Pest Information - Ants

There are almost 9,000 species of ants and they can be found from the Arctic Circle to the Tropics. This site will focus on the ants most commonly found in Hawaii. Learn about their Appearance, Habitat, Diet, Type of Damage, and Life Cycle.
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Big Headed Ant

Big-Headed Ant

Scientific Name

Pheidole megacephala (Fabricius)

Appearance

Big-headed ants are light brown to dark reddish brown, a have two sizes of workers.  One size is 1/8 inch long, has an enormous head and is sometimes called a seed cracker worker.  The minor workers (1/16 inch) do not have enlarged heads but can be recognized by the shape of their heads, which narrow abruptly behind the eyes.  Big headed ants have two nodes on their pedicel, one pair of spines on its thorax and 12-segmented antennae with a 3-segmented club.

Habitat

Big-headed ants are found in warmer and dryer sections of the United States, and have very similar habits to fire ants. Nests are found in exposed soil or under cover and in rotting wood.  They rarely nest indoors, but may invade homes to forage for food.  Big-headed ants prefer meats, greases, and breads.  They superficially resemble fire ants but can be distinguished from them by the presence of 12 segments in the antenna, with a 3-segmented antennal club.

These ants can be found nesting in the soil around homes in many areas of the United States.  They have become a persistent problem in the South, with reports of workers invading homes in their search for food.

Diet

Big-headed ants feed on live and dead insects, seeds, and the honeydew produced by homopterous insects (e.g., aphids, mealy bugs and scale insects). In houses, they seem to prefer protein foods, such as meats and peanut butter, but will also feed on greases and sweets such as fruit juices.

Type of Damage

This ant displaces most native invertebrate faunas directly through aggression, and as such is a serious threat to biodiversity. Evidence also exists of reductions in vertebrate populations where this ant is extremely abundant. Effects on plants and horticultural crops can be direct through the likes of seed harvesting, or indirect through the likes of harboring aphids and scales to feed on their honeydew, which reduce plant productivity. It is known to facilitate the invasion of introduced plant species. This ant is known to chew on irrigation, telephone cabling, and electrical wires.

Life Cycle

This ant's life-cycle developmental time and longevity of each stage is highly dependent on temperature. Incubation time of eggs ranges from13 to 32 days. Duration of the larval stage ranges from 23 to 29 days. Duration of the pupal stage ranges from 10 to 20+ days. The lifespan of minor workers has been shown to be 78 days at 21°C, and 38 days at 27°C.

Interesting Facts

Big headed ants nest in soil, sometimes with donut of dirt around the hole.