Common ant species

Some ant species live in colonies that are supported by a single queen while others are supported by multiple queens. Although there are 40 ant species known in New Zealand, there are relatively few that we commonly see as pests. These include:

Argentine ant

(Linepithema humile)

Appearance

• Workers about 1.6mm long.
• Light to dark brown in colour.
• Do not swarm.
• Bite – do not sting.

Life cycle and habits of the Argentine ant

Lifecycle

• Worker ants produced in spring and increase in numbers up until autumn.
• Winged ants (reproductive Kings and Queens), produced in early spring, before the workers, mature within three months and mate soon afterwards.
• Argentine ants mate in their nest so no swarming is seen.

Habits

• Worker ants will follow food trails for long distances so nests are not easy to track.
• They prefer sweet foods but will also eat live and dead insects, meats, cereals and damaged fruit.
• Argentine ants drive out other ant species from an area.

Black house ant

(Ochetellus)

Appearance

• Shiny and black.
• 2.5 - 3mm long.

Life cycle and habits of the Black house ant

Lifecycle

• Larva hatches out of the egg as a white grub which is narrower towards the head. They are fed by the adults.
• The larva pupates and appears creamy-white, looking similar to an adult. Sometimes they have a protective silk cocoon around them.
• The adult emerges with the three defined body sections: head, thorax and abdomen.
• The length of time between the egg stage and ants emerging as adults can take 6 weeks or more; it depends on a variety of factors such as the species of ant, the temperature and the availability of food.
• Fertilised eggs become female, unfertilised become males.

Habits

• These ants are regarded as a nuisance and scavenge in kitchens, garbage and also dog excrement, therefore potentially spreading diseases such as salmonella.
• 'Common Ants' include the intensely black 'Black House Ants', and they are attracted to sweets.
• The light yellowish brown 'Coastal Brown Ant' prefers to feed on meat products and grease.
• The most effective control measure is to find the colony and treat it.

Fire ant

(Solenopsis spp)

Appearance

• Queens 1.59cm long. 
• Workers 3.18mm-6.35mm long. 
• Coppery–brown on the head and body, with a darker abdomen. 
• Solenopsis has a very distinctive two–segment antennal club, which is most visible in the front view of the female reproductive ant.

Life cycle and habits of the Fire ant

Lifecycle

• After swarming from the nest and mating, the queen searches for a suitable spot to lay her eggs. Once found, she can lay up to 125 eggs in late Spring. 
• Larvae hatch within 8 to 10 days, and the pupal stage lasts for 9 to 16 days. 
• Larvae feed on secretions from the queen’s salivary glands and broken down wing muscles until the first worker ants emerge. After this first batch of larvae moult into workers the queen’s role returns to egg laying – she can lay up to 1500 per day. Worker ants continue with larval care, nest building and food foraging. 
• Fertile males are produced later in the season.

Habits

• Foraging workers diet consists of dead animals, including insects, earthworms, and vertebrates. Workers also collect honeydew and forage for sweet food, proteins, and fats. 
• Swarming characteristics – mating between queens and fertile males takes place on the wing mid to late Summer. Males perish after mating. 
• Nest locations can be a mound of up to 40 cm or next to objects found on the ground, e.g. logs. 
• If aggravated, these react aggressively and can inflict a painful sting, resulting in a pustule some 48 hours later. 
• These ants are a major agricultural and urban pest, destroying crops and invading residential areas both outdoors and indoors.

Ghost ant

(Tapinoma melanocephalum)

Appearance

• Pale/Translucent legs and abdomen.
• 1.6mm long.

Life cycle and habits of the Ghost ant

Lifecycle

• Continuous breeding colonies.

Habits

• Feeding – indoors: sweet substances and grease; outdoors: insects that produce honeydew.
• Nesting – indoors: small spaces, wall voids; outdoors: in flowerpots, under objects on the ground, under loose bark.
• Locations - attracted to high moisture areas, can be found in kitchen and bathroom cabinets.
• Colonies can occupy several different nesting sites.

Green head ant

(Rhytidoponera spp)

Appearance

• 5-6mm. 
• Black with metallic green head. 
• Distinctive appearance and odour

Life cycle and habits of the Green head ant

Lifecycle

• The ant’s life cycle passes through egg, larva, pupa, and adult phases.

Habits

• Typically nests in small colonies under paths and among rockeries. 
• They live in bushy and urban areas. 
• Feeds mainly on materials of vegetable origin. 
• Rarely enters houses. 
• Can inflict a painful sting to humans.

Odorous house ant

(Tapinoma sessile)

Appearance

• Brown or black. 
• 1.59mm-3.18mm long. 
• Antennae have 12 segments and are not terminated with a club. 
• 6 legs.

Life cycle and habits of the Odorous house ant

Lifecycle

• Time to adult phase of development is 34-38 days. 
• Typically live for several years.

Habits

• Feeding - eat most household foods, especially sugary food, eg sweets and fruits such as melon. Also eat pet food. 
• Locations – attracted to moisture. In hot, dry environments nests can be found in house plants and even lids of toilets. 
• Odour - produce a coconut smell when crushed. 
• Colonies - range in size from 100-10,000.

Singapore ant

(Monomorium destructor)

Appearance

• 2-3mm. 
• Light brown with darker posterior abdomen. 
• Head flattened and blocky.

Life cycle and habits of the Singapore ant

Lifecycle

• The ant’s life cycle passes through egg, larva, pupa and adult phases.

Habits

• Eats a variety of food materials, including protein and sugar-type materials. 
• Typically nests in and around buildings, in cracks, crevices, wall cavities, behind skirting, under paths etc. 
• The most problematic feature of this pest is its attraction to plastics in electrical, irrigation and other equipment. 
• It has a fairly painful sting.

Southern ant

(Monomorium antarcticum)

Appearance

• Worker 3-5mm
• Some are orange, others are black in colour

Life cycle and habits of the Southern ant

Lifecycle

Continuous breeding colonies.

Habits

• This species is a general savenger Workers forage haphazardly rather than following specific routes, which is in line with the apparent absence of trail pheromones.
• They live in most habitats, such as forest, open grassland, rotting logs and gardens. Nests can be small or highly populous with thousands of workers; construction can be complex with galleries at different levels, particularly in soil under stones.
• They gather plant seeds, storing them as food in their nests.

Sugar ant

(Camponotus app)

Appearance

• This species vary greatly in shape, size and colour. 
• Range from 2.5 to 15 mm, and are some of the most often seen ants due to their size and often bright in colouring.

Life cycle and habits of the Sugar ant

Lifecycle

• The ant’s life cycle passes through egg, larva, pupa and adult phases.

Habits

• Often nests in a variety of sites ranging from holes in wood to the roots of plants, twigs of trees and shrubs, between rocks or in the soil. 
• They can also be seen during the day however, they are most active at night. 
• They are unable to sting, but they do possess strong mandibles which can bite. In self-defense these ants are also able to spray acid from their abdomens to deter predators. 
• They feed on dead and lives insects, household waste and are attracted by sweet food. 
• They rarely enter houses.

Whitefooted house ant

(Technomyrmex difficilis)

Appearance

• Dark brownish / black colour.
• Yellow-white feet.
• Approx 3mm in length.

Life cycle and habits of the Whitefooted house ant

Lifecycle

• A colony can contain up to a million ants, thus these are very invasive ants which can be hard to eradicate.
• Nearly half a colony is made up of fertile females so reproductive capabilities are huge. These are winged and larger than wingless females.
• Winged males mate once before they die, wingless males are capable of multiple mating.
• Adult workers are wingless females and are the ones seen looking for food.

Habits

• They do not bite or sting.
• Although colonies are vast in numbers, they tend to spread out into satellite colonies which nest in different locations.
• Ideal nesting locations outside include trees - in trunks or galleries that might have once been created by termites, under loose bark or plant debris, nearer the home in attics, under roof shingles, in wall voids, along fences and in outdoor furniture. Indoors they can be found in the kitchen area near bins or where food is stored or prepared.
• These ants are attracted to sweet substances - plant nectars, flowers and sweet human food substances. Also attracted to aphids and mealy bugs which secrete honeydew.
• Most likely to be seen foraging for food in large numbers, most likely at night if temperatures are high.