Vitex agnus castus and Euphorbia characias ssp. wulfenii as reservoirs of aphid parasitoids (Hymenoptera, Braconidae, Aphidiinae)

Abstract

The role of the self-sown shrubs Vitex agnus castus and Euphorbia characias ssp. wulfenii as reservoirs of aphid parasitoids was investigated. In field studies, V. a. castus grew adjacent to an orchard of Citrus sinensis and E. characias ssp. wulfenii adjacent to an orchard of Prunus dulcis. The relative abundance of the parasitoids of Aphis viticis Ferrari on V. a. castus, Toxoptera aurantii (Boyer de Fonscolombe) on C. sinensis, Aphis euphorbiae Kaltenbach on E. characias ssp. wulfenii and Brachycaudus amygdalinus (Schouteden) on R dulcis in various parts of Greece was assessed during 1996-2005. Aphidius colemani Viereck predominated on A. viticis and T aurantii in all sampling cases. In contrast, Ephedrus persicae Froggatt was the dominant species parasitizing A. euphorbiae on E. characias ssp. wulfenii and B. amygdalinus on R dulcis. Furthermore, to illustrate the agro-ecosystem relationships through the reservoirs, we present the distribution and host range patterns of parasitoids associated with aphids on V. a. castus and Euphorbia spp. in southeastern Europe. A key for the identification of aphid parasitoids on V. a. castus and Euphorbia spp. is provided.