Eurytoma mayri Ashmead, 1887

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 : 310-311

Eurytoma mayri Ashmead, 1887

MATERIAL EXAMINED. — Ex Diastrophus rubi : Spain. Asturias, Ajuyán-Oviedo, 7.IX.2005, L. Parra leg (n = 116, of which 2 specimens MNHN-EY 6414).

DESCRIPTION

n = 116; body length 2.03 mm (range 1.0-2.7); body width 0.73 mm (0.5-1.5) ( Figs 5E ; 7E ); body fusiform, slightly broadest in mid-region, tapering slightly anteriorly and posteriorly; ratio L/W = 2; ventral margin of body segments clearly convex; anterodorsal protuberances present from second thoracic segment to the eighth abdominal and clearly protruding beyond the dorsal margin of body segments ( Fig. 7E ).

Antero-medial setae of the antennal area situated below the antennae; antero-medial setae of vertex situated midway between anterior margin of vertex and the antennae ( Fig. 9D ); ratios SA/LAA = 0.22 and SA/DAV = 1.33; dorsal-labral setae longer than clypeal setae; ventral margin of clypeus indistinct; labrum with slight divisions restricted to its apical part; two lateral flaps and five poorly differentiated lobes; maxillary palps conspicuous ( Fig. 11E ).

Mandibles with tip of the first tooth clearly visible ( Fig. 11E ) with two main teeth, but with the inner margin forming two small projections close to the base of the second tooth, giving an appearance of four teeth; ratio L/W 1T = 2; outer margin of first tooth strongly convex, tip moderately recurved; apex of the second tooth straight, directed upwards in the same direction as the first tooth and more or less acute ( Fig. 13E ).

BIOLOGY

The species Eurytoma mayri is a primary monophagous ectoparasitoid of Diastrophus rubi (Bouché, 1834) on different species of Rubus (Rosaceae) . Fully-grown larvae usually overwinter and adults emerge in the spring when the new Diastrophus galls are developing on the running twigs of Rubus .

REMARKS

The larvae of this species are readily separated from larvae of other species associated with cynipid galls by the peculiar shape of their mandibles, with the two small projections near the base of second tooth giving an appearance of four 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. 9. — Anterior views of the head of terminal-instar eurytomid larvae: A, Eurytoma aspila (Walker, 1836) ex Phanacis caulicola; B, E. brunniventris Ratzeburg, 1852 ex Cynips quercus (A); C, Eurytoma infracta Mayr, 1904; D, Eurytoma mayri Ashmead, 1887; E, Eurytoma pediaspisi Pujade i Villar, 1994; F, Eurytoma robusta Mayr, 1878. Scale bars: A, B, D, F, 400 μm; C, 300 μm; E, 200 μm.

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.