Special considerations for tree planting
Before planting trees in known wingless grasshopper-infested areas, use insecticides for at least one or two seasons to reduce infestations. Locate and treat emergence sites. Since wingless grasshoppers do not move far, but tend to drift between tree areas and pasture, effective control over an area for at least one or two years is needed. Remove sources of infestation by locating and treating the emergence sites. Extend the treatment outwards to increase the grasshopper-free area.
Since the grasshoppers do not move freely through dense vegetation, planting trees into a crop should provide some protection for one or two seasons.
Alternatively, the movement of grasshoppers from open paddocks into plantations may be impeded by planting high density guard rows of cereal rye or triticale along the edges of shelterbelts. These also protect seedlings from wind and sandblast in the first years of growth.
Two metre-wide cultivated strips maintained on either side of tree plantings can provide ideal sites for bait placement. If fences are erected around tree plantings, the growth of a thick grass barrier between the trees and fence also reduces grasshopper movement into the planting site.
Protect existing trees by fencing them off; this encourages plant cover and reduces the amount of bare, sandy ground ideal for egg laying.
Individual trees can be protected with mesh fences or products which when placed around the trunks of young trees, prevent the grasshoppers from climbing into the foliage.
Planting resistant species of trees into shelter belts is another alternative. Contact the Department of Biodiversity, Conservation and Attractions - Parks and Wildlife Service for information on such species.