White-footed ants
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harms crops |
lives in trees |
lives on ground |
day active |
The three white-footed ant species (Technomyrmex spp.) are almost impossible to distinguish from each other without a good microscope. The PIAkey has an excellent comparison chart (you will need to click on the Comparison Chart tab) that illustrates the differences between the three, but even the experts sometimes get it wrong.
These ants also behave very similarly, so it is very likely that many impacts associated with the white-footed house ant (T. albipes) were actually caused by misidentified difficult (T. difficilis) or Fijian (T. vitiensis) or other species of white-footed ants, which is why we present information on the three in one section instead of a separate section for each. To make matters more confusing, Fijian white-footed ants are native to Fiji, so is not an invasive species there.
Difficult white-footed antScientific name: Technomyrmex difficilis Fijian white-footed antScientific name: Technomyrmex vitiensis White-footed house antScientific name: Technomyrmex albipes All white-footed antsSize: varies slightly between 2 and 4 mm, still considered monomorphic Colour: dark brown to black General description: the pointed abdomen of white-footed ants is quite distinctive. The lower half of their legs is contrastingly light compared to the rest of their body. Habitat and nesting: the difficult white-footed ant nest at or above ground level in close to sources of food and moisture. The ant will make its nest in wall void and attics of houses in urban areas, but nests are more typically found outside structure than in them. Nests may also be found in trees, bushes, stem or trunk holes and under rubbish, mulch, leaf litter or debris. The Fijian white-footed ant is typically a ground dwelling species that nests in leaf litter, under stones and in rotten wood. The ant may also build nests in rot holes and flowers in low lying vegetation. The white-footed house ant is mostly an above ground dwelling species that makes tent like nests in vegetation from debris. Nests are mainly found in trees, bushes and in leaf litter, but may also be found in rotting logs and occasionally in soil under stones. In urban areas the ants may nest in wall cavities and attics and are seen inside houses where they search in long trails for water. The white-footed house ant is typically found at elevations between 300 and 1500 metres. Rate of spread: unknown. Distribution: see our invasive ant distributions page for the worldwide distributions of these three species of white-footed ants. Reproduction: white-footed ants have an unusual reproductive system. As well as 'normal' queens and workers, these ants have intercaste workers. New colonies are founded by flying mated queens, but reproduction in established colonies is through the intercaste workers. This enables the colony to build up rapid numbers, and also makes management more complex. For detailed descriptions and identification of white-footed ants: |
One of the white-footed ant species foraging (© Meghan Cooling, Pacific Biosecurity)
Difficult white-footed ant workers (Technomyrmex difficilis) (© Mario David Bazan, Creative Commons License) Fijian white-footed ant worker (Technomyrmex vitiensis)(© AntWeb, Creative Commons Attribution, Share Alike CC BY-SA License)
White-footed house ant workers (Technomyrmex albipes) (© Quah, Ants and Termites of Malaysia) |
PIAkey: Technomyrmex albipes (see diagnostic characters tab)
PIAkey: Technomyrmex difficilis (see diagnostic characters tab)
AntWeb: Technomyrmex difficilis
PIAkey: Technomyrmex vitiensis (see diagnostic characters tab)
AntWeb: Technomyrmex vitiensis
Social, agricultural and environmental impacts of white-footed ant species
White-footed ants can be significant household pests as they are often found foraging in kitchens, bathrooms and on the outside of homes. They are attracted to light switches and may eventually cause them to fail.
These species farm various sap-sucking insects like scale insects and mealybugs on crop plants, often causing outbreaks of these pests.
Outbreaks can lead to the death of the plant and, because these bugs also carry plant viruses, the spread of pathogens such as pineapple wilt disease.
Currently white-footed house ants are causing problems in Fiji, where they form associations with mealybus, aphids, scale insects and whitefly. This mutualism has led to high ant and plant pest abundances, and the ants are invading peoples homes.
Fijian white-footed ants foraging on sugar bait in Fiji, Vimeo video. The other two white-footed ant species would look and act very similarly (© Eli Sarnat, Creative Commons Attribution, Share Alike CC BY-SA License) |
Fijian white-footed ants tending to aphids for their honey dew in Hawaii, Vimeo video. The other two white-footed ant species would look and act very similarly (© Eli Sarnat, Creative Commons Attribution, Share Alike CC BY-SA License) |
Information sources
AntWiki, Difficult white-footed ant, Fijian white-footed ant, White-footed house ant
Global Invasive Species Database (GISD)
Global Register of Introduced and Invasive Species (GRIIS)
PIAkey, Difficult white-footed ant, Fijian white-footed ant, White-footed house ant
Thaman. 2018. The 2016 Fiji ant-mealybug bioinvasion. Note that the species causing problems in Fiji has been confirmed as T. albipes (white-footed house ant) by New Zealand Ministry of Primary Industries and University of the South Pacific in Suva.
University of Florida webpage, Difficult white-footed ant
University of Hawaii Extension, White-footed house ant
Yamauchi, Furukawa, Kinomura, Takamine, Tsuji. 1990. Secondary polygyny by inbred wingless sexuals in the dolichoderine ant Technomyrmex albipes. Behavioral Ecology and Sociobiology. 29:313-319
Content reviewed by Eli Sarnat, Antwork Consulting, LLC, June 2017