Sycophila flavicollis (Walker 1834)

Gómez, J. F., Nieves-Aldrey, J. L. & Stone, G. N., 2013, On the morphology of the terminal-instar larvae of some European species of Sycophila (Hymenoptera: Eurytomidae) parasitoids of gall wasps (Hymenoptera: Cynipidae), Journal of Natural History 47 (47 - 48), pp. 2937-2960 : 2952-2953

Sycophila flavicollis (Walker 1834)

( Figures 4C , 5C , 6C , 7C , and 8C )

Description

Body length 1.2 mm (range 1.1–1.3; n = 11); body width 0.6 mm (0.5–0.67) ( Figures 4C and 5C ); body barrel-shaped, depressed dorsoventrally, tapering slightly posteriorly and with lateral margins of abdominal segments 1–6 almost straight; ratio L/W = 2.14; ventral margin of body segments 4–8 in lateral view straight or slightly convex; anterodorsal protuberances absent, the intersegmental membranes not protruding.

Dorsal margin of the vertex straight or slightly concave; ratio SA/DAV = 1.1; relative distance between the anteromedial setae of vertex about as long as the distance between antennae; anteromedial setae of vertex situated midway between anterior margin of vertex and the antennae; ventral margin of clypeus indistinct ( Figure 6C ); labrum with deep divisions almost reaching the level of labral setae, showing seven clearly differentiated lobes; maxillae well-differentiated from labium ( Figure 7C ).

Mandibles with two teeth, ratio L/W 1T = 2.4 ( Figure 8C ); apex of the second tooth slightly blunt; inner margin of mandible from the base of second tooth straight, not interrupted.

Remarks

Relatively similar in shape of body to the larva of S. mayri . Both species can be separated by the characters such as the ventral margin of clypeus and the shape of the apex of second tooth.

Biology

The species S. flavicollis is a polyphagous endoparasitoid reared from galls of different species of gall wasps on Quercus (Fagaceae) . It is usually associated with twig galls in subterranean or semi-subterranean locations. Specimens for this study were reared from sexual generation galls of Andricus quercusradicis (Fabricius) on Quercus faginea Lam. (Fagaceae) ( Figure 9F ).

Material examined

ex Andricus quercusradicis (sex.): Spain, Madrid: Dehesa de Arganda , 14 December 2003, J.L. Nieves leg, (n = 11) .

Figures

Figure 4. Ventral views of terminal-instar larvae. (A) Sycophila biguttata; (B) Sycophila binotata; (C) Sycophila flavicollis; (D) Sycophila mayri; (E) Sycophila submutica ex Isocolus scabiosae form rogenhoferi; (F) Sycophila submutica ex Isocolus lichtensteini.

Figure 5. Lateral views of terminal-instar larvae. (A) Sycophila biguttata; (B) Sycophila binotata; (C) Sycophila flavicollis; (D) Sycophila mayri; (E) Sycophila submutica ex Isocolus scabiosae form rogenhoferi

Figure 6. Anterior view of the head of terminal-instar larvae. (A) Sycophila biguttata; (B) Sycophila binotata; (C) Sycophila flavicollis; (D) Sycophila mayri; (E) Sycophila submutica ex Isocolus. scabiosae form rogenhoferi; (F). Sycophila submutica ex Isocolus lichtensteini.

Figure 7. Anterior view of mouthparts of terminal-instar larvae. (A) Sycophila biguttata; (B) Sycophila binotata; (C) Sycophila flavicollis; (D) Sycophila mayri; (E) Sycophila submutica ex Isocolus scabiosae form rogenhoferi.; (F) Sycophila submutica ex Isocolus lichtensteini.

Figure 8. Anterior view of the right mandible of terminal-instar larvae. (A) Sycophila biguttata; (B) Sycophila binotata; (C). Sycophila flavicollis; (D) Sycophila mayri; (E) Sycophila submutica ex Isocolus scabiosae (k) form rogenhoferi (k).

Figure 9. (A) Cross-section of gall of Andricus grossulariae showing chamber with fully-grown larvae of Sycophila biguttata; (B) habitus of Sycophila biguttata, adult female; (C) fresh galls of asexual generation of Andricus quercustozae on Quercus faginea.; (D) habitus of Sycophila binotata, adult female; (E) galls of asexual generation of Plagiotrochus gallaeramulorum on Quercus coccifera.; (F) cross-section of sexual gall of Andricus quercuradicis on Quercus faginea; (G) habitus of Sycophila mayri, adult female; (H) cross-section of Phanacis centaureae galls on stems of Centaurea spp.; (I) head and mandibles view of fully grown larva of Sycophila submutica ex gall of Isocolus lichtensteini; (J) habitus of Sycophila submutica, adult female; (K) larval cell of Isocolus lichtensteini with terminal-instar larvae of S. submutica; (L) fresh gall of Isocolus lichtensteini on Centaurea aspera.