When plant pest incursions take place there is a great deal of pressure on policy-makers to get the response right. They must make critical risk management decisions that have uncertain effects on complex agricultural, ecological and social systems despite knowing little about their resilience and adaptability to change. In this paper, we demonstrate how some of this uncertainty can be captured in a bioeconomic model to help guide response policy decisions using the example of coconut rhinoceros beetle (Oryctes rhinoceros), or CRB, in Hawaii.
CRB is a large beetle native to Southeast Asia capable of damaging palm species that has recently been introduced to the Hawaiian island of Honolulu. The beetle has caused severe damage to coconut palms (Cocos nucifera) on the island of Guam despite concerted efforts to mitigate its spread and impact there. The impact of CRB could be equally severe to native and introduced palm species in Hawaii resulting in substantial economic losses to commercial nurseries, as well as Hawaii’s residents and tourists who value palm trees for their aesthetic value.
We use data from CRB spread in Guam to validate a jump diffusion model of spread that is then used to predict the insect's future distribution and impact in Hawaii under different response policies. The costs of response actions and impacts of CRB on commercial nurseries and ornamental palms is simulated over a 30-year period, and the value of resultant damages compared. We find that eradication represents a net-benefit-maximising response provided the non-market (i.e. environmental and social) impacts of CRB exceed $6.9 million per annum.