Black widow spiders feed on a variety of arthropods (flies, mosquitos, beetles, grasshoppers, caterpillars, ants, chilopods and diplopods), scorpions and sometimes on woodlice.
Black widow spiders are carnivores. They eat everything that’s trapped in their web and killed. Even small mammals, reptiles and birds can become a food of black widow spiders.
Black widows may have the size of a pea but they are one of the most venomous spiders in North America. They are found in basements and garages commonly. The venom of black widow spider acts quickly and is believed to be 15 times more poisonous than that of a rattlesnake.
What do Black Widow Spiders Eat?
Black widow spiders don’t have a specific food. They eat all the insects that get trapped in web.
They can eat a lot of food compared to their size at any given time. This gives them the ability to survive without prey for long period.
When food is not available, they conserve energy. Experiments have shown that they can survive 3-4 months easily without food. So, they adjust their appetite and energy requirements according to the availability of food.
Following are some of the most common insects and other small animals that black widow spiders eat.
Arthropods are commonly trapped by black widow spiders in their web. Chilopods and diplopods are types of arthropods that have multiple legs. They are commonly called centipedes and millipedes respectively.
Centipedes and millipedes have segmented bodies and are soft. They become delicious meal for black widow spider if trapped in web.
Flies are small in size and found abundantly in the habitat of black widow spiders. For these reasons, flies are amongst the most common foods of black widow spiders. Small size makes them easy to entangle in the web.
When a fly lands on web, the black widow spider starts wrapping it in the silk web. When the fly becomes motionless, it is injected with venom. This venom has digestive enzymes and liquefies the fly. The liquefied material is sucked by spider through fangs.
Flies get entangled in the web of the spiders. Flies are much faster than black widow spiders but the web is strong enough to capture and kill them.
Mosquitos aren’t the most common food type of black widow spiders but surely if any mosquito gets trapped, he’ll be consumed by the spider.
The method followed by spider for entangling and digesting the captured mosquitos is the same as in case of flies and arthropods.
Small grasshoppers who get entangled in the web are eaten by black widow spiders. Grasshoppers are very agile and jump to much height but if they get trapped in web, black widow spiders don’t spare them.
Caterpillars are small in size and lack any hard outer covering so they are easy prey for black widow spiders. They are larval stage of insects from order lepidoptera. Caterpillars are easily liquefied with the digestive enzymes of spider. The fluid is then sucked by black widow spider.
Poisonous and non-poisonous insects are part of black widow spiders’ diet. We may think that scorpions are poisonous and even an animal shouldn’t eat them. But black widow spiders don’t follow such things.
Spiders may go for exotic taste and entangle woodlice in their web. These types of prey are quite rare but as mentioned earlier, whoever gets in the web, gets consumed by black widow spider.
8. Ants and Beetles
Ants and beetles can also become a meal of black widow spider if they get trapped in the spider’s web. However, they are less commonly caught in the webs because they are ground-dwelling creatures.
Do Female Black Widow Spiders Eat their Males?
Female black widow spiders are notorious for their tendency to eat the male spiders approaching them for mating. But research has shown that this happens in some cases only.
In most cases, male spiders run away safely after mating. In some cases, male spiders offer themselves for cannibalism.
Male black widow spiders are smaller in size. Male spiders do not bite humans.
The bite of the black widow spider is not fatal in humans but it results in enormous pain and suffering.
How do Black Widow Spiders Trap their Prey in the Web?
Black widow spiders hang upside down from their web when waiting for prey.
When an insect touches the web, black widow spider knows through vibrations. The spider starts wrapping its prey in the silk web.
The bristles on the hind legs also help the spiders in trapping their prey. This makes the prey motionless.
After trapping prey in the web, they use their fangs to inject the venom having digestive enzymes. These digestive enzymes liquefy the prey’s body. The resulting fluid is sucked up by the spider. They use fangs as straws for suction.
How to Distinguish a Female Black Widow from a Male?
Female black widow spiders are larger in size and have an hourglass-shaped mark on abdomen. Abdomen is orange to red in color and is a warning sign for insects to stay away.
Should you Feed a Black Widow Spider?
It’s not a good idea to get close to a black widow spider or encourage its presence in your house.
Black widows are some of the most venomous spiders in North America. Their Australian cousins, the redback spider, are also highly venomous. Don’t get too close to them and keep a clean house to discourage their presence.
If you have a black widow infestation, seek professional pest control help immediately. The spider poses a threat to yourself, your pets, and your children.
Other Black Widow Comparisons:
Black widow spiders eat everything that gets trapped in their web. Mosquitos, flies, grasshoppers, caterpillars and arthropods are the most commonly eaten insects by spiders.
Insects that are found abundantly and are caught easily are consumed more frequently. Some less frequent meals include scorpions, woodlice and caterpillars.
Prey is entangled in the web and venom is injected. This liquefies the prey, which is then sucked by spider with fangs. Digestion takes place outside the body.