Andricus barriosi Medianero & Nieves-Aldrey, 2019

Medianero, Enrique & Nieves-Aldrey, José Luis, 2019, Andricus Barriosi: a new species of oak gall wasp (Hymenoptera: Cynipidae: Cynipini) from Panama, Zootaxa 4577 (3), pp. 585-595 : 586-592

Andricus barriosi Medianero & Nieves-Aldrey , new species

Figs 1–6

Type material. HOLOTYPE ♀ (Fig. 3A) [in Museo Nacional de Ciencias Naturales, Madrid, Spain (MNCN), card mounted. Cat. no. 2859]: PANAMA, Chiriquí, Volcán Barú, 8°47´50.8” N, 82°29´35.9” W, 1,800–2,070 m; ex gall on leaf of Quercus bumelioides Liebm. (Fagaceae) ; gall collected 08-V-2008; insect emerged V-2008, E. Medianero & J. L. Nieves leg.

Paratypes: 5♀, PANAMA, Chiriquí, Volcán Barú, 8°47´50.8” N, 82°29´35.9” W, 1,800–2,070 m; ex gall on leaf of Quercus bumelioides Liebm. (Fagaceae) ; gall collected 8-V-2008; insect emerged VI-2008, E. Medianero & J. L. Nieves leg. 1♀, same data but collected 30-I-2008; insect emerged ii-2008, E. Medianero leg.; 4♀, PANAMA, Chiriquí, Alto Quiel, Boquete, 8°49´01.7” N, 82°28´32.3" W, 1,600 m; ex gall on leaf of Quercus insignis M. Martens & Galeotti (Fagaceae) ; gall collected 27-XI-2008; insect emerged I.2009. 1♀, same data but collected 19- XII-2008; insect emerged I-2009, E. Medianero leg. Paratypes in Maestría en Entomología, Universidad de Panamá (MEUP).

Additionally, 2♀ paratypes of the type series were dissected for SEM observation (in MNCN).

Etymology. Named after our colleague and friend Dr. Héctor Barrios for his contribution to the development of entomology in Panama.

Diagnosis and comments. The new species is closely allied to A. nievesaldreyi Pujade-Villar (= A. mexicanus Kinsey ) and A. georgei Pujade-Villar , both from Mexico, and to A. maesi Pujade-Villar from Nicaragua. All these species induce similar galls and share the majority of diagnostic morphological characters of the adults, including a sculptured metasoma. However, A. barriosi may be readily distinguished from the other three species by the characters presented in the identification key.

The new species differs from all the other mentioned species by its darker coloration with head and body being predominantly brown to black, while the other species are predominantly reddish to amber. A. barriosi may be distinguished from A. georgei by the complete notauli, which are faint anteriorly in A. georgei . In A. barriosi , the scutellar foveae are not well differentiated on the posterior edge, whereas in A. georgei , the scutellar foveae are well differentiated and separated by a trapezoidal area. A. barriosi differs from A. maesi in the sculpture of the second metasomal segment and the type of gall. The striated sculpture in the second metasomal tergum is weak in A. maesi but strongly marked and extended in the new species. The galls of the two species are also different – galls of the new species are formed on leaves while that of A. maesi are on stems or twigs. A. barriosi differs from A. nievesaldreyi not only in its darker adult coloration but also in the relative extension and definition of the striated sculpture on T2, which is much more marked in the new species, and in the presence of a smooth area in the mesopleura, which is missing in A. nievesaldreyi .

The gall of the new species is similar to that of Cynips guatemalensis Cameron (1883) (cited as A. guatemalensis by Medianero & Nieves-Aldrey 2011), a species that has been considered incertae sedis by Pujade- Villar et al. (2011).

General Description. Body length, 3.5 mm (range 2.9–4.1 mm; N = 7) for females. Female body predominantly brown. Head with vertex, occiput and central area of face dark brown to black. Mesosoma dark brown to black (in some individuals). Metasoma dark brown. Scape, pedicel, legs (except the tibiae and metatarsomeres), area postero-lateral of protorax and area lateral-ventral of the tergites of metasoma yellow brown. Forewings hyaline with all the veins dark brown.

Female. Head, with frons and face rugose, genae alutaceous. Face with radiating striae from clypeus, reaching basal and lateral margin of eye. Face and occiput moderately pubescent, front with only one row of setae lateral, genae without setae. Head in dorsal view approximately 2.52 times wider than long (Fig. 1A). POL 2.0 times longer than OOL; posterior ocellus separated from inner orbit of eye by 1.3 times its longest diameter (Fig. 1A). Head in anterior view generally oval (Fig. 1B), 1.24 times wider than high. Genae slightly expanded behind eyes. Clypeus trapezoidal, 1.6 times wider than high, alutaceous, moderately pubescent, ventral margin slightly sinuate and projecting over mandibles. Anterior tentorial pits conspicuous; epistomal sulcus and clypeo-pleurostomal lines distinct. Malar space 0.3 times height of compound eye, without a distinctive malar sulcus. Distance between antennal rim and compound eye 1.2 times width of antennal socket including rim. Ocellar plate raised. Head, posterior view (Fig. 1C). Gula relatively short; distance between occipital and oral foramina as long as the occipital foramen. Without an occipital carina.

Mouthparts (Fig. 1C). Mandibles strong and exposed, moderately pubescent; right mandible with three teeth, left with two teeth. Cardo of maxilla visible, maxillary stipes approximately 2.6 times longer than wide. Maxillary palp five-segmented. Labial palp three-segmented.

Antennae (Fig. 2E) of moderate length, as long as 1/2 body length, with 14–15 segments; flagellum not broadening toward apex, with short, erect setae and elongate placodeal sensilla visible only on flagellar segments 2–12. Relative lengths of antennal segments 13:15:33:25:24:22:21:20:16:14:13:13:11:24. Pedicel globose, small, 0.9 times as long as scape; F1 1.3 times as long as F2 (Fig. 2G); F12 2.6 times longer than wide and 2.2 times as long as F11 (Fig. 2F).

Mesosoma (1D–H). Uniformly alutaceous, moderately pubescent, in lateral view 1.2 times as long as high, strongly convex dorsally (Fig. 1H). Pronotum, densely pubescent; with long and dense white setae, lateral surface of pronotum with longitudinal wrinkles; (Fig. 1H). Pronotum short medially, ratio of length of pronotum medially/ laterally = 0.2. Pronotal plate indistinct dorsally (Fig. 1D).

Mesonotum. Mesoscutum alutaceus, only slightly pubescent with scattered setae anterior, lateral and posteriorly, with a row of setae along the notauli. Notauli percurrent, smooth, well impressed along entire length, reaching pronotum, convergent posteriorly, with an indistinct median mesoscutal impression. Anteroadmedian signa clearly visible. Parapsidal signa broad, smooth. Transscutal fissure narrow (Fig. 1E). Scutellum (Fig. 1F), rounded, approximately 0.7 times as long as mesoscutum, rugose, posterior margin not emarginate. Scutellar foveae not well differentiated, shallow, smooth and indistinct margins posteriorly. Scutellum, overlapping the dorsellum posteriorly in lateral view. Axillula moderately pubescent, their anterior margins and posterior marked. Mesopleuron medially with some longitudinal rugae, the sculpture being weak or almost smooth basally and posterodorsally; the pubescence is moderate, with the mesopleural triangle densely pubescent (Fig. 1H).

FUGURE 1 Andricus barriosi , new species, asexual female (A) Head, dorsal view. (B) Head, anterior view. (C) Head, posterior view. (D) Pronotum, antero-dorsal view. (E) Mesosoma, dorsal view. (F) Scutellum. (G) Propodeum. (H) Mesosoma, lateral view.

FUGURE 2 Andricus barriosi , new species, asexual female (A) Metasoma, lateral view. (B) Detail of the reticular area of the metasoma. (C) Metasoma, ventral view. (D) Detail of the ventral spine of the hypopygium, ventral view. (E) Female antenna. (F) Detail of the last flagellomeres. (G) Detail of basal flagellomeres. (H) Legs. (I) Metatarsal claw.

Metanotum (Fig. 1G and H). Metapectal-propodeal complex. Metapleural sulcus reaching posterior margin of mesopectus at mid-height of metapectal-propodeal complex (Fig. 1H). Lateral propodeal carinae distinct, strong and arched in their medial portion (Fig. 1G). Median propodeal area wide and bare (Fig. 1G). Lateral propodeal area densely pubescent. Nucha rugose.

Legs (Fig. 2H). Moderately pubescent, metatarsal claws with an acute basal lobe or short tooth (Fig. 2I).

Forewing (Fig. 3A). As long as body, veins strongly pigmented. Radial cell 4.0 times longer than wide, open along anterior margin, areolet large, triangular, closed. Rs slightly bowed, reaching wing margin. M nearly straight, not reaching wing margin. Rs+M reaching basalis at mid-height. First abscissa of radius (2r) slightly curved, 2r-m straight. Basal cell pubescent. Apical margin of wing with moderately long hair fringe.

Metasoma (Fig. 2A). Large, as long as head and mesosoma combined, 1.3 times as long as high in lateral view. T2 covering approximately 2/3 of metasoma and strongly and longitudinally striated, with a group of sparse short setae anteromedially; following tergites with well marked reticulate sculpture, with one to three short setae in each cell (2B). Projecting part of hypopygial spine, beyond attachment of lateral flap, relatively short (Fig. 2C); approximately 2.0 times as long as basal height of the spine; lateral margins of hypopygial spine with long setae projecting over apical end of the spine (2D).

FUGURE 3 Andricus barriosi , new species, asexual female: (A) Forewing. (B) Habitus. (C) Andricus nievesaldreyi , habitus of female.

Gall (Figs. 4 A–D). Galls present as dense, spherical masses covered with light brown hairs on the midrib of leaves (Fig 4A and B). The gall is first orange, becoming dark brown when mature (Fig. 4C). Diameter measures 2.09 to 2.16 cm. The majority of galls are solitary and develop indistinctly on the upper or lower surface of the leaf blade. The internal structure of the gall shows a highly lignified core enclosing several larval cells (Fig. 4D and E)

Distribution. Andricus barriosi was found between 1,000–2,070 m asl at Volcán Barú and Alto Quiel, Chiriquí Province, Panama.

Biology. Only the asexual generation of A. barriosi is known, which induces galls on leaves of Quercus bumelioides Liebm. and Q. insignis M. Martens & Galeotti ( Fagaceae , sect. Quercus ). The galls are found between December and May, during the dry season, when new leaves of Q. bumelioides and Q. insignis begin to emerge. The adult insects emerge from mature galls from June to July.

FUGURE 4 Galls of Andricus barriosi , new species, (A), (B) and (C) mature galls on Quercus bumelioides . (D) and (E) Sections of galls showing the inner structure.

FUGURE 5 Detail of the sculpture of the mesopleuron in (A) Andricus barriosi and (B) Andricus nievesaldreyi . FUGURE 6 Detail of the sculpture of the metasoma in (A) Andricus barriosi and (B) Andricus nievesaldreyi .