Phidippus Johnsoni

The Red-backed Jumping Spider, scientifically known as Phidippus johnsoni, is a fascinating species that has garnered significant interest due to its unique characteristics and behavior. Here is an in-depth fact-page about the Red-backed Jumping Spider:

Species Name

  • Scientific Name: Phidippus johnsoni
  • Common Names: Red-backed Jumping Spider, Johnson Jumping Spider

Geographical Range

The geographical range of the Red-backed Jumping Spider (Phidippus johnsoni) is quite extensive and diverse, primarily encompassing a large portion of Western North America. This range is characterized by a variety of habitats, indicative of the spider’s adaptability to different environmental conditions. Here’s a more detailed look at its distribution:

Expanded Geographical Range

  • Western North America Dominance: This spider is predominantly found in Western North America. It is one of the most common and populous jumping spider species in this region.

  • Boundaries: The range is notably bounded by the Great Plains to the east, the Pacific Ocean to the west, extending north into southern Canada, and reaching south into northern Mexico. This distribution suggests a wide adaptability to various climatic and geographical conditions.

  • Diverse Habitats: The Red-backed Jumping Spider thrives in a range of habitats, from sea level to the tree line. This includes:
    • Coastal Dunes: In these areas, the spiders utilize the sandy and often vegetation-sparse environment, possibly for hunting and nesting.
    • Oak Woodlands: These areas provide a contrasting environment with more vegetation cover and a different array of prey and ecological interactions.

  • Urban and Suburban Adaptation: While they are commonly found in natural habitats, these spiders are also known to inhabit human-modified landscapes such as gardens, parks, and even buildings, indicating their adaptability to urbanized areas.

Ecological Role

  • Pest Control: In their natural habitat, these spiders play a crucial role in controlling insect populations, which can be beneficial in managing pest species that might otherwise damage local flora.
  • Indicator Species: Due to their sensitivity to environmental changes, their presence or absence can indicate the health of their ecosystem.

Climate Adaptability

  • Range of Elevations: The fact that they inhabit areas from sea level to the tree line suggests a high level of adaptability to different atmospheric conditions, including variations in oxygen levels, temperature, and humidity.
  • Seasonal Adjustments: Their presence across a range of latitudes implies an ability to adjust to varying seasonal conditions, from the colder climates of Canada to the warmer regions of Mexico.

Conservation Status

The conservation status of the Red-backed Jumping Spider (Phidippus johnsoni) is noteworthy for its apparent stability within its natural range. While not listed on any major conservation lists such as the IUCN Red List or CITES, this does not necessarily imply that the species is devoid of any conservation concerns. Here’s a more detailed exploration:


  • Not Listed on Major Conservation Databases: As of now, the Red-backed Jumping Spider is not explicitly listed on globally recognized conservation databases. This is typically indicative of a species that is not currently facing significant threats to its survival.

  • Population Stability: This species is considered to be one of the most populous and commonly encountered jumping spiders in Western North America. This population stability is a positive sign of its current conservation status.

  • Adaptability: A key factor contributing to their stable conservation status is their adaptability to a range of environments, from natural habitats to urban areas.

  • Indicator of Environmental Health: The presence of Phidippus johnsoni in diverse environments can serve as an indicator of the ecological health of those areas. A stable or increasing population could suggest a healthy ecosystem, whereas a decline might signal environmental issues.


The appearance of the Red-backed Jumping Spider (Phidippus johnsoni) is quite distinctive and contributes significantly to its recognition and interest among enthusiasts and researchers. Their physical characteristics are not only striking but also serve functional purposes in their behavior and ecology. Here’s a more detailed description of their appearance:


  • Size: Adult Red-backed Jumping Spiders are relatively small, with an average body length of about one centimeter (approximately 0.4 inches). This size may vary slightly between individuals.

  • Abdomen Coloration: Both male and female spiders showcase a vivid red abdomen, which is one of their most distinctive features. This bright coloration is often a key identifying trait.

  • Female Distinctive Markings: Females of this species can be distinguished by a black central stripe on their abdomen. This feature adds to the sexual dimorphism observed in the species.

  • Chelicerae (Mouthparts): The chelicerae of these spiders are noted for their shining teal color, adding to the visual appeal and distinctiveness of the species.

  • Overall Body Color: The rest of the body, apart from the abdomen and chelicerae, is predominantly black. This contrast in coloration makes their red abdomen stand out even more.

  • Mimicry: The coloration of Phidippus johnsoni, particularly its bright red abdomen, is not just a random aesthetic feature; it plays a significant role in the spider’s survival and behavior. 

Life Span

The lifespan of the Red-backed Jumping Spider (Phidippus johnsoni) varies significantly depending on whether the spider is in the wild or in captivity, which is indicative of the different environmental pressures and care they receive.


Lifespan in the Wild

  • Average Duration: In their natural habitats, these spiders typically live between six months to two years.
  • Factors Influencing Lifespan: Several factors can influence their lifespan in the wild, including:
    • Predation: They face threats from various predators, which can significantly shorten their lifespan.
    • Food Availability: Access to prey can vary, impacting their nutrition and health.
    • Environmental Conditions: Weather patterns, habitat destruction, and competition for resources can also affect their longevity.
  • Natural Lifecycle: The life cycle of Red-backed Jumping Spiders in the wild is geared towards rapid maturity to ensure reproduction within their shorter lifespan.

Lifespan in Captivity

  • Extended Lifespan: Under optimal conditions in captivity, some Red-backed Jumping Spiders can live up to three years.
  • Care Factors: The extended lifespan in captivity can be attributed to factors such as:
    • Controlled Environment: Captive environments can be regulated to avoid extreme temperatures and humidity levels, which can stress the spiders.
    • Consistent Food Supply: A steady and nutritious diet provided in captivity ensures better health and longevity.
    • Predator-free: The absence of predators in a captive environment removes a significant threat to their survival.
    • Health Monitoring: In captivity, it’s easier to monitor and address any health issues that may arise, contributing to a longer lifespan.

Implications of Lifespan

  • Reproduction and Maturity: The relatively short lifespan in the wild indicates a life strategy focused on rapid growth and early reproduction.
  • Observational Studies: The difference in lifespan between wild and captive spiders provides an interesting opportunity for scientific observation and study, helping researchers understand the impact of environmental factors on the spider’s life cycle.

Life Cycle and Breeding

The life cycle and breeding habits of the Red-backed Jumping Spider (Phidippus johnsoni) are characterized by a series of distinct stages and behaviors, each playing a crucial role in the continuation of the species. Here’s a more detailed breakdown:

Egg Laying and Incubation

  • Frequent Egg Laying: Female Red-backed Jumping Spiders can lay eggs repeatedly throughout their lifespan, with the capacity to produce a new egg sac approximately every 25 to 30 days.
  • Egg Sac Capacity: Each egg sac can contain a substantial number of eggs, ranging from 40 to as many as 300 eggs, depending on environmental conditions and the health of the female.
  • Egg Sac Construction: The female constructs the egg sac using silk, often in a concealed or protected location to ensure safety from predators and environmental hazards.

Development of Spiderlings

  • Incubation Period: After laying, the eggs go through an incubation period within the sac. The duration of this period can vary but typically lasts a few weeks.
  • Emergence of Spiderlings: Upon hatching, the young spiders, known as spiderlings, emerge from the egg sac. Initially, they may stay close to the maternal web.
  • Dispersal Mechanism: Soon after hatching, spiderlings disperse to find their own territories. This dispersal is often aided by a process known as ballooning, where the spiderlings use silk strands to catch the wind and travel to new locations.

Growth and Maturity

  • Molting: As they grow, spiderlings undergo several molts, shedding their exoskeleton to allow for growth. This molting process is critical for their development.
  • Reaching Maturity: The time it takes for spiderlings to reach maturity can vary, but generally, they mature rapidly to ensure they can reproduce within their relatively short lifespan.

Mating and Reproductive Behavior

  • Courtship Rituals: Once mature, these spiders engage in complex courtship behaviors, with males often performing elaborate dances to attract females.
  • Risks During Mating: The mating process can be perilous for males due to the risk of being consumed by females, a behavior observed in many spider species.

Life Cycle Completion

  • Continuation of the Cycle: Successfully mated females will then go on to lay eggs, continuing the life cycle. The entire cycle from egg to reproducing adult can happen within a single season, depending on environmental factors.


The diet of the Red-backed Jumping Spider (Phidippus johnsoni) is quite diverse and plays a significant role in natural pest control. Here’s an expanded view of their dietary habits:

Variety of Prey

  • Insect Predation: These spiders primarily feed on a variety of insects. Their diet includes flies, moths, bugs, and moth caterpillars. Their ability to capture and consume these insects highlights their role as agile and effective hunters.
  • Feeding on Other Spiders: In addition to insects, Red-backed Jumping Spiders are also known to prey on other spider species, demonstrating their position as a top predator in their micro-ecosystem.
  • Size of Prey: They typically target prey that is about half their size or smaller, although they are capable of taking down larger prey relative to their size in some instances.

Hunting Strategy

  • Active Hunting: Unlike web-building spiders that passively wait for prey to be ensnared, Red-backed Jumping Spiders actively stalk and pounce on their prey, utilizing their excellent vision and jumping ability.
  • Precision and Speed: Their hunting method involves quick, precise jumps to capture prey, a strategy that is highly effective and energy-efficient.

Use as Pets

Red-backed Jumping Spiders (Phidippus johnsoni) have gained popularity as pets, especially among those new to spider keeping, due to several attributes that make them suitable for domestic care. Here’s an expanded view on their use as pets:

Advantages of Keeping Red-backed Jumping Spiders as Pets

  • Size: Their small size makes them manageable for most pet owners. A small enclosure can easily accommodate their space needs.
  • Temperament: They are generally non-aggressive towards humans, reducing the risk of bites or other defensive behaviors.
  • Interactive and Interesting: These spiders are known for their active hunting style and curious nature, which can be fascinating to observe. They often display interesting behaviors, such as stalking their prey and exploring their environment.
  • Low Maintenance: Compared to other pets, Red-backed Jumping Spiders require relatively minimal care, making them a good choice for beginners. Their dietary and habitat needs are straightforward and easy to manage.

Care Requirements

  • Habitat: A small terrarium or enclosure with adequate ventilation is suitable for housing. It should include substrates like soil or coconut fiber, and structures like plants or branches for climbing and hiding.
  • Diet: Their diet in captivity can consist of small insects like fruit flies, small crickets, or other suitable small invertebrates. Feeding can be done every few days.
  • Temperature and Humidity: While they are adaptable to various environments, maintaining a moderate temperature and humidity level similar to their natural habitat is beneficial.
  • Handling: While they can be handled, it’s important to do so gently and infrequently, as they are delicate and can be easily stressed.

Lifespan Considerations

  • Short Lifespan: With a lifespan of typically 1-2 years in the wild and possibly up to three years in captivity, potential owners should be prepared for a relatively short commitment compared to other pets.

Educational Aspect

  • Learning Opportunity: Keeping a Red-backed Jumping Spider can be an educational experience, especially for children, as it provides insights into arachnid behavior and biology.

Ethical Considerations

  • Responsible Pet Ownership: As with any pet, it’s important to ensure that you are prepared to meet all the needs of a Red-backed Jumping Spider, including proper habitat, diet, and care.
  • Source of the Spider: Prospective owners should acquire their spiders from reputable sources to ensure they are not contributing to the depletion of wild populations.