Thomisidae – Crab spiders or the Thomisidae family include spiders commonly known as crab spiders. They are named for their crab-like appearance, with two pairs of long front legs oriented sideways and two pairs of shorter rear legs. They hunt by directly grabbing their prey with their legs!
In 2021, there were 171 genera counted (World Spider Catalog).
List of Thomisidae genera (external link Araneae)
Genus Diaea
The Diaea (Tamerlan Thorell - 1869) spiders reach up to 5mm. They especially like vegetation, particularly flowers. Their varied colors allow them to blend into the surroundings.
Diaea dorsata, the Tricolored Crab Spider
| Order | Aranea |
|---|---|
| Family | Thomisidae |
| Genus | Diaea |
| Species | Dorsata |
| Identifier | Fabricius |
| Year identified | 1777 |
| Male size min | 3 |
| Male size max | 4 |
| Female size min | 5 |
| Female size max | 6 |
| Color | green/brown/beige |
| Prosoma/Cephalothorax | pale green/brown lines in male |
| Opisthosoma/Abdomen | brown folium bordered with whitish, pairs of pale spots |
| Spider legs | pale green/brown ringed in male |
| Habitat | Forest, Bush, Trees |
| Web | does not weave webs |
| Period start | January |
| Period end | December |
| Zone | Europe |
| Particularity |
Females have green legs and cephalothorax with a large brown patch on the abdomen. Males have brown-ringed legs. Their body can be brownish.
References:
https://www.gbif.org/species/2165401
https://fr.wikipedia.org/wiki/Diaea_dorsata
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Genus Ebrechtella (Dahl, 1907)
Spiders of the genus Ebrechtella reach up to 6mm for females and 3mm for males. They are easily confused with Diaea, living in the same environment and visually close.
Ebrechtella tricuspidata, the Three-spotted Crab Spider
| Order | Aranea |
|---|---|
| Family | Thomisidae |
| Genus | Ebrechtella |
| Species | Tricuspidata |
| Identifier | Fabricius |
| Year identified | 1776 |
| Male size min | 3 |
| Male size max | 3 |
| Female size min | 6 |
| Female size max | 6 |
| Color | Yellow/Green/Brown |
| Prosoma/Cephalothorax | brown translucent in males |
| Opisthosoma/Abdomen | pentagonal, very wide posteriorly, yellow to green; three small reddish-brown spots / large light green or white patch on brown background |
| Spider legs | – |
| Habitat | Bush, Sunny and dry, Dry grass |
| Web | does not weave webs |
| Period start | May |
| Period end | August |
| Zone | Palearctic zone |
| Particularity |
References:
https://www.gbif.org/species/2166830
https://fr.wikipedia.org/wiki/Ebrechtella_tricuspidata
http://unmondedansmonjardin.free.fr/FR/pages/ebrechtella_tricuspidata.htm
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Genus Misumena
Misumena is a genus of crab spiders mainly found on flowers.
Misumena vatia – Goldenrod Crab Spider
| Order | Aranea |
|---|---|
| Family | Thomisidae |
| Genus | Misumena |
| Species | Vatia |
| Identifier | Clerck |
| Year identified | 1757 |
| Male size min | 3 |
| Male size max | 5 |
| Female size min | 7 |
| Female size max | 11.5 |
| Color | variable in females between yellow – green – white by homochromy |
| Prosoma/Cephalothorax | white or yellow with broad brown-yellow stripe on each side in females / reddish-brown or black with yellowish stripe in males |
| Opisthosoma/Abdomen | broad, sometimes white, yellow or green with longitudinal stripes on anterior half in females / matte white with two parallel black-bordered lines in males |
| Spider legs | long |
| Habitat | Bush, Garden, flowers |
| Web | does not weave webs |
| Period start | May |
| Period end | July |
| Zone | Holarctic zone |
| Particularity |
This species present in Europe, Misumena vatia, changes color to adapt to its substrate. This color change takes a few days.
Males measure 3 to 5 mm and females 7 to 11.5 mm
The abdomen has a more or less triangular shape. In females, the cephalothorax has a brown-yellow band on each side.
References:
https://www.gbif.org/species/2165951
https://fr.wikipedia.org/wiki/Misumena_vatia
Genus Synema (Simon, 1864)
Synema globosum, the Globose Crab Spider
| Order | Aranea |
|---|---|
| Family | Thomisidae |
| Genus | Synema |
| Species | Globosum |
| Identifier | Fabricius |
| Year identified | 1775 |
| Male size min | 4 |
| Male size max | 4 |
| Female size min | 6.8 |
| Female size max | 8 |
| Color | Black/white/yellow/orange/red |
| Prosoma/Cephalothorax | dark brown |
| Opisthosoma/Abdomen | varied color in females (white, yellow, orange or red), Napoléon bicorne shape |
| Spider legs | dark brown |
| Habitat | House/habitat, Bush, Sunny and dry, Dry grass, Path edges, flowers |
| Web | does not weave webs |
| Period start | March |
| Period end | October |
| Zone | Palearctic zone |
| Particularity | male abdomen smaller, darker and less marked |
Synema globosum, the globose crab spider, also known as the Napoléon spider, shows a pattern on its abdomen resembling the silhouette of the Emperor wearing his bicorne hat.
References:
https://www.gbif.org/species/5171516
https://fr.wikipedia.org/wiki/Synema_globosum
Les Carnets Nature de Jessica