Charles McClintock of Sumitomo Chemical Australia examines the best methods for treating various ant infestations according to species and behaviour. 

Success with ant baiting largely comes down to bait choice – are you choosing the correct bait for the targeted species, to match their feeding preferences at that time of year? It’s not always easy, but here’s a brief summary of the recommended bait options for the key pest species.

Firstly, it is important to remember that in many cases, ant baits should be used as part of an ant management plan. Insecticide sprays, particularly ‘non-repellent’ products, insecticide granules and dusts all have a role to play depending on the ant species, the location of the problem and the level of infestation.

Secondly, it is important to remember that all ants are omnivorous – they all need a combination of carbohydrates, protein and fats to survive – it’s just that many species show a preference for a particular food group. To make life even more di cult, their preference may change during the season.

Black ants causing problems inside buildings, commonly the black house ant (Ochetellus glaber), white-footed house ant (Technomyrmex albipes) and the ghost ant (Tapinoma melanocephalum) tend to show a preference for sugar-based baits. However, it is important to identify the species, as although the black house ant can successfully be tackled by using baits alone as they have a single nest, single queen colony structure, the white- footed house ant and ghost ant with their multi-nest, multi-queen colony structure will need to be tackled with a combination of sprays and baits.

A number of brown ants can cause problems inside the home, such as the Singapore ant (Monomorium destructor), Pharaoh ant (Monomorium pharaonis, pictured above) and the coastal brown or big-headed ant (Pheidole megacephala). These tend to show a preference for protein and fats – the pharaoh ant has a well-known reputation for causing problems in hospitals where they feed o dried blood and other bodily fluids!

Although a multi-queen/multi-nest species, granular baits can be a good option for coastal brown ants

Such ants can be successfully treated with Synergy Pro from Sumitomo, a unique granular bait, as it contains two different food granules: one protein-based and one oil-based. Although these small ants can lift the Synergy Pro granules, often the holes they go through are too small for the granule to fit. The ants themselves may pick o pieces of the granule to make them small enough or another way to tackle these species is to grind up some of the granules and place them in a bait station.

Whereas treating ant problems indoors often focuses on bait treatments, dealing with ants outdoors generally requires a combination of sprays and insecticide granules, as well as baits. Partly due to their food preferences and partly due to the need to apply bait over a larger area, granular baits are often the preferred baiting format for outdoor treatments.

Green-headed ants (Rhytidoponera metallica) in lawns show a strong preference for protein, foraging on dead insects. They can be successfully targeted with granular baits, especially with one such as Synergy Pro that includes a protein granule. Protein is also a key component of baits to target tyrant ants, the fast moving, small black ants, which often occur in lawns.

Single queen species, such as the black house ant can be tackled using baits alone

Large infestations of coastal brown ants can be greatly diminished by using granular baits, but due to their multi-nest, multi-queen colony structure, even if they are eliminated from the property, it is likely they will move back in over time from the surrounding area.

Funnel ants can be successfully treated using fipronil-based sprays and granules. Until now, baits have not been an option, but Synergy Pro has shown success in controlling funnel ants in initial field trials in the southern species of funnel ant (Figure 1), more work needs to be carried out on the northern species and although the label allows for application on funnel ants, work is being carried out to fine tune the application technique to match the ants’ unique foraging behaviour.

Figure 1: Performance of Synergy Pro on the southern funnel ant

Although this provides a general guide for bait choice, before carrying out an application it is always wise to place a small amount of the bait in areas where the ants are active, to access acceptability. Synergy Pro provides pest managers with a bait that appeals to a wide range of species. Although the two separate food granules are designed to target protein and oil feeders, the inclusion of sugar means it can also be an option for ants with a sugar preference, especially in outdoor areas.

Charles McClintock, Professional Products Business Manager, Sumitomo Chemical Australia

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