Parasitoid communities and interactions with Diuraphis noxia in Australian cereal production systems

New information is presented on previously introduced aphid parasitoids using the newly arrived Russian wheat aphid (RWA), Diuraphis noxia Kurdjumov 1913 (Hemiptera: Aphididae) in South Australia including species diversity and relative abundance, population dynamics and regional differences in communities. In total, eight species of primary braconids (Hymenoptera) were identified from D. noxia: Aphidius colemani Viereck, 1912 A. platensis Bre`thes 1913, A. ervi Haliday 1834 (Hymenoptera: Braconidae), A. rhopalosiphi De Stefani Perez, 1902, A. salicis Haliday, 1834, A. smithi Sharma and Subba Rao, 1959, Diaeretiella rapae (McIntosh, 1855) and Lysiphlebus testaceipes (Cresson, 1880). The predominant parasitoids of D. noxia were D. rapae, A. colemani and A. platensis which was consistent across regions. This study indicates the pre-emptive importation of biological control agents (generalist parasitoid wasps) contributed to limiting an invasive pest. Data presented provides a baseline for further research on parasitoid species to reduce D. noxia, a new pest species in Australian cereal ecosystems.