Host plant and habitat preferences of Lygus bugs: consequences for trap cropping applications

Abstract

Lygus bugs (Hemiptera: Miridae) can damage economically important crop plants by feeding on their active growing points, such as the apical meristem and buds, and reproductive organs, such as flower buds, flowers, seeds, and fruits. Plant injury is a combination of mechanical damage by the stylet and the effects of saliva, which contains enzymes that break the plant cells. On some occasions, oligophagous Lygus species can act as biocontrol organisms when predating on eggs and larvae of pest insects. This review summarises studies where trap crops have been used to control Lygus bug populations on various crops and to reduce damage to crops. We also focus on the factors that affect the host plant and habitat selection of the highly polyphagous Lygus bugs and discuss the reasons why a less favourable host plant in the laboratory might become attacked by Lygus bugs in the field. An analysis of rapidly developed worldwide Lygus damage problems in conifer nurseries in the late 1970s and early 1980s is presented as an example of how rapidly Lygus bugs can adapt to changes in environmental conditions and new types of crops. We suggest that the rate of crop irrigation and the efficiency of weed control could be factors augmenting Lygus populations and the severity of Lygus damage. These factors should also be considered in the planning of trap crop strategies for Lygus spp.