Pharaoh ant
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2008-07-12T13:42:08Z
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Date the maintenance tags or general fixes
{{Unreferenced|date=September 2007}}
{{Expand|date=June 2008}}
{{Cleanup|date=January 2008}}
{{Taxobox
| image =
| image_caption = ''M. pharaonis'' worker
| image_width = 200px
| regnum = [[Animal]]ia
| phylum = [[Arthropod]]a
| classis = [[Insect]]a
| ordo = [[Hymenoptera]]
| familia = [[Ant|Formicidae]]
| genus = ''[[Monomorium]]''
| species = '''''M. pharaonis'''''
| binomial = ''Monomorium pharaonis''
| binomial_authority = ([[Carolus Linnaeus|Linnaeus]], 1758)
| range_map =
| range_map_width = 250px
| synonyms =
''Formica pharaonis''
}}
The '''pharaoh ant''' (''Monomorium pharaonis'') is a small (2 [[millimetre|mm]]) yellow or light brown, almost transparent [[ant]] known for being a major [[building|indoor]] [[nuisance]] [[pest (animal)|pest]], especially in [[hospital]]s. The origin of this 'tramp' ant is uncertain, although favoured alternatives include West Africa and Indonesia. The Pharaoh ant has been introduced to virtually every area of the world including [[Europe]], the Americas, Australasia and [[Southeast Asia]]. Pharaoh ants are a tropical species but they thrive in buildings anywhere, even in temperate regions provided central heating is present.
[[Image:Pharaoh Ant close up.JPG|left|thumb|400px]]
Unlike most ants the Pharaoh ant is polygynous, meaning its colonies contain many queens (from 2 to over 200). An individual colony normally contains 1000 - 2500 workers but a high density of nests gives the impression of massive colonies. Colonies also lack nestmate recognition so there is no hostility between neighbouring colonies. Pharaoh ants lack the normal cycle of reproduction observed in most ants; they are able to produce sexual reproductive individuals as required. Laboratory colonies exhibit weak reproductive cycles but this cannot be assumed to be the natural condition.
Colonies reproduce 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 the 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 contract into smaller colonies and 'weather the storm' of a baiting programme only to rebound when baiting is withdrawn.
Pharaoh ants are a major hazard in [[hospital]]s, where their small size means they can access wounds, driplines, and instrumentation, causing spread of infection and electrical interference.
Pharaoh ants have become a serious nuisance 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]]. Also, these ants gnaw holes in [[silk]], [[rayon]] and [[rubber]] goods. In hospitals, foraging ants have been found in surgical wounds, I.V. glucose solutions, sealed packs of sterile dressing, soft drinks, water in flower displays and water pitchers. These ants are capable of mechanically transmitting diseases and contaminating sterile materials. Some feel ''[[Staphylococcus]]'' and ''[[Pseudomonas]]'' infections, occurring from time to time in hospitals, are associated with these ants.
== Identification ==
Pharaoh workers are very small (about 1/16-inch long, or 2.0 milimeters), light yellow to reddish brown in color with the abdomen (hind portion of body) somewhat darker. There is a stinger. The petiole (narrow waist between the thorax and abdomen) has two nodes and the thorax has no spines. Eyes are poor and possess on average 32 ommatidia. The antennal segments end in a distinct club with three progressively longer segments.
== Life Cycle and Habits ==
Female Pharaoh ants can lay 400 or more 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 80°[[Fahrenheit|F]] (27°[[Celsius|C]]) and 80 percent [[relative humidity]], eggs hatch in five to seven days. The larval period is 18 to 19 days, prepupal period three days and pupal period nine days. About four more days are required to produce sexual female and male forms. The entire life cycle takes about 38 to 45 days depending on temperature and relative humidity. Unlike most ants, they breed continuously throughout the year in heated buildings and mating occurs in the nest. A single queen can produce many hundreds of workers in a few months. Mature colonies contain several queens, winged males, sterile females or workers, eggs, larvae, prepupae and pupae growing to as large as 2,500 or more members. Unicoloniality means that contiguous colonies can give the impression of massive [[Group size measures|colony size]], when in fact one is observing a supercolony which may contain many hundreds of thousands of individuals from dozens of smaller, separate colonies.
Pharaoh ants engage in a behavior pattern known as "satelliting," "fractionating" or more usually "budding". Part of the colony migrates to a new location, which contrasts with the more common mechanism of colony reproduction where single females disperse and independently found colonies after a reproductive swarm. A queen together with a few workers carrying immatures (eggs, larvae and pupae) leave the nest and set up a new colony elsewhere. Budding is a major factor in the rapid spread of infestations.
Nests can be very small for example, located between sheets of paper, in clothing or laundry, furniture, foods, etc. Nests usually occur in walloids, under floors, behind baseboards, in trash containers, under stones, in cement or stone wall voids, in linens, light fixtures, etc. They prefer dark, warm areas near hot water pipes and heating tapes, in bathrooms, kitchens, intensive care units, operating rooms, etc. They are "trail-making" ants and often are found foraging in drains, toilets, washbasins, bedpans and other unsanitary sites as well as in sealed packs of sterile dressing, intravenous drip systems, on surgical wounds, food and medical equipment.
== Management ==
Control of Pharaoh ants is difficult, due to their nesting in inaccessible areas. Treatment must be thorough and complete at all nesting sites, as well as the foraging area. Thus, treatment must include walls, ceilings, floor voids, and electrical wall outlets. Baits are now the preferred method of control for Pharaoh ants and several baits (insecticides) are labeled for indoor ant control. A Pharaoh ant infestation of a multifamily building requires treatment of the entire building to control the infestation. Ants nesting on the outside may be controlled by also using a perimeter barrier treatment (Smith and Whitman 1992).
Baits cannot be placed in just any location and be expected to work. Pharaoh ant trails and their resources (both food and water) must be located for proper placement of baits and effective control (Klotz et al. 2000). Non-repellent baits (such as boric acid, hydramethylon or sulfonamide) should be used, as repellent baits can worsen the situation by causing the colony to fracture and bud. As a result, ant activity will briefly diminish as as the new colonies establish themselves, then again become a problem as the foragers resume activity (Smith and Whitman 1992).
In addition, insect growth regulators (IGR) are marketed for indoor control of Pharaoh ants. The IGR is used as a bait, and ants must be allowed to transport the bait back to their nests. The IGR prevents the production of worker ants and sterilizes the queen. Therefore, it is necessary to allow up to several weeks or months (depending on the size of the colonies or number of colonies) for ants to die naturally with the use of IGR.
== '''Ant Management Guide''' ==
{{Cleanup|section|date=July 2008}}
[http://edis.ifas.ufl.edu/IG080 University of Florida IFAS Extension http://edis.ifas.ufl.edu/IG080]
'''Introduction'''
Ants are pests around the home because they feed on and contaminate human foods, infest structures, and build unsightly mounds in lawns. In some cases, ants are able to inflict painful bites or stings. Ants do not attack or eat fabrics, leather or wood in houses; however, some species can establish nests in decaying wood in structures.
Several species of ants are found in or around houses in Florida. In general, the most common ants can be grouped as house-infesting ants, yard-infesting ants, and carpenter ants. The most commonly encountered pest ants are pharaoh, ghost, carpenter, native fire, imported fire, crazy, thief, acrobat, and big-headed ants.
'''Identification'''
Ants can be recognized from other insects because they have a narrow waist with one or two joints (nodes) between the thorax and abdomen. Also, ants have elbowed antennae. Winged reproductives have four wings with the first pair being much larger in size than the hind pair.
Ants are frequently confused with termites. However, termites have a broad waist between the thorax and the abdomen. Termite reproductives have four wings of equal size.
'''Biology'''
Ants are social insects. Two castes (workers and reproductives - females and males) can be found in most colonies. Worker ants, which are sterile females, are seldom winged. They often are extremely variable in size and appearance within a given species (monomorphic - one form; dimorphic - two forms; polymorphic - many forms). The function of the worker is to construct, repair, and defend the nest; and feed the immature and adult ants of the colony, including the queen.
Reproductive females normally have wings but lose them after mating. Therefore, queens do not have wings. The primary function of the queen is reproduction; however, in some of the more highly specialized ants the queen cares for and feeds the first brood of workers on her salivary secretions. The queen may live for many years and in some species is replaced by a daughter queen. Depending on the species, ants can have one or more queens.
The male is usually winged and retains its wings until death. The sole function of the male is to mate with an unfertilized female reproductive. After mating occurs, the male dies. Males are produced in old or very large colonies where there is an abundance of food. After reaching maturity, the male usually doesn't remain in the colony very long.
Ants have an egg, larva, pupa, and adult stage. Eggs are almost microscopic in size and hatch into soft legless larvae. Larvae are fed by workers, usually on predigested, regurgitated food. Most larvae are fed liquids, although some older larvae are able to chew and digest solids. The pupa resembles the adult except that it is soft, uncolored and immobile. In many ant species the pupa is in a cocoon spun by the larva. Six weeks to 2 months are required for development from egg to adult in some species.
Ants establish new colonies by two main methods: flights of winged reproductives and budding. The most common method is for male and female reproductives to leave the nest on mating flights. The mated queen constructs a cavity or cell and rears a brood unaided by workers. The small first brood workers then forage for food. The colony grows in size and numbers as more young are produced.
Budding occurs when one or more queens leave the nest accompanied by workers who aid in establishing and caring for the new colony. Some of the most difficult ant species to control spread colonies by budding. Pharaoh ants, some kinds of fire ants, ghost ants, and Argentine ants spread colonies by budding.
'''Food Preferences'''
Most ants eat a wide variety of foods, although some have specialized tastes. Fire ants feed on honeydew, sugars, proteins, oils, seeds, plants and insects. Pharaoh ants ( Figure 3 ) feed on sugars, proteins, oils and insects. Crazy ants (Figure 7 ) like sugars, protein, and insects; carpenter ants prefer sugars and insects.
Ants use scouts to locate food. When a scouting ant finds promising food, she carries it or a piece of it back to the nest. Some ants leave scent trails that others can follow to the food source. Ants require water and will travel some distance for it if necessary. Workers are able to bring water to the colony in their guts.
Despite their name and where they are found, Florida carpenter ants ( Figure 8 ) do not eat wood (as is the case with termites) but excavate galleries in it to rear their young. They feed on honeydew from sucking insects and household food scraps and do not damage sound wood to any extent.
'''Control'''
Prevention. Prevention is the best line of defense against the establishment of any pest insect. Relatively small ants, such as the white-footed ant can fit through extremely small openings to gain access into the home. If these entry points can be located, they can be blocked by application of caulk or some other exclusion device. This can also help to prevent other insects from gaining access into your home.
The best approach to ant control in the home is cleanliness. Any type of food or food particles can attract and provide food for ants. Store food in tight containers. Remove plants that can attract ants or control aphids, whiteflies and other insects that produce honeydew. Reduce moisture sources, including condensation and leaks.
Inspection. Location of the nest is the key to control because ants are social insects. Large numbers of individual ants can be killed without ever solving the problem. Determine the kind of ant infestation. Most species of ants never enter buildings; others build their nests near buildings and forage indoors. Others usually nest indoors.
Keep a record of where ants have been seen. Some ants follow definite trails. If possible, follow these trails to the nest. Placement of attractive materials, such as jelly, oils, protein and other materials can attract large numbers of ants so they can be followed to their nest.
Often children like to watch ants and can be very useful in tracing their trails. Outdoors, ant nests can often be located by seeing ant hills on the ground. Some ants deposit earth on the soil surface when they construct the nest. Fire ants and certain other ants build conspicuous mounds. Nests may also be constructed next to or under the house foundation, under sidewalks, driveways and patios, or in decaying logs or tree trunks.
Indoors, ants may nest in walls, behind a baseboard or under the house. Often ant trails enter through a crack but the nest may be some distance away. Some ants may also nest in decayed or rotting wood in the house.
Chemical Control. Ants can be controlled with baits, crack and crevice treatments, indoor space and surface treatments, outdoor barrier and broadcast treatments, as well as void and attic treatments. However, methods that target individual trails of ants such as crack and crevice treatments and indoor space and surface treatments are usually a "quick fix" and ineffective in the long term because they do not significantly reduce the ant population and do not affect the queen.
Ant baits, however, were developed to exploit the foraging and nest mate feeding behaviors of ants. Bait treatments are effective for control of many ant species and are available in homeowner and professional product versions. Since ants rely heavily on trophallaxis (reciprocal feeding), the bait toxicant can be thoroughly distributed to the members of the colony, including the queen and brood. Baits are effective because they not only kill the foraging members of the colony, but they kill the queen(s) so no other ants are produced.
The ideal bait contains a slow-acting, non-repellent toxicant that is incorporated into a preferred food substrate. There are many types of baits on the market. Some baits contain:
* Insect growth regulators that primarily impact brood production and development (Extinguish, Award, Distance, etc.)
* Metabolic inhibitors that primarily kill the foraging workers, the brood and queen (Amdro, Combat, etc.)
''In general, ant baits can be found as:''
* Granules for broadcast
* Liquids
* Gels
* Ready-to-use, tamper resistant containers
Both granules and liquids can be used in specially designed stations. Liquids are usually prepackaged for use or come as part of a system that uses a bait station. Gel baits usually come prepackaged in large syringes for crack and crevice treatments.
For large areas, the most efficient management method is to broadcast bait with a granular. Granular ant baits can be broadcast in the landscape around structures and in lawns. Most granular baits that are labeled for broadcast use are also labeled for individual mound or nest treatments.
Use the following guidelines for successful baiting:
* Use the following guidelines for successful baiting:
* Use fresh bait. If the bait is not fresh, ants will be less likely to eat it. Ants must eat the bait in order to be effective. If the bait smells like rancid oil or stale potato chips, the bait is spoiled.
* Wash your hands before baiting to prevent contamination from other products (and after baiting).
* Do not smoke while baiting. The nicotine will contaminate the bait.
* Timing of the application is as important as the choice of control. Granular broadcast applications should be done in good weather. A good rule of thumb is to bait on a day that you would have a picnic; about 70 to 90°F and not immediately before or after a drenching rain. Also, turn off any irrigation for a few hours before and after baiting.
* Bait after the dew, rain or irrigation has dried. Water can ruin baits.
* Bait where you see the ants foraging.
* Store bait in an airtight container and place in a cool dry place, away from other pesticides or potential contaminants.
Gel baits are particularly useful in crack and crevice treatments. In all cases of bait use, do not spray any insecticides around the bait application. Sprays are repellent and if they contaminate the bait, the bait treatment will be ineffective because the ants will not eat it.
Baits are effective for many sweet-feeding ant species. However, they provide control only if ants ingest them. Management of some ant species has been accomplished by treating infested homes exclusively with baits that contain boric acid. A 1 percent boric acid concentration in sugar water seems to be effective. However, a lot of bait may need to be dispensed and made available to ants over several weeks. Baits may need to be placed outside of the structure rather than indoors.
Residual insecticide sprays, applied outside the home as a barrier can provide temporary relief from invading ants. Ants that cross the barrier do not die immediately but at some point they will die and carcasses may be found within the home. In addition, foraging and nesting ants in the landscape should be treated. For example, if ants are observed moving up and down the trunk of a tree, the trunk should be treated. After the effectiveness of the chemical barrier has subsided, ants may continue to forage inside.
For more details on baiting, see "Ant Trails: A Key to Management with Baits," ENY-259 .
For heavy infestations, we recommend the Florida 3-Step Program.
1. Treat the perimeter with a repellent liquid or granular insecticide.
2. Broadcast bait with the appropriate product for your ant problem.
3. Individually treat remaining infestations, whether they are indoor or outdoor, such as fire ant mounds.
'''Footnotes'''
1. This document is ENY-203 (IG080), one of a series of the Department of Entomology and Nematology, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Publication date: April 1994. Revised: August 2007. Please visit the EDIS Web site at http://edis.ifas.ufl.edu.
2. P. G. Koehler, professor/extension entomologist, R. M. Pereira, associate research scientist, and F. M. Oi, assistant extension entomologist, Entomology and Nematology Department, Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611.
The use of trade names in this publication is solely for the purpose of providing specific information. UF/IFAS does not guarantee or warranty the products named, and references to them in this publication does not signify our approval to the exclusion of other products of suitable composition. All chemicals should be used in accordance with directions on the manufacturer's label. Use pesticides safely. Read and follow directions on the manufacturer's label.
The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other extension publications, contact your county Cooperative Extension service.
U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Larry Arrington, Dean.
== References ==
* Sudd, J. J. (1960) Anim. Behav. 8, 67–75.
* Hoelldobler, B. & Wilson, E. O. (1990) The Ants (Belknap, Cambridge, MA).
* Beatson SH. 1972. Pharaoh ants as pathogen vectors in hospitals. Lancet 1: 425-427.
* Bosik JJ. 1997. Common Names of Insects and Related Organisms. Entomological Society of America, Lanham, MD
* Creighton WS. 1950. The ants of North America. Bulletin of the Museum of Comparative Zoology 104: 1-585.
* Drees BM, Jackman J. (1999). Pharaoh ant. A Field Guide to Common Texas Insects. http://insects.tamu.edu/images/insects/fieldguide/cimg358.html (29 May 2003).
* Ebeling W. (1978). Urban Entomology. Agricultural Sciences Publications, University of California, Berkeley, CA.
* Erdos MD, Koncz A. 1977. Experience in the control of Pharaoh's ants in Hungary. International Pest Control 19: 12-13.
* Fasulo TR. (2002). Cockroaches and Pest Ants. Bug Tutorials. University of Florida/IFAS. CD-ROM. SW 157.
* Haack KD, Granovsky TA. (1990). Ants. In Handbook of Pest Control. Story K, Moreland D (editors). Franzak & Foster Co., Cleveland, OH. pp. 415-479.
* Klotz J, Williams D, Reid B, Vail K, Koehler P. (September 2000). Ant trails: a key to management with baits. EDIS. http://edis.ifas.ufl.edu/IG123 (29 May 2003).
* Koehler PG, Short DE, Fasulo TR. (2002). Pests In and Around the Home. UF/IFAS. SW-126.
* Lyon WF. (Unknown). Pharaoh ant. Factsheet. http://ohioline.osu.edu/hyg-fact/2000/2136.html (29 May 2003).
* Peacock AD, Hall DW, Smith IC, Goodfellow A. 1950. The biology and control of the ant pest Monomorium pharaonis (L.). Department of Agriculture of Scotland Miscellaneous Publications 17. 51 p.
* Smith EH, Whitman RC. 1992. Field Guide to Structural Pests. National Pest Management Association, Dunn Loring, VA.
* Smith MR. 1965. House-infesting Ants of the Eastern United States: Their Recognition, Biology, and Economic Importance. USDA-ARS Technical Bulletin 1326. 105 p.
* Wheeler WM. 1910. Ants: Their Structure, Development, and Behavior. Columbia University Press. NY. 633 p.
* Wilson GR, Booth MJ. 1981. Pharaoh Ant Control with IGR in Hospitals. Pest Control 49: 14-19, 74.
==External links==
{{commons|Monomorium pharaonis}}
* [http://www.ipm.ucdavis.edu/PMG/M/I-HY-MPHA-AD.001.html Picture of a ''M. pharaonis'']
* [http://ohioline.osu.edu/hyg-fact/2000/2136.html Ohio State University Extension Fact Sheet]
* [http://creatures.ifas.ufl.edu/urban/ants/pharaoh_ant.htm Florida Department of Agriculture and Consumer Services - Monomorium pharaonis (Linnaeus) (Insecta: Hymenoptera: Formicidae)]
[[Category:Myrmicinae]]
[[Category:Invasive animal species]]
[[cs:Mravenec faraon]]
[[de:Pharaoameise]]
[[eo:Formiko faraona]]
[[fr:Fourmi pharaon]]
[[nl:Faraomier]]
[[no:Faraomaur]]
[[pl:Mrówka faraona]]
[[ru:Фараонов муравей]]
[[fi:Faaraomuurahainen]]