Coastal Islands Under Threat By Pest Ants Identified In Mackay

One of the World’s Worst 100 Invasive Species has been detected in Mackay, posing a serious threat to biodiversity.

The Department of Agriculture and Fisheries has confirmed the presence of African big-headed ants (Pheidole megacephala) in Mackay. These ants will displace most native insects through aggression.

African big-headed ants (ABHA) are widespread on the Australian mainland, making them extremely difficult to eradicate from the Mackay locality. However, Reef Catchments Coordinator Cass Hayward said that It’s very important to raise awareness now to prevent the ants being transported from Mackay to nearby islands.

One such project is the ABHA eradication program on Bushy Island, being delivered by Reef Catchments through the Australian Government’s Reef Trust funding. The ants threaten not only the food-web, but also the island’s forest of Pisonia trees, of which there are only 190 hectares in the entire country.

“African big-headed ants form super colonies, with multiple queens and very high numbers of ants per square metre. They force out native species through sheer numbers. They also protect sap-sucking insects, such as scale insects, which results in damage to trees,” Ms Hayward said.

“We ask people to care about what they are transporting from place to place. Just like you wouldn’t want damaging pests on your property, we don't want pests in fragile island environments.”

This isn’t the first time that African big-headed ants have damaged island ecosystems. The Pisonia forest on Tryon Island was almost completely destroyed due to scale insects and the pest ants. To avoid these situations, Reef Catchments offers some strategic advice for island visitors:

● Check your shoes for seeds and plant material. They are often stuck in shoelaces or in dirt/mud on the bottom of shoes.

● Take all food in airtight containers.

● Check your gear, such as swags and tents, for insects, insect eggs and plants.

● Many weeds can shoot from leaves and stems (not just seeds), so make sure to brush your gear down.

Invasive ant species can be easily transported in the clothing, food or equipment of recreational boaters, campers, hikers and day-visitors.  Once this happens, it can cost millions of dollars to control or eradicate the species.

Reef Catchments are holding an Invasive Ant Workshop on the 29th of November. The workshop aims to upskill staff at Ports, Harbours, Marinas and Councils so these key groups can be on alert for new introductions of invasive ants.

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