Eurytoma cynipsea Boheman, 1836

Gómez, José Francisco, Nieves-Aldrey, José Luis, Nieves, María Hernández & Stone, Graham Nicholas, 2011, Comparative morphology and biology of terminalinstar larvae of some Eurytoma (Hymenoptera, Eurytomidae) species parasitoids of gall wasps (Hymenoptera, Cynipidae) in western Europe, Zoosystema 33 (3), pp. 287-323 : 306

Eurytoma cynipsea Boheman, 1836

MATERIAL EXAMINED. — Ex Aulacidea freesei / Phanacis zwolferi : Spain. Madrid, Arganda, 7.XI.2002, J. L. Nieves leg (n = 1). — Madrid, Monte Pajares, 7.XI.2002, J. L. Nieves leg (n = 10, of which 2 specimens MNHN- EY 6412).

Ex Aulacidea pilosellae : Spain. Madrid, Valgallego, 19. VI.2004, J. L. Nieves leg, (n = 3).

Ex Isocolus lichtensteini : Spain. Madrid, Arganda, 24.III.2002, J. L. Nieves leg (n = 1).

Ex Timaspis cichorii : Spain. Madrid, Arganda, 8.XI.2003, J. L. Nieves leg (n = 1).

Ex Timaspis ursopermi : Spain. Málaga, Casares, VIII.2002 and II.2003, J. L. Nieves leg (n = 2).

Ex Phanacis hypochoeridis : Spain. Pontevedra, Islas Cíes, 16.VII.03, J. L. Nieves leg, (n = 1).

DESCRIPTION

n = 19; body length 1.6 mm (range 1.0-2.3); body width 0.9mm (0.4-1.5)( Figs5C ; 7C );body fusiform, ratio L/W = 1.7; ventral margin of body segments clearly convex; anterodorsal protuberances protruding from second thoracic segment to the seventh abdominal segment ( Fig. 2 ). Antero-medial setae of antennal area at the same level as the antennae; ratio SA/LAA = 0.55; ratio SA/DAV between 0.38-0.53; antero-medial setae of vertex situated relatively high on the upper face ( Fig. 3 ); dorsal-labral setae as long as clypeal setae; ventral margin of clypeus indistinct; labrum with deep divisions forming a pair of flaps and five well differentiated lobes; maxillary palps conspicuous ( Fig. 11C ). Both mandibles with two teeth and apical tooth clearly visible ( Fig. 11C ); ratio L/W 1T between 0.6-2.0, varying according to each specific host; outer margin of first tooth strongly convex, with the tip moderately recurved; the shape of apex of the second tooth varies from pointed to blunt depending on the specific host, but is always straight and directed upwards in the same direction as the first tooth ( Fig. 13C ).

BIOLOGY

The species Eurytoma cynipsea is also a polyphagous ectoparasitoid reared from galls of different Aylacini species ( Cynipidae ) on various species of Asteraceae . Fully-grown larvae consume gall tissue, and slightly enlarge the host gall cell ( Fig. 14H, I ). Larvae overwinter and adults emerge in the following year when new galls are available on the host plants.

REMARKS

As with E. aspila , E. cynipsea belongs to the cynipsea species-group ( Zerova 1993); their larvae have a similar appearance, with very large sclerotized and exposed mandibles. However, the mandible of E. cynipsea has only two teeth.

Figures

FIG. 5.— Ventral views ofterminal-instar eurytomidlarvae:A, Eurytomaaspila (Walker,1836) ex Phanacis caulicola; B, E.brunniventris Ratzeburg, 1852 ex Cynips quercus (A); C, E. cynipsea Boheman, 1836 ex Phanacis hypochoeridis; D, E. infracta Mayr, 1904; E, E. mayri Ashmead, 1887; F, E. pediaspisi Pujade i Villar,1994; G, E. robusta Mayr, 1878; H, E. rosae Nees, 1834 ex Diplolepis rosae. Scale bars:1 mm.

FIG. 7.— Lateralviews ofterminal-instar eurytomidlarvae:A,Eurytoma aspila (Walker,1836) ex Phanacis caulicola; B, E.brunniventris Ratzeburg, 1852 ex Cynips quercus (A); C, E. cynipsea Boheman, 1836 ex Phanacis hypochoeridis; D, E. infracta Mayr, 1904; E, E. mayri Ashmead, 1887; F, E. pediaspisi Pujade i Villar,1994; G, E. robusta Mayr, 1878; H, E. rosae Nees, 1834 ex Diplolepis rosae. Scale bars:1 mm.

FIG. 2. — Body in lateral view of Eurytoma cynipsea Boheman, 1836.Abbreviations:ABS1-ABS9, abdominal segments;ANS, anal segment; THS1-THS3, thoracic segments; other abbreviations, see Material and methods; distributions of setae are referred to as: D, dorsal area; P, pleural area; V, ventral area.

FIG. 3. — Anterior view of head of Eurytoma cynipsea Boheman, 1836, illustrating the terminology used for general description. Abbreviations: see Material and methods.

FIG. 11. — Anterior views of mouthparts of terminal-instar eurytomidae larvae:A, Eurytoma aspila (Walker,1836) ex Phanacis caulicola; B, E. brunniventris Ratzeburg, 1852 ex Cynips quercus (A); C, E. cynipsea Boheman, 1836 ex Phanacis hypochoeridis; D, E. infracta Mayr, 1904; E, E. mayri Ashmead, 1887; F, E. pediaspisi Pujade i Villar, 1994. Scale bars: A, E, 200 μm; B-D, F, 100 μm.

FIG. 13.— Anterior views of the right mandible of terminal-instar eurytomid larvae:A, Eurytoma aspila (Walker,1836) ex Phanacis caulicola; B, E. brunniventris Ratzeburg, 1852 ex Cynips quercus (A); C, E. cynipsea Boheman, 1836 ex Phanacis hypochoeridis; D, E. infracta Mayr, 1904; E, E. mayri Ashmead, 1887; F, E. pediaspisi Pujade i Villar, 1994; G, E. robusta Mayr, 1878; H, E. rosae Nees, 1834 ex Diplolepis rosae; I, E. rufipes Walker, 1832; J, E. sp. cf. aspila; K, E. sp. cf. jaceae; L, E. strigifrons Thomson, 1876 (right mandible); M, E. strigifrons (left mandible); N, E. timaspidis (Mayr, 1904). Scales bars: A, D-G, I-N, 50 μm; B, 20 μm; C, H, 100 μm.

FIG. 14. — A, terminal-instar larva of Eurytoma aspila (Walker, 1836) ex gall of Aulacidea tragopogonis; B, larval cells of Phanacis centaureae with terminal-instar larvae of E. aspila; C, cross-section of Cynips quercus (A) leaf gall showing terminal-instar larva of E. brunniventris Ratzeburg, 1852, with debris of adult host; D, ventral view of terminal-instar larva of E. brunniventris ex gall of C. quercus (A);E, cross-section of a gall of Cynips divisa (A) showing fully-grown larva of E. brunniventris; F, terminal-instar larva of E.brunniventris ex gall of Plagiotrochus australis (S);G, anterior view of head of fully-grown larva of E.brunniventris ex gall of P.australis (S); H, larval cells of Aulacidea pilosellae with terminal-instar larva of E. cynipsea Boheman, 1836; I, larval cell on Silybum marianum with terminal-instar larva of E. cynipsea feeding on gall tissue; J, terminal-instar larva of E. robusta Mayr, 1878 in cell of Isocolus leuzeae gall; K, cross-section of Diplolepis centifoliae leaf gall showing terminal-instar larva of E. rosae Nees, 1834; L, lateral view of fully-grown larva of E. rosae ex gall of D. centifoliae.