Eurytoma rufipes Walker, 1832

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 : 313-314

Eurytoma rufipes Walker, 1832

MATERIAL EXAMINED. — Ex Xestophanes brevitarsis : Spain. La Coruña, Arins, 17.VII.2003, J. L. Nieves leg (n = 2). Ex X. potentillae : Spain. Madrid, Cotos de Monterrey, 24. VI.2004, J. F. Gómez leg (n = 16, of which 1 specimen MNHN-EY 6413). — Tarragona, Colldejou, 14.VIII.2003, J. L. Nieves leg (n = 6).

DESCRIPTION

n = 24, body length 1.7 mm (range 1.2-2.4;); body width 0.9 mm (0.3-1.3) ( Figs 6A ; 8A ); body barrelshaped, tapering posteriorly, widest at segments 1-3; ratio L/W = 1.74; ventral margin of body segments slightly convex; anterodorsal protuberances present from second thoracic segment to the eighth abdominal and not protruding beyond the dorsal margin of body segments ( Fig. 8A ).

Antero-medial setae of the antennal area situated slightly below the antennae; antero-medial setae of vertex situated more or less midway between anterior margin of vertex and the antennae ( Fig. 10B ); ratios SA/LAA = 0.2 and SA/DAV = 1.4; dorsallabral setae as long as clypeal setae; ventral margin of clypeus with a distinct suture; labrum with slight divisions limited to apical part of labrum, showing a pair of lateral flaps and five poorly differentiated lobes; maxillary palps conspicuous ( Fig. 12C ).

Mandibles with two teeth, exposed in part, with the tip of the first tooth visible ( Fig. 12C ); ratio L/W 1T = 1.93; 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; inner margin of mandible, from the base of second tooth, forming a small projection relatively separated from the base of the second tooth ( Fig. 13I ).

BIOLOGY

This is an ectoparasitoid associated with galls of Xestophanes brevitarsis (Thomson, 1877) and X. potentillae (Retzius, 1783) , both developing in runners on different species of Potentilla (Rosaceae) . Univoltine and oligophagous, attacking the gallinducing cynipid larva ( Fig. 15B ). Fully-grown larvae overwinter inside the gall and the adults emerge in synchrony with the development of new Xestophanes galls.

REMARKS

The larvae of E. rufipes is similar to the larvae of E. mayri and E. pediaspisi in terms of the position on the head of the antero-medial setae of vertex, and by the presence of only slight apical divisions on the medial part of the labrum. They differ from other larvae in having mandibles with a small projection on the inner margin at the base of the second tooth.

Figures

FIG. 6.— Ventralviews of terminal-instar eurytomid larvae:A, Eurytoma rufipes Walker, 1832; B, E. sp. nr. aspila; C, E. sp. nr. jaceae; D, E. strigifrons Thomson, 1876; E, E. timaspidis (Mayr, 1904). Scale bars: 1 mm.

FIG. 8.— Lateral views of terminal-instar eurytomid larvae:A, Eurytoma rufipes Walker,1832; B, E. sp. cf. aspila; C, E. sp. cf. jaceae; D, E. strigifrons Thomson, 1876; E, E. timaspidis (Mayr, 1904). Scale bars: 1 mm.

FIG. 10. — Anterior views of the head of terminal-instar eurytomid larvae:A, Eurytoma rosae Nees,1834 ex Diplolepis rosae; B, E. rufipes Walker, 1832; C, E. sp. cf. aspila; D, E. sp. cf. jaceae; E, E. strigifrons Thomson, 1876; F, E. timaspidis (Mayr, 1904). Scale bars: A-C, 300 μm; D, 200 μm; E, F, 400 μm.

FIG. 12. — Anterior views of mouthparts of terminal-instar eurytomidae larvae:A, Eurytoma robusta Mayr,1878; B, E. rosae Nees,1834 ex Diplolepis rosae; C, E. rufipes Walker,1832;D, E.sp.cf.aspila; E, E. sp. cf. jaceae; F, E.strigifrons Thomson,1876; G, E.timaspidis (Mayr, 1904). Scale bars: A-E, 100 μm; F, G: 200 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. 15. — A, section of a gall of Diplolepis mayri showing a fully-grown larva of Eurytoma rosae Nees, 1834; B, cross-section of Xestophanes brevitarsis (Thomson,1877) gall showing fully-grown larva of E. rufipes Walker, 1832 with host larva; C, cross-section of old gall of Aulacidea subterminalis Niblett, 1946 showing fully-grown larva of E. sp. cf. aspila; D, detail of mandibles of E. sp.cf. aspila ex gall of A. subterminalis; E, lateral view of terminal-instar larva of E. strigifrons Thomson,1876 ex gall of Isocolus lichtensteini (Mayr, 1882); F, cross-section of fresh gall of Timaspis phoenixopodos Mayr, 1882 showing fully-grown larvae of E. timaspidis (Mayr, 1904); G, larval cell of T. phoenixopodos with terminal-instar larvae of E. timaspidis.