C17 Preventing the introduction of invasive alien 
species is the most cost-effective management 
option (Figure SPM.6) (well established) {5.5.1}. 
Prevention measures through pathway management, 
including strictly enforced pre-border quarantine, import 
controls and border biosecurity, have increased interception 
rates and slowed the rate of invasive alien species arriving 
and establishing globally (well established) {5.4.3.1, 5.5.1}. 
For example, in Australasia, the number of interceptions of 
Halyomorpha halys (brown marmorated stink bug), 
recognized as a major threat in the agricultural sector, have 
declined following implementation of a systems-based 
pathway management approach (well established) {5.5.1}. 
Measures to address escape from confinement are also 
necessary (established but incomplete) {5.3.1.1}. It is, 
however, difficult to prevent further natural dispersal of 
invasive alien species from a previously invaded range (well 
established) {5.5.1, Box 1.6}. Prevention is important on 
islands and in ecosystems where eradication poses 
significant technical challenges (well established) {5.3.2}. 
Effective prevention measures depend on adequate and 
sustained funding, capacity-building, technical and scientific 
cooperation, transfer of technology, monitoring, and relevant 
SUMMARY FOR POLICYMAKERS
19SUMMARY FOR POLICYMAKERS
BACKGROUND
Table SPM 1 Objectives and actions for managing biological invasions. 