Effects of cycloxaprid, a novel cis-nitromethylene neonicotinoid insecticide, on the feeding behaviour of Sitobion avenae

BACKGROUND: Cycloxaprid with cis-configuration is a novel neonicotinoid insecticide, developed in China, that has good industrialisation prospects for its high activity against imidacloprid-resistant pests. Studies were carried out to investigate the biological activity of cycloxaprid and its effect on the feeding behaviour of Sitobion avenae. RESULTS: The results demonstrated that cycloxaprid had good contact and root-systemic activity. The electrical penetration graph (EPG) revealed that cycloxaprid significantly increased the total time of non-probing periods and greatly inhibited phloem ingestion of treated aphids because it significantly reduced the total time and the frequency of phloem ingestion. Furthermore, cycloxaprid can increase the phloem salivation of treated aphids by comparison with aphids treated with imdacloprid and distilled water. Consequently, a sublethal dose of cycloxaprid impaired aphid ingestion of phloem sap and thereby reduced the weight of aphids. On the other hand, EPG data showed that a sublethal dose of cycloxaprid had no significant effect on xylem sap ingestion, in contrast to imidacloprid. CONCLUSION: All these tests indicated that cycloxaprid had both contact and root-systemic activity, with sublethal effects resulting in reduction in Sitobion avenae phloem-feeding behaviour and growth rate. Copyright (c) 2012 Society of Chemical Industry