Pharaoh's Ant
Pharaoh's ants originated in the North Africa/Mediterranean region, spread along international trade routes and are now widely distributed. Their need for warm humid conditions means that in temperate lands they are confined to buildings. Infestations can he found in a wide variety of locations including residential blocks, hotels, hospitals and other institutions, food handling premises, zoos and on board ship. In warm climates infestations can be found outside.
The insects may be associated with the fabric of buildings (e.g. wall voids, windows, storage areas etc), plants and sterile supplies. Infestations spread through buildings by way of service ducts (e.g. heating and electrical conduits). The ants will forage for water around sinks and where condensation has occurred (e.g. windows, walls etc).
The ants can survive low temperatures for prolonged periods with the workers continuing to forage for food. The minimum temperature for success is 18ºC and the colonies thrive at 30°C. Infestations in buildings are relatively unaffected by the seasons although may be encouraged when heating systems are switched on during the winter.
Life Cycle
Pharaoh's ants are social insects and live in colonies. These range in size from a few dozen to 300,000 ants. Colonies consist of: workers (sterile females), fertile males and queens (fertile females). There are usually many queens in a colony (multi-queen colonies) and they co-exist amicably. The queens can he replaced so colonies will survive indefinitely. New colonies are typically formed by budding and may he encouraged by disturbing nests. Adult ants are responsible for this process which may include queens. Worker ants carry larval stages to anew nest site from which they can rear queens and males. Temporary nests may he established whilst the workers search for new sites. If established in mobile equipment infestations can he widely distributed.
The workers provide food for the colony and maintain the nest. Only 5-10% of workers are actually engaged in foraging. Fertile males and females develop from well fed larvae. Flying swarms are never seen, with mating taking place in the nests and interstices of buildings.
Each queen produces up to 350 eggs. These hatch in about a week to give legless larvae which are fed by the queens and tended by the workers. Larval development takes approximately three weeks. The pupal stage lasts about nine days. The whole cycle from egg laying to adult takes about 5½ weeks depending upon temperature.
Control
Successful control of Pharaoh's ants requires the destruction of nests. This is difficult to achieve because nests are often located in inaccessible places. You should seek professional help to control Pharaoh's ants.
