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Dimorphic Jumping (Maevia inclemens)

Dimorphic jumping spider is a colorful and commonly found species of the jumping spider indigenous to North America. The word dimorphic stands for two. They are named so due to the two forms or variations displayed by the males, a rarely observed phenomenon in zoology.

Dimorphic Jumping Spider

Physical Description and Identification

Adults

Size:  The females are 0.26 – 0.31 inches (6.5 – 8.0 mm) long, while males are a little smaller and possess a body length of 0.18 – 0.25 inches (4.75 – 6.50 mm).

Color: The overall colors can be black or beige, as well as red, white, tan, or yellow.

The two forms of males, as discussed above, would show a variety of coloration. The “tufted” morph’s body and pedipalps are black. They even have three black tufts on their head, alongside pale legs. The grey morph is striped in black and white throughout with orange palps, but devoid of tufts.

On the other hand, the females have a light brown carapace, chalky or rust shaded abdomen, with chevron pattern at the center, pale legs without marking, black band on each side of its body with thinly covered orange scales. 

Other Characteristic Features: Of the eight eyes, the main ones are large, situated in the frontal-center position. The rest of the three pairs lie on their heard sides, mainly used for detecting motion.Like most other jumping spider species, their forelegs are large while the back legs remain powerful but short.  

Eggs

The small, round eggs remain enclosed in a thick and fluffy sac.

Spiderlings

They are small and disperse to live independently upon maturation.

The Web

Like all other jumping spiders, this one too does not spin a web but produces silk to catch prey, lay eggs, and molt.

Is the Dimorphic Jumping Spider Venomous

They might bite when scared or provoked, but the venom present in their fangs would not pose any medical threat to humans. Most of the jumping spider species have a docile nature, running away from people instead of attacking them.

Dimorphic Jumping Spider Male
Dimorphic Jumping Spider Female

Quick Facts

Other NamesDimorphic jumper
DistributionEastern and mid-western parts of United States including Alabama, Virginia, Wisconsin, Illinois, Kansas, Louisiana, Michigan, Indiana, Pennsylvania, Virginia, New York, Connecticut, Massachusetts, and New Jersey; parts of Canada including Manitoba, and Quebec
HabitatForests, near vine and ivy vegetations, as well as human-made structures
PredatorsSpecies of the wandering and wolf spider family
DietSmaller insects, mites, scorpions and also other spiders
LifespanApproximately one year

Did You Know

  • They are known for their excellent vision that is keener than a cat’s and about ten times acute as that of a dragonfly.
  • Inclemens in Latin stands for harsh, rough, or cruel.
  • Studies show that females do not incline towards a particular male morph during courtship. Instead, they get attracted to males based on their movement.  Yet, the grey morphs are said to attract the female’s attention faster than the tufted ones.

Image Source: Bugeric.blogspot.com, Live.staticflickr.com

Dimorphic jumping spider is a colorful and commonly found species of the jumping spider indigenous to North America. The word dimorphic stands for two. They are named so due to the two forms or variations displayed by the males, a rarely observed phenomenon in zoology.

Dimorphic Jumping Spider

Physical Description and Identification

Adults

Size:  The females are 0.26 – 0.31 inches (6.5 – 8.0 mm) long, while males are a little smaller and possess a body length of 0.18 – 0.25 inches (4.75 – 6.50 mm).

Color: The overall colors can be black or beige, as well as red, white, tan, or yellow.

The two forms of males, as discussed above, would show a variety of coloration. The “tufted” morph’s body and pedipalps are black. They even have three black tufts on their head, alongside pale legs. The grey morph is striped in black and white throughout with orange palps, but devoid of tufts.

On the other hand, the females have a light brown carapace, chalky or rust shaded abdomen, with chevron pattern at the center, pale legs without marking, black band on each side of its body with thinly covered orange scales. 

Other Characteristic Features: Of the eight eyes, the main ones are large, situated in the frontal-center position. The rest of the three pairs lie on their heard sides, mainly used for detecting motion.Like most other jumping spider species, their forelegs are large while the back legs remain powerful but short.  

Eggs

The small, round eggs remain enclosed in a thick and fluffy sac.

Spiderlings

They are small and disperse to live independently upon maturation.

The Web

Like all other jumping spiders, this one too does not spin a web but produces silk to catch prey, lay eggs, and molt.

Is the Dimorphic Jumping Spider Venomous

They might bite when scared or provoked, but the venom present in their fangs would not pose any medical threat to humans. Most of the jumping spider species have a docile nature, running away from people instead of attacking them.

Dimorphic Jumping Spider Male
Dimorphic Jumping Spider Female

Quick Facts

Other NamesDimorphic jumper
DistributionEastern and mid-western parts of United States including Alabama, Virginia, Wisconsin, Illinois, Kansas, Louisiana, Michigan, Indiana, Pennsylvania, Virginia, New York, Connecticut, Massachusetts, and New Jersey; parts of Canada including Manitoba, and Quebec
HabitatForests, near vine and ivy vegetations, as well as human-made structures
PredatorsSpecies of the wandering and wolf spider family
DietSmaller insects, mites, scorpions and also other spiders
LifespanApproximately one year

Did You Know

  • They are known for their excellent vision that is keener than a cat’s and about ten times acute as that of a dragonfly.
  • Inclemens in Latin stands for harsh, rough, or cruel.
  • Studies show that females do not incline towards a particular male morph during courtship. Instead, they get attracted to males based on their movement.  Yet, the grey morphs are said to attract the female’s attention faster than the tufted ones.

Image Source: Bugeric.blogspot.com, Live.staticflickr.com

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