Barn spiders, scientifically known as Araneus cavaticus, are common inhabitants of North America, often found in and around wooden structures. While their size and appearance may be intimidating to some, these spiders are beneficial predators that play a crucial role in controlling insect populations. This article delves into the diet of barn spiders, exploring what they eat, how they hunt, and other fascinating aspects of their feeding habits.
Appearance and Habitat
Barn spiders are characterized by their rusty red to brown abdomen, often with a less distinct pattern compared to other orb weavers in the Neoscona genus. Their cephalothorax is covered in small, rusty red to brown hairs, and their legs are typically lighter in color, with a reddish-brown hue closer to the body. Females range from 1 to 2 centimeters in length, while males are smaller, measuring between 0.5 and 1.5 centimeters.
As their name suggests, barn spiders are commonly found in barns, sheds, porches, and other outdoor structures. They prefer corners, eaves, and hidden areas that offer shelter and proximity to a plentiful supply of insects. They can also be found in boats or any other wooden corners that provide shelter. Out in the wild, they can be found near cliffs, on trees, or in crevices. Whether in urban areas or not, this spider species can survive.
Carnivorous Diet
Barn spiders are carnivores, meaning their diet consists primarily of other animals. They are predators of insects and other arthropods, including insects, spiders, crustaceans, and millipedes. Because barn spiders are carnivorous, their diet is largely based on other insects, such as beetles, moths, and ants.
Hunting and Web Construction
Like other orb-weaver spiders, barn spiders are known for constructing intricate, wheel-shaped webs to trap their prey. Only female barn spiders construct webs. The barn spider’s web is truly a marvel of engineering! The delicate, spiral shape of the web is perfectly designed to catch flying insects as they flit about. It’s like a natural trap waiting for its next meal.
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Barn spiders typically build a new web every day, usually close to dusk, and take it down at dawn by consuming the web. This behavior allows them to conserve resources and rebuild their webs in optimal locations. They like to build webs in areas that can inconvenience people as they go about daily activities and can get in areas such as windows, door frames, walking paths, and other areas around the home. The silk produced by Barn Spiders can be sticky or non-sticky, depending on the purpose. Sticky threads trap insects while non-sticky ones provide support without getting in the way.
Prey Selection
Barn spiders have a preference for flying insects such as moths and crane flies. They feed on several different types of insects, such as beetles, ants, moths, flies, and mosquitoes. Once caught in sticky strands of the web, they are bitten and trussed by the spider, which later eats them.
Hunting Method
Barn spiders have poor eyesight and rely on vibrations to detect their prey. They calmly wait in their webs before wrapping any trapped prey in silk. It’s like they have their little spider grocery shop at home! Once prey is trapped in their web, barn spiders wrap it in their web’s silk to feed on it. They then inject the prey with a venomous bite. When the prey dies, the spider begins to suck out its blood and juices of it. It covers its prey’s body with digestive fluids so that it disintegrates more quickly.
Barn spiders are nocturnal and find their food at night, retracting their webs during the day. Then in the evening, the female builds another web to capture prey.
Predators and Threats
Barn spiders are preyed upon by any animals that happen to be bigger than them. Common predators of the barn spider are birds, lizards, and other larger spider species. Humans also pose a threat to the barn spider since they live typically live in and around man-made structures. Nevertheless, they survive in urban and natural environments, so their population is still stable.
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When threatened, barn spiders bounce up and down in their webs to appear intimidating. This unique behavior can also be seen if there is prey in the barn spider’s web and it wants to throw off any leaves or debris off the prey. To scare away predators, Barn Spiders sometimes drop from their webs and play dead, tricking others into thinking they are no longer alive!
Life Cycle and Behavior
Barn spiders, like all other spiders, prefer to live alone as solitary species. The males are seldom seen unless they want to mate. The females build the web and keep their young close in the beginning. However, nurturing aside, these species live alone for most of their lives.
Male barn spiders impregnate one or more females in their lifespan. To make matters a bit easier for the male, the female communicates to the male that she is sexually mature through her dragline, which leaves a trail of pheromones. A dragline is a string of silk dangling from the female’s backside. Once the male has located a female, he fights any other males that might be hovering around the female to mate. Whichever male emerges victorious gets to mate with the female. But before doing so, the male needs to signal to the female that he belongs to the same species as her and wishes to mate. He does so by attaching a thread to the female’s web and sending out specific vibrations as a form of signal for mating. If the female recognizes the male spider as the same species, the female then positions herself for sex. Then the male deposits the sperm in the female’s genital opening. The female stores these sperm near her ovaries, and fertilization occurs when she is ready to lay eggs about a month later.
The babies of a barn spider are known as barn spiderlings. Until hatching, the mother keeps the eggs safe from predation by wrapping them up in silk in an egg sac.
On average, barn spiders can live for about a year. And during their lives, they face some common diseases as they age. Dehydration - if the barn spider is living in a scorching environment with little to no moisture, or an area facing drought, it can become dehydrated and begin to shrink in size over time. While they might be able to survive long enough without water, harsh weather conditions can affect them more in the later months of their life.Fungal issues - Sometimes, fungus and mold can grow onto the bodies of an aging barn spider.
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Barn Spiders and Humans
Despite their intimidating appearance, barn spiders are not hostile towards humans and prefer to focus on their insect meal. Barn spiders are poisonous, yet their venom does not harm people. Barn spiders can bite if they feel threatened, although they are not hostile to people. You can treat the barn spider bite the same way as any other insect bite: by cleaning the area and applying some moisturizer to stop the itching and mitigate the redness.
Barn spiders are only going to be found inside as incidental pests. If a barn spider does happen to make its way into your home it was not intentional and it will not be able to survive.
Interesting Facts
- Barn Spiders use their silk to create beautiful spirals in their webs, which not only catch food but also dazzle anyone who sees them!
- A Barn Spider can produce up to seven different types of silk for various jobs, like wrapping prey or building their nests. That's like having a toolbox full of different tools!
- Barn Spiders can regrow their legs if they lose one, making them like superheroes with the power of regeneration!
- Believe it or not, Barn Spiders can survive in winter by finding cozy spots in buildings or under leaves, curling up until spring returns.
- With their eight eyes, Barn Spiders can see in almost all directions at once, allowing them to spot sneaky insects or lurking predators!
- Barn Spiders are not aggressive and prefer to stay hidden, making them more like shy artists than fierce animals!
- Charlotte is a barn spider, scientifically called Araneus cavaticus. In fact, Charlotte’s full name is Charlotte A. Cavatica, which is a reference to the spider’s scientific name!