Crab spider web. Crab spiders, one of the Bug Lady’s favorite creatures, are featured in this week’s episode as stars rather than insects. They belong to the class Arachnida and are true spiders in the order Araneae.
They belong to the phylum Arthropoda (“jointed legs”) which includes Crustaceans, Insects, and Arachnids.
(In other words, Arachnids are protected by the huge Arthropod “umbrella,” which protects shrimp, crabs, sowbugs, scorpions, spiders/spider relatives/mites/ticks and millipedes.)
The Arachnid umbrella encompasses Araneae (genuine spiders). A cephalothorax and an abdomen, as well as eight legs, make up their two body segments.
Crab spiders have crab-like front legs that they use to sidle over the flower tops. North America is home to around 200 species.
The Thomisidae family includes 2100 species, roughly 175 genera, and numerous clades.
The Misumena, Bassaniana, and Amyciaea genera are among them. The goldenrod crab spider, Misumena vatia, belongs to the Misumena genus.
The holarctic realm, which is north of the equator, is home to this spider. Although their “resting” color is white or yellow, they are well-known for their ability to change color.
These spiders may range in color from pink to pale mint green, and they can even imitate their prey’s color.
Bark crab spiders can be found in North America, Europe, and Asia, and they are known as Bassaniana crab spiders.
Although they wait for prey among the black, brown, and gray tree bark, they have a mottled brown, gray, and black coloration that hides them.
The Amyciaea genus of crab spiders has developed to look like ants, especially weaver ants.
The ant is deceived into thinking it’s one of them, and the spider murders and devours it. Amyciaea ants can be found in Oceania, Asia, and Africa, and there are five species.
Other genera in the Thomisidae family include:
While there are certain steps you may take, don’t try to tackle this challenge on your own.
Before these insects take over the home, clean up your residence and property and install spider traps. The rest is handled by Beeline Pest Control. You’ll sleep better knowing that spiders aren’t in your home, and they will be.
-Xysticus with about 360 species
-Thomisops, with 10 species
-Loxobates, with 10 species
There are 14 species in the genus Platythomisus. With the exception of P., all species are found here.
All Platythomisus spiders are female or immature, as defined by jucundus. P. caribaea has crabs spiders of all kinds. Males make up the bulk of the jucundus.
It can camouflage itself in the grass or on a leaf by turning bright green. There are a total of 26 species.
One of the most recently discovered genera is Boomerangia. In Australia, this genus was discovered in 2014.
So far, there is only one species, B. The dimidiata is the species name for this plant.
Bird droppings are imitated by Phrynarachne spiders. This genus contains 30 species.
Misumena vatia, also known as the flower spider or goldenrod spider, is a common species. These are Red-spotted Crab spiders, which come in white and yellow versions with crimson racing stripes.
White spiders on white flowers and yellow spiders on yellow (but they don’t turn purple or pink) are capable of changing color in roughly ten days.
Appearance: How To Identify Crab Spiders
The four front legs of crab spiders are longer and thicker than the four back legs, allowing them to be identified.
They have eight eyes, which are usually set on tubercles, like other spiders. They have crabwise-held legs and a flat body with two claws. They may run sideways by holding their legs. Laterigrade is the term given to this.
Crab spiders come in a wide range of colors and patterns, in addition to this.
White and black, brown, sky blue, goldenrod yellow, cherry blossom pink, and leaf green are among the colors available with stripe patterns, bands, spots, and blotches.
The average length of a male spider is 0.079 inches, while a female spider is 0.16 inches long on average.
Habitat
They live in a variety of habitats, ranging from grassland to bushes and other low vegetation.
By blowing out their silks into the wind and soaring through the air, several spiders may travel long distances.
Spiders do this for a variety of reasons, including to locate food and mates, to investigate prospective spiderling birth sites, and in the event of spiderlings, to get away from cannibalism.
In some cases, ballooning has allowed spiders to cross oceans, thanks to their ability to travel long distances.
Reproduction
After mating, crab spiders begin producing eggs within a few weeks.
Two silken egg sacs are attached to create a center join for these eggs. Their eggs, on the other hand, are not kept in a web. Female eggs sacs frequently protect their young from predators by remaining nearby.
Environmental conditions determine when hatching will take place. Spiderlings grow up to be adults when they emerge. Before becoming adult and fertile, these tiny spiders go through a series of molts.
Crab Spider Web
Crab spiders overpower their prey with their elongated first and second legs, rather than making catching webs. They’re ambush predators that wait for passing prey to arrive before springing out and attacking them.
These spiders are ambush hunters who do not weave webs. In comparison to the rest of the legs, the two front limbs are typically longer and stronger.
The hind two legs are shorter and are typically covered in a row of robust spines.
Brown, grey, or dazzling green, pink, white, or yellow are their dull colors. They move sideways or backwards and are named for the shape of their bodies.
While the crab spiders are usually smaller, these spiders are quite simple to distinguish and may be mistaken with Sparassidae.
Behavior
Although all Thomisidae produce silk for drop lines and other reproductive needs, some are wandering hunters and the most well-known are ambush predators. They do not build webs to capture prey.
Several species capture passing insects while sitting on or beside flowers or fruit.
Some species, such as Misumena vatia and Thomisus spectabilis, are able to change color over a period of days in order to match the flower on which they are sitting.
Some species sit in the open, where they are startlingly good mimics of bird droppings, while others frequent promising positions among leaves or bark where they await prey.
The spiders that are commonly known as bird-dropping spiders, not all of which are close relatives of crab spiders, should not be confused with these members of the Thomisidae family.
Some crab spiders, such as the flattened-body species, hunt during the day and return at night to look for prey in tree trunks’ cracks or beneath loose bark.
The leaf litter on the ground is where members of the genus Xysticus hunt. Crab spiders paralyze their prey with a venomous bite before using their strong front legs to grab and hold it.
In the late 1980s, the Thomisidae family was expanded to include the spider Aphantochilidae. The mimicry of Cephalotes ants by Aphantochilus species serves as a food source.
Thomisidae spiders are not known to be dangerous to humans.
Recluse spiders are close cousins of Sicarius spiders, which are sometimes referred to as “crab spiders” or “six-eyed crab spiders,” and are extremely venomous. Human bites, however, are uncommon.
Diet
Crab spiders use camouflage to catch their prey instead of webs. Some appear to be fruits, leaves, grass, or flowers, while others seem to be bird droppings. Others may alter their coloration completely.
These spiders attack and inject poisonous venom when prey comes into range. Large insects are paralyzed by crab spider venom.
Are crab spiders dangerous?
While they are venomous for their size, crab spiders are not poisonous to humans.
They can consume insects that are much larger than they are thanks to this venom. A human might experience a toothache that lasts a few hours, but it isn’t life-threatening.
Crab spiders do not actively pursue their prey and instead rely on camouflage to capture it.
With long front legs that are often positioned out to the sides of their body, crab spiders get their name from their crab-like appearance.
Many of these spiders have particular colors that are especially suited to their hunting sites. The goldenrod crab spider, for example, is a vivid yellow color that helps it blend in with the goldenrod blossoms’ yellow petals.
Crab spiders, which eat a variety of insect pests in gardens and flower beds, are considered beneficial to humans.
Several crab spiders’ venoms are thought to be more powerful than the venoms of most spiders, according to scientists.
Crab spiders can capture insects like bees quicker since they are smaller. Humans have not been bitten by crab spiders.
Tiny Crab Spiders Study the Wind
By letting out their silks into the wind and soaring through the air, some spiders may travel vast distances.
Spiders do this for a variety of reasons, including to discover food and mates, seek out promising spots for a new colony, and in the case of spiderlings, to escape cannibalism at their birth places.
Some spiders have been able to cross oceans thanks to ballooning, which has aided them become great travelers.
Crab spiders are careful, deliberate fliers who don’t just launch themselves into the air at random.
The ballooning process was divided into several stages. To ensure they did not get blown away before they were ready to fly, the spiders would first anchor themselves with a strand of silk.
They would then stay stationary, using their sensory hairs on their legs to check the wind conditions.
The spiders would raise one or two of their front legs and hold them up, sensing the motion of the wind, if the wind seemed favorable and blowing at speeds less than 7 miles per hour with mild updrafts, according to a press release announcing the new research.
Spiders would raise their abdomens, orient their bodies toward the wind, and spin up to 60 ballooning silks that stretched an average of 10 feet long in the final phases.
According to Yasemin Saplakoglu of Live Science, the strands created a triangular sheet that tossed spiders through the air like “weak, silky kites.”
According to the research, the safety line that had kept them in place before takeoff broke mechanically when it expanded from 10 to 16 feet long.
Sexual dimorphism
In crab spiders, there are a variety of different forms of sexual dimorphism. Color dimorphisms exist in some species, although the biggest dimorphism is the size differential between men and femen.
Femen of Misumena vatia are roughly twice the size of their male counterparts, which is relatively small in some species.
The discrepancy is substantial in other circumstances; female Thomisus onustus are around 60 times heavier than males on average.
The development of sexual size dimorphisms in the Thomisidae and other related taxa is explained by several proposed explanations.
The fecundity hypothesis is the most widely accepted idea for female development: larger women are selected because they can create more eggs and healthier offspring.
Because size growth does not confer a fitness advantage since males do not carry and lay eggs,
Male dwarfism, on the other hand, may cause sexual dimorphism in size. According to the gravity idea, since the male is smaller, he has a greater chance of meeting partners since he can travel with more ease.
Females are more sedentary and can take bigger prey, such as butterflies and bees, which provide extra calories needed for egg creation. Females have a bigger size that allows them to capture bigger prey.
Some studies claim that sexual dimorphism in size developed by chance and that larger females and smaller males have no selective advantage.
Fast Facts
Crab spiders number in the thousands across the globe, with over 200 species in North America alone.
Crab spiders do not create webs out of silk, despite the fact that they can make it. Instead, before ambushing their prey, they stalk and capture it by blending in with their surroundings.
Crab spiders’ silk is still very valuable, despite the fact that it isn’t used in web construction. Both to protect their eggs and to create balloons that will elevate them into the air, these spiders utilize silk.
The eggs of female crab spiders are protected and they wait for them to hatch, which can take three weeks or more. Shortly after the eggs hatch, females do not eat and die of exhaustion and malnutrition.