Druon quercuslanigerum ( Ashmead, 1881 ) Cuesta-Porta & Melika & Nicholls & Stone & Pujade-Villar, 2022

Cuesta-Porta, Victor, Melika, George, Nicholls, James A., Stone, Graham N. & Pujade-Villar, Juli, 2022, Re-establishment of the Nearctic oak cynipid gall wasp genus Druon Kinsey, 1937 (Hymenoptera: Cynipidae: Cynipini), with description of five new species, Zootaxa 5132 (1), pp. 1-92 : 54-62

Druon quercuslanigerum ( Ashmead, 1881) , comb. nov.

Figs. 151–189

Cynips q. lanigera Ashmead, 1881 : xiii, female, gall.

Andricus (Andricus) lanigera Ashmead, 1885: 295 [unjustified emendation].

Andricus laniger (Ashmead) : Weld, 1951: 634.

Andricus quercuslanigera (Ashmead) : Burks, 1979: 1088.

Types examined. The Holotype Catalogue of the Smithsonian Institution (http://usnmhymtypes.com/) has no record of the type of Andricus quercuslanigera Ashmead. We did not find it either in the type collection nor in the general collection of Cynipidae , and consider the types to have been lost. The type of this species is also absent from the Entomology Type Collection at the Academy of Natural Sciences of Philadelphia . Only 7 simple specimens of “ Andricus laniger Ashmead ” can be found in the collection, no type specimens (https://ansp.org/research/systematics-evolution/entomology/entomology-collections/).

Additional material examined. Specimens deposited in the USNM, examined by GM: http://n 2t.net/ark:/ 65665/3aaf842bd-1838-4735-8301-16be3bef5d82. About 20 females “ USA, Florida, Highlands Co., Archbold Biological Station, Lake Placid , Q. geminata , leg. G. Melika, 1995.ii.01. ” Twelve females “ USA, Florida, Jacksonville, Q. virginiana, FL 926, gall type 7, leg. J.A. Nicholls, 2007.x.19. ” Variety fuscum: 1 asexual female “ USA, FL, Jonathan Dickinson State Park , gall type 7, ex Q. geminata , coll. 1994.xii.06., leg. G. Melika ”; 1 asexual female “ USA, FL, Archbold Biological Station , ex Q. geminata , coll. 1995.ii.01., leg. G. Melika ”; 11 female “ USA, FL, Jacksonville, FL926 , ex Q. virginiana , coll. 2007.x.19., leg. J.A. Nicholls ”; 9 asexual females “ USA, Texas, Eisenhower Park , TX17, TX25-27, ex Q. fusiformis , coll. 2008.xii.24., leg. K. Lohse ”; 11 females ( UB) “ Mexico, Hgo. , San Bartolo Tutotepec , Los Reyes 20º23’51.0”N, 99º12’00.0”W; Code 504; ex Quercus oleoides ; coll. 2019.i.14, emergence 2019.iii.28; leg. Chagoyán-García ”. Variety striatum: about 40 females ( UB) “ Mexico, Chih. , Ciudad de Chihuahua; Code 391; ex Q. virginiana ; coll. 2016. i.14, emerge 2016.ii.1–15; leg. E. Jiménez-Quiroz. ”

Diagnosis. The typical specimens, D. quercuslanigerum var. quercuslanigerum , differ in colour from all other known Druon species; it is the only species with a yellow to yellowish-brown body; morphologically resembles D. garciamartinonae , D. pattoni , D. protagion , D. rusticum , and D. receptum by having a rounded or trapezoid head, with the gena only slightly broadened behind the eye in frontal view, the mesoscutellum rounded or slightly elongate and the second metasomal tergum pubescent anterolaterally. However, it differs from those four species by the presence of the median mesoscutal line ( Fig. 158 ). The specimens from var. fuscum , collected in Texas ( USA) and Hidalgo ( Mexico), are morphologically identical to var. quercuslanigerum except for a darker body colour and absence of the median mesoscutal line ( Figs. 171 , 184 ). Variety striatum, from Chihuahua ( Mexico), differs from the typical series by having a darker body colour, weak striae on the second metasomal tergum and a reticulate third tergum ( Fig. 189 ). The sculpture of the third metasomal tergum is a morphological character shared with D. linaria , but in D. quercuslanigerum var. striatum the second metasomal tergum is weakly striate ( Fig. 189 ) (smooth or reticulated posteriorly in D. linaria ( Fig. 110 )), the head is trapezoidal ( Fig. 177 ) (transversally ovate in D. linaria ( Fig. 101 )), and the antennae are thicker in their distal half ( Fig. 181 ) (not thickened in D. linaria ( Fig. 104 )). Variety striatum has a dark brown body, with median mesoscutal line absent or indistinct ( Fig. 158 ), three lobes of the mesoscutum with dark spots (as in var. fuscum ); notauli in mid height of mesoscutum almost parallel ( Fig. 184 ) (clearly divergent in var. quercuslanigerum ( Fig. 158 )); the areolet in the fore wing is distinct, of normal size ( Fig. 187 ) (small and indistinct in var. quercuslanigerum );

Redescription. Asexual female ( Figs. 151–161 ; 164–189 ). Body, antenna, mandibles, palpi, legs uniformly yellowish to amberine; eyes black. Specimens from Texas and Mexico are darker, brownish (see comments).

Head alutaceous, with sparse setae, denser on lower face, trapezoid, 1.3× as broad as high and slightly broader than mesosoma in frontal view; 2.1× as broad as long in dorsal view. Gena alutaceous, not or very slightly broadened behind eye in frontal view, narrower than transverse diameter of eye in lateral view. Malar space alutaceous, with striae radiating from clypeus and not reaching eye, malar sulcus absent. Eye 3.25× as high as length of malar space. Inner margins of eyes parallel. POL 2.4× as long as OOL, OOL as long as diameter of lateral ocellus (or very slightly longer) and slightly shorter than LOL, all ocelli ovate, of same size. Transfacial distance slightly shorter than height of eye; toruli located slightly above mid height of eye, frons shorter than lower face, diameter of antennal torulus 2.0× as long as distance between them, distance between torulus and eye equal to diameter of torulus; lower face alutaceous, glabrous, with dense white setae, without striae; slightly elevated median area delicately coriaceous, glabrous, with few setae. Clypeus trapezoidal, broader than high, smooth, glabrous, with long setae along ventral edge; ventrally rounded, not emarginate and without median incision; anterior tentorial pit small, rounded, distinct, epistomal sulcus distinct, clypeo-pleurostomal line well impressed. Frons uniformly alutaceous, without striae and setae, interocellar area alutaceous. Vertex, occiput and postocciput alutaceous; postgena smooth, without setae; posterior tentorial pit large, elongated, area below impressed; occipital foramen as high as height of postgenal bridge; hypostomal carina emarginate, continuing into straight postgenal sulci which diverge strongly toward occipital foramen, postgenal bridge ventrally 4.0x narrower than dorsally, near occipital foramen. Antenna slightly longer than head+mesosoma, with 12 flagellomeres (suture between F12 and F11 indistinct but visible), pedicel slightly longer than broad; flagellomeres subsequently broadening towards apical end of antenna; scape+pedicel longer than F1; F1 2.0× as long as pedicel and 1.25× as long as F2; F2=F3, F3 1.3× as long as F4, F4=F5, F6–F12 nearly equal in length; placodeal sensilla on F4–F12, absent on F1–F3.

Mesosoma 1.2× as long as high, with a few white setae, setae denser along propleuron and on lateral propodeal area. Pronotum smooth, glabrous dorsally, with numerous delicate parallel striae extending onto entire pronotum laterally (ventrolateral rugae stronger), with piliferous points around setae; anterior rim of pronotum impressed, foveolate; propleuron smooth, glabrous. Mesoscutum uniformly and entirely reticulate, with a few white setae anteriorly, slightly longer than broad (greatest width measured across mesoscutum level with base of tegulae). Notaulus complete, strongly converging posteriorly; at posterior end distance between notauli shorter than distance between notaulus and side of mesoscutum; anterior parallel line invisible; parapsidal line marked with more delicate sculpture; median mesoscutal line visible, narrow, short (not reaching 1/4 of mesoscutum length) or indistinct (see comments); parascutal carina broad, reaching notaulus. Mesoscutellum slightly longer than broad, broadest part in posterior 1/3 of its length; disk of mesoscutellum dull rugose, with stronger rugae laterally and posteriorly, overhanging metanotum, with sparse setae; circumscutellar carina complete. Mesoscutellar foveae transverse, 2.0× as broad as high, smooth, glabrous, divided by broad rugose elevated central carina. Mesopleuron entirely striatoreticulate, with delicate interrupted parallel striae, extending across mesopleuron, with long white setae only in posteroventral part; mesopleural triangle smooth, glabrous, without striae, with long white setae; dorsal and lateral axillar areas smooth, glabrous, with a few setae, piliferous points; axillula with delicate parallel longitudinal striae; subaxillular bar smooth, glabrous, triangular, posteriorly higher than height of metanotal trough; metapleural sulcus reaching mesopleuron slightly above half of its height, separating smooth, glabrous area, with some setae; upper part of sulcus indistinct. Metascutellum alutaceous, glabrous, as high as height of smooth, glabrous ventral impressed area; metanotal trough smooth, glabrous; central propodeal area smooth, glabrous, without rugae; lateral propodeal carinae present bent outwards in posterior 1/3; lateral propodeal area smooth, glabrous, with long white setae, with rounded bump at the base of each seta. Nucha with numerous irregular sulci dorsally and laterally. Tarsal claws with basal lobe.

Fore wing longer than body, hyaline, with short cilia on margin, veins brown, radial cell open, 3.0× as long as broad; Rs and R1 nearly reaching wing margin; areolet present, triangular, closed or indistinct (see comments). Rs+M distinct for 3/4 of its length, its projection reaching basalis slightly below its mid height.

Metasoma slightly longer than head+mesosoma, slightly longer than high in lateral view; second metasomal tergum with white long setae anterolaterally, smooth, without micropunctures, sometimes with some striae (see comments); all subsequent terga, including hypopygium with rare micropunctures, sometimes third metasomal tergum reticulate (see comments). Prominent part of ventral spine of hypopygium 2.0× as long as broad in ventral view. Body length 2.0– 2.3 mm (n = 10).

Sexual females are described in Hood et al. (2018). See also Comments.

Gall. Asexual generation galls ( Fig 162–163 ). Creamy white wool-covered gall usually on the underside of the leaf midrib, occasionally also on twigs; whole gall 1.0–7.0 mm in diameter and 2–3 mm high. Pubescence yellows slightly in older galls. Individual hairs making up the wool are straight and 0.5–2.0 mm long. The interior of the gall contains pale brown larval chambers that can be solitary or in groups of 3–6 along the midrib. Sexual generation galls. Small, on average 1 mm, swelling of the central stem of catkins, with gall shape similar to a grain of rice, or ovate. Surface of gall indistinct from the rest of the central stem of catkin except for swelling ( Hood et al. 2018).

Biology. Alternate asexual and sexual generations are known. The asexual leaf galls (also rarely on twigs) develop in autumn and winter, sexual galls on catkins in spring ( Hood et al. 2018); both generations develop on Q. minima and Q. virginiana and asexual galls have also been found on Q. fusiformis , Q. geminata , Q. oleoides (all Section Virentes ).

Distribution. USA: Georgia, Florida, Alabama, Missouri, Louisiana, Texas, and Mexico: Hidalgo. Also introduced with its host plant Q. virginiana in California (Stockton) and Chihuahua (Chihuahua City).

Comments. The light-colored specimens of D. quercuslanigerum have been collected in Florida on Q. virginiana , Q. geminata and Q. minima ( Figs. 151–161 ). DNA sequence data group these light-colored specimens as conspecific with two other dark-bodied morphotypes: specimens from Texas ( USA) on leaves of Q. fusiformis and from a cluster of pubescent twig galls off Q. oleoides in Hidalgo ( Mexico) that are darker in color and with the median mesoscutal line absent ( Figs. 164–176 ), and a second set of specimens mentioned in Pujade-Villar et al. (2016) from introduced Q. virginiana in Chihuahua ( Mexico) with the second metasomal tergum weakly striate and the third metasomal tergum reticulated ( Figs. 177–189 ; metasoma detailed in Figs. 188–189 ). Two individuals from each of the three morphotypes were sequenced for cytb; identical haplotypes were found in the Texas and Chihuahua populations, while the eastern sequences differed from those sampled from further west by an average of 1.47% (GenBank MW388888 , MZ935710 – MZ935714 ). In addition, ITS2 sequences between a Texas and a Chihuahua individual were identical except for a single additional A in the Texan sequence within a polyA region ( MZ927181 – MZ927182 ). Hence, we assign three new morphologically distinct varieties within this species: var. quercuslanigerum (Florida) , var. fuscum (Texas and Hidalgo), and var. striatum (Chihuahua) .

The description of the sexual generation of D. quercuslanigerum in Hood et al. (2018) was based on two females and two males reared from galls on catkins. Figure 1V in Hood et al. (2018) shows the sexual female of D. quercuslanigerum , but figures 2C & D in the same work show a cynipid inquiline of the genus Synergus labelled as the sexual female of D. quercuslanigerum . This inquiline was reared from the sexual gall and must have been considered a sexual female of D. quercuslanigerum . With only two females, one of which is presumably the Synergus specimen, the description of the sexual female of D. quercuslanigerum likely contains mixed characters of the Synergus and Druon specimens and requires validation.

Figures

FIGURES 151–156. Druon quercuslanigerum var. quercuslanigerum, comb. nov., asexual female (Florida). 151–154, head: 151, frontal view, 152, dorsal view, 153, lateral view, 154, posterior view. 155, antenna. 156, mesosoma and propleura, frontal view.

FIGURES 157–160. Druon quercuslanigerum var. quercuslanigerum, comb. nov., asexual female (Florida). 157, mesosoma, lateral view. 158, mesoscutum and mesoscutellum, dorsal view. 159, mesoscutellum, dorsal view, 160, metascutellum and propodeum, posterodorsal view.

FIGURES 161–163. Druon quercuslanigerum var. quercuslanigerum, comb. nov., asexual female (Florida). 161, metasoma, lateral view. 162–163, galls: 162, on leaves, 163, on twigs.

FIGURES 164–169. Druon quercuslanigerum var. fuscum, comb. nov., asexual female (Texas). 164–167, head: 164, frontal view, 165, dorsal view, 166, lateral view, 167, posterior view. 168, antenna. 169, mesosoma and propleura, frontal view.

FIGURES 170–173. Druon quercuslanigerum var. fuscum, comb. nov., asexual female (Texas). 170, mesosoma, lateral view. 171, mesoscutum and mesoscutellum, dorsal view. 172, mesoscutellum, dorsal view, 173, metascutellum and propodeum, posterodorsal view.

FIGURES 174–176. Druon quercuslanigerum var. fuscum, comb. nov., asexual female (Texas). 174, fore wing. 175–176, metasoma: 175, lateral view, 176, dorsal view.

FIGURES 177–182. Druon quercuslanigerum var. striatum, comb. nov., asexual female (North Mexico). 177–180, head: 177, frontal view, 178, dorsal view, 179, lateral view, 180, posterior view. 181, antenna. 182, propleura, frontal view.

FIGURES 183–186. Druon quercuslanigerum var. striatum, comb. nov., asexual female (North Mexico). 183, mesosoma, lateral view. 184, mesoscutum and mesoscutellum, dorsal view. 185, mesoscutellum, dorsal view, 186, metascutellum and propodeum, posterodorsal view.

FIGURES 187–189. Druon quercuslanigerum var. striatum, comb. nov., asexual female (North Mexico). 187, fore wing. 188–189, metasoma: 188, lateral view, 189, dorsal view.

FIGURES 110–112. Druon linaria, comb. rev., asexual female. 110, metasoma, lateral view. 111, third and subsequent terga, with reticulate sculpture. 112, gall.

FIGURES 101–105. Druon linaria, comb. rev., asexual female. 101–103, head: 101, frontal view, 102, dorsal view, 103, posterior view. 104, antenna. 105, pronotum, dorsal view.

FIGURES 1–5. Druon alexandri, sp. nov., asexual female. 1–3, head: 1, frontal view, 2, dorsal view, 3, posterior view. 4, antenna. 5, mesosoma and propleura, frontal view.