Leather Jacket Warning: Any damage caused to your turf is usually superficial and most lawns will recover once the larvae metamorphosise into adults and fly away. In most cases the larvae will have no long-term effect on a lawn and will simply run their life-cycle unnoticed. Occasionally, however, and when populations are high there is a possibility that more severe damage can be caused, either via extensive larval feeding on the root system, or by surface damage caused by secondary predation, i.e. birds, mammals foraging for the larvae as a food source