Variation in the Acceptability of Cereal Grasses by Rhopalosiphum padi (L.) (Hemiptera: Sternorrhyncha: Aphididae) from Different Geographical Areas in Russia

Global warming and changes in grass biodiversity increase the vulnerability of agricultural crops to the harmful bird cherry-oat aphid, Rhopalosiphum padi. This study examined 23 wild grass species, wheat, and maize as hosts for R. padi. We studied aphid development on different hosts to estimate reproduction of apterous females and their progeny winging using clones of R. padi originated from the Krasnodar Region (Southern Russia) and two districts of the Leningrad Region (Northwestern Russia). Within the framework of “outdoor microcosm” experiments, a highly significant influence of the host, the regional origin of the clone, and the interaction of these factors was detected. The most favorable for R. padi development species (along with wheat and maize) were Poa trivialis, Lolium multiflorum, and Hordeum jubatum. The least suitable were Panicum miliaceum, Agrostis capillaris, Leymus arenarius, Setaria viridis, Elymus repens, and Bromus erectus. There was a tendency to decrease aphid reproduction on wild plants with the C4 type of photosynthesis. When feeding on less suitable host plants, R. padi offspring tend to develop wings quickly, even at low colony density, thereby triggering dispersal. Aphids showed some local trophic specialization: a negative correlation was observed between the offspring of one female during the first 14 days of breeding (P14) and its winging in clones collected from the Leningrad Region, but not from the Krasnodar Region, indicating some spatial heterogeneity in the ecological strategies of aphids. The results obtained may be useful for improving R. padi control systems.