The jumping spider (family Salticidae) is an agile, diurnal predator, unlike spiders that passively wait for prey in a web. Their exceptional vision allows them to effectively stalk and capture meals.
Primary Arthropod Diet
The jumping spider’s diet is almost exclusively carnivorous, consisting of a wide array of small arthropods they encounter while wandering. As generalist hunters, they prey upon nearly any soft-bodied insect they can successfully overpower. Common targets include mosquitoes, small flies, and various larvae and caterpillars.
Jumping spiders are also known to consume other arachnids, including smaller members of their own species, exhibiting opportunistic cannibalism. Their ability to capture prey is directly limited by their own size, as they generally target insects no more than 1.5 times their body length.
Hunting and Consumption Strategies
The success of the jumping spider as a predator hinges on its highly developed visual system, which is among the most acute in the arthropod world. Their large, forward-facing anterior median eyes provide high-resolution vision and stereopsis, allowing them to accurately judge the distance to their target. This binocular sight enables a precise, calculated approach as they stalk their prey from distances up to 30 centimeters away.
The final strike is a powerful leap, which is not driven by large muscles, but by an internal hydraulic system. By rapidly increasing the pressure of their body fluid, or hemolymph, the spiders can powerfully extend their hind legs to launch themselves. Before initiating this jump, the spider instinctively anchors a silk dragline to the surface, creating a safety tether to arrest a fall or provide a quick retreat if the pounce misses.
Once the prey is captured, the spider delivers a venomous bite to subdue it. Consumption relies on external digestion, a method common to most spiders. Digestive enzymes are injected into the immobilized prey, which liquefies the internal tissues. The spider then sucks up the resulting nutrient-rich fluid, leaving behind the empty exoskeleton.
Supplemental Nutrition and Hydration
While their diet is primarily meat-based, jumping spiders require non-prey sources for survival, particularly hydration. They cannot get all necessary water from solid food and must actively drink water droplets. Spiders are frequently observed sipping from dew or misted surfaces, as hydration is important for processes like molting.
Beyond water, some species supplement their carnivorous diet with plant materials. They occasionally consume nectar or pollen, which provides carbohydrates when insect prey is scarce. This behavior technically classifies them as omnivores, though plant matter is a minor part of the diet for most species. One notable exception is the species Bagheera kiplingi, which exhibits significant herbivory, feeding mainly on specialized protein- and fat-rich plant structures known as Beltian bodies.