White Footed Ants

WHITE FOOTED ANT

Biology

White footed ants do not bite or sting, nor have they been reported to cause any type of structural damage. They are, however, attracted to sweet foods.  Thus, it is common to find them foraging indoors and outside on hedges infested with honey-dew producing insects such as aphids and scales.    Several biological aspects of the white footed ant make a difficult pest to control, almost impossible totally eliminate from an infested home:

  1.  Huge size (in population) of ant colonies.
  2. Tremendous reproduction capabilities (through budding and swarming).
  3.  Variety of food preferences.
  4.  Tiny body size enables entry to most structures, natural and man-made.
  5.  Nests (or ant beds) in a wide variety of areas, all connected and part of super colony.
  6.  Not all foods are shared from foraging workers to larvae (making ant baits ineffective).
  7.  Sterile workers lay unfertilized eggs:  this is food for non-foraging members of the any colony.

Armed with the knowledge of the white footed ant colony structure, methods of reproduction, food preferences / feeding habits, nesting habits and ant colony structure, you will be successful in your ant control program.

Colony Structure

Estimations vary, but most agree that the average number of ants in a white-footed ant colony will range from 400,000 to well over 1 million ants.  The sheer size of these colonies puts food at a premium;  these pests must forage over a wide range and feed on several food sources.  Colonies tend to be “spread out” as interconnected satellite colonies.

Approximately one half of the colony is made up of sterile, female workers.  These worker ants forage for food, are responsible for brood care, and nest maintenance.  There are wingless males and females, that in addition to the founding king and queen, mate and lay fertile eggs.  Thus, the reproductive potential of the multiple queen white-footed ant society is much greater than that of many other ant species. 

Reproduction

Like many other ants, white-footed ant colonies produce winged males and females which, at certain times of the year, leave their nest to start new colonies.  This is called “swarming”.  Winged females who mate with winged males during a mating flight found new colonies.  Winged males mate once before they die.  Winged females die about 400 days after starting a colony.  The queen is then replaced by a wingless daughter that mates with a wingless male who is capable of multiple matings.

In addition, white-footed ants can initiate new colonies by budding.  Budding is a process where many workers and wingless reproductive males and females leave the mother nest and crawl some distance to start a new colony.  The wingless reproductives look very much like workers, and in many cases cannot be distinguished from sterile workers by external appearance.  These worker look-alikes, called intercastes, make up almost 50% of a colony.  Thus, mass movements of white-footed ants carrying their whitish-coloured larvae and pupae may be observed during the budding process.

Workers of many sweet-feeding ants, such as the ghost ant, ingest liquefied food and carry it within their crop (first of three stomachs) back to the nest.  Within the nest, workers regurgitate this food and share it with members of the colony that never leave the nest, such as workers tending offspring, the queen, and the developing brood.
This is why baits are so effective with certain other ant species, but not on white-footed ants:  a worker ingests toxic food and takes it back to the nest where it is shared with others. 
 

Feeding Habits

Even with only half the colony feeding on food outside the nests, this large population obviously needs a great deal of food to survive.  One of their preferred foods is dead insects.  White-footed ants are strongly attracted to sweet foods but have been observed in the laboratory feeding on termites and dead cockroaches.  Sources of sugar can be found at many locations within structures and in the surrounding landscape.  Indoor locations include the recycle bin, the kitchen, pantry, and wherever else food is stored, consumed or prepared.  Outdoors, sugary food sources are found at extrafloral nectaries, within flowers, at wounds in trees, and as honeydew (excrement from sap sucking insects such as aphids and mealy bugs).  With all of these potential food sources available, it is common to find white-footed ants foraging indoors and outside.  Typically, white-footed ants show up at food sources in large numbers, resulting in easily observed foraging trails leading to and from the food.  Most foraging occurs at night during the summer, but may be at any time of the day when temperatures moderate.

White footed ants will protect and feed on aphids and scales which attack certain ornamental plants.  Not only do they feed on these plant pests, but will actually nurture them collecting and feeding on sweet honey-dew produced by aphids.  This behaviour has been observed in other ant species as well.  The alarming aspect of this behaviour in white-footed ants is the abnormally large supply of food needed by the colony.  This “farming” of plant pests can put your ornamentals at great risk.

White-footed ants are unusual in that food ingested by foraging workers is not regurgitated, nor is it shared with others.  The sterile workers of the white-footed ant are capable of laying unfertilized eggs.  These eggs, called trophic eggs, are sterile, and are thinner and more fragile than fertile eggs. Trophic eggs are fed to adults within the colony that are not actively foraging and also to the developing offspring.  Therefore, toxic baits affect only those members of the colony that directly ingest baits.  Baits are not shared with the other half of the colony.
 

Nesting Habits  

White-footed ant nests have been observed in many locations in the landscape, and in the home. In New Zealand, favoured nest sites are within old trees and walls or roof cavities of houses. White-footed ants can be found under loose bark, within natural or artificially created cavities in the stem, in rotten trunks or limbs, and in galleries created at one time by termites.  In addition, white-footed ants have been observed nesting in attics, under roof shingles, in wall voids, in cardboard boxes, in the petiole bases of palms, under leaf litter, in compost piles, under rocks, along fence lines, under doormats, and in outdoor furniture.  Many other damp locations may serve as suitable nest sites for this species. Remember that insects need moisture.

Although a colony may be made up of a million individuals, they usually do not all nest in one location.  Colonies tend to be spread out as interconnected satellite  colonies.  Therefore, ants within the same colony may be found nesting at several locations around a structure.  Nesting sites usually contain eggs, the developing offspring, and pupae as well as adult ants.
 

Identification

This small (about  3 mm long) ant is easily confused with Crazy ants and Odorous House Ants if not properly identified.  Although the body of the white-footed ant closely resembles that of the crazy ant, its legs and first segment of its antennae are much shorter.  This ant’s body colour is darker than that of the odorous house ant.  The white-footed ant (which has one node) has one distinguishing characteristic which sets it apart from similar ants:  the tarsi (section at the end of the legs) are a very light yellow or yellowish white in colour.  This gives it the appearance of having “white feet”, hence its name.
 

White Footed Ant Elimination and Control Measures

Once White-footed ants have infested a structure, it is doubtful that they will ever be totally eliminated from the building.  We can, however, implement measures to keep existing infestations manageable and help un-infested homes from being invaded.  If you live in an area where white footed ants are a potential problem, preventative treatments would indeed be wise.  Prevention is the best line of defense against the establishment of any pest insect.
A concentrated effort (using several different control methods) is your only chance of getting a handle on white-footed ant infestations.  This effort is Integrated Pest Management (IPM) at its best.  In this section, we will cover:
           • Structural Change
           • Ant Baits
           • Perimeter Insecticide Sprays
           • Indoor Sprays
           • Total Ant Bed (or Mound) Elimination
Using only one control method will probably result in failure.  Using several in concert will achieve best results.
 

Structural Change

Relatively small ants, such as the white-footed 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.  Sanitation can also help to prevent infestation by white-footed ants, as well as other ant species.  Eliminate ant access to sugars within the home.  Clean areas where food is handled and quickly and thoroughly clean up spilled, sugar-based foods.  In addition, store food in containers with tight fitting lids.  Also, eliminate potential food sources outside, such as by controlling pests in your landscape that produce honeydew.  In addition, trim tree branches away from the structure, this will help prevent ants within the tree from gaining access to the structure.  Removal of fallen leaves and compost piles near the structure has also proven to be an effective sanitation procedure by removing desirable habitat.
 

Baiting for White Footed Ants

With only half of the colony foraging and feeding on outside sources, ant baits will not eliminate white-footed ant colonies.  Baits are sometimes used to help reduce the visible worker ants (those foraging in the open) inside homes – but that is all that baits can do.  The interior half of the ant colony (which feeds on trophic eggs) are not killed by baits because the ant bait is never transferred to them.  If you desire to bait indoors, use EXTERM-AN-ANT gel only. Outdoors, you might see white-footed ants taking bait but (just like the indoor baiting) the colony is not being damaged to any great extent.
 

Eliminating Ant Mounds

Inspect and locate any outdoor colonies on your property and eliminate them by drenching.  Drenching ant beds simply means using enough insecticide solution to the point of where you are drowning all possible ants in the area.  This method works better than trying to kill the ant bed with sprays or spot-treating with insecticide granules. BIFORCE Granules is one product that is effective for this purpose.
 

Pesticides for Killing and Controlling White-footed Ants

A combination of products and methods must be used.  Indoor baits such as EXTERM-AN-ANT will help reduce the population to some extent.  It seems that the best control is to use the following: Broadcast BiForce Granules over the entire property and at least repeat application 3 times covering bark gardens, lawn areas, and around any long grass or shrubby areas. Indoors, you may also apply a good, safe insecticide dust to any crack, crevice, hiding place, entry pointsuch as window vents, wall void or attic – places where ants are most likely to hide, colonize, forage for food, etc. PERMEX and Dust2Dust are best for killing white-footed ants. PERMEX or Dust2Dust should be used where you cannot treat with a spray and where people and pets cannot come into contact with the material.  Dusts (such as PERMEX are very safe to use, when applied properly. A good liquid spray to use indoors is RECRUIT. In summary, you need: BiForce Granules, EXTERM-AN-ANT, and RECRUIT in combination to begin to reduce these ant populations.
X-IT Ant spray is effective also for outdoor walls and fence lines, paths and driveways and tree trunks.
 

Summary

   1. Seal all possible entry points leading into your home.
   2. Trim branches (shrubs, trees, etc) away from the structure.
   3. Remove any excess vegetation, compost or mulch if too close to the building.
   4. Remove all possible food sources indoors (good sanitation) and outdoors (treat for aphids, scales on plants).
   5. Locate and drench all existing mounds with an approved synthetic insecticide. Broadcast area with BIFORCE Granules to kill   foraging workers and prevent ants from migrating to your property.
   6. Spot-treat indoors with a safe, low odour insecticide (RECRUIT is best) to kill any existing white-footed ants that forage inside your home.
   7. Dust all wall voids, cracks, crevices, attics (above and below insulation!), crawl spaces.  Any place where you cannot spray, where people and pets do not contact but where ants can hide should be dusted. PERMEX or DUST2DUST is best for killing ants, white-footed ants and other insects.


Disclaimer
This information is given in good faith and is based on information readily available, but as the actual conditions of use and storage are out of our control, no liability is accepted for any loss or damage caused directly or indirectly through the use of the recommendations contained herein. Intending users should satisfy themselves as to the suitability of any product used for any particular purpose, by carrying out appropriate tests.
Date; 29/06/17

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