The red-backed jumping spider is a common inhabitant of gardens and homes, often sparking curiosity due to its distinctive appearance. Many people wonder about their potential danger, particularly regarding whether they possess venom. This article aims to clarify the nature of the red-backed jumping spider and its venom, addressing common concerns.
Meet the Red-Backed Jumping Spider
The red-backed jumping spider, scientifically known as Phidippus johnsoni, is one of the most frequently observed jumping spiders in western North America. This spider is relatively small, typically measuring about one centimeter (0.4 inches) in body length. Its most striking feature is a vivid red abdomen, which contrasts sharply with its predominantly black body. Females often display an additional black central stripe on their red abdomen, while males usually have a uniformly red back.
Beyond their coloration, these spiders have iridescent teal-colored mouthparts, known as chelicerae. Unlike many spiders that rely on webs to catch prey, red-backed jumping spiders are active daytime hunters. They possess exceptional vision with eight eyes, allowing them to stalk and pounce on insects, often jumping distances exceeding 50 times their body length. They are generally non-aggressive towards humans, opting to flee or jump away when approached.
Assessing the Venom’s Impact
The red-backed jumping spider is indeed venomous, using its venom to subdue prey. However, its venom is considered to be of mild intensity and poses minimal health risks to humans. Bites from Phidippus johnsoni are rare, typically occurring only when the spider feels threatened or is accidentally pressed against the skin. These defensive bites are generally not life-threatening and are often compared to a bee sting in terms of their effect.
Symptoms from a red-backed jumping spider bite are usually localized and mild, including slight pain, redness, mild swelling, and itching at the bite site. Severe reactions are uncommon and typically occur only in individuals with specific allergies to the spider’s venom, similar to allergic reactions to bee stings. It is important to distinguish Phidippus johnsoni from the Australian redback spider (Latrodectus hasselti), which is a different species and a highly venomous widow spider known for causing severe pain and systemic symptoms due to its neurotoxic venom. Unlike the Australian redback, the red-backed jumping spider’s venom does not cause medically significant systemic effects in healthy individuals.
Responding to a Bite
Given the mild nature of red-backed jumping spider bites, first aid is typically straightforward and can be managed at home. If a bite occurs, the first step is to clean the affected area thoroughly with soap and water to prevent infection. Applying a cool compress or ice pack to the bite site can help reduce any swelling and alleviate discomfort. Over-the-counter pain relievers or topical creams may also be used if needed.
While most bites resolve without further intervention, it is advisable to monitor the bite area for any changes. Seek medical attention if symptoms worsen, such as increased redness, swelling spreading beyond the initial area, or signs of infection like pus or fever. If an individual experiences symptoms of an allergic reaction, such as difficulty breathing, widespread rash, or dizziness, immediate medical evaluation is necessary.