Camponotus modoc

Wheeler, 1910

Western Carpenter Ant, Western Black Carpenter Ant

Camponotus modoc, the western carpenter ant, is a large black native to western North America. exhibit , ranging from 7 to 13 mm in length, with dark red legs contrasting against a black body. The species constructs nests in dead wood, including forest logs and human structures, and is known for its mutualistic associations with aphids, particularly Cinara occidentalis on white fir. Research demonstrates trail fidelity and colony recognition abilities, with workers returning to specific colonies even after displacement.

Camponotus modoc by (c) Don Loarie, some rights reserved (CC BY), uploaded by Don Loarie. Used under a CC-BY license.

Camponotus modoc casent0005347 label 1 by wikipedia. Used under a CC BY 4.0 license.

Pronunciation

How to pronounce Camponotus modoc: //ˌkæmpəˈnoʊtəs ˈmoʊˌdɔk//

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Identification

are entirely black with dark red legs, distinguishing them from other western Camponotus . Size ranges from 7 to 13 mm. The smooth, evenly rounded thoracic profile in lateral view separates carpenter ants from field ants (Formica), which possess a distinct mesonotal constriction. is pronounced, with major workers substantially larger than minors.

Images

Habitat

Found in western North American forests, particularly giant sequoia forests. Nests in dead wood including fallen logs, stumps, and standing dead trees. Moisture-dependent; primary colonies occur in high-humidity decaying wood. Satellite colonies establish in damp structural wood of human dwellings.

Distribution

Western North America, including California (Sierra Nevada, Sequoia-Kings Canyon National Park), Nevada, and adjacent regions.

Diet

. Consumes solid food items and honeydew from aphids. demonstrate size-based dietary specialization: smaller workers more frequently transport solid food and attend aphids, while larger workers specialize in honeydew collection.

Host Associations

Cinara occidentalis - mutualist on white fir (Abies concolor); attendance essential for aphid survival and protection
Cinara spp. - mutualistMultiple tended on conifers

Behavior

exhibit strong trail fidelity, returning to identical trunk trails and specific colonies after removal. Colony recognition allows workers to identify original aphid colonies among up to eight alternatives on the same tree. Long-term site fidelity observed, with individual workers remaining at aphid colonies for extended periods. Foraging decisions mediated by and glyceride chemical cues on object surfaces. Alarm communication involves bimodal signal modulation.

Ecological Role

Keystone mutualist in conifer forest . Protects colonies from including Neomysia oblonguttata, Deraeocoris brevis, Passaloecus cuspidatus, and Pityophyphantes spiders. Attendance alters aphid , reducing production and improving colony survival to oviparae stage. Contributes to nutrient cycling through wood excavation and aphid honeydew processing.

Human Relevance

Significant structural pest. Satellite colonies in homes cause damage by excavating galleries in damp wood for larval and pupal development. indicated by accumulation, regular presence of large indoors, and spring of winged reproductives. Control requires colony location and elimination, moisture source remediation, and barrier maintenance between vegetation and structures.

Similar Taxa

Camponotus vicinusOverlapping western range and similar size; distinguished by coloration and leg
Camponotus pennsylvanicusEastern counterpart with similar ; distribution separates
Formica subsericeaSimilar size and coloration; distinguished by thoracic profile with mesonotal constriction versus smooth carpenter ant