Likelihood of entry is: unlikely with high uncertainty. We assume there have been extensive imports of hosts’ plants from New Zealand over many years, but there are only two confirmed cases where O. hirta is known to have arrived in UK from New Zealand (1x 1983, 1x 2010). The evidence suggests that this is a rare event. However, like other internal feeders, O. hirta is difficult to detect and this does not mean that O. hirta has not already arrived, escaped detection and established. A rigorous national survey would help determine if this beetle had already established in the UK. 

Likelihood of establishment is: likely with low uncertainty. The climate of New Zealand and UK is very similar. Hosts are available in UK. In New Zealand O. hirta can cause serious damage to species native to Britain. 

Economic impact is expected to be: medium with moderate uncertainty. In the UK, the main host, Citrus, is not a commercial fruit crop although it has value as an ornamental. Forestry (hardwood and softwood) and amenity trees, in addition to top fruit and ornamentals are at risk. 

Endangered area: the south east of England is considered the most endangered area of the UK although O. hirta does present a risk to all parts of the UK. 

Risk management: cerambycid beetles are difficult to detect. Once detected the most effective means of control is through the destruction of infested trees.