Browsing ant

Browsing ants originated in the drier climates of Southern Europe and the Mediterranean. They are an invasive species not previously found in Queensland, but they have been found in both Western Australia and the Northern Territory, where they are subject to eradication programs.

Globally, not a lot is known about browsing ants; however, they share traits and behaviours with other well-known invasive ants such as yellow crazy ants and red imported fire ants.

Browsing ants pose no threat to human health.

A single browsing ant colony can support many queens, making them able to form super colonies, which can seriously impact the surrounding native flora and fauna.

Scientific name

Lepisiota frauenfeldi

Similar species

  • Black crazy ant

Description

  • Small and slender.
  • Shiny black.
  • 3–4mm long.
  • Long antennae.
  • Long legs.
  • Body is tapered from the head to the abdomen.
  • Move in a similar manner to other known 'crazy ants', occasionally jerking as they walk across the ground.

Habitat

  • Prefer dry climates.
  • Adapt to the local landscape.
  • Do not build any obvious nest. They simply move into a space or cavity where they tend to the colony's eggs and larvae.
  • Nest in:
    • dry organic matter
    • piles of building rubble
    • gardens
    • structures
    • cavities in buildings
    • utilities pits.

Distribution

  • Current range is extensive, from Portugal west through parts of the Mediterranean, northern Africa, the Middle East and India.
  • Commonly found in:
    • Timor Leste
    • Malaysia.
  • Occur in:
    • Guam
    • Hawaii.

Life cycle

Browsing ants can form multi-queened, super colonies.

Fertile queens can:

  • bud off from the original colony
  • quickly form dense populations
  • establish super colonies where they eat other ants and compete for food and resources.

Worker ants will forage up trees and up to 50m from the nest.

Impacts

Environmental

  • Omnivorous—eat other ants and insects, spiders, centipedes and crustaceans.
  • Significantly affect our native biodiversity, either through predation or by competing with native animals.
  • Super-colonies can:
    • displace important local ant species
    • harm native vegetation
    • disrupt ecosystems.

Economic

  • Protect honeydew-producing scale insects, mealybugs and aphids, and feed on the honeydew as a reward. These insects reduce plant health and can spread serious disease, impacting agricultural and horticultural plants.

Social

  • Don't sting or produce venom.
  • Cause no recorded human health impacts, making them less obvious in human interactions than other invasive ant species.
  • Forage and nest in rubbish receptacles and outdoor areas such as:
    • yards
    • gardens
    • public parks
    • reserves
    • irrigation points.

Control

Check and report

Restrict movement of any cargo, materials or equipment. If you suspect browsing ant, call the Exotic Plant Pest Hotline immediately on 1800 084 881.

Surveillance

Biosecurity Queensland's browsing ant surveillance team locates nests or foraging browsing ants using:

  • lures—consisting of store-bought maple syrup or hot dogs placed in open specimen jars and laid on the ground about 5m apart. These are collected after 1 hour, which is enough time to attract a foraging ant. A qualified entomologist identifies the collected specimens
  • observation—trained officers perform a visual inspection to look for and sample any suspect ants
  • odour detection dogs to locate nests or foraging browsing ants—trained dogs can detect them, even when no visible signs of a nest are present. We also deploy dogs to confirm the success of previous surveillance and control efforts.

Treatment

Browsing ant nests can be difficult to detect; therefore, you should contact Biosecurity Queensland or a licenced pest control technician.

Legal requirements

Browsing ants are not a prohibited or restricted invasive species under the Biosecurity Act 2014; however, everyone has a general biosecurity obligation (GBO) to take reasonable and practical steps to minimise the risks associated with invasive plants and animals under their control.

Further information