Surveillance programmes facilitate early detection of invasive ant species, allowing response to be rapid. In addition, regular surveillance assures trade partners that exports are safe. The information gathered also contributes to our wider knowledge of rates of spread of pest species.
Prevention is better (and cheaper) than cure! Surveillance of high risk sites is the best form of post-border defence against incursions of invasive ant species. High risk areas for entry of invasive ant species include seaports, airports, devanning sites, sea container storage sites and transitional facilities.
If an unwanted ant does invade, movement controls will ensure that it doesn't spread, particularly to high value sites.
- Active surveillance: where surveys are undertaken using a number of techniques including visual surveys, pitfall traps and attractive lures
- Passive surveillance: involves building public awareness of emerging biosecurity risks and acting on any sightings of target organisms that are reported
Surveillance can require a lot of resources, particularly time, but as the table below shows these costs are only a tiny fraction of what would need to be spent to control an established invader or of the economic and social costs invasive species can impose.
The MPI Surveillance Guide is an excellent resource that explains the various stages of planning surveillance with examples.
Extract from the New Zealand Ministry for Primary Industries Biosecurity Surveillance Guide (© New Zealand MPI)
Active surveillance involves looking for one or more species that are high risk and unwanted.
This type of surveillance can be time consuming, but finding a species early can save much time and money in the long run. New Zealand operates a National Invasive Ant survey (NIAS) to regularly check ports for high-risk invasive ants.
Surveillance techniques are typically very much the same as those used for delimiting, except rather than focussing on where you know the ant is and working from there, you might target secondary contact points e.g. where containers were moved to post entry. Another main difference is that every ant found should be identified, which can be difficult as there are thousands of ant species. This is why we generally advise focussing on major problem species if identification resources or skills are not available.
Enlisting the help of the general public is a cost effective way to monitor for incursions of invasive ant species. Public awareness campaigns using posters, leaflets, talks, radio advertising etc. are a good way to gather information about incursions. It is important that any awareness campaign has a clear line of communication and that well defined response protocols are in place to promote rapid deployment.
The biggest advantage of visual surveillance is the capacity to incorporate it into villagers’ everyday life. As soon as people know what they should look for, each person becomes a potential biosecurity inspector.
Surveillance capability can be increased by engaging the community. Posters, public talks and word of mouth can be used to raise general awareness of potential threat species.
Key messages should include:
You can use the PIAT to create your own posters based on the PIAT poster templates like the example on the right.
Posters should be placed in high risk areas such as on boats and ferries, and in ferry terminals, airports and importers sites. Posters should also be placed in high value sites such as reserves, market places etc., as well as community gathering places.
It is important to have a centralised group or individual that people can report their sightings to. These reports should be investigated promptly and feedback to be given to the reporter.
Poster in Gilbertese to raise awareness of the yellow crazy ant in Kiritimati, Kiribati