In order to slow down the dispersal of C. perspectalis, public awareness should be raised by communicating the risk of displacing eggs, larvae and pupae when moving infested box trees. The trade of infested box-trees may still be the most important dissemination pathway. Surveys of garden centres have shown that infested box trees are available for sale without the knowledge of the seller, most probably due to the difficult detection of early larval sages or eggs (Leuthardt et al., 2010).
Due to the high mobility of adults and the wide distribution of its host plant, the eradication of C. perspectalis is a difficult task once it has established itself in an area.
C. perspectalis was featured on the alert list of the European Plant Protection Organisation (EPPO) between 2007 and 2011. The pest has been removed from the list because of its wider distribution and rapid expansion that could not be controlled (EPPO, 2013).
In small trees, manual removal of larvae can be an effective control measure if it is repeated every 2-3 days.
The only detected parasitoids feeding on C. perspectalis in Europe are polyphagous species (Wan et al., 2014) and predation by birds is low, probably due to the high levels of toxic alkaloids sequestered by the larva (Leuthardt and Baur, 2013). Therefore, neither would be useful biological control agents. Trichogramma, pathogens and entomopathogenic nematodes are effective in the laboratory, but not yet in the field (Göttig and Herz, 2014; Wan et al., 2014). The introduction of specific parasitoids from the area of origin should be envisaged because it represents the only long-term control option in natural habitat. Unfortunately, little is known on the natural enemies of the moth in Asia.
Chemical control with contact or systemic insecticides are very effective but may harm natural enemies and other species using the box trees for shelters, such as arachnids and other insects. Insecticides working by ingestions are also very effective, although the lag until death of all larvae is usually longer. Biopesticides based on Bacillus thuringiensis are usually the preferred option on ornamental box trees because of their limited impact on the environment.
Monitoring and Surveillance
Monitoring of C. perspectalis populations and their life-cycle can be achieved by using UV-light traps or pheromone traps which are now commercially available (Göttig and Herz, 2014).
Even severely defoliated box trees are able to recover if they have not been severely debarked and if they do not suffer from renewed attacks. However, severely damaged box trees in an area where C. perspectalis has established itself are less likely to survive. This also applies to naturally occurring box trees in the understories of forests in the invaded range of C. perspectalis.