Misumena vatia is a species of crab spider found in Europe and North America. In North America, it is called the goldenrod crab spider or flower (crab) spider, as it is commonly found hunting in goldenrod sprays and milkweed plants. They are called crab spiders because of their unusual ability to walk sideways as well as forwards and backwards. Both males and females of this species progress through several molts before reaching their adult sizes, though females must molt more to reach their larger size. Females can grow up to 10 mm (0.39 in) while males are quite small, reaching 5 mm (0.20 in) at most. Misumena vatia are usually yellow or white or a pattern of these two colors. They may also present with pale green or pink instead of yellow, again, in a pattern with white. They have the ability to change between these colors based on their surroundings through the molting process. They have a complex visual system, with eight eyes, that they rely on for prey capture and for their color-changing abilities. Sometimes, if Misumena vatia consumes colored prey, the spider itself will take on that color. Misumena vatia feed on common insects, often consuming prey much larger than themselves. They use venom to immobilize their prey, though they are harmless to humans. They face threats due to parasites and larger insects. For Misumena vatia, survival depends on the choice of hunting site. The spiders closely monitor multiple sites to see if others nearby are frequented by greater numbers of potential prey. The primary sex ratio is biased toward females. Females are stationary and choose a flower to settle on, while males cover great distances searching for mates. Females do not emit pheromones; rather, they leave "draglines" of silk behind them as they move, which males follow. Females live longer than males, on average. After mating, females guard their nests until the young have hatched, after which they die.
Taxonomy and phylogeny The species Misumena vatia was first described by Swedish arachnologist and entomologist Carl Alexander Clerck in his book Aranei Svecici. Misumena vatia belongs to the family Thomisidae, or spiders known as crab spiders. The family includes more than 2,000 species, which are found all over the world. The genus Misumena includes many other species which are found worldwide. Misumena vatia falls into the Thomisus clade. Other clades in the family Thomisidae include the Borboropactus clade, the Epidius clade, and the Stephanopis clade.
Similar species Close relatives include Mecaphesa asperata, which is also found in North America, as well as Central America and the Caribbean. It is similar in size and shape but is light-gray to brown with pink stripes on the abdomen and cephalothorax. It is also coated with hairs that are short and stiff. Similar species of the Misumenoides and Misumenops genera tend to be found south of Misumena vatia’s home range, but some species, such as Misumenoides formosipes, are found in North America as well. Philodromidae is a closely related family of wandering spiders. These spiders differ from those in the family Thomisidae in that their front legs are of a similar length as their back legs. Thus, their hunting style is quite different.
Description
This species has a wide, flat body that is short and crab-like. It can walk sideways in addition to being able to move forward and backward. Of its eight legs, the first two pairs are the longest. These sets of legs are usually held open, as the spider uses them to capture its prey. Misumena vatia is harmless to humans, as its fangs are not powerful enough to penetrate human skin and its venom is too weak to harm larger animals.
Color These spiders may be yellow or white. This ultimately depends on the flower on which they are hunting (active camouflage). Younger females especially, which may hunt on a variety of flowers such as daisies and sunflowers, have a strong tendency to adapt to the color of the surrounding flower. However, the color-changing process is not instant and can require up to 25 days to complete. Older females need large amounts of relatively large prey to produce the best possible clutch of eggs. In North America, they are most commonly found in goldenrods, bright yellow flowers which attract large numbers of insects, particularly in autumn. It is often very hard even for a searching human to spot this spider on a yellow flower. These spiders are sometimes called 'banana spiders' because of their striking yellow color. Females have light complexions, either white or yellow with darker sides. They may have some markings on the abdomen that can be brown or red. These markings are genetically determined and not affected by a background color change. Males are darker than females, with red or brown outer shells. They have a characteristic white spot in the middle that continues through the area around the eyes. Males specifically have two sets of red and white bands both dorsally and laterally. Similar species of the crab spiders appear in a variety of colors such as those of the genus Diaea, which can be lime green, or some species of Xysticus and Coriarchne which are brown.
Color change
… excerpt ends here. Continue reading the full article.
