Optimization of protein marking and detection system for the study of intercrop movement behavior of Lygus hesperus (Knight)

Lygus hesperus (Knight) (Hemiptera: Miridae) is an economically important pest of many field crops in the western USA. Information on movement and dispersal behavior of Lygus hesperus is very important in developing ecologically sound pest management strategies for this pest. Various movement detection methods can be used for the study of inter-crop movement behavior of Lygus, among which the protein marking technique is one of the novel approaches. The protocols for internal, external and field marking with bovine milk casein and chicken egg albumin protein have been optimized for the quantification of inter-crop movement of Lygus hesperus in a cotton-alfalfa farming system near Lubbock, Texas. The optimized technique was evaluated for quantification of inter-crop movement and host selection behavior of Lygus in cotton-alfalfa farming system of the Texas High Plains. In addition a 3-year field survey (2005-2007) was conducted to determine the field population dynamics of Lygus in a cotton-alfalfa agro-ecosystem system. Both field survey and protein marking studies revealed that alfalfa located near a cotton field acts as both a source and sink for the Lygus in cotton field. Depending on crop phenology and growth conditions, Lygus were found to move back and forth between cotton and alfalfa. Roadside alfalfa harbored significantly higher numbers of Lygus compared with near by cotton field thus Lygus preferred alfalfa over the cotton as a host. Successful application of milk casein and egg albumin protein markers for quantification of Lygus hesperus movement behavior by indirect ELISA technique will be discussed.