Eurytoma timaspidis (Mayr, 1904)

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 : 314-315

Eurytoma timaspidis (Mayr, 1904)

MATERIAL EXAMINED. — Ex Timaspis phoenixopodos : Spain. Madrid, Dehesa de Arganda, 29. VI.2005, J. L. Nieves leg (n = 24, of which 1 specimen MNHN-EY 6409).

DESCRIPTION

n = 24; body length 2 mm (range 1.8-2.7); body width 1.05 mm (0.9-1.2) ( Figs 6E ; 8E ; 15G ); body more or less fusiform anteriorly and posteriorly; ratio L/W = 1.84; ventral margin of body segments clearly convex; anterodorsal protuberances present from second thoracic segment to the seventh abdominal, and protruding beyond the dorsal margin of body segments ( Fig. 8E ).

Antero-medial setae of antennal area situated at the same level as antennae; antero-medial setae of vertex situated relatively high on the upper face ( Fig. 10F ); ratios SA/LAA = 0.57 and SA/DAV = 0.65; dorsal-labral setae longer than clypeal setae; ventral margin of clypeus indistinct; labrum with deep divisions almost reaching the level of labral setae; a pair of lateral flaps and five relatively welldifferentiated irregular lobes; maxillary palps conspicuous ( Fig. 12G ).

Mandibles with two teeth; tip of the first tooth completely visible ( Fig. 12G ); ratio L/W 1T = 1.77; 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 rounded; inner margin of mandible, from the base of second tooth, more or less straight with margin not interrupted ( Fig. 13N ).

BIOLOGY

The species Eurytoma timaspidis is a polyphagous primary ectoparasitoid associated with several cynipid galls on herbs. It has been recorded from galls of Isocolus , Phanacis and Timaspidis species ( Askew et al. 2006). The specimens in this study were reared from galls of Timaspis phoenixopodos Mayr, 1882 on stems of Lactuca viminea (L.) J. Presl & C. Presl ( Asteraceae ). Fully-grown larvae of E. timaspidis feed actively on gall tissue and enlarge the original host larval cell ( Fig. 15F ). Fully-grown larvae overwinter inside the gall and the adults emerge in synchrony with the appearance of new Timaspis galls.

REMARKS

Larvae of E.timaspidis are similar to those of E.aspila and E. cynipsea in having left mandibles with three teeth. Eurytoma timaspidis is easily separated from the others by its clearly two-toothed right mandibles; Eurytoma timaspidis differs from E. cynipsea mainly by having a relatively shorter second mandible 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. 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.

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.