Philonix fulvicollis Fitch, 1859 (1858)

Nicholls, James A., Melika, George, Digweed, Scott C. & Stone, Graham N., 2022, Pairing of sexual and asexual generations of Nearctic oak gallwasps, with new synonyms and new species names (Hymenoptera: Cynipidae, Cynipini), Zootaxa 5145 (1), pp. 1-79 : 56-61

Philonix fulvicollis Fitch, 1859 (1858) , sexual generation

Figs 183–202 , 204

Synonyms: Philonix fulvicollis Fitch (1859: 783) , asexual females; Cynips (Teras) fulvicollis combination by Osten Sacken (1865: 379); Biorhiza fulvicollis combination by Ashmead (1885: 296); Biorrhiza fulvicollis combination and incorrect spelling by Dalla Torre (1893: 61); Philonyx fulvicollis combination and incorrect spelling by Smith (1910: 598); Cynips (Philonix) fulvicollis var. fulvicollis form fulvicollis combination by Kinsey (1930: 262); Cynips (Philonix) fulvicollis combination by Kinsey (1936: 207).

Philonix nigricollis Fitch, 1859 . Synonymized by Kinsey (1930: 262).

Acraspis niger Gillette, 1889 . Acraspis nigra corrected spelling by Dalla Torre (1893: 64); Philonix nigra combination by Beutenmueller (1909: 251); Philonyx nigra combination and incorrect spelling by Smith (1910: 598); Philonix niger correction by Felt (1918: 96). Synonymized by Kinsey (1930: 262).

Acraspis gillettei Bassett, 1900 . Acraspis gillettii incorrect spelling by Beutenmueller (1904: 25); Philonix gillettei combination by Felt (1906: 711); Philonyx gillettei combination and incorrect spelling by Smith (1910: 598). Synonymized by Beutenmueller (1909: 252).

Kinsey (1930, 1936) described 6 additional species from the asexual generation and included them within his “ fulvicollis complex”: Cynips (Philonix) canadensis Kinsey, 1930 on Q. alba , Q. macrocarpa , Q. michauxii , and Q. muehlenbergii ; Cynips (Philonix) major Kinsey, 1930 on Q. alba , Q. macrocarpa , Q. michauxii , and Q. muehlenbergii ; Cynips (Philonix) rubricosa Kinsey, 1930 on Q. alba and Q. stellata , Cynips (Philonix) vorisi Kinsey, 1930 on Q. bicolor , Q. michauxii , and Q. macrocarpa ; Cynips (Philonix) insulensis Kinsey, 1936 on Q. gambelii and Q. macrocarpa ; and Cynips (Philonix) latigenae Kinsey, 1936 on Q. gambelii . Kinsey also included in this complex the taxa Philonix gigas Weld, 1922 on Q. lyrata and Philonix lanaeglobuli ( Ashmead, 1887) on Q. michauxii , both known only from an asexual generation, plus Philonix pallipes ( Bassett, 1900) , known only from a sexual generation on Q. alba . Since then, Melika & Abrahamson (2002) synonymized Philonix pallipes to Acraspis gemula (Bassett, 1881) . Weld (1951) and Burks (1979) treated Philonix insulensis (Kinsey) , Philonix latigenae (Kinsey) , Philonix gigas Weld , and Philonix lanaeglobuli (Ashmead) as distinct valid species, while the rest were treated as varieties of P. fulvicollis . We follow this treatment, thus Philonix fulvicollis var. canadensis (Kinsey) , syn. nov., Philonix fulvicollis var. major (Kinsey) , syn.nov., Philonix fulvicollis var. rubricosa (Kinsey) , syn. nov. and Philonix fulvicollis var. vorisi (Kinsey) , syn. nov. are all considered synonyms of P. fulvicollis .

Material examined: One sexual female and one male labelled as “ CANADA: Alberta, Edmonton, 3761-20 Street, 53.47371°N, 113.37202°W, GPS ± 10m, reared 1.vi.2008 ex bud galls on Quercus macrocarpa, S. Digweed , det. Philonix fulvicollis Fitch , sexual generation female, S. Digweed 2008”. The female and male specimens have been deposited at the PHDNRL .

Diagnosis. Sexual Philonix most closely resemble sexual Acraspis . In Acraspis the postgenal bridge shorter than the height of occipital foramen, the mesoscutum entirely smooth, notaulus incomplete, the mesoscutellum rounded, uniformly rugose; the metasoma only slightly longer than high. In Philonix the postgenal bridge as high as the occipital foramen, most of the mesoscutum smooth, except delicately alutaceous in the anterior part between notauli, notaulus complete, the mesoscutellum elongated with a smooth, glabrous surface in anterior half; the metasoma much higher in lateral view.

Description. Sexual female ( Figs 183–187 , 192–196 , 200–201 ). Body uniformly reddish brown, antenna slightly lighter, palpi yellow, legs uniformly yellow.

Head alutaceous, with sparse white setae, denser on lower face, with distinct rows of setae along inner margin of eye; slightly broader than high and as broad as mesosoma in frontal view, 1.9× as broad as long in dorsal view. Gena alutaceous, not broadened behind eye in frontal view, 0.5× width of transverse diameter of eye in lateral view. Malar space alutaceous, with delicate striae radiating from clypeus and reaching eye margin; eye 3.8× as high as length of malar space. Inner margins of eyes parallel. POL 1.5× as long as OOL, OOL 1.9× as long as diameter of lateral ocellus and 1.7× as long as LOL, all ocelli ovate, of same size. Transfacial distance as long as height of eye; diameter of antennal torulus shorter than distance between them, distance between torulus and eye as long as diameter of torulus; lower face alutaceous, slightly elevated median area alutaceous. Clypeus rectangular, nearly 2.0× as broad as high, alutaceous, with a few long setae along ventral edge; ventrally rounded, slightly emarginate, without median incision; anterior tentorial pit rounded, distinct, epistomal sulcus distinct, clypeo-pleurostomal line well impressed. Frons and interocellar area uniformly alutaceous, without striae or setae. Vertex, occiput, postocciput and postgena alutaceous, with sparse white setae; posterior tentorial pit large, ovate, area below impressed; occipital foramen slightly higher than height of postgenal bridge; hypostomal carina emarginate, continuing into postgenal sulci which are not united and diverge toward occipital foramen, postgenal bridge anteriorly as broad as occipital foramen. Antenna longer than head+mesosoma, with 12 flagellomeres, scape only slightly longer than pedicel, pedicel slightly longer than broad, flagellomeres slightly broader towards apex; F1 2.0× as long as pedicel and 1.2× as long as F2; F2 slightly longer than F3; F3 slightly longer than F4, F5=F6, all subsequent flagellomeres equal in length; F12 slightly longer than F11; placodeal sensilla on F3–F12, absent on F1–F2.

Mesosoma slightly longer than high. Pronotum smooth, glabrous, with sparse setae in dorsolateral part, with delicate short parallel striae along posterior edge; propleuron smooth, glabrous, with sparse white setae. Mesoscutum smooth, glabrous, delicately alutaceous at the anterior end between notauli, with a few white setae along notauli, slightly longer than broad (greatest width measured across mesoscutum level with base of tegulae). Notaulus complete, reaching pronotum, well impressed along entire length, with smooth bottom, posteriorly slightly converging; anterior parallel line inconspicuous, marked with slightly impressed narrow area, extending to 1/6 of mesoscutum length; median mesoscutal line absent; parapsidal line indistinct, circumscutellar carina narrow but distinct, reaching notaulus. Mesoscutellum quadrangular, longer than broad, with parallel sides, uniformly dull coriaceous, with strong irregular rugae along sides and posteriorly; posteriorly rounded, overhanging metanotum. Anterior part of mesoscutellum impressed, smooth, glabrous, in the form of a semilunar impression, with rugose triangular central area dividing anterior part into two halves. Mesopleuron smooth, glabrous, with a few white setae on the most posteroventral part; mesopleural triangle smooth, glabrous, with a few delicate longitudinally orientated striae and a few setae; dorsal and lateral axillar areas smooth, glabrous, with sparse setae; subaxillular bar smooth, glabrous, triangular, gradually higher toward posterior end, at posterior end as high as height of metanotal trough; metapleural sulcus distinct, reaching mesopleuron at half of its height. Metascutellum smooth, 0.5× as long as height of smooth, glabrous ventral impressed area; metanotal trough smooth, glabrous, without setae; central propodeal area lyre-shaped, smooth, glabrous, with a few short rugae, in posterior half the rugae continue onto nucha; lateral propodeal carinae distinct, complete, bent slightly outwards in posterior 1/3; lateral propodeal area smooth, glabrous, with sparse long white setae. Nucha with parallel longitudinal rugae dorsally and laterally. Tarsal claws simple, without basal lobe.

dorsal view.

Forewing longer than body, hyaline, with short cilia on margin, veins brown, radial cell open, 3.8x as long as broad; R1 and Rs nearly reaching wing margin; areolet triangular, closed and distinct. Rs+M narrow, indistinct, reaching basalis slightly below mid height.

Metasoma as long as head+mesosoma, as long as high in lateral view; 2nd metasomal tergum extending to 1/3 length of metasoma in dorsal view, with a few setae laterally, without micropunctures; subsequent terga smooth, glabrous, without micropunctures. Hypopygium without micropunctures, prominent part of ventral spine of hypopygium short, longer than broad in ventral view, with some long setae ventrally which extend far beyond apex of spine. Body length 1.9 mm (n = 1).

Male ( Figs 188–191 , 197–199 , 202 ). Similar to female but head, antenna, mesosoma, metasoma uniformly brown; mandibles light brown, mouthparts and legs uniformly yellow. Head transverse in frontal view; ocelli bigger than in female; malar space with striae, radiating from clypeus and reaching eye margin; ocelli elevated. Antenna as long as body, with 13 flagellomeres; scape+pedicel as long as F1, F1 slightly curved and broadened apically, longer than F2; F13 shorter than F12; placodeal sensilla on all flagellomeres. Metasoma shorter than mesosoma; 2nd metasomal tergum in the form of a narrow long petiole; metasomal tergum 3 longer than all subsequent terga together; all terga smooth, without micropunctures. Body length 1.8 mm (n = 1).

Gall. The sexual generation galls ( Fig. 204 ) occur s ingly in terminal buds of twigs of Q. macrocarpa . The gall is a relatively robust, seed-like, sub-ovoid cell approximately 2 mm long, dark brown when mature with longitudinal striations. Occupies the entire bud when mature, causing stunting or suppression of shoots and leaves produced from the bud.

Biology. See Fitch (1859), Weld (1922a, 1926), and Kinsey (1930, 1936) for the biology of the asexual generation. Asexual generation galls ( Fig. 203 ) in Kinsey’s (1936) “ fulvicollis ” complex have been recorded on leaves of Q. alba , Q. bicolor , Q. chapmanii , Q. gambelii , Q. lyrata , Q. macrocarpa , Q. michauxii , Q. muehlenbergii , and Q. stellata , ( Kinsey 1930, 1936; Burks 1979). Asexual generation females only begin to emerge from galls in the autumn of the year following the year of gall formation ( Kinsey 1930), and we recorded females emerging up to four years after the year of gall formation.Adult females of the asexual generation (from galls collected in Manitoba but reared in Edmonton) emerged during the second half of October and early November. Sexual generation galls matured in May in Edmonton, and adults emerged 1–3 June 2008. Galls of the asexual generation appeared on leaves in Edmonton in July.

Distribution. USA: New York, Michigan, Tennessee, Illinois, Kansas ( Burks 1979); Canada: Manitoba, Ontario, Quebec, New Brunswick.

Molecular taxonomy. Alternate sexual and asexual generations were proposed by Digweed (2010) and are herein confirmed on the basis of similarity in cytb and ITS2 sequence data generated for four individuals (three asexual females, one sexual female). Cytb sequences were on average 1.04% divergent (range 0.69–1.39%; GenBank accessions OM321652 – OM321655 ). Two ITS2 alleles were observed across the four individuals that differed by 0.20% ( OM331841 – OM331844 ).

Comments. Kinsey (1930) transferred Dryophanta pallipes Bassett, 1900 to Philonix and proposed it as the sexual generation of P. fulvicollis , although no justification for this synonymy was provided. Weld (1959) wrote that P. pallipes might be well a synonym of Acraspis gemula . Melika & Abrahamson (2002) compared the three specimens of P. pallipes (from Beutenmueller collection, USNM, Washington, DC) with the paratypes of the sexual generation of A. gemula and found no differences, thus Philonix pallipes was synonymized with A. gemula . Digweed (2010) treated Philonix gigas (Weld) , Philonix insulensis (Kinsey) , and Philonix nigra (Gillette) as synonyms of P. fulvicollis , although without formal synonymization. Molecular analysis, however, shows that P. fulvicollis and P. nigra are distinct species. Two cytb haplotypes obtained from P. nigra (GenBank MW388894 , OM321656 ) were on average 3.46% divergent (range 3.00–3.93%) from cytb haplotypes of P. fulvicollis .

Figures

FIGURES 183–191. Philonix fulvicollis Fitch, sexual generation. 183–186, head, female: 183, frontal view, 184, dorsal view, 185, lateral view, 186, posterior view. 187, antenna, female, part. 188–190, head, male: 188, frontal view, 189, dorsal view, 190, lateral view. 191, antenna, male.

FIGURES 192–195. Philonix fulvicollis Fitch, sexual generation, female. 192, pronotum and propleuron, frontal view. 193– 195, mesosoma: 193, lateral view, 194–195, dorsal view.

FIGURES 196–199. Philonix fulvicollis Fitch, sexual generation. 196, metascutellum and propodeum, female, posterodorsal view. 197–199, male: 197, mesosoma, lateral view, 198, mesosoma, dorsal view, 199, metascutellum and propodeum, postero-

FIGURES 200–202. Philonix fulvicollis Fitch, sexual generation. 200–201, metasoma, female: 200, lateral view, 201, ventral view. 202, metasoma, male, lateral view.

FIGURES 203–204. Philonix fulvicollis Fitch. 203, asexual gall. 204, sexual gall.