The Pharaoh ants are small ants, measuring from 1.5 to 2 mm (1/16th to 1/12th an inch) in size. The workers are all one size (monomorphic). The colour of Pharaoh ants colour varies from golden yellow to reddish. Pharaoh ants originated in and derive from the tropics, meaning they cannot survive outside in Canada year round.
Scientific Name – Monomorium pharaonis
Life cycle and habits
The pharaoh ant queen can lay hundreds of eggs in her lifetime. Most lay 10 to 12 eggs per batch in the early days of egg production and only four to seven eggs per batch later. At 27 °C (80 °F) and 80 percent relative humidity, eggs hatch in five to seven days. The larval period is 18 to 19 days, pre pupal period three days and pupal period nine days. About four more days are required to produce sexual female and male forms. From egg to maturity takes about 38 to 45 days depending on temperature and relative humidity. They breed continuously throughout the year in heated buildings and mating occurs in the nest. Mature colonies contain several queens, winged males, workers, eggs, larvae, pre pupae and pupae.
The Pharaoh ant is polygynous, meaning its colonies contain many queens (up to 200). An individual colony normally contains 1,000-2,500 workers but a high density of nests gives the impression of massive colonies. Colonies also lack nest mate recognition so there is no hostility between neighboring colonies, which is known as unicoloniality. They produce sexually reproductive individuals roughly twice a year in established colonies but in the laboratory colonies can be manipulated to produce sexual at any time of year. Colonies proliferate by “budding”, where a subset of the colony including queens, workers and brood (eggs, larvae and pupae) leave the main colony for an alternative nest site. Budding is a major factor underlying the invasiveness of Pharaoh ants. A single seed colony can populate a large office block, almost to the exclusion of all other insect pests, in less than six months. Elimination and control are made difficult because multiple colonies can also consolidate into smaller colonies and “weather the storm” of a baiting programme only to repopulate when baiting is withdrawn. Pharaoh ants are a major hazard in hospitals, where their small size means they can access wounds, drip lines, and instrumentation, causing the spread of infection and electrical interference.Females mate and procreate in the nest. The new colonies of Pharaoh ants are formed by budding. In budding process, the part of the main colony moves to a new location, and the number of ants in one colony may be up to hundreds of thousands. A female produces 350-400 eggs in her whole lifetime. Normally, the life cycle is completed in 38 to 45 days. The life span of workers is approximately nine to ten weeks, while queens live four to twelve months.
Occurrence
Pharaoh ants nest in a wide variety of locations within a structure. It is very difficult to control and locate them. It is essential to look near sources of water and food to locate them. Normally, they nest in warm, hard to reach areas such as walls, splash boards of kitchen counter tops and in wall sockets. Pharaoh ants have become a serious pest in hospitals, rest homes, apartment dwellings, hotels, grocery stores, food establishments and other buildings. They feed on a wide variety of foods including jellies, honey, shortening, peanut butter, corn syrup, fruit juices, baked goods, soft drinks, greases, dead insects and even shoe polish. They can also gnaw holes in silk, rayon and rubber goods.Pharaoh ants prefer meats or greases, but will also feed on sugar syrups and jellies.
Control
It is essential that Pharaoh ants are treated by using protein and sugar baits placed as close as possible to the nest areas.Renewing the baits once or twice may be necessary. It is recommended not to exterminate using sprays and dusts because they will cause the pharaoh ants to scatter. Proper cleaning of a dwelling also helps to minimize the infestation.
