Carpenter Ants in Alaska Cover Photo: Carpenter ant gallery in the rotted base of inch long, that care for the queen, eggs, and Written in 1982 by Edward H. Holsten, Research Carpenter Ants a tree. (Photo: Ed Holsten, USDA Forest Service) developing larvae. Entomologist; Revised, 2004 Cynthia Synder, Biological Queens are generally black while workers will Science Technician; Revised 2013 by Elizabeth Graham, , Camponotus spp. Carpenter ants either have some red or brown on their legs or Entomologist. USDA Forest Service, R10 Forest Health in Alaska (Hymenoptera: Formicidae), are among the body. Carpenter ants have a smoothly rounded Protection largest members of the ant family in the United arched shape to the top of the thorax, elbowed Additional information on this insect can be obtained from States. Under natural conditions, nests can be antennae, and constricted waists with a single your local Alaska Cooperative Extension office, Alaska State found in rotting logs, stumps, or occasionally node between the thorax and abdomen. Forestry office, or from: in damp heartwood of live trees. However, Workers have a large head and small thorax, Forest Health Protection they may also construct their nests in house while swarmers have a smaller head and State and Private Forestry timbers or other manmade structures where larger thorax to accommodate flight muscles. USDA Forest Service wood becomes moist. Occasionally, they are Swarmer wings are long, with the forewing 11175 Auke Lake Way found tunneling into styrofoam insulation. Well Juneau, AK 99801-8626 longer than the hindwing, clear or brownish with established ant colonies may cause structural Phone: (907) 586-8883 prominent veins (Figure 3). damage in homes, resulting in the need for Forest Health Protection extensive repairs. Carpenter ants are also Swarmers emerge from mature colonies usually State and Private Forestry a nuisance when invading homes, crawling in May and June. Males die after mating but the USDA Forest Service over kitchen surfaces and getting into food. newly fertilized females, which are mated for 3700 Airport Way Camponotus spp. (Figure 1) are not known to life, either reestablish an old colony or establish Fairbanks, Alaska 99709 a new satellite colony in a small cavity in down Phone: (907) 374-3758 occur in Southeast Alaska, however ants in the genus Lasius behave similarly to carpenter logs or stumps or in deteriorating moist wood. Forest Health Protection ants and are found throughout Alaska. The new queen loses her wings and lays 15 to 20 eggs over the next 15 days. Eggs are about State and Private Forestry Carpenter ants may be active indoors during USDA Forest Service 1/8–inch long, oval, and cream colored. 161 East 1st Avenue spring and summer while foraging for their Anchorage, Alaska 99501 favored foods including sweet or fatty fare such Phone: (907) 743-9456 as syrup or honey. If these are not available, the ants will feed on dead or living insects or other http://www.fs.fed.us/r10/spf/fhp types of organic material. If more than 20 ants are found in a home, especially in the winter The U.S. Department of Agriculture (USDA) prohibits months, the infestation is most likely within the discrimination in all its programs and activities on the basis home and needs to be treated. of race, color, national origin, sex, religion, age, disability, political beliefs, sexual orientation, or marital or family Description and Life History status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means Carpenter ants are social insects and live for communication of program information (Braille, large in colonies made up of three castes: (1) print, audiotape, etc.) should contact USDA’s TARGET “swarmers”, winged females, up to 3/4–inch Center at (202) 720-2600 (voice and TDD). long, and much smaller winged males; (2) a To file a complaint of discrimination, write USDA, wingless queen, which never leaves the nest Director, Office of Civil Rights, Room 326-W, Whitten and spends her entire life laying eggs; and (3) Building, 1400 Independence Avenue, SW, Washington, workers, of which there are major workers, DC 20250-9410, or call (202) 720-5964 (voice and TDD). Figure 1. Camponotus spp. (Photo: Derek Sikes, Alaska Region about 1/2–inch long, that guard the colony USDA is an equal opportunity provider and employer. United States Department of Agriculture R10-TP-156 University of Alaska Museum) Forest Service June 2013 and forage for food, and minor workers, 1/4– Eggs hatch after 24 days and the larvae emerge. sites and adjacent areas should be cleared of Check with your local Cooperative Extension Larvae are legless and grub-like with their size stumps and partially decayed logs. If possible, Service office for insecticides that are currently varying according to their ultimate adult form buildings should be positioned on concrete or registered for carpenter ant control. (i.e. swarmer, worker, etc.). Larvae pupate masonry foundations or on treated timbers. in tough, tan-colored, silken cocoons often Lumber, firewood, and debris should not be erroneously referred to as “ant eggs” (Figure stored next to the house or in basements and 2). The larval stage is usually completed in 21 crawl spaces. Wood that is stored in or near days and the pupal stage completed 21 days the house should be kept dry and, if possible, later. However, cold winter weather may delay elevated to allow air circulation. Food, including the life cycle. pet food, should be kept in sealed containers. All eggs produced in the first three years The most important factor in carpenter ant become sterile female workers. These workers Figure 2: Lasius sp. tending to a pupa (Photo: control is locating the nest. Nest can be located assume the duties of collecting food, feeding Derek Sikes, University of Alaska Museum) by following foraging worker ants back to their the queen, excavating galleries to enlarge the nest, generally between sunset and midnight. nest, and tending the eggs, larvae, and pupae by termites. At present time, termites are not Carpenter ants can travel over 100 feet from of the next generation. Workers are able to known to exist in Alaska. their nest to feeding sites. Once the nest is forage for food up to 200 yards from the nest found, control may be easy. Sometimes more All kinds of houses, from the newest to the oldest, and although they do not sting, their bite can be than one colony is present in a structure or may become infested. In cities, carpenter ants Figure 4. Left: Advanced carpenter ant painful. Colonies mature and begin to produce surrounding grounds, so a thorough inspection are usually found in wooded areas, but may damage. Right: Frass piles are evidence swarmers in three to six years. A mature colony is very important. Once the nest is located, also be found in crowded residential districts as of carpenter ants. (Photos: Ed Holsten and has 2,000 to 4,000 individuals and will produce infested wood can be removed or chemically well. Richard Warner, USDA Forest Service) 200 to 400 winged swarmers each year. There treated and the causes of moisture damage is normally only one functioning wingless Guidelines for Reducing Damage can be corrected. CAUTION: Pesticides can be injurious queen in a colony, and she generally lives and The most obvious sign of infestation is the to humans, domestic animals, desirable produces young for up to 15 years. presence of ants inside the house, especially plants, and fish or other wildlife, if they are Damage Caused in winter. Carpenter ants may remain active not handled or applied properly. Use all year-round in heated spaces; otherwise they Carpenter ants do not eat wood, but excavate pesticides selectively and carefully. Since become inactive in the winter. They do most galleries to rear their young. They prefer moist approved uses of a pesticide may change of their foraging at night. Other indications of (but not wet), deteriorating wood that may frequently, it is important to check the label infestation include piles of the sawdust-like be found in existing cavities or void areas in frass expelled from small cracks or openings for current approved and legal use. Follow structures. Nests are commonly found in porch found in dark closets, under porches, along sills, recommended practices for the disposal pillars, roofs, windowsills, and structural wood or at the base of infested timbers (Figure 4b). of surplus pesticides and pesticide in contact with soil. Workers cut galleries in Carpenter ant frass can be distinguished from containers. Mention of a pesticide in the wood, often extending into adjacent sound regular sawdust by the presence of fragments Winged female and a much this publication does not constitute a wood, expanding the nest size for the en- Figure 3: of ants and other insects mixed with the wood smaller winged male carpenter ant. (Photo: larging colony. Galleries are irregular, usually recommendation for use by the USDA, debris. Whitney Cranshaw, Colorado State University, excavated with the wood grain (Figure 4a); the nor does it imply registration of a product Bugwood.org) walls are smooth and clean with shredded wood Prevention is the best control method; measures under Federal Insecticide, Fungicide, and fragments (frass) deposited outside of the nest. to prevent structural timbers from becoming wet Rodenticide Act, as amended. Mention of The clean galleries of carpenter ants are easily may protect a house from infestation. Building a proprietary product does not constitute distinguished from mud-lined galleries created an endorsement by the USDA.