Lasius claviger

(Roger, 1862)

smaller yellow ant, common citronella ant, yellow ant, lemon ant, citronella ant

Lasius claviger, commonly known as the smaller or citronella ant, is a North ant described by Roger in 1862. Formerly classified in the (now subgenus) Acanthomyops, it belongs to the genus Lasius. The species is notable for producing a distinctive lemony citronellal scent from glands near its when disturbed, and for its habit of tending root-feeding for . Winged reproductive forms swarm in late autumn and early winter, often causing concern when mistaken for .

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Pronunciation

How to pronounce Lasius claviger: //ˈleɪ.si.əs ˈklæ.vɪ.dʒər//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Distinguished from by elbowed (not bead-like) , narrow waist (not broad junction between and ), and winged forms with unequal and sizes. Separated from other Lasius by the characteristic citronellal odor, coloration, and late-season swarming . Smaller than Lasius interjectus (larger yellow ) and distinguished by morphological details of the petiole and antennal .

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Appearance

Small to -sized with to yellowish- coloration. are wingless; reproductive forms ( and males) possess . are distinctly elbowed. The (narrow waist between and ) is pronounced, with a single node. Winged forms have noticeably larger than , with few prominent —features that distinguish them from .

Habitat

Nests in soil, often in moist or shaded locations. Frequently found under stones, logs, or other ground cover. Associated with open woodlands, forest edges, meadows, and suburban lawns. Colonies typically located near roots of plants where tending occurs.

Distribution

to the United States. Distributed across eastern and central North America, with records from the Mid-Atlantic region, Midwest, and extending into the South. The has been documented swarming in Maryland in December and January.

Seasonality

Winged reproductive forms emerge and swarm in late autumn through early winter (October–January in temperate regions), with peak activity often occurring around December. This unusual winter swarming distinguishes the from most temperate that swarm in spring or summer.

Diet

Feeds primarily on excreted by root-feeding that the tend and protect. Also consumes soft-bodied and other small . (food exchange between colony members) is an important mechanism for nutrient distribution within the colony.

Host Associations

Lasius flavus - eatsLasius claviger is not associated with Lasius flavus; this appears to be a name confusion in some sources. Lasius flavus is a European .

Life Cycle

with , , , and stages. Colonies contain wingless (sterile females), winged reproductive and males, and (eggs, larvae, pupae). New colonies are founded by mated queens following . Development time from egg to adult varies with temperature and season.

Behavior

Exhibits herding with root-feeding , moving them between plants to optimize production. When threatened, release citronellal from as an , recruiting nestmates to defend the colony. Glands near the tip produce formic acid as a defensive chemical. Workers engage in (regurgitation of liquid food) to feed nestmates, , and . Winged reproductives swarm in large numbers for mating.

Ecological Role

Functions as an engineer through soil excavation and nest construction. Acts as a of soft-bodied and as a mutualist with , protecting them from predators and in exchange for . The aphid-tending influences root health and . Serves as for various - predators and .

Human Relevance

Often mistaken for when winged forms swarm near homes in winter, causing unnecessary concern. Does not damage wood or structures. The citronellal odor may provide minor natural repellency. Not considered a significant pest, though large swarms can be a nuisance. E. O. Wilson studied Lasius including this in Rock Creek Park, Maryland, during his youth—research that contributed to his lifelong passion for myrmecology.

Similar Taxa

Lasius interjectusLarger with similar biology and citronellal odor; distinguished by larger size and subtle morphological differences in structure
Reticulitermes flavipesEastern ; winged forms superficially similar but have bead-like , broad waist, and equal-sized —easily distinguished with close examination
Lasius neonigerSimilar-sized Lasius but darker in color, lacks citronellal odor, and swarms in late summer rather than winter

Misconceptions

Winged swarms are frequently mistaken for , leading to unnecessary alarm and pest control treatments. Unlike termites, L. claviger does not consume wood or damage structures. Some sources conflate this with European Lasius species (e.g., Lasius flavus) due to outdated or translation errors, but L. claviger is strictly North .

More Details

Chemical defenses

Produces citronellal (lemon-scented compound also found in lemongrass and eucalyptus) from as , and formic acid from abdominal glands for defense against .

Aphid mutualism

actively transport root-feeding between plants to maximize production, a described as 'herding' that represents one of the classic examples of .

Taxonomic history

Originally described in Acanthomyops, which is now treated as a subgenus of Lasius. The epithet 'claviger' refers to the clubbed characteristic of the group.