CARPENTER ANT

Subfamily Formicinae

Camponotus Spp.

GENERAL DESCRIPTION

Adult - The most visible ant found in and around buildings; they are large, approximately 1 /4" to 3/4" in length. Thorax evenly rounded. Circle of hairs at abdomen tip. (Polymorphic adults will vary in size in the same nest.) Black, yellowish or black variegated with reddish (rusty) brown or grayish in color. At least ten species are native to the United States; they are found nesting in decaying wood, including lumber in buildings, but do not eat wood; primary foods are honeydew derived from other insects, as well as fruit, fruit juice, meat, grease, fat and dead insects. Their thin waist consists of one petiole or "knot" which is pointed. The legs are long and the antennae elbowed. The winged forms have four wings, the front wings longer and larger than the hind wings. The male can be distinguished from the female by its smaller head and protruding genitalia. Ants in the genus Crematogasta are also called "carpenter ants". The most common species is Lineolata (Say) which is variably colored and only about 1/8" long. They sound like crinkling cellophane as they move about inside their nests.

Larva - White grub-like young found only within the nest where it is fed and cared for by adult workers.

Pupa - Brown in paper-like cocoon. Size of the cocoon is dependent on the type of pupa inside-worker, female or male.

Egg - Small, white, egg-shaped object laid singly by the queen ant within the nest.

LENGTH OF LIFE CYCLE - Approximately 2-1/2 months or longer. Colonies of ants mature in 2 to 6 years and normally contain 2,000 - 3,000 individuals. Swarms of 200-400 winged reproductive forms are then produced each spring or early in the summer - they mate in the air.

HABITAT - They can be found outside or inside or any room in a structure, particularly where food or garbage is stored, prepared or handled. Initial nesting usually occurs in softer wood, such as decaying logs, moist or rotted beams, structure siding, trees and wood fences, hollow doors, window and door sills, decks, fireplaces, sill boxes, etc. especially wherever there is or has been a source of moisture. They are nocturnal by choice and are, therefore, best observed at night. They love high humidity (wood or voids with over 20% moisture content), so use a dehumidifier and repair all moisture problems.

NATURE OF INJURY - These ants carve galleries into the damaged/soft wood (with the grain) to make their nest. They may eventually hollow out and damage sound structural timbers. They are also a visual annoyance as they wander in search of food, and the foraging workers have rather large mandibles with which they can bite. Bang on the wall and then listen for carpenter ant nests with a stethoscope.

FOOD - They do not eat wood, they only cut galleries and create frass (wood fragments or sawdust) as they hollow out their nests from decayed areas in your building. Workers forage for sweet food such as honeydew, syrups, honey, jelly sugar and other sweet materials, e.g., apples and fruit, or even garbage, dead or living insects, grease, fat and/or meat scraps. They may travel 300 feet or more from the brood nest to find food. Food is carried back to the nest where it is regurgitated and used to feed the queen, larva and non-foraging workers.

HARBORAGE POINTS (Nests) - Typical carpenter ant nesting sites are found inside branches, hollow porch columns, exposed wood beams, floors and walls near leaking plumbing, roof areas with leaks or built-up roofs, walls near stopped-up gutters, hollow core doors, wallboards, particularly under sinks, toilets, dishwashers and/or windows that sweat such as storm windows, cabinet bases, planter boxes, wood shingle roofs, firewood in fireplaces, or in any damp or rotten structural members of a structure. In the woods, they will be found in fallen logs, hollow trees, or around broken limbs. Galleries are continually being carved inside timbers to create the ever-expanding nest . As the colony numbers increase the nest will eventually extend into dry, sound lumber. Galleries are irregular in shape, smooth surfaced and clean; they look like they have been sand-papered. Frass or wood fragments are carried from the nest and deposited outside. Piles of this frass or sawdust (which can also include insect fragments, soil particles and food residues) may often be found beneath infested wood members and is very helpful in locating the nests. Inspections should also be made at night using red or yellow light.

For control of carpenter ant infestation, you must locate the nest. Some people have had success putting out sugary food and/or trays of frozen crickets and following the ants carrying food back to their nest. If you can remove the nest completely, no further control will be needed. Otherwise, poison the nest with boric acid, sodium borate, silica gel or diatomaceous earth. Install negative ion plates.

Remove and replace all damaged and wet wood and do all necessary repairs to prevent future moisture build-up in wood. Also take precautions to prevent access to your building, e.g., trim branches that touch or overhang the building and remove debris on the roof..

Even if least-toxic pesticide poisons are to be used, only use them to spot treat the nest. Never allow monthly synthetic pesticide poison applications or allow an application of these toxic materials to the entire building. These practices are unnecessary and very dangerous to people and pets.

Control is easily accomplished if the nests can be located. Tap the walls and hollow doors and listen for a rustling noise in the wall, floor, woodwork or prefabricated doors that is loud enough to hear when you place your ear against the surface adjacent to the nest. A thorough initial inspection should be made both indoors and outdoors to locate the colony sources. When a nest is located, it should be treated with boric acid or other desiccation dust, or you can completely treat the wood with sodium borate or use baits. Install a dehumidifier.

OUTSIDE TREATMENT - Carpenter ants migrate from recently removed trees and buildings and from rotten structural timbers, trees, old logs, fireplace wood and similar areas to enter your building. Remove and burn all infested wood, hollow trees, old logs, firewood, etc. and/or treat with boric acid and/or sodium borate and fill all cavities. If your building has with vine covered walls (which are particularly attractive to ants), you should consider removing the vines completely. Carpenter Ants may also use crevices in wood shingle roofs for harborage. If found, caulk these areas completely. Prune all tree limbs and branches so that they do not touch or overhang the building and correct all visible moisture problems that cause wet and rotting wood. Install and properly maintain eavestroughs and downspouts. Do not forget to install enough dehumidifiers. Attics and crawl spaces should be inspected and spot treated or baited and properly vented. If necessary, they may even be treated completely with sodium borate per the label directions. Spray nests with white vinegar and/or with enzyme cleaners.

INTERIOR WORK - Thoroughly caulk all cracks and crevices that ants could use to migrate from wallboards and other similar areas to their food sources. Watch for ants or the sawdust like material they discard in building their nests. When the actual nests are located or suspected, treat the voids with dusts, e.g. boric acid and/or sodium borate. Nests in wall voids such as under windows may require drilling. Be sure to reseal with a caulk or plaster any holes you make to inject boric acid, silica gels, diatomaceous earth and/or sodium borate.

Reinfestations - Reinfestations usually indicate that more ants have moved into the structure or that ants have not contacted earlier controls in their foraging trips. Be sure that enough time has elapsed (at least two weeks) to gain control before making any retreatments. Make a careful re-examination to try to locate the nests. Look for sawdust or ants. Small jar lids of honey or jelly or cut up crickets can attract ants so that you may be able to follow them to the nests. Carpenter ants, however, may not go directly to a nest but take other erratic paths. Thus, considerable time may be required to find all of the nests. At night follow them with a flashlight covered with red or yellow cellophane. Properly place use either labeled commercially prepared baits or equal portions of honey or jelly and/or peanut butter and boric acid. Place the baits out of reach of children, pets and food. If you find ants dead by the bait, cut back on the boric acid.

LARGE ANTS (1/2 Inch or Larger)

CARPENTER ANT CAMPONOTUS SUMMARY

There are many species of Carpenter Ants in North America; few enter structures to forage; fewer nest in structures. But these two habits (foraging and nesting inside) coupled with their large size and vigorous activity make these invaders impossible to ignore. Two species claim the majority of attention: the Black Carpenter ant of the eastern and southern United States and the Western Carpenter ant, a particular problem in the Pacific northwest. As their name implies, carpenter ants work and live in wood; they do not digest it. They mate in teh air - the queen gets enough sperm to last 10 years or more.

An important first consideration in the control of ants is to determine whether:

the colony is located inside the structure, or

the colony is located outside the structure.

Indications that a colony is inside are when: ant workers are consistently found inside over a long uninterrupted period, nest building is observed inside (Look for wood shavings of carpenter ants, "dumping " materials of pavement ants, etc.), the infestation is located in a high-rise building, or inside swarming is observed.

Indications that a colony is outside are when:  ants outside can be seen coming inside.

Nesting sites outside are near the structure with an inside infestation, (Look for mounds next to the foundation, or trees with large carpenter ant colonies touching an infested portion of the house.)

ants nest under slabs or swarm inside, but workers do not forage inside.

ants inside can be "trailed" outside

Whether the colony is inside or outdoors, ants that are known to tend honeydew-producing insects often forage inside before plant insect populations can buildup outside. After populations of aphids, mealybugs, scale insects, white flies and plant-hoppers become numerous (in late spring), ant colonies nearby put a great deal of energy into tending and protecting these plant-sucking insects. Worker ants foraging inside kitchens and basements often leave houses at this time. They may return in dry weather seeking moisture, but often will not be seen until the next spring. When pest control efforts coincide with this period, it is often difficult to tell whether the pest management procedures are effective, or whether the ants. abandoned the structure due to natural habit.

Attend to the following general considerations in developing an ant control plan:

Inspection

Talk to the occupants. Get all information possible from the residents.

Observe ant worker movement and plot on diagram if need be. Look for the focus of the infestation.

To confirm observations, use traps baited with a grease and a sugar or syrup or other ingredients suggested in The Best Control individual control notes, e.g., peanut butter and cookies.

Inside: Inspect holes and cracks where workers enter, old or new moisture stains, food accumulations, e.g., dry pet food, activity near appliances. e. g., dishwasher and washing machines, under bath tubs, showers, in drawers, corresponding areas in adjoining room or rooms above and below activity.

Outside: Inspect for workers behind vines, shrubs, other plants near house, expansion joints, slabs, patio blocks, bricks, boards, plant pots, under and inside wooden columns and pillars, outside door and window frames, window wells, penetrations of house wall by telephone wires, air conditioning refrigerant pipes, trees that harbor colonies and provide access to houses by overhanging limbs that touch or even scratch shingles; water meters and storm drain inspection manholes. Inspect plants for ants tending aphids, mealybugs. Note: Leaf-cutter ants will not defoliate tall plants, e.g., roses, fruit trees, etc. if loosely-wadded sheep wool is tied around the stem; ants don't like to cross it and it is almost totally effective.

Habitat Alteration

• Caulk wall penetrations and mortar masonry cracks. Wall penetrations include utility lines, air conditioning, refrigerant pipes, phone lines, etc.

• Tighten door and window frames. Sprinkle talcum powder and/or Gold Bond® powders.

• Repair water leaks.

• Trim shrubbery away from house.

• Remove firewood that is stacked close to buildings; boards, stones, etc. that encourage nesting; screen openings in hollow pillars, columns, and ventilators.

• Control ant-tended aphids and mealybugs with horticultural pesticides, such as oils or soaps.

Control

Conduct a thorough inspection. Install negative ion plates. Spray and/or mop with borax.

Consider the species when choosing bait. Use baits with stomach poisons, e.g., boric acid, or with insect growth regulators. Baits are excellent in critical areas, e.g., computer or hospital rooms. Do not spray or dust around baits. Never store baits or bait materials where they can be contaminated with any other odors, especially fumes of pesticides. Ants and other insects can detect minute amounts of foreign or repellent chemicals and will avoid chalk lines.

Vacuum and then carefully caulk/seal all cracks and crevices where a nest is suspected.

Spray nests with white vinegar, enzyme cleaners or sprinkle them with baby powder or crushed chalk.

Develop a specific pest management plan. Where large outside areas need treatment, e.g., fire ant problems; do not treat with pesticide poisons as an extension of a yard problem. Ants use two methods to establish trails - phermones and structural guideline orientation - investigate both. Properly install negative ion plates; use borax laundry powder and/or spray with white vinegar, enzyme cleaners and/or soapy water. Practice proper sanitation, structural alterations and moisture source reduction.

Follow-up - Reinspect in two weeks; ask all occupants if they have seen any remaining troublesome ant problems. Remember, pesticide poison treatments can repel ants and make them active in other areas. Colonies with multiple queens may break up into several colonies, so do not use synthetic pesticide poisons for this reason, and because they are very dangerous to you, the occupants and the environment. Use IGR's, baits, vacuums and, if absolutely necessary, you may apply spot treatments of silica aerogel and/or boric acid dusts as a last resort.

Carpenter ants are usually a symptom of a water leak or moisture problem because they usually nest in wood that remains wet. Check for leaks around windows and doors, plumbing fixtures and under shingles and make necessary repairs. Keep foods in tightly sealed containers or in the refrigerator. Most ants prefer sweets, protein, fats or grease. Practice good sanitation. Avoid leaving dirty dishes or food particles where they are accessible to ants. Caulk cracks and crevices in building foundations. Remove rotted lumber, firewood and stumps inside crawls and from around buildings. Prune tree branches that overhand or touch buildings to prevent carpenter ants from coming inside.

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