Micaria

Westring, 1851

ant spiders

Micaria is a of small ground in the Gnaphosidae, first described by Niklas Westring in 1851. The genus contains over 127 distributed across the Holarctic, Indomalayan, Australasian, and Afrotropical regions. These spiders are commonly known as spiders due to their pronounced ant-mimicking appearance and . Most species are ground-dwelling and primarily , hunting on the substrate surface. The species is Micaria fulgens.

Micaria gertschi by (c) Jared Shorma, some rights reserved (CC BY), uploaded by Jared Shorma. Used under a CC-BY license.

Micaria pulicaria by (c) Jared Shorma, some rights reserved (CC BY), uploaded by Jared Shorma. Used under a CC-BY license.

Pronunciation

How to pronounce Micaria: /mɪˈkɛəriə/

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Identification

Micaria can be distinguished from other gnaphosid by the piriform gland , which are similar in size to the major ampullate gland spigots. The genus is further characterized by small body size (1.3–6.5 mm, with most 1.85–5 mm), -like body form, and ground-dwelling habits. Species delineation within Micaria is challenging due to exceptionally high intraspecific morphological variation that obscures species boundaries, necessitating integrative taxonomic approaches combining molecular data, morphometrics, and genitalic characters.

Images

Habitat

Ground-dwelling; occupy terrestrial across diverse including temperate, tropical, and arid regions. Specific microhabitat associations vary by species.

Distribution

Holarctic, Indomalayan, Australasian, and Afrotropical zoogeographic regions. Documented from Europe (including Poland, with M. nivosa recorded as rare), Turkey (M. formicaria), China, South Africa (Northern Cape, Western Cape, KwaZulu-Natal, Free State provinces), Namibia, and throughout the Afrotropical Region.

Behavior

-mimicking is a defining characteristic of the . Micaria sociabilis exhibits reversed sexual , in which males kill and consume females; this behavior has been observed as a male foraging strategy influenced by availability, male feeding during ontogeny, and female-biased sex ratios. Reversed sexual cannibalism frequency increases when males encounter reduced prey availability after developing during periods of high prey occurrence.

Ecological Role

Ground-dwelling that hunt on the substrate surface. - likely provides protective resemblance and may facilitate capture or predator avoidance.