Small Honey Ant

Prenolepis imparis

Characteristics:

  • Workers 1/8 inch long, (monomorphic)
  • Antennae 12-segmented without club
  • Integument soft, flexible, smooth, shiny body
  • Thorax small, slender, with a strong constriction in the mesonotum
  • Abdominal pedicel composed of a single segment, the petiole
  • Have a circle of hairs at the tip of their abdomen

New colonies are started when the over wintering female and male alates make their nuptial flights from March to April. Even though mating flights occur, it appears that most mating takes place on the ground. In northern sections of the United States, the inseminated female sheds her wings and finds shelter in a crevice in the soil and starts a colony independently. In Florida, a colony may be founded by several fertile females that choose the same nest site. Brood is produced during mid- and late summer, but no brood is over wintered in the nest. Repletes, which are a worker "caste" that serves for food storage, hang from the nest chamber ceiling with their gaster greatly distended with honeydew. Colonies are small, containing only a few thousand individuals. In Florida, colonies may survive more than nine years, and workers may live at least two years. Unlike most ants, Prenolepis imparis is active above the ground during the winter and does not maintain a strict hibernation; it maintains a distinct aestivation period underground during the summer.

Distribution

The small honey ant is a native species, sometimes referred to as the false honey ant. It is also known as the winter ant, because it is more cold tolerant than other species that infest structures. It ranges from Ontario, Canada, to Nebraska, south to Texas and Florida, and also occurs in New Mexico, California, Oregon and Washington.

Small honey ant workers are monomorphic. They are dark brown to black, and the body is smooth and shiny. Workers are 0.08-0.16 inches (2-4mm) in length. The queen is similar to workers, but is larger, 0.28 inches (7mm) in length. Antennae are 12-segmented, without a club. The abdominal pedicel consists of a single segment, the petiole. This ant can be recognized by the strong constriction in the mesonotum that divides the slender thorax into two parts.

These ants commonly invade houses from outdoors but are capable of nesting indoors. Their nests may occur in soil associated with slab expansion joints. Entire colonies have been collected from potted plants. Small honey ants are persistent invaders and forage in trails. They contaminate and feed on a variety of household foods, such as sugar, syrup, honey, cakes, breads, fruits and meats. They damage plants such as roses and oranges by gnawing into the flower buds and other soft tissue to obtain sap or juice. They tend aphids, scale insects, and treehoppers for their secreted honeydew, which is a favorite food.

Management

Surveys should be done inside and outside the structure to locate all colonies. Outdoor colonies can be easy to eliminate because the nest chambers are small, containing several hundred to a thousand individuals with numerous queens, so the entire colony can be reached during treatment. Treatments should be made by injecting an appropriate residual insecticide, using a compressed air sprayer equipped with a crack-and-crevice tip, into the cracks and crevices. Indoors, a light amount of residual insecticide dust can be injected into cracks and crevices in uncarpeted areas where ants disappear into cracks. Carpet should be pulled back where ants were seen and treatments made directly to foraging ants. If there are no cracks where ants are following trails, the area can be treated with a wettable powder or micro encapsulated insecticide labeled for this type of application. For this treatment, use a compressed air sprayer set on fine fan spray. Sweet baits also can be an option.