The buffer zone, established in 2019, is a 10-kilometer radius around Perth, encompassing the city and surrounding suburbs. This zone is designed to prevent the spread of the pest to other parts of the Western Australian state. The buffer zone is a temporary measure, intended to buy time for the development of more effective control strategies. The invasive polyphagous shot-hole borer, also known as the “shot-hole borer,” is a beetle that attacks trees, causing significant damage.

This symbiotic relationship between borers and fungus is a complex one, involving a specific type of fungus called *Ophiostoma novo-ulmi*. This fungus is known for its ability to infect and kill trees, particularly those of the elm family. *Ophiostoma novo-ulmi* is a highly specialized fungus, meaning it has evolved to specifically target and infect certain tree species. The borers, on the other hand, are insects that feed on the wood of trees.

The emerald ash borer (EAB) is a destructive invasive insect that has devastated ash trees across North America. To combat this threat, local authorities have implemented a series of containment zones. These zones are designed to limit the spread of the EAB and protect healthy ash trees. There are two main zones: Zone A and Zone B. Zone A is the most heavily infested area, with high numbers of EAB beetles. It is characterized by suburbs with a high density of ash trees. Heavy restrictions are imposed on movement of plants, gardening equipment, and wood out of Zone A.