Andricus grossulariae Giraud, 1859

Shachar, Einat, Melika, George, Inbar, Moshe & Dorchin, Netta, 2018, The oak gall wasps of Israel (Hymenoptera, Cynipidae, Cynipini) - diversity, distribution and life history, Zootaxa 4521 (4), pp. 451-498 : 463-464

Andricus grossulariae Giraud, 1859

Host plants. Israel: Q. boissieri (asexual generation) and Q. ithaburensis (sexual generation). Elsewhere: several species from section Quercus (asexual generation) and section Cerris (sexual generation).

Life history. Until recently, A. grossulariae was known only from its sexual generation, but rearing experiments ( Walker 2002) and molecular data ( Stone et al. 2008) associated it with galls that had been traditionally attributed to the asexual generation of A.mayri / A.panteli , hence these two species were synonymized under A. grossulariae . The sexual generation induces conical, pointy catkin galls, up to 7 mm long, singlechambered, and usually in clusters. They are light green and soft when very young ( Fig. 49 ), turning bright red to deep purple and woody when mature ( Fig. 50 ). Old galls remain on the tree until the next year. The asexual generation develops in bud galls that are up to 50 mm in diameter, composed of thick, tapering projections that form a sphere ( Fig. 9 ), and are multi-chambered. They are bright green and sticky when young, turning light brown, woody, and not sticky when mature. Old galls may remain on the tree for a year.

Phenology. In Israel, galls of the sexual generation begin to develop in late February to early March and adults emerge from them in late March, but in higher, colder localities (e.g., Odem Forest and En Zivan) they develop later in the season and adults emerge in May. Galls of the asexual generation develop during the fall and adults emerge in January.

Distribution. Israel: Galls of the sexual generation are common and widespread throughout the distribution range of Q. ithaburensis in the country. Galls of the asexual generation are common in the northern part of Israel but are rare in Zur Hadassa (Judean Mountains). Elsewhere: A widespread and locally common species from Northern Africa through the Iberian Peninsula across Europe and the Balkans to Asia Minor, Iran and Caucasia.

Comments. Galls of the sexual generation are very similar to those of A. coriariformis on Q. libani , but develop on Q. ithaburensis . They are also somewhat similar to galls of A. vindobonensis ( Fig. 51 ) but differ from them in having pointed apices and in their bright red color when mature, whereas the galls of A. vindobonensis are kidney- or bean-shaped, and dull purple-green when mature. Galls of the asexual generation are somewhat similar to the less common morphologies of A. coriarius galls ( Fig. 16 ) but are more robust, and their lobes are shorter, more numerous and less tapered.

Figures

FIGURES 47–52. Sexual generation galls on Quercus ithaburensis. 47. Andricus cecconii; 48. Same, old gall; 49. Andricus grossulariae, young galls; 50. Andricus grossulariae, old galls (arrow); 51. Andricus vindobonensis; 52. Andricus coriarius.

FIGURES 5–10. Galls on Quercus boissieri. 5. Andricus lucidus, asexual generation (arrow) and Andricus moreae, asexual generation (bottom); 6. Andricus cecconii, asexual generation; 7. Andricus caputmedusae, asexual generation, young gall; 8. Andricus caputmedusae, asexual generation, mature gall; 9. Andricus grossulariae, asexual generation; 10. Andricus hystrix, asexual generation.

FIGURES 11–16. Asexual generation galls on Quercus boissieri. 11. Andricus curtisii; 12. Andricus chodjaii; 13. Andricus quercustozae, young gall; 14. Andricus quercustozae, mature gall; 15. Andricus coriarius, mature gall; 16. Andricus coriarius, old gall.