Eurytomidae, Illiger, 1807

Delvare, G., Escolà, A. Ribes, Stojanova, A. M., Benoit, L., Lecomte, J. & Askew, R. R., 2019, Exploring insect biodiversity: the parasitic Hymenoptera, chiefly Chalcidoidea, associated with seeds of asphodels (Xanthorrhoeaceae), with the description of nine new species belonging to Eurytomidae and Torymidae, Zootaxa 4597 (1), pp. 1-90 : 20-22

Eurytomidae

Eurytomidae is by far the best represented chalcidoid family in asphodel seeds, with the seed-eating Bruchophagus species supporting a parasitoid fauna that includes the eurytomid genera Eurytoma Illiger and Aximopsis Ashmead. Species of Eurytoma were reared from samples of asphodel fruits that always also produced Bruchophagus , and we believe that Eurytoma behave as parasitoids of Bruchophagus in the seeds, although the possibility that larvae of E. asphodeli are partly phytophagous is discussed below.

Segmentation of the antenna. The antenna of Eurytomidae is composed of a basal scape followed by a pedicel and a multisegmented flagellum. The flagellum is composed of a single anellus which lacks MPS, a funicle of four to six segments and an apical clava of up to three segments ( Figs 10D, 10E , 16C, 16D , 25C ). The anellus is designated the first flagellomere, the first funicle segment (F1) is the second flagellomere, F2 is the third flagellomere and so on. Variation in segmentation between the studied species occurs in two regions of the antenna.

Firstly, flagellomere 7 is incorporated in the clava in females of most species so that the clava is preceded by a 5-segmented funicle ( Figs 16C , 25C ), but in the first of the newly described Bruchophagus species flagellomere 7 is the last segment in a 6-segmented funicle, being separated from flagellomere 8 by a short petiole ( Fig. 10E ).

The second region of segmental variation is the clava, and this may often be appreciated with certainty only after microscopic examination. Three transverse rows of linear sensilla on the clava of most species indicate a trimerous condition but microscopic examination shows that in some species the two last flagellomeres are actually fused and that there is no suture between them, the clava then being effectively 2-segmented ( Figs 12E , 16D , 20B , 21D ). This is the condition in apparently all Eurytoma species and in many species of Bruchophagus . It is seen in the species illustrated by Lotfalizadeh et al. (2007) and referred to as ‘ Bruchophagus Alicante’, here described as Bruchophagus lecomtei Delvare sp. nov..

Eurytomidae associated with asphodels. A key to the eleven species of Eurytomidae found associated with asphodels in Europe follows. In using the key it is essential to ensure that the true condition of the clava is recognised, requiring a carefully check of the segmentation of the flagellum as there is often a false suture, situated at the apex of the second sensilla row of the clava, between the supposedly penultimate segment and the terminal one.

Eight new species are described with observations on all species, and E. asphodeli is redescribed with an account of its considerable variation.

Figures

FIGURES 10A–I. Bruchophagus abscedus. A–H, ♀. I, ♂. A, head in frontal view. B, same in dorsal view. C, same in posterior view. D, pedicel and flagellum. E, clava mounted on slide. F, mesonotum. G, propodeum. H, fore wing. I, antenna. Abbreviation. pgg, postgenal groove. A, E & F, ex A. cerasiferus from Fraga, Huesca, Spain. G, ex A. ramosus from Banyulssur-Mer, Pyrénées-Orientales, France. B, D, G & I, ex A. cerasiferus from Pégairolles-de-l'Escalette, forêt de Parlatges, Hérault, France. C, ex A. cerasiferus from Aitona, Lleida, Spain.

FIGURES 12A–L. Bruchophagus ribesi. A–K, ♀. L, ♂. A, head in frontal view. B, same in dorsal view. C, antenna of first morphotype. D, antenna of alternate morphotype. E, clava mounted on slide. F, pro- and mesonotum. G, propodeum. H, metacoxa. I, fore wing. J, fore wing venation. K, metasoma. L, antenna. A, C, G, I, J & L, ex A. albus delphinensis from Vielha, Lleida, Spain. B, E & K, ex A. albus delphinensis from Vallée d'Ossoue, Gavarnie-Gèdre, Hautes-Pyrénées, France. D & F, female collected on flower spike of A. cerasiferus, Lapanouse-de-Cernon, Aveyron, France.

FIGURES 16A–G. Bruchophagus asphodelinae. A–F, ♀. G, ♂. A, head in frontal view. B, same in dorsal view. C, pedicel and flagellum. D, apex of antenna mounted on slide. E, mesosoma in dorsal view. F, fore wing venation. G, antenna. All specimens ex A. lutea, Vizzini, Monte Iblei, Sicilia, Italy.

FIGURES 20A–D. Bruchophagus lecomtei, ♀ [SEM photographs]. A, head in posterior view. B, clava. C, mesosoma in ventral view. D, petiole in lateral view. Specimen from Calpe, Alicante, Spain.

FIGURES 21A–H. Bruchophagus lecomtei. A–G, ♀. H, ♂. A, head in frontal view. B, same in dorsal view, C, pedicel and flagellum. D, antenna mounted on slide. E, mesonotum. F, propodeum. G, fore wing. H, pedicel and flagellum. A, C & G, ex A. fistulosus, Banyuls-sur-Mer, Pyrénées-Orientales, France. B & F, ex A. fistulosus, Sarroca, Lleida, Spain. E & H, collected on a flower spike of A. fistulosus, Mireval, Hérault, France.

FIGURES 25A–G. A–E, Eurytoma genale. A–D, ♀; E, ♂. A, head in frontal view. B, same in lateral view. C, antenna. D, pro- and mesonotum. E, antenna. F–G. Eurytoma pistaciae Rondani, ♀. F, antenna. G, hind leg and metasoma. All specimens from Vizzini, Monte Iblei, Sicilia, Italy; E. genale ex A. lutea, E. pistaciae from A. ramosus.