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
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