Anoplolepis gracilipes

Ant identification can be done using morphological characters by a trained entomologist to species level. The Pacific Invasive Ant Key (PIAKey) and Pacific Invasive Ants Taxonomy Workshop Manual can both be used in identifying invasive ants in the Pacific region. A key diagnostic feature of A. gracilipes is the antennae, which have 11 segments and an antennal scape length more than 1.5 times the head length (Sarnat, 2008;Csurhes, 2012).
The detection method described below can be carried out in the field or in a port environment:
Bait station surveillance with high energy food source and visual inspection should be carried out to detect any suspected ants. Ant detection surveys should be conducted on sunny days between 20°C (18°C for cooler areas) and 36°C. Optimal temperatures are required to take advantage of the most favourable foraging conditions as an increase in temperature increases ant activity. Surveying is stopped if it rains or there is high wind.
Ensure survey/surveillance occurs within the defined ‘risk area’. A risk ais any place where an imported risk item (sea containers or imported timber, for example) has rested. Surveillance areas are defined as habitable ground within a 150 m radius of a risk site.
Visual Surveillance
Visual inspection should be carried out while conducting the bait station surveillance over the area and inspecting all trees and shrubs that are flowering or exhibit symptoms of sooty mould growth from eye height down. Where ants are found, collect specimens and place in labelled sample bottles. Mark each location where ants were found so that the locations can be found again.
Separate protein and sugar based baits should be composed and laid as follows:
Protein based bait: prepare protein based bait station (~60ml clear plastic container with a lid) by smearing in a line the blended peanut butter and soybean oil (the size of half a pea) to the inner side of each bait container on the side corresponding with the back of the label. In addition, a slice of processed sausage or smear of raw sausage meat is to be placed inside each pot.
Sugar based bait composition: prepare sugar based bait station by placing a plug of cotton wool soaked in 30% sugar solution inside the container, being sure to squeeze out the cotton ball to ensure ants can feed on the liquid without drowning. Alternatively, a smear of sugary jam may be used.
Each bait container (station) should be labelled with at least the date and the site name. Ants typically locate these baits with their natural foraging behaviour and will recruit additional worker ants to feed upon the bait.
Where the ant habitat is continuous, baits should be laid in rows 7-8 m apart, alternating between protein and sugar baits. Where the ant habitat is isolated, at least one of each bait type should be laid (minimum of one protein and one sugar bait stations within 15 square metres), ensuring they are at least 1 m apart. Ground locations of the bait stations should be marked with a crayon or spray paint spot during the course of surveillance. Bait stations should be collected approximately after two hours when temperature is between 20-24.9°C and after 30 minutes between 25-36°C after being laid. In the tropics bait stations should be placed in the shade where possible, as at temperatures above 28°C these baits are known to rapidly dry out, reducing their attractiveness to ants. Lids are put on the bait containers (station) to prevent ants escaping when they are collected. All bait stations should be sent to an entomologist to identify all samples in the bait station (as more than one species could be found in a bait station) and may require assistance from an expert to confirm the identifications (Sarty, 2007;Stringer et al., 2010;Gunawardana et al., 2013).