Dolichoderus

Lund, 1831

Species Guides

4

Dolichoderus is a of ants comprising 181 valid (131 extant, 50 extinct), representing the sole member of tribe Dolichoderini and type genus of Dolichoderinae. are small (approximately 4 mm), possess a thick sculptured , and lack a functional sting. The genus exhibits remarkable ecological diversity: most species are honeydew collectors that tend aphids and scale insects, while the D. cuspidatus group in Southeast Asia practices unique nomadic farming with obligate mutualist mealybugs. The genus has an extensive fossil record in Baltic amber.

Dolichoderus by (c) Jonghyun Park, some rights reserved (CC BY), uploaded by Jonghyun Park. Used under a CC-BY license.Dolichoderus pustulatus by (c) Jonghyun Park, some rights reserved (CC BY), uploaded by Jonghyun Park. Used under a CC-BY license.Dolichoderus taschenbergi by (c) Jonghyun Park, some rights reserved (CC BY), uploaded by Jonghyun Park. Used under a CC-BY license.

Pronunciation

How to pronounce Dolichoderus: //ˌdɒlɪˈkoʊdərəs//

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Identification

Distinguished from other dolichoderine by the combination of: thick, sculptured, inflexible ; flange near mandibular base; deeply impressed metathoracic ; concave propodeal ; and horizontal slit-like cloacal orifice. The genus can be separated from the superficially similar former genera Monacis and Hypoclinea (now synonymized) by the above character combination as defined by Shattuck's revision. -level identification requires examination of the head flange and propodeal shape.

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Appearance

typically measure approximately 4 mm in body length. The is thick, inflexible, and strongly sculptured. A distinctive flange is present on the underside of the near the mandibular base, which is tooth-like in some . The longitudinal in the central plate of the is deeply impressed. The propodeum (first abdominal segment) has a distinctly concave when viewed laterally. The and mesosoma are separated by a single petiolar segment. The cloacal orifice is a horizontal slit rather than circular, sometimes surrounded by a few stiff erect bristles.

Habitat

Colonies occupy diverse nesting sites including soil, curled leaves, hollow plant stems, and carton nests constructed from masticated wood mixed with secretions. Some exhibit pronounced flexibility: Dolichoderus pustulatus nests underground in northern United States but lives exclusively arboreally in southern populations. The D. cuspidatus group does not build permanent nests, being nomadic.

Distribution

Present on all continents except Africa; notably absent from North America west of the Rocky Mountains and the Southern Cone of Australia. Native to eastern North America, Central America, tropical South America, Europe, most of Asia, and Australasia. The has been intercepted in international trade, including Dolichoderus quadripiunctatus detected in ceramic tile shipments from Italy to Baltimore, USA.

Diet

collect honeydew excreted by sap-sucking hemipterans, particularly aphids and scale insects. They also feed on small arthropods. The D. cuspidatus group maintains obligate mutualisms with coevolved pseudococcid mealybugs, transporting these 'livestock' during nomadic movements.

Host Associations

  • Aphids - tended for honeydewDolichoderus taschenbergi avidly collects honeydew from pine aphids
  • Scale insects - tended for honeydewD. taschenbergi tends tuliptree , increasing their survival from 8.2% to 46.8%
  • Mealybugs (Pseudococcidae) - obligate mutualismD. cuspidatus group only; coevolved, nomadic farming system

Life Cycle

Colonies vary in size and may be polygynous (multiple queens present). have been observed foraging trails to colonies to imbibe honeydew before returning to the nest, suggesting pre- resource acquisition. Developmental details otherwise unspecified at level.

Behavior

establish well-defined, persistent foraging trails. They actively tend sap-feeding insects and defend them against and . Some emit a pungent defensive fluid characteristic of the . The D. cuspidatus group exhibits unique nomadic , lacking permanent nests and regularly relocating with their mealybug mutualists. Dolichoderus taschenbergi may be a temporary social parasite of D. plagiatus.

Ecological Role

Mutualist with sap-feeding hemipterans: significantly increases survival rates of tended insects by interfering with natural enemies. Acts as an engineer through carton nest construction. The D. cuspidatus group represents a specialized herbivore-mutualist system unique among ants.

Human Relevance

Occasional nuisance pest in plants, buildings, and households; Dolichoderus sp. has been targeted for using fungi. Subject to biosecurity interception due to potential for establishment (D. quadripiunctatus intercepted at US ports).

Similar Taxa

  • TapinomaBoth in Dolichoderinae and lack functional sting; distinguished by Tapinoma's smooth, flexible versus Dolichoderus thick sculptured
  • LinepithemaSimilar honeydew-foraging ; separated by Dolichoderus flange and propodeal concavity
  • TechnomyrmexFormerly confused due to convergent ; Dolichoderus has single petiolar node and distinct texture

More Details

Fossil Record

Extensive fossil history documented from Baltic amber deposits in Europe; 50 extinct recognized as of 2026, indicating long evolutionary persistence of the .

Taxonomic History

Historically fragmented into up to seven subgenera or including Monacis and Hypoclinea. Shattuck's revision synonymized all under Dolichoderus, which remains the current valid circumscription.

Gynandromorphism

Bilateral -male gynandromorphism has been documented in D. scrobiculatus from Australia, with male traits restricted to the right side of the body.

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