsey) : Weld, 1952a: 334.

Andricus crenatus Weld, 1952b: 330 , female (asex), gall. Synonymy in Dailey & Sprenger, (1973a).

Types examined. HOLOTYPE: sexual female of Andricus gigas “Mercred Falls Cal. , gall 3.28.20.”, “ Q. douglasii, Kinsey coll.”, pink “ A. gigas female, Holo-COTYPE” deposited in AMNH, NYC, examined by GM. Andricus crenatus HOLOTYPE: asexual female, “Los Gatos, Cal.”, “ Q. dumosa ”, “1735”, red label “Type No. 60117 USNM”, handwriting label “ Andricus crenatus Weld ”. Specimen data and images available at http://n 2t.net/ark:/ 65665/3ddf41be9-a5bb-4dc8-91b3-45e7d8fadfb6

Additional material. Asexual females: 2 females “ USA: CA, Del Puerto Canyon , Q. douglasii , leg. R. Challis, 2004.10.21 ” ; 3 females “ USA: CA, Clearlake , Q. douglasii, CA 17, galltype 135, leg. J.A. Nicholls, 2007.11.03.” ; 3 females “ USA: CA, 30km SW of Williams , Q. douglasii, CA 17, galltype 135, leg. J.A. Nicholls, 2007.11.02 ” . One male “ USA: CA, Dye Creek Preserve , Q. douglasii, CA1037 , gall type 239, leg. J.A. Nicholls, 2008.03.30 ” .

Diagnosis. Asexual females belong to the group of Feron species in which the body is never black; the head is rounded or trapezoid to triangular in frontal view, ocelli are not elevated above the frons; eyes are parallel or very slightly converging ventrally, the transfacial distance is equal or longer than the height of eye; toruli located above the mid-height of eyes; the eye is less than 3.0× as high as the length of the malar space; lateral ocelli are smaller, OOL at least 2.5× as long as the diameter of ocellus, or if shorter then the head and mesosoma are not yellowish or light brown; the pronotum laterally with longitudinal carinae; the mesoscutum alutaceous to coriaceous, rugose-reticulate, reticulate, without piliferous points and the mesopleuron with a transverse reliculate-carinate band at mid-height; these charcters are shared with F. parmula (asex), F. tibiale (asex), F. syndicorum (asex) and F. stellulum (asex). Differs from F. tibiale and F. syndicorum in the gena which is not broadened behind the eye in frontal view. It differs from F. parmula in having a malar space with a few delicate striae radiating from the clypeus, mesoscutellar foveae are defined and the prominent part of the ventral spine of the hypopygium 4.5× as long as broad in ventral view; see more characters at couplet 37 in the key. The most similar species is F. stellulum but in F. gigas the antenna has 12 flagellomeres (11 in F. stellulum ), the eye 2.2× as high as the length of the malar space (longer in F. stellulum ), veins are pale (brown in F. stellulum ), the areolet absent (present in F. stellulum ) and the central propodeal area without rugae (with rugae in F. stellulum ). Sexual females of this species belong to the group of Feron species with a black body, the frons is flat, not or only slightly bulging in frontal view, inner margins of eyes never strongly converging ventrally, the mesoscutum uniformly alutaceous-reticulate, glabrous and the mesoscutellum is uniformly alutaceous with numerous setae on piliferous points; as in F. comatum (sex), F. apiarium (asex), F. kingi (sex) and F. pattersonae (sex). Feron gigas differs from these species in having notauli distinct only at their posterior end but discontinuous or absent at their finely coriaceous anterior end and the mesopleuron is smooth with transverse striae in its central part. Males differ from all other Feron in the notaulus which is narrow, distinct only posteriorly, fragmented or absent anteriorly where mesoscutum is delicately coriaceous.

Re-description. Asexual female ( Figs 203–214 ). Body, antenna, legs, uniformly rusty brown, some specimens uniformly dark brown.

Head reticulate, with sparse setae on lower face, gena and posteriorly, 1.2× as broad as high and slightly narrower than mesosoma in frontal view; 2.0× as broad as long in dorsal view. Gena reticulate, not broadened behind eye in frontal view, in lateral view dorsal part of gena at least 2.0× narrower than transverse diameter of eye and much broader on ventral part. Malar space alutaceous, shining, with striae radiating from clypeus and reaching to 1/3 of malar space length; eye 2.2× as high as length of malar space; malar sulcus absent. Inner margins of eyes parallel. POL 1.6× as long as OOL, OOL 2.1× as long as diameter of lateral ocellus and slightly longer than LOL, all ocelli ovate, of same size. Antennal toruli located above mid-height of eyes. Transfacial distance 1.3× as long as height of eye; diameter of antennal torulus 1.6× as long as distance between them, distance between torulus and eye 1.4× as long as diameter of torulus; lower face delicately coriaceous, with white setae; slightly elevated median area coriaceous, without setae. Clypeus impressed, rectangular, 1.5× as broad as high, delicately coriaceous, with transverse striae, with a few setae scattered all over; ventrally rounded, emarginate, without median incision; anterior tentorial pit large, rounded, deep, epistomal sulcus broad and deep, clypeo-pleurostomal line well impressed. Frons, interocellar area, vertex uniformly reticulate, without striae and setae; area under central ocellus impressed, smooth, glabrous; occiput, postocciput reticulate; postgena smooth, with few setae; posterior tentorial pit large, elongated, area below impressed; occipital carina black, clearly visible beside occipital foramen; occipital foramen as high as height of postgenal bridge; hypostomal carina emarginate, continuing into strong postgenal sulci which diverge until half the height of postgenal bridge, beyond which sulci are parallel and run alongside foramen until 1/3 of its height. Antenna slightly longer than head+mesosoma, with 12 flagellomeres (suture between F12 and F11 indistinct but present); F1–F3 with sparse white setae, F4–F12 with dense setae; pedicel 1.7× as long as broad; F1 2.1× as long as pedicel and 1.2× as long as F2; F2=F3, F4 slightly shorter than F3, F5=F6 and shorter than previous; all subsequent flagellomeres shorter and equal in length; F12 slightly longer than F11; placodeal sensilla on F3–F12.

Mesosoma longer than high, with a few scattered setae. Pronotum smooth, with sparse setae along smooth anterolateral edge; with parallel transverse delicate interrupted striae laterally; propleuron alutaceous, with very sparse white setae. Mesoscutum longer than broad (greatest width measured across mesoscutum level with base of tegulae), uniformly alutaceous-reticulate. Notaulus complete, deep, posteriorly converging strongly and broader than anteriorly, with smooth and glabrous bottom; at posterior end the distance between notauli shorter than distance between notaulus and side of mesoscutum; anterior parallel line marked by smooth stripes, reaching to half-length of mesoscutum; parapsidal line indistinct, not marked; median mesoscutal line absent; parascutal carina broad, reaching notaulus. Mesoscutellum trapezoid, longer than broad, broadest part in posterior 1/3; center part of mesoscutellar disc rugoso-coriaceous, with stronger rugae posteriorly and laterally, overhanging metanotum, with long setae. Mesoscutellar foveae rounded, as broad as high, with smooth, glabrous bottom, divided by a triangular coriaceous elevated carina. Mesopleuron with parallel delicate transverse striae, speculum smooth, glabrous; mesopleural triangle smooth, with dense white setae and piliferous points; dorsal and lateral axillar areas smooth, with setae; axillula with delicate parallel longitudinal striae; subaxillular bar smooth, glabrous, triangular, posteriorly as high as height of metanotal trough; metapleural sulcus reaching mesopleuron above half of its height, lower part delimiting smooth area with few setae, upper part of sulcus indistinct. Metascutellum coriaceous, as high as height of smooth, glabrous ventral impressed area; metanotal trough smooth, with a few setae; central propodeal area lyre-shaped, smooth, glabrous; lateral propodeal carinae strong, broad and high, bent outwards in posterior 1/3; lateral propodeal area smooth, with long white setae and piliferous points. Nucha with net of irregular strong rugae dorsally and laterally. Tarsal claws with acute basal lobe.

Fore wing longer than body, hyaline, with short dense cilia on margin, veins light brown, radial cell open, 4.4× as long as broad; Rs and R1 nearly reaching wing margin; areolet absent, Rs+M invisible.

Metasoma longer than head+mesosoma, higher than long in lateral view; 2nd metasomal tergum extending to 2/3 length of metasoma in dorsal view, with patch of dense white setae anterolaterally, with band of micropunctures posteriorly; all subsequent terga and hypopygium with dense micropunctures; prominent part of ventral spine of hypopygium 4.7× as long as broad in ventral view, with few short white setae ventrally.

Body length 1.2–1.6 mm (n = 10).

The description of the sexual generation (female, male and gall) is given after Kinsey (1922), with some modifications.

Sexual female. Head black, mandibles rufous brown; antenna brown, basal three or four antennomeres yellowish brown; mesosoma and metasoma dark brown to black. Legs yellowish-brown, femora especially hind femora darker, coxae brown, tips of tarsi darker; finely and not densely hairy.

Head finely coriaceous, about as broad as mesosoma in frontal view, gena only slightly broadened behind eyes; frons and lower face minutely punctate, with sparse, fine setae on sides of head. Antenna with delicate setae, with 12 flagellomeres, F1 slightly longer than F2.

Pronotum smooth, shining with sparse setae on dorsal edge, with some delicate striae along posterior edge. Mesoscutum mainly smooth and shining, coriaceous anteriorly; notaulus fine but visible only posteriorly, less evident, discontinuous or absent anteriorly where area finely coriaceous; median mesoscutal line, anterior parallel line and parapsidal line absent; mesoscutellum finely rugose, hairy, with small, elevated, smooth, shining area at apex; mesoscutellar foveae in the form of an anterior arcuate impression, shallow, smooth. Mesopleuron mostly smooth, shining with delicate striae only centrally. Fore wing hyaline, with fine, brown hairs, with cilia on margins; veins brown; areolet moderately small to closed; cubitus very fine, not reaching basalis; radial cell long and open, second abscissa of radius somewhat curved; first abscissa nearly straight, without projection. Tarsal claws simple.

Metasoma protruding dorsally, 2nd metasomal tergum occupying nearly half-length of metasoma, with a few setae anteroventrally; ventral spine of hypopygium yellow-piceous; smooth, shining, short, with a few setae ventrally.

Body length 1.5–2.0 mm (n = 3).

Male. Differs from the female as follows: antenna entirely brown, 13 flagellomeres; areolet smaller, metasoma short, with moderately long petiole. Body length around 1.5 mm.

Galls. Sexual galls are small, 1–2 mm in diameter, round, pale yellow, on catkin coming off catkin stem at same place as stamens, sometimes on edge of leaf. Asexual spangle galls ( Fig. 215 ) about 4 mm in diameter, usually on the upper side of the leaf, saucer shaped, with a thin crenate margin when young, with a prominent hump in center. The mature gall has a lens-shaped larval cavity inside, on the floor of which is a thin, white, circular disk with radiating prominent lines.

Biology. Alternation of sexual and asexual generations was determined by Dailey & Sprenger (1973a). Alternate sexual and asexual generations are also confirmed herein using DNA data, with four individuals (three asexual females, one sexual male) sequenced for cytb and three individuals (two asexual females, one sexual male) sequenced for cytb. Cytb sequences were on average 0.82% divergent (range 0–1.66%; GenBank accessions KX683598, OQ446198–OQ446199) and ITS2 sequences were identical among the three individuals except for two additional bases within a polyA region in one sample (GenBank accessions OQ448240–OQ448242).

This species induces galls on Q. douglasii and Q. dumosa (section Quercus , subsection Dumosae). Young asexual galls are present in August, mature in autumn; asexual adults emerge in February. Sexual galls are mature in April; adults emerge by the end of April.

Distribution. USA: California.

Figures

FIGURES 203–208. Feron gigas, comb. nov., asexual female. 203–206, head: 203, frontal view, 204, dorsal view, 205, lateral view, 206, posterior view. 207, antenna. 208, mesosoma and propleura, frontal view.

FIGURES 209–212. Feron gigas, comb. nov., asexual female. 209, mesosoma, lateral view. 210, mesoscutum, dorsal view. 211, mesoscutellum, dorsal view. 212, metascutellum and propodeum, posterodorsal view.

FIGURES 213–215. Feron gigas, comb. nov., asexual generation. 213–214, asexual female: 213, fore wing, part, 214, metasoma, lateral view. 215, gall.