Environmental Safety of Inundative Application of a Naturally Occurring Biocontrol Agent, Serratia entomophila

The grass grub, Costelytra zealandica (White) (Coleoptera: Scarabaeidae), has been one of New Zealand’s most troublesome grassland pests. It is one of a small number of endemic insects that have been able to flourish in the modified grassland habitats of New Zealand developed by the European settlers. Grass grub has been recorded as a pest since the origins of pasture development for grazing animals. The insect is widespread throughout the country and has been well known as a chronic problem, reducing persistence and yield of sown pasture, and sometimes occurring in outbreaks that cause total pasture loss.