Camponotus floridanus (Buckley) – Florida Carpenter Ant

California Pest Rating for
Camponotus floridanus (Buckley) – Florida Carpenter Ant
Hymenoptera:  Formicidae
Pest Rating: A

Initiating Event:

Camponotus floridanus is intercepted by CDFA and presently has a temporary rating of “Q”. A pest rating proposal is required to determine a permanent pest rating.

History & Status:

Background: The Florida carpenter ant complex is comprised of several species, two of which are common around structures: Camponotus floridanus (Buckley) and Camponotus tortuganus (Emery). These bicolored arboreal ants are among the largest ants found in Florida1. These ants are amorg the most common indoor insect pests; they can be found nesting throughout homes in wooden support pillars, window frames, attics, and wooden structures2 . During the flight season, usually between April and June, carpenter ants can be found in alarming numbers1. Camponotus floridanus nests in existing empty spaces in wood or burrow into soft materials like pithy wood and styrofoam. These ants are primarily nocturnal in their foraging behavior. They have the legs and antennal scapes with numerous long, coarse brown to golden erect hairs that are longer than body hairs. Mating flights of these ants occur in Spring and are triggered by environmental factors such as changes in photoperiod and temperature. Fertilized queens nest under loose bark or wood debris on the ground. Worker ants from the first brood are called minims and they help feed the queen and maintain the nest. Workers have a strong bite and are called “bull dogs” or “bull ants” in Florida. The developmental cycle from egg to adult ranges from 50-70 days2.  The colonies may contain up to 8,000 individuals4.

Worldwide Distribution: There are an estimated 1000 species of Camponotus worldwide4.

US Distribution: There are 25 species of Camponotus in United States and most are native species. Camponotus floridanus is a pest in the southeastern Unites States. This species ranges from North Carolina to Florida and west to Mississippi4.

Official Control: Camponotus floridanus has been listed as a harmful organism in Taiwan and both Australia and Nauru consider all ants (Formicidae) as harmful6 .

California Distribution:  The two most destructive Camponotus species found in California are C. modoc and C. vicinus 5. Camponotus floridanus has never been found in the natural environment of California.

California InterceptionsCamponotus floridanus has been intercepted 20 times between January 1, 2000 and November 2016 through CDFA’s border station inspections, dog teams and red imported fire ant program7.

The risk Camponotus floridanus (Florida Carpenter Ant) would pose to California is evaluated below.

Consequences of Introduction: 

1) Climate/Host Interaction: Camponotus floridanus feeds on trees and shrubs infested with honeydew producing insects such as aphids, scales, and mealybugs. These honeydew producing ornamentals, fruit trees and landscape shrubs are grown throughout California. This species also feed on sweet floral nectar and can be found near campgrounds, near soda machines and areas where sweets are readily accessible. floridanus also forages in homes, looking for moisture in kitchens, bathrooms and in other rooms with water leakage from plumbing, around doors and windows1 . It receives a Medium (2) in this category.

Evaluate if the pest would have suitable hosts and climate to establish in California:

Score: 2

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

Medium (2) may be able to establish in a larger but limited part of California.

– High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: Known hosts of Camponotus floridanus include hardwoods, softwoods and structural timber of buildings3. Additionally, this species feeds on honeydew producing trees and shrubs that are grown throughout California3. It receives a Medium (2) in this category.

Evaluate the host range of the pest:

Score: 2

– Low (1) has a very limited host range.

Medium (2) has a moderate host range.

– High (3) has a wide host range.

3) Pest Dispersal Potential: Winged males and females of Camponotus floridanus leave the nest in spring –summer and mate. Females establish a nest in suitable wood (loose bark or wood debris on the ground). When mated, the queen rears her first brood in isolation. Carpenter ants can reach alarming numbers during flight season. Typical nests will contain several thousand individuals, have all developmental stages present and can exist for several years3 . These ants can move long distances inside homes, via wall voids, attic insulation and eaves, under bath tubs, windows and door frames, around skylights, in boxes, closets, and under appliances. Queenless satellite nests can be found within 20-100 feet of a mature nest1. It receives a High (3) in this category.

Evaluate the natural and artificial dispersal potential of the pest:

Score: 3

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Camponotus floridanus is active year–round. These are serious house-infesting ants. They do not eat wood but remove it to construct galleries for their nests. These ants can expand their nests into sound wood, wall voids, hollow doors, insulation and compromise structural integrity of homes. Infestations can even occur in new buildings. Worker ants of this species can bite and spray formic acid for defense1. Carpenter ants have been reported preying on grasshoppers, crickets, leafhoppers, honey bees and caterpillars This species could be more injurious to the livestock than existing ant species in California.  In natural settings, fungi can be vectored by carpenter ants. They can hollow out wood that has been softened by moisture or fungi to create nests. This wood include tree stumps, dead tree limbs, or residential structures. These infestations can play an important part in the decomposition of wood5 .It receives a High (3) in this category.

Evaluate the economic impact of the pest to California using the criteria below:

Economic Impact: B, E, F

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 3

– Low (1) causes 0 or 1 of these impacts.

– Medium (2) causes 2 of these impacts.

High (3) causes 3 or more of these impacts.

5) Environmental Impact: Camponotus floridanus is not likely to disrupt natural communities, lower biodiversity and change ecosystem processes in California. This species also does not directly impact any threatened species. If it were to become established, however, homeowners would need additional private treatments. Direct treatment of nesting sites, baits, spraying in forage areas like trees and shrubs would be needed to eliminate established colonies. Elimination of insect bridges, caused by trees and shrubs touching house exterior, would require professional treatments by pest control operators. Since tree branches and shrubs infested with honeydew producing insects can act as substrate for these ants, removal of these trees would require additional efforts1. It receives a Medium (2) in this category.

Evaluate the environmental impact of the pest on California using the criteria below:

Environmental Impact:  D

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Score the pest for Environmental Impact:

Environmental Impact Score: 2

– Low (1) causes none of the above to occur.

Medium (2) causes one of the above to occur.

– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Camponotus floridanus (Florida carpenter ant): Medium (12)

Add up the total score and include it here:

-Low = 5-8 points

-Medium = 9-12 points

-High = 13-15 points

6) Post Entry Distribution and Survey Information: Camponotus floridanus has never been found in natural environment in California and receives a Not established (0) in this category.

Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included:

Score: 0

Not established (0) Pest never detected in California, or known only from incursions.

-Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

-Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

-High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: High (12)


At least 15 Camponotus species are known from the state in limited areas. Camponotus floridanus would be likely to impact structures, specifically homes and wood quality if it establishes in the state. There have not been any formal surveys for Camponotus floridanus in California. This species has been intercepted through regulatory pathways by CDFA, but it is possible that it might be present in certain areas of the California.

Conclusion and Rating Justification:

Camponotus floridanus has never been found in natural environment of California and would likely have significant economic and environmental impacts if it were to enter the state.  An “A” rating is justified.

  1. Warner John and Scheffrahn Rudolph H., University of Florida- Entomology and Nematology; Featured Creatures; Florida Carpenter Ant
  1. Vazquez R.J., Koehler P.G., Pereira R.M., Warner J. and Scheffrahn; UF-IFAS Extension; Publication # SP486C; Florida Carpenter Ants
  1. Florida Department of Agriculture and Consumer Services; Florida Forest Services; Forest Health Publications: Florida Carpenter Ant
  1. Urban and Structural Entomology program at Texas A & M University: Carpenter Ants, Camponotus sp
  1. Klotz, J.H., Rust, M.K. and Hansen, L. D., University of California, Davis- Statewide IPM Program; Pest Notes: Carpenter Ants
  1. USDA Phytosanitary Certificate Issuance & Tracking System (PCIT): Phytosanitary Export Database (PExD): Camponotus floridanus
  1. Pest and Damage Report Database: Plant Heath and Pest Prevention Services: California Department of Food and Agriculture.

Responsible Party:

Raj Randhawa, 1220 ‘N’ Street, Room 221, Sacramento CA 95814, (916) 403-6617,[@]

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Pest Rating: A

Posted by ls