Amphibolips spinosa Ashmead, 1887

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 : 16-20

Amphibolips spinosa Ashmead, 1887 , sexual generation

Figs 29–41 , 43

Synonyms: Amphibolips spinosa Ashmead (1887: 141) , females and galls. Amphibolips spinosus corrected spelling by Dalla Torre & Kieffer (1910: 591).

Material examined: 5 females labelled as “ USA, FL., Walton Co., Gratin Beach Island, Coast Scrub, coll. 3 May 1995; emerged 16 May 1995. G. Melika; ex Quercus myrtifolia ”. One male labelled as “ USA, FL., Highlands Co. , Josephine Creek, leg. J. Nicholls, 2008.04.16. Code FL1075 ; ex Quercus incana ” . 2 females have been deposited at the USNM , Washington, DC; 3 females and 1 male at the PHDNRL .

Diagnosis. The sexual galls resemble those of A. quercuscitriformis (Ashmead, 1881) , but differ from them in having much thicker and harder walls, the surface of the gall is rough, and they are appreciably narrower, and turn dirty brown when mature; in contrast the galls of A. quercuscitriformis are much more fragile at maturity, with thinner walls, the surface of the gall is smooth and glabrous, are much broader in diameter, remain lemon-yellow after adult emergence. Below the description of the sexual female and male are given according to the current morpho-description requirements.

Description. Sexual female ( Figs 29–33, 36–41 ). Head, mesosoma, metasoma, antennae, legs uniformly reddish brown.

Head dull rugose, with sparse short white setae, denser on lower face, gena and postgena, quadrangular, 1.3× as broad as high, narrower than mesosoma in frontal view; 1.9x as broad as long in dorsal view. Gena dull rugose, not broadened behind eye in frontal view, narrower than transverse diameter of eye in lateral view. Malar space rugose, without striae. Eye 2.0× as high as length of malar space. POL 2.0× as long as OOL, OOL longer than LOL, lateral ocellus 2.2× as long as LOL; ocelli ovate, of same size. Transfacial distance slightly longer than height of eye; diameter of antennal torulus 1.7x as long as distance between toruli, and 1.4x as long as distance between torulus and eye; lower face dull rugose, without striae and with narrow elevated rugose median area. Clypeus coriaceous, rectangular, broader than high; ventrally rounded, emarginate, without median incision; anterior tentorial pits small, indistinct, epistomal sulcus impressed, clypeo-pleurostomal line indistinct. Frons, vertex and occiput uniformly dull rugose. Interocellar area dull rugose, with large strongly elevated ocelli. Postocciput and postgena smooth, glabrous, impressed around occipital foramen; posterior tentorial pits large, deep, area around them strongly impressed; occipital foramen at least 4.0× as high as height of postgenal bridge; hypostomal carina emarginate, continuing into postgenal sulci which are not united. Antenna slightly longer than head+mesosoma, with 10 flagellomeres; scape 2.0× as long as pedicel, pedicel subglobose, F1 2.8× as long as pedicel and 1.4× as long as F2; F2 slightly longer than F3, F3=F4, subsequent flagellomeres shorter, F10 2.0× as long as F9, placodeal sensilla on all flagellomeres.

Mesosoma slightly longer than high in lateral view. Pronotum rugose dorsally, with numerous transversely orientated strong irregular rugae laterally which are absent in smooth, glabrous anterolateral part. Mesoscutum uniformly dull rugose, slightly longer than broad (greatest width measured across mesoscutum level with tegulae base). Notaulus indistinct in dull rugose sculpture; anterior parallel line extending to 1/3 length of mesoscutum, slightly impressed, marked by more delicate sculpture; parapsidal line distinct, originating away from posterior margin and extending to nearly half the length of mesoscutum, marked by elevated lines; median mesoscutal line absent; circumscutellar carina broad, extending to level of tegula. Mesoscutellum uniformly dull rugose, trapezoid, slightly longer than broad, without posteromedian depression, with median incision, overhanging metanotum. Mesoscutellar foveae large, deep, slightly longer than broad, with a few striae on smooth, glabrous bottom, with distinct elevated narrow median carina; lateral sides of foveae with strong carinae, separating them from dorsoaxillar areas. Mesopleuron, including speculum, uniformly dull rugose. Mesopleural triangle smooth, glabrous, with dense white setae; dorsal axillar area delicately rugose with dense setae; lateral axillar area coriaceous, with a few short, white setae; subaxillular bar smooth, glabrous, with parallel sides, its height less than height of metanotal trough, posterior end extending to half height of mesoscutellum; metapleural sulcus hidden in dull rugose sculpture. Metascutellum uniformly coriaceous, metanotal trough coriaceous, with dense white setae; ventral impressed area smooth, slightly shorter than height of metascutellum; central propodeal area lyre-shaped, smooth, glabrous, with strong median longitudinal carina; lateral propodeal carinae bent slightly outwards medially; lateral propodeal area with irregular strong rugae and dense white setae. Nucha short, with irregular sulci. All legs with dense short white setae; tarsal claws with acute basal lobe.

Forewing longer than body, infuscate, margin with short dense cilia and dark brown rounded spot in radial cell; R1 and Rs weakly pigmented, light, nearly reaching wing margin; radial cell narrow, open, slightly longer than broad; areolet small, triangular, closed, distinct; Rs+M reaching basalis (M) slightly above half its height.

Metasoma longer than head+mesosoma, longer than high in lateral view; 2nd metasomal tergum extending to 2/3 of metasoma length, smooth, glabrous, with short dense setae anterolaterally, with band of micropunctures posteriorly; all subsequent terga and hypopygium uniformly and entirely micropunctate.Ventral spine of hypopygium robust, long, needle-like, prominent part 6.5× as long as broad, with two rows of white setae ventrally, extending beyond apex of spine. Body length 4.5–4.8 mm (n = 5).

Male ( Figs 34–35 ). Similar to female but head more rounded in frontal view, eye 4.2× as high as length of malar space; POL 2.5× as long as OOL, OOL longer than LOL; interocellar area strongly elevated in frontal view; antenna with 13 flagellomeres, pedicel as long as broad, F1 the longest flagellomere, slightly curved and broadened in distal half and 1.4× as long as F2, F2=F3=F4, subsequent flagellomeres shorter and nearly equal in length, placodeal sensilla on all flagellomeres. Body length 2.1 mm (n = 1).

Gall ( Fig. 43 ). Spindle-like bud galls, green and soft while young and growing, 20–25 mm in length, 5–7 mm in diameter. The surface is rough, not shiny, with pale spots, interior filled with dense radiating filaments that support the central larval cell. After the gall matures, it turns dirty brown, the walls are very hard and approximately 1 mm thick.

Biology. Alternate asexual and sexual generations are known. Asexual galls ( Fig. 42 ) are ovate, about 10 mm long, in buds on Q. laurifolia and Q. myrtifolia . The sexual bud galls begin to develop in early May, mature in May-June, adults emerge in May through June. We recorded sexual galls on Q. myrtifolia , Q. laurifolia , Q. inopina and Q. incana .

Distribution. USA: Florida, Highlands, Manatee, Martin, Walton, Liberty, Brevard Counties. We found this species also in North Carolina (Patsy Pond Area and Croatan National Forest, Carperet Co.).

Molecular taxonomy. Alternating generations were matched using DNA data, with seven individuals (five asexual females, one sexual female, one sexual male) sequenced for cytb and six individuals (four asexual females, one sexual female, one sexual male) sequenced for ITS2. Cytb sequences were on average 0.99% divergent (range 0–1.85%; GenBank accessions OM321616 – OM321622 ); ITS2 sequences were all identical ( OM331810 – OM331815 ).

Figures

FIGURES 29–36. Amphibolips spinosa Ashmead, sexual generation. 29–32, head, female: 29, frontal view, 30, dorsal view, 31, posterior view, 32, lateral view. 33, antenna, female. 34–35, male: 34, head, frontal view, 35, antenna. 36, forewing, part, female.

FIGURES 37–41. Amphibolips spinosa Ashmead, sexual generation, female. 37–39, mesosoma: 37, lateral view, 38–39, dorsal view. 40, metascutellum and propodeum, posterodorsal view. 41, metasoma, lateral view.

FIGURES 42–43. Amphibolips spinosa Ashmead. 42, asexual gall. 43, sexual gall.