Furrow spiders have a lower row of 6 eyes, paired horizontally across their heads, and an additional pair of eyes located directly above the center of the lower row. Females produce pheromones during mating season, which are detected by males through chemoreceptors. These spiders also are extremely sensitive to vibrations that they sense using macrosetate and filiform hairs along their legs (filiform hairs are also located on their abdomens). Small receptors called slit sensilla are arranged along their exoskeletons, detecting any pressure against their bodies.
Communication Channels: visual ; tactile ; chemical
Other Communication Modes: pheromones ; vibrations
Perception Channels: visual ; tactile ; vibrations ; chemical
This species is common throughout its range and currently has no special conservation status.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
Once eggs are fertilized by the male, female furrow spiders hide their egg sacs within large web cocoons on leaves. Fertilized eggs hatch in the cocoon within a month. Hatched spiderlings remain in the protective cocoon for two to three months until they reach maturity. When they have fully matured, spiderlings disperse in search of foraging opportunities.
Although venomous, these spiders only bite humans if their webs are threatened and, even then, bites are only superficial and do not typically require medical attention. There are no known adverse effects of furrow spiders on humans.
Negative Impacts: injures humans (bites or stings, venomous )
Furrow spiders provide some assistance through their predation on insects considered to be pests by humans.
Positive Impacts: controls pest population
Furrow spiders are primarily predators of small insects and bugs. Their webs may keep populations of these animals in check, especially in man-made settings like barns, houses, and bridges.
These spiders are primarily insectivores. They use varying sizes of orb webs to capture prey during the day; prey items typically include damselflies (Platycnemis pennipes), gnats, and common mosquitoes (Culex pipiens). Like many arachnids, this species produces a venom in the anterior prosoma within a specialized gland which is connected to the chelicerae via small canals. Each chelicera has four pairs of teeth. Once snared and entangled within the orb web, furrow spiders wrap their prey in silk and immobilize it, injecting venom through their chelicerae, and transport it off the web. Digestive enzymes break down the prey's internal organs into a fluid form for consumption, leaving very little waste for excretion. Larger prey are stored in order to give digestive enzymes ample time to act.
Animal Foods: insects
Foraging Behavior: stores or caches food
Primary Diet: carnivore (Insectivore )
Furrow spiders are a holartic species commonly found throughout North America, from northern Mexico, throughout the United States and into Canada, as well as southern and eastern Alaska. This species is also ubiquitous throughout Europe and western Asia. Smaller distributions exist in the Korean and Kamchatka penninsulas, eastern China, and Japan, as well as in parts of Africa including northeastern Algeria and Egypt. Single records also exist from Australia, Greenland, and Iceland.
Biogeographic Regions: nearctic (Native ); palearctic (Native ); oriental (Native ); australian (Introduced )
Other Geographic Terms: holarctic
Furrow spiders are commonly found in moist areas near bodies of water or areas of dense vegetation. Man-made structures like barns, houses, and bridges also make ideal habitats for these spiders as they provide suitable coverage from the sun.
Range elevation: 2 to 700 m.
Average elevation: 300 m.
Habitat Regions: temperate ; terrestrial
Terrestrial Biomes: taiga ; savanna or grassland ; forest
Wetlands: marsh
Other Habitat Features: urban ; suburban ; agricultural ; riparian
Furrow spiders are capable of surviving cold winter seasons. Although they most commonly reach maturity during the spring, they may reach maturity at any time during the year. These spiders may live up to two years.
Typical lifespan
Status: wild: 1 to 2 years.
Average lifespan
Status: wild: 1 years.
These orb weaving spiders have large, bulbous, oval-shaped abdomens, which are dorsoventrally flattened. The abdomen ranges in color including black, grey, red and olive, and the carapace features a lighter colored, arrow shaped pattern that points towards the cephalothorax. Their legs have a striped pattern matching the carapace and are covered in large hairs (macrosetae). The two pairs of forward legs are very long (typically equal to the entire body length) while their rear legs are shorter. Males tend to be smaller and lighter in color than females, ranging in size from 5 to 9 mm in length, while females range from 6 to 14 mm. Legspans for both sexes may range from 18 to 35 mm.
Range mass: .1 to .3 g.
Average mass: .23 g.
Range length: 5 to 14 mm.
Average length: 7 mm.
Other Physical Features: ectothermic ; bilateral symmetry ; venomous
Sexual Dimorphism: female larger; sexes colored or patterned differently; female more colorful
Many birds feed on these spiders, especially if they are not well hidden during the day. Larger insects such as black and yellow mud daubers (Sceliphron caementarium) are also predators of adult furrow spiders, while flesh fly larvae (Sarcophaga sexpunctata)are known predators of their egg cocoons.
Known Predators:
Females furrow spiders produce a silken cocoon that can fit both male and female inside during copulation. Once it is made, females reside in this cocoon and emit pheromones, which males sense through chemoreceptors. Females carry unfertilized eggs inside the cocoon and, once inside the cocoon, males insert sperm into females using their pedipalps. Fertilized eggs, which are yellow in color, are then nested within an egg sac, which the female will place in a protected location such as the underside of a leaf. Further copulation may occur if a female has additional unfertilized eggs after mating once, provided a male is still present and protecting the hidden egg sac. Males are sometimes (but not always) killed and eaten following successive mating; regardless, they typically die soon after mating. Females die following egg laying, sometimes surviving until spiderlings have hatched from their cocoon.
Mating System: monogamous
When females are well fed, they focus on creating more eggs for reproduction rather than web construction. When food is difficult to find, no resources are put into producing unfertilized eggs or a silken cocoon for reproduction. Mating can occur from spring through fall and is usually only limited by resource availability.
Breeding interval: Furrow spiders breed only once in their lifetimes.
Breeding season: Breeding occurs from late spring to early fall.
Range number of offspring: 3 to 5.
Range gestation period: 1 to 1 months.
Range time to independence: 1 to 4 months.
Average time to independence: 3 months.
Range age at sexual or reproductive maturity (female): 4 to 18 months.
Average age at sexual or reproductive maturity (female): 6 months.
Range age at sexual or reproductive maturity (male): 4 to 18 months.
Average age at sexual or reproductive maturity (male): 6 months.
Key Reproductive Features: semelparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); oviparous
Before any mating or egg fertilization takes place, females create a silken retreat in a protected location where eggs will be placed. After fertilization, mating pairs coexist and protect the cocoon for a time; both parents die at some point following copulation and egg laying, although survival time varies.
Parental Investment: male parental care ; female parental care ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Protecting: Male, Female); pre-weaning/fledging (Protecting: Female)
Larinioides cornutus, the furrow spider,[1] furrow orb spider, or foliate spider[2] is an orb-weaver spider with Holarctic distribution.
Females reach a body length of about 6–14 mm, males up to 5–9 mm. Leg spans range from 18 to 35 mm.[1]
These spiders can be identified by their large, oval-shaped, bulbous abdomens. Colors can range from black, grey, and shades of red. The carapace on their abdomen almost always has a lighter shaded arrow pointing toward their cephalothorax, while the legs also have a similar arrow pattern.[3]
Their eye structure consists of a horizontal row of 6 eyes, with an additional pair above the center of the row. A common misconception is that spiders cannot hear, due to their lack of ears of other common structures. However, these animals do have the ability to sense sound due to macrosetate and filiform hairs on their legs.[4]
These spiders are most often found in moist areas, especially near water. The web is built between grass or in low shrubbery. They hide during the day in a silken retreat that opens at the bottom, masked with plant and animal matter and leave it during the night. The web is remade in the evening.[5] Unlike many other species of animal and spider, the cornutus does not hibernate in winter, and instead has an annual cycle of seasonal resistance. While their supercooling point in summer is -8 °C, in winter it drops to -20 °C.[6]
Like mating in many other spiders, the females create a silk cocoon for copulation. The females reside in the cocoon, and emit pheromones to lure males, who can sense them through chemoreceptors. The males insert sperm using their pedipalps, and fertilize the eggs of the female. These become yellow egg sacs. Like many other types of spiders, males typically die after mating, oftentimes by being eaten by the female. This evolutionary trait of spiders still remains partially unknown.
The male lives with the female during mating time, which is in autumn and again in spring. The female produces three to five yellow egg sacs during the summer.[5]
There is possibly a distinct species L. folium, which is very similar but occurs in dry habitat.[5]
Furrow Orb Weaver found in Northern Kentucky Larinioides cornutus, the furrow spider, furrow orb spider, or foliate spider is an orb-weaver spider with Holarctic distribution.
