What Is A Black Spider With White Spots?
What Is A Black Spider With White Spots On Its Back?
- 1 What Is A Black Spider With White Spots On Its Back?
- 2 Anatomy and Behavior
- 3 Eyesight and Spatial Awareness
- 4 These Spider are Smart
- 5 Urban Spider Chart
- 6 Jumping Spider
- 7 Facts, Identification & Control
What should you do if you see a black spider with white spots on its back? Well, the answer to that question depends on exactly what kind of spider it is. Most peoples’ natural reaction to seeing a spider is one of fear and aversion. These eight-legged arthropods are among the most versatile and diverse groupings of creatures found in the animal kingdom and live on every continent except for Antarctica.Despite their sinister reputation, most species of spiders are harmless to humans and provide a number of benefits, from eating smaller pests such as flys and mosquitos, the silk they produce, and the potential medicinal properties of their venom. Still, others are of interest to scientists due to the ecological role they play and the complex behavior and hunting strategies they exhibit.
A particularly unique species of spider is the phidippus audux, otherwise known by the name the bold jumping spider. Most commonly found in North America, the bold jumping spider is one of over 6,000 species of spider in the Salticidae family. Though native to temperate grassy areas, human activity has introduced them into more arid desert regions. Fossilized specimens of jumping spiders indicate that the species has been around for at least 42 million years.
“I wish I could have become a spider, then I would have hold you in my web forever.” — Krish
Anatomy and Behavior
The bold jumping spider, as its name would imply, is known for its peculiar habit of jumping around. Most specimens are small, ranging from about 8-19mm for females, and 6-13 mm for males. They are easily identified by the unique white, orange, or yellow patterning on their backs and their iridescent chelicerae (mandibles).The color of the chelicerae are not due to pigment, but due to the reflection of light on tiny scales that line the mandibles. Like all spiders, it has a segmented body with two main parts: a head and a cephalothorax. They have 8 legs, each tipped with an appendage specialized for grasping branches, blades of grass, and prey.
On males, the tufts of hair can sometimes give the appearance of eyebrows. They are most commonly found in open fields, as unlike other spiders, they generally do not build webs to catch food. Instead, they primarily use their jumping ability for hunting, as their quick leaps allow them to sneak up on their prey unnoticed. Phiddipus do however use their silk to create tents to store eggs, protect them when they molt, and provide shelter from rain or other detrimental weather. They also engage in “ballooning,” a common behavior among spiders where they will produce a strand of silk to catch drafts and drift away in the air.
By altering the pressure of hemolymph (a fluid analogous to blood in vertebrates) in their bodies, they extend their limbs rapidly and use the force to launch themselves into the air. This mechanism is analogous to that found in a hydraulic press, the pressurized liquid expands rapidly and the force straightens the legs and launches the spider into the air. Using their powerful legs, bold jumping spiders can leap a distance of up to 50 times their body length. For reference, that would be the equivalent of an adult human male of average height (5′ 10″) jumping over a football field
Bold jumping spiders have a rather dangerous mating ritual. Males are indiscriminate in their choice of mate, attempting to copulate with any female they come across. Females are larger and more aggressive so the male’s indiscriminate mating can result in them being eaten by the larger female. Male jumping spiders are even known to attempt to mate with spiders of different species, often with unfortunate results.
The mating ritual involves a courtship display where the male will display its bright chelicerae and show its colored spots. Like many kinds of spiders, female jumping spiders do not have a specialized opening for insemination. Instead, the male directly injects its semen into the female’s ova by way of a specialed appendage.Females can produce up to 6 clutches of eggs which can each contain anywhere from 30-170 individual eggs.
The eggs are laid in the early spring and the newborns emerge by late spring/early summer. The average lifespan of a jumping spider is approximately 1 year.
Eyesight and Spatial Awareness
A unique feature of the bold jumping spider is its sharp eyesight. In particular, the anterior median eyes have very good vision. Anatomical experiments have shown that jumping spiders have up to 4 different kinds of receptor cells and possibly have tetrachromatic color vision, as opposed to trichromatic color vision in humans. Their eyes are too close together to have proper depth perception like humans do, but they make use of a technique known as “image defocusing” to gauge the distance between them and objects in their environment. Incoming green light entering the spider’s anterior median eyes is focused on the deepest layer of the retina, while other layers receive a fuzzy image. By calculating the disparity between the focused and defocused layer, the spider can determine how far away things are in its environment and act accordingly.
Jumping spiders also demonstrates a keen 3-dimensional awareness of their environment and essentially have 360-degree vision. Because they rely on jumping to capture prey, bold jumping spiders must be able to spot their prey, adjust their body accordingly, and determine a possible trajectory before they jump. This sequence of events requires that jumping spiders be able to visualize themselves and their prey in a 3-dimensional space. They also must be able to calculate a specific trajectory for their jump from an extremely large pool of possible trajectories, a computationally very difficult problem. They also have a tendency to fixate on objects and their environment and exhibit a curiosity not seen in other spiders. For example, they will often approach humans rather than scurry away, strange behavior for a spider.
These Spider are Smart
Advanced capacities such as their precise vision and 3-dimensional awareness indicate that bold jumping spiders are capable of complex cognitive tasks. Despite the fact that their brain is the size of a poppy seed, researchers have shown that jumping spiders demonstrate a high level of intelligence not found in other species of spider. A widely referenced study by Robert Jackson and Fiona Cross in the 1980s demonstrated that some subspecies of jumping spider can make and execute complex strategies for hunting. In addition, jumping spiders seem to be able to visualize hidden food and plan a path to get there.
“You don’t work with spiders very long before you start noticing how important silk is to their life and just how special that is for spiders.” — Cheryl Hayashi
In a related 2016 study, Jackson & Cross demonstrated that other subspecies of jumping spiders also exhibit complex planning behavior. In the study, the researchers situated the spiders atop a tower from which they had a view of two separate boxes and two pathways leading to the boxes. One of the boxes contained leaves and the other contained food. After leaving the tower, the spiders were unable to see the boxes and had to choose one of two walkways to reach the box containing food.
All 15 species of jumping spider tested chose the correct walkway more often than the incorrect walkway to a statistically significant degree, providing evidence that the spiders were remembering where the box containing food was, even though the box had left their immediate field of vision. Further manipulations showed that even when the spiders initially chose the incorrect path, they would stop and change their movement. The researchers take these findings as evidence that jumping spiders exhibit genuine cognition based on representation. In other words, it seems like the spiders were thinking before acting and were capable of changing plans mid-execution.
In the study, Jackson & Cross distinguish between three different ways that organisms operate in their environment, Darwinian, Skinnerian, and Popperian. Darwinian animals rely on “hardwired” responses to stimuli, while Skinnerian organisms can modulate their hardwired behavior dependent on feedback stimuli from the environment. Popperian animals, on the other hand, are unique in that they can formulate plans ahead of time and act on those plans. The discovery that jumping spiders may fall under the third category of organisms is an exciting prospect and adds to the growing list of evidence of advanced cognition in non-human species.
So what do these spiders mean for humans? Like most species of spider, jumping spiders are non-aggressive so they pose little to no danger to humans unless threatened. Though they technically are venomous, as they use their venom to incapacitate their prey, they very rarely bite. Even if they do, they are unable to administer a large enough quantity of venom to be harmful to humans. Being bitten produces a reaction similar to that of a mosquito bite. In fact, many gardeners are fans of the creatures as they eat up pests that would otherwise ruin crops. So if you see one of these unique creatures in the wild, take a moment to enjoy its affable appearance and behavior, but otherwise leave it be!
Urban Spider Chart
The majority of Kentucky’s spiders are harmless to humans, even when they enter our living environments. This chart is designed to help with quick identification of spiders that are commonly encountered in homes, buildings, yards, and other urban environments. Click on the spider to read more about it.
Spiders of Medical Significance
Size: Adult female is about 1/2 inch long.
Color: Adult females are glossy black with a variable number of red markings on the top and bottom of abdomen. Adults males are similar, but with a few white markings. Juveniles are highly variable.
Features: Abdomen is nearly spherical on adult females and juveniles. Male is slimmer with longer legs (pictured here).
Notes: Bites are very serious and require immediate medical attention, but the spider is timid and unlikely to bite unless handled. Black widows are common all over Kentucky. They tend to occur in concealed outdoor locations: piles of rocks, piles of firewood, and dark corners of garages and out-buildings. Females are common; males are very rarely encountered.
Size: About the size of a U.S. quarter, with legs outstretched.
Color: Tan to dark brown, abdomen and legs are uniformly colored with no stripes, bands, or mottling. The legs are long and thin and lack conspicuous spines.
Features: Dark violin-shaped mark on back, with the neck of the violin pointing toward the rear (abdomen) of the spider. This feature is consistent in adult brown recluses, but can be hard to see and is less obvious in younger spiders. Also, brown recluses only have six eyes: most Kentucky spiders have eight.
Notes: Bites are very serious and require immediate medical attention, but brown recluses are timid and unlikely to bite unless handled. These spiders are more common in Western KY, less common in Central and Southeastern KY. They tend to occur in hidden locations indoors and outdoors: piles of cardboard or paper, stacks of cut wood, and wall-voids of buildings.
Size: About the size of a U.S. quarter, with legs outstretched.
Color: Brown with prominent longitudinal gray or tan stripes.
Features: Prominent hind spinnerets: these are two, small, finger-like projections on the end of the grass spider’s abdomen (used to spin the web). Many other spiders have spinnerets, but they are very large and distinctive in grass spiders.
Notes: Grass spiders are very common in Kentucky lawns where they build large, funnel-shaped webs. They also occasionally wander into homes. Because they are brown and of a similar size, grass spiders are often mistaken for brown recluses. Like most Kentucky spiders, though, the bites of grass spiders are harmless except to allergic individuals.
Size: Wolf spiders range in size from tiny (the size of a pencil eraser) to about the size of a U.S. silver dollar, with legs outstretched
Color: There are many species of wolf spiders in Kentucky, but most are dark or light brown, usually with contrasting spots or stripes.
Features: Wolf spiders are fast-moving and they are typically seen running on the ground. They are not web builders.
Notes: Wolf spiders often wander into homes. Because they are brown in color, wolf spiders are often mistaken for brown recluses. Like most Kentucky spiders, the bites of wolf spiders are harmless except to allergic individuals. Wolf spiders are among the most common kinds of spiders in Kentucky.
Size: A little larger than a U.S. silver dollar, with legs outstretched.
Color: Brown with contrasting, darker brown patterns.
Features: Very large brown spiders; sometimes seen running on the ground or sitting motionless on tree trunks.
Notes: Fishing spiders are common near streams and wooded areas in Kentucky, and they sometimes wander into nearby homes. They are among the largest spiders in our state, but they are not considered dangerous. Like most Kentucky spiders, the bites of fishing spiders are harmless except to allergic individuals. They are sometimes mistaken for brown recluse spiders, but adult brown recluses are smaller and lack the fishing spider’s distinct dark brown patterning.
American House Spider
Size: About the size of a U.S. nickel, with legs outstretched.
Color: Brown and tan highlighted with dark brown patterns
Features: Spherical abdomen; almost always encountered in its compact, messy cobweb
Notes: The American House Spider is one of the most commonly encountered spiders in Kentucky and is found in many homes and buildings. Because it is brown in color, American house spiders are often mistaken for brown recluses. Unlike brown recluses, though, house spiders are almost never found outside of their webs. Like most Kentucky spiders, the bites of house spiders are harmless except to allergic individuals. The American House Spider is a type of cobweb spider.
Size: About the size of a U.S. half-dollar, with legs outstretched.
Color: Light tan or gray with darker contrasting markings.
Features: Small, thin body with long, thin legs; almost always encountered in its messy cobweb.
Notes: Cellar spiders are among the most commonly encountered spiders in Kentucky and they are found in many homes and buildings.
Like most Kentucky spiders, the bites of cellar spiders are harmless except to allergic individuals. Cellar spiders are sometimes called «daddy-long-legs» or «granddaddy-long-legs,» but they are not closely related to harvestmen (which are not true spiders), which are also known as daddy-long-legs.
Yellow Sac Spider
Size: About the size of a U.S. nickel, with legs outstretched.
Color: Tan legs and head, yellow abdomen
Features: Low, flat spider; does not build a web
Notes: The yellow sac spider is commonly found in homes and it is often mistaken for the brown recluse because it is similar in shape, but the yellow sac spider lacks the «fiddle» pattern of the brown recluse. Also, the sac spider has eight eyes instead of six. The bite of a yellow sac spider can be painful, but it is not medically significant except to allergic individuals.
Size: Orb weavers range in size from tiny (the size of a pencil eraser) to a little larger than a U.S. silver dollar, with legs outstretched.
Color: There are many species of orb-weaver spiders in Kentucky.
Some are solid tan or brown, while others are colorful with vivid patterns.
Features: Orb weavers are distinguished by their webs: no other common Kentucky spiders make organized, circular, grid-like webs. Orb weavers are almost always encountered inside their webs.
Notes: Orb weavers are commonly found on porches and gardens in Kentucky, especially in late summer. Occasionally, they will wander into a home and build a web in a doorway or windowsill. Some orb weavers are very large, but, like most Kentucky spiders, the bites of orb weavers are harmless except to allergic individuals. The Yellow-and-black Argiope (pictured below, top left), one of the largest spiders in Kentucky, is a type of orb weaver.
Size: Typical jumping spiders are about the size of a U.S. dime, with legs outstretched.
Color: There are many species of jumping spiders in Kentucky. Many are gray or black, while some are vividly colored.
Features: Jumping spiders have distinctive, large eyes and a «flat faced» look. They are characterized by quick, herky-jerky motions and they do not build webs.
Notes: Jumping spiders are common on the outsides of homes and buildings and they often wander into homes. Because some are brown in color, jumping spiders are sometimes mistaken for brown recluses. Like most Kentucky spiders, though, the bites of jumping spiders are harmless except to allergic individuals.
Size: About the size of a U.S. nickel, with legs outstretched.
Color: Dark, reddish-brown head, gray abdomen, orange legs.
Features: Woodlouse hunters are distinguished by their very large fangs and low, flat shape. They are not web-builders.
Notes: Woodlouse hunters are often found outdoors under rocks and logs near buildings where they hunt for woodlice (a.k.a. roly-polies or pillbugs) and they sometimes wander into homes. Because these spiders are brownish in color and similar in size, they are occasionally mistaken for brown recluses. Like most Kentucky spiders though, the bites of woodlouse hunters are harmless except to allergic individuals, despite their large fangs.
Size:Typical crab spiders are about the size of a U.S. nickel, with legs outstretched.
Color: There are many species of crab spiders in Kentucky. Some are brown or tan, but most common species are bright white or vivid «neon» green or yellow.
Features: Crab spiders are low and flat and their front two pairs of legs are very long. Crab spiders are not web builders.
Notes: Crab spiders are very common in Kentucky flowers (where they hunt for bees), but they sometimes wander into homes. Because some crab spiders are brown in color, they are occasionally mistaken for brown recluses. Like most Kentucky spiders, the bites of crab spiders are harmless except to allergic individuals.
Size:Purseweb spiders are about the size of a U.S. half-dollar, with legs outstretched.
Color: Shiny black; some have white marks behind the fangs.
Features: Purseweb spiders are large spiders with low, flat bodies.
Notes: Purseweb spiders are common in Kentucky forests. Their webs are hidden, so they are rarely seen. Males, however, are sometimes found wandering on roads and sidewalks in the spring. These spiders are almost never found in homes. Because of their shiny, black color, they are occasionally mistaken for black widows. Purseweb spiders are larger than black widows, though, and lack red markings. Like most Kentucky spiders, the bites of purseweb spiders are harmless except to allergic individuals.
CAUTION! Pesticide recommendations in this publication are registered for use in Kentucky, USA ONLY! The use of some products may not be legal in your state or country. Please check with your local county agent or regulatory official before using any pesticide mentioned in this publication.
Phidippus audax, is one of the most common and conspicuous of the jumping spiders often called Orchard spiders. It is black with a distinct irregular orange to white spot on the back of the abdomen. It can be found in gardens and around homes. Photo 2 is a life jpg from a rolled up newspaper – the spider jumped out with pedapalps raised in the typical defense posture.
Jumping spiders are in the family Salticidae. Salticid spiders come in many sizes and color patterns. Hunters during the day only, they have good eyesight, relying primarily on movement to locate prey. They stalk their prey before attacking in a fast leap. Jumping spiders put out a line of webbing when they jump and can sometimes be seen dangling from this silken dragline after a leap that fails.
They often have conspicuous bands of black and white on their bodies or legs for background matching on trees etc.. Others have velvety red abdomens and some even have metallic colors on the chelicerae. Jumping spiders have eight eyes, with one large pair in the front. Like most spiders, jumping spiders are not considered harmful to humans and are unlikely to bite unless cornered or handled. But the bite is painful and can penetrate tough human skin.
Facts, Identification & ControlThe daring jumping spider, also known as the bold jumping spider, has a distinctive black or dark-gray hairy abdomen.
- Spots: Most members of this species have three white spots on their abdomen, but in some species the spots may be red or orange.
- Size: The adult female is about 3/8 to ¾ inch long, and the adult male is about ¼ to ½ inch long.
- Hair: Tufts of hair over the male spider’s eyes give them the appearance of having “eyebrows”.
- Legs: Daring jumping spiders have eight legs with bands of white spaced up and down the legs
- Eyes: eight eyes (the center two are very large and prominent)
- Mouth: mouthparts that are iridescent blue or green in color
How Did I Get Daring Jumping Spiders?
Like other arachnids, daring jumping spiders, also known as bold jumping spiders enter homes in search of protection, warmth and food. Though they prefer to live outside in barns and sheds, these pests occasionally find their way indoors. Loose-fitting screens and gaps around doors or windows are common access points. Their natural habitats include grasslands, gardens and open wooded areas.
How Serious Are Daring Jumping Spiders?
Daring jumping spiders are non-aggressive, do not pose any serious danger to humans, but may bite in self-defense. Bites typically result in slight pain and small, itchy bumps on the skin that heals quickly. However, the spiders appearance, their quick movements, and their ability to jump may be unsettling.
How Can I Get Rid of Them?Keeping spiders and pests out of your home is an ongoing process, not a one-time treatment. Orkin’s exclusive A.I.M. solution is a continuing cycle of three critical steps — Assess, Implement and Monitor.
Signs Of A Daring Jumping Spider InfestationThe most obvious evidence of daring jumping spiders is their appearance during daylight hours when they are most likely to be seen hunting and seeing them in their sheltered locations.
Behavior, Diet & HabitDaring jumping spiders may bite humans in self-defense. Their daytime hunting habits help reduce the number of human bite cases. If bitten, symptoms usually involve slight pain, itching and local reactions such as red bumps that last from 1-2 days.
What do they eat?The daring jumping spider eats a range of insects and other spiders, and these spiders are known prey for dragonflies, birds and lizards.
ActivityLike most species of the jumping spider group, daring jumping spiders are solitary hunters who are active during the day. Jumping spiders have extremely good vision, a characteristic useful for observing both prey and predators.
DistributionThe daring jumping spider is one of the most common species found in North America. Phidippus audax is generally found in North America. Distribution ranges from southeastern Canada to British Columbia and as far south as northern Mexico to Florida.
Where do they live?
The daring jumping spiders are very diverse and are frequently seen in urban, suburban and agricultural habitats. Their natural habitats include grasslands, prairies old fields backyards, gardens and open woodlands. This species will enter homes and outdoor structures, but isn’t as likely to be seen in a home as it is in barns, storage sheds, on tree trunks and under limbs or ground litter.
These spiders do not build webs to catch prey, but they do build protective webs.
Reproduction & Life Cycle
WebsThese spiders do not build webs to catch prey, but they do build protective webs.
Reproduction & Life Cycle
Daring jumping spiders reach maturation in the springtime, and mating begins around late spring or early summer. Reproductive females will produce as many as eight eggs sacs per year with each egg sac containing from 30-170 eggs. The spiders living in the warmer portions of their distribution range usually live longer and produce more offspring.
Prevention of daring jumping spiders begins with making sure the population of insects that serves as food for the spiders is kept to a minimum and that holes, cracks and gaps in the home’s doors, windows and foundation are properly sealed to prevent entrance into the home’s living space. In addition, removing ground litter that serves as harborage for spiders is also helpful. Should the homeowner need assistance in control of these or any other spider, contact your pest management professional and request an inspection. Your pest management professional can then use his inspection findings to prepare a comprehensive pest management plan that will effectively and efficiently deal with the specific pest problem.