Control at the border involves inspection of incoming goods and passengers and post-entry quarantine.
Border inspection of incoming goods
Ideally, all incoming goods including those brought in via a passenger pathway should be inspected by trained quarantine officers in a designated clean area. However, in situations where the volume of incoming goods is high, it may become necessary for a sub sample from each consignment to be checked. A few resources and tools are required to undertake border inspections (and post-entry quarantine checks).
Minimum sampling protocols should be devised to reduce the chances of ants being overlooked. These protocols are usually designed and undertaken by the exporter, and should afford the importer 95% confidence that the consignment has been checked and is below the importing country’s specified maximum pest limit (usually 0.5% of a consignment). Any ants detected must be reported immediately and the action advised by the in-country biosecurity team such as fumigation, cleaning, destruction or reshipping should be carried out as soon as possible.
Pathways for invasive ants
Invasive ants are typically "hitchhikers", travelling long distances secreted in or on cargo moved as part of human mediated trade or travel. Known pathways for invasive ants include:
- Sea containers
- Fresh produce (e.g. banana, taro)
- Cut flowers
- Potted plants (extreme high risk in the case of little fire ants)
- Copra shipments
- Personal effects
- Ships in dock, private yachts, cruise ships
- Gravels, sands and soils (these are usually prohibited imports as the risk of invasion is so high)
These pathways should be given special attention when inspecting incoming goods. Specific information for each species, based on reported interceptions of the 18 most harmful ant species in the Pacific can be found in this table.
Biosecurity / Quarantine declarations (arrival cards)
Post Entry Quarantine (PEQ)
Import Health Standards may specify a period of post entry quarantine for high risk items, or items from high risk areas before they are allowed to be released into the importing country. Typically PEQ is used to test for fungal and viral disease or stem burrowing larvae that might not immediately present symptoms in nursery stock and seed imports.
Although in some places regulations assume that detection of invasive ants usually occurs during border inspections, and PEQ is therefore not required, this is perhaps a less cautious approach than desirable. Also, post-border transportation of some commodities is desirable. For example, potted plants, which are host to little fire ants, should be subject to quarantine if they are leaving an area with little fire ants.
Preventative toxic baiting
- Strategically placed toxic bait at high risk sites such as entry points, devanning (container checking) sites and quarantine areas reduces the chances of undetected invasive ant species establishing
- Such baits may be in the form of liquids in pre-loaded bait stations or paste baits such as Vanquish® Pro. Contact sprays may also be used
- The manufacturer of each bait will issue guidelines for optimum bait application rates and these must be followed, particularly closely in high risk areas (e.g. where people may be affected, areas with high conservation values)
- Details about optimum bait application and area calculation
Read about an example of how this is done in the Sea Container Hygiene System case study.
content reviewed by Souad Boudjelas, Pacific Invasives Initiative, November 2016