Enhancement of Natural Control Function for Aphids by Intercropping and Infochemical Releasers in Wheat Ecosystem

Abstract

Wheat Triticum aestivum is the most important food crop in the world. In China, wheat is the second largest crop after rice in cultivated area, and its yield accounts for one fifth of China’s total grain output. Wheat aphids (Hemiptera: Aphididae) including Sitobion avenae, Rhopalosiphum padi, Schizaphis graminum as well as Metopolophium dirhodum can cause heavy economic damage to wheat both as phloem feeders and as vectors of plant viruses. Extensive application of pesticides are performed to control aphids in wheat fields, which has led to many well-known problems such as chemical residues and resistance to the applied pesticides in the target pest species. Increased attention needs to be paid to sustainable agricultural production by increasing natural control functions and ecological services. Intercropping and/or infochemical release techniques are potential alternative methods to reduce aphid damage through improving natural control functions in agroecosystems. Here we demonstrate how to increase the natural control function by optimizing the intercropping and infochemical release, and how to take phylogenic, phenological and physiological characteristics of intercropping plants or crops into practice. We also propose and show the infochemical screening, formulation production, and release equipment devises for field use. We suggest that entomologists, agronomists, ecologists, chemists, government officials, and farmers could work together to develop and demonstrate the new strategy and tactics to reduce pesticide use on crops, and to increase incomes to satisfy the ecological, economic and social constraints on the farms.