Huntsman spiders, belonging to the family Sparassidae (formerly Heteropodidae), are known for their impressive size, speed, and hunting prowess. Often mistaken for tarantulas due to their hairy appearance, huntsman spiders are easily distinguished by their laterigrade legs, which extend forward in a crab-like fashion. These spiders are native to tropical and warm temperate regions worldwide and are commonly found under rocks, bark, and in sheds and garages. This article delves into the dietary habits of these fascinating creatures.
Identifying Huntsman Spiders
Huntsman spiders, also called giant crab spiders or wood spiders, possess several distinct characteristics. They are eight-eyed spiders, with their eyes arranged in two rows of four on the front of their prosoma. Their legs, twisted in a way that allows them to extend forward, give them a crab-like appearance. While their upper surfaces are typically inconspicuous shades of brown or grey, many species have undersides marked with black and white patterns. Their legs are noticeably spiny, while the rest of their bodies are smoothly furry. The banded huntsman (Holconia) exhibits striped bands on its legs, while the badge huntsman (Neosparassus) is larger, brown, and hairy. The tropical or brown huntsman (Heteropoda) is also large and hairy, with mottled brown, white, and black markings.
Hunting Strategy
Unlike many other spider species that rely on webs to capture prey, huntsman spiders are active hunters. As adults, they do not build webs but instead forage for food. They are known for their speed and agility, often using a springing jump while running, allowing them to travel quickly on walls and even ceilings. This hunting strategy is reflected in their name, as they actively "hunt" their prey.
Dietary Preferences
Huntsman spiders are carnivorous, with a diet primarily consisting of insects and other invertebrates. They have pincer-like claws called chelicerae in front of their mouths, which they use to capture and subdue their prey. Their diet includes:
- Insects: Cockroaches, moths, caterpillars, and other insects form a significant part of their diet.
- Invertebrates: Smaller spiders and other invertebrates are also consumed.
- Small Reptiles: Occasionally, huntsman spiders may prey on small skinks and geckos.
They typically hunt and feed during the night, preying on smaller spiders, pests, and even lizards. Cockroaches are known to be one of their favorite foods.
Read also: Spider Beetle Identification
Habitat and Distribution
Huntsman spiders thrive in tropical and warm climates. They are commonly found in:
- Australia: Australia is home to a large number of huntsman spider species.
- New Zealand
- The Mediterranean
- Southeast Asia
- Southern Africa
- United States: States such as Florida and Hawaii also have populations of huntsman spiders.
Their preferred habitats include crevices of rocks, tree barks, logs, and under stubs and foliage. Their flat bodies enable them to squeeze into narrow spaces, and they are often found inside sheds and garages.
Social Behavior and Reproduction
While most huntsman spiders are nomadic and hunt alone, some species exhibit social behavior. Delena canerides, or the social huntsman, lives in large family groups and shares food. These spiders are more active during the night and protect their young until they reach sexual maturity.
The mating process involves a unique courtship ritual. Males of the huntsman spider Heteropoda venatoria produce substrate-borne sounds to attract females. When a male detects a female's pheromone, he anchors himself to the surface and uses his legs to transmit vibrations from his body. These vibrations, produced mainly by strong abdominal movements, create a characteristic frequency and pattern that identifies him to potential mates.
After mating, the female produces an egg sac wrapped in white silk, containing up to 200 eggs, which she places under barks or rocks. She fiercely guards the sac until the spiderlings hatch. The hatching period varies depending on climatic conditions. Baby huntsman spiders are born with an ashen color and undergo several molts to attain their characteristic brown shade. The spiderlings stay with their mother for several weeks until they reach maturity.
Read also: Diet of the Brown Recluse Spider
Huntsman Spiders and Humans
Despite their large size and hairy appearance, huntsman spiders are generally not dangerous to humans. They are timid and will typically only bite if provoked. While their fangs contain venom, a bite is usually not medically significant and may cause only mild swelling and pain, which can be alleviated with a cold pack. It is important to note that huntsman spiders are venomous, not poisonous.
Reports of severe bites are rare but have been documented for genera such as Palystes and Neosparassus. The effects of these bites can include local swelling and pain, nausea, headache, vomiting, irregular pulse rate, and heart palpitations, suggesting the presence of some systemic neurotoxins.
Prevention and Control
To prevent huntsman spiders from entering homes, it is advisable to:
- Seal cracks and crevices: Ensure windows and doors are properly sealed.
- Use insect screens: Install insect screens to prevent their entry.
- Maintain a clean and tidy environment: Reduce clutter both indoors and outdoors.
- Control insect populations: Since huntsman spiders are attracted to homes in search of prey, controlling insect populations can help deter them.
If a huntsman spider is found indoors, it can be gently captured and released outdoors.
Giant Huntsman Spider
The giant huntsman spider (Heteropoda maxima) is a notable species within the Sparassidae family. Discovered in a cave in Laos in 2001, it boasts the largest leg span of any known spider, reaching up to 30 cm (almost 12 inches). Its body measures about 4.6 cm (1.8 inches) long, and it weighs around 167 grams (5.9 ounces).
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The giant huntsman spider's flattened body is yellowish-brown with irregularly distributed dark spots. Its legs are banded with brown or gray markings. Like other huntsman spiders, its legs splay out to the sides, giving it a crab-like appearance.
This species prefers living in caves, as indicated by its coloration, long legs, and special hairs on the second pair of legs in the male. However, the lack of reduction of the eyes suggests that it lives near cave entrances rather than deep inside.
The giant huntsman spider actively hunts its prey, which includes insects, small rodents, and reptiles. It subdues its prey with venom before feeding. Despite its intimidating appearance, it is not considered dangerous to humans, and bites are rare and typically cause only mild symptoms.