Formica dirksi

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Formica dirksi
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Formicinae
Tribe: Formicini
Genus: Formica
Species group: microgyna
Species: F. dirksi
Binomial name
Formica dirksi
Wing, 1949

Formica dirksi casent0105597 profile 1.jpg

Formica dirksi casent0105597 dorsal 1.jpg

Specimen labels

Known from a single queen collected in Daigle, Maine. She is a social parasite and was found in a colony of her host, Formica subaenescens. This colony was located at the edge of a small clearing in mixed woods, which were predominantly coniferous forest, and was located under loose bark in the wood of a large, erect, partially decayed, dry stump. The galleries of the nest were partially filled with a the detritus, which was also banked around the base of the stump. The colony was very large, consisting of several hundred workers, and a large number to pupae.

At a Glance • Temporary parasite  


Wing (1949) states that this species is related to Formica microgyna. He notes several differences between the two, including 1) its larger size (total length 5.1 mm); 2) the antepenultimate segment of the maxillary palp is longer (0.23 mm) then the penultimate joint (0.11 mm), as compared to the situation in F. microgyna, in which the two segments are approximately equal in length; 3) the mandible is 7-toothed in-stead of 8-toothed as in the typical F. microgyna; 4) the apex of the petiole is lower and more blunt than in F. microgyna; 5) the petiole has small, posterior lateral the he directed lobes on the ventral surface, where the petiole joins the gaster, which are absent in the typical F. microgyna; 6) hairs are more numerous and slightly shorter, the hairs on the gaster of F. microgyna are fewer in number dorsally and nearly absent ventrally; 7) the pubescence on the gaster is longer, more dense, whiter, and with a silvery tinge, the similar pubescence in F. microgyna has a yellowish tinge; 8) this species is distinctly darker in color, and the areas of infuscation are deeper and more extensive, the gaster of F. microgyna is lighter. This species should be easily separated from F. microgyna, which is known primarily from western United States, and does not occur in Maine.

Keys including this Species


Distribution based on Regional Taxon Lists

Nearctic Region: United States (type locality).

Distribution based on AntMaps


Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.

Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.




The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

  • dirksi. Formica dirksi Wing, 1949: 13 (q.) U.S.A.

Type Material



References based on Global Ant Biodiversity Informatics

  • Wing M. W. 1949. A new Formica from Northern Maine, with a discussion of its supposed type of social parasitism (Hymenoptera: Formicidae). Canadian Entomologist 81(1):13-17