Southern house spider
Encyclopedia
The Southern house spider (Kukulcania hibernalis) is a species of large North America
n spider
which exhibit strong sexual dimorphism
. The males very closely resemble brown recluses
, having similar coloration and body structure, though they have slender bodies and are uniformly brown
, unlike the brown recluse. The females are dark brown or black and more compact. Both sexes may grow to be roughly 2 inches (5.1 cm) across (legs extended), with the males typically having longer legs, and the females often having larger, bulbous bodies. The abdomen
of the southern house spider is covered with fine velvet
y light gray hair.
Female southern house spiders are rarely seen, as they build radial webs
around crevices, for which reason their family (Filistatidae) is called crevice weaver
s. Females seldom move except to capture prey caught in their webs. Males, on the other hand, typically wander in search of insect
s and females to mate with, having no particular territory.
The southern house spider is a cribellate spider. That is, its spinnerets do not produce adhesive
webbing. Instead, to capture prey the spider uses its legs to comb webbing across its cribellum
, a spiked plate near the spinnerets. This combing action frays and tangles the strands, producing a fine, velcro
-like netting that ensnares insect legs.
Male southern house spiders sometimes appear aggressive, but they do not bite
unless trapped, and their mouthparts are too small to easily penetrate human skin. They do, however, have an unnerving tendency to crawl across anything in their path regardless of whether it is alive. This is not aggression; these spiders are simply nearly blind and cannot see larger animals. Indeed, these spiders instinctively play dead if they feel threatened (a tactic which is effective against their common predators).
Southern house spiders are capable of crawling through crevices as narrow as 1/4 in (0.66 cm) due to their elongated bodies and compact legs.
is a lengthy (over an hour) and elaborate process with long periods during which neither the male nor the female moves considerably. When the wandering male encounters a female's web, there may be an initial confrontation where each scares the other. Upon recovering, the male then constructs a large web around the female's crevice. When this web is complete, the male pulls on its strands continuously to draw the female out of her hole, which may take several minutes. Following her emergence, each spider will tap at the other in an effort to grasp the other by the forelegs, with the male remaining suspended in his web.
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
n spider
Spider
Spiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...
which exhibit strong sexual dimorphism
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
. The males very closely resemble brown recluses
Brown recluse spider
The brown recluse spider or violin spider, Loxosceles reclusa, is a member of the family Sicariidae . The spider has a venomous bite....
, having similar coloration and body structure, though they have slender bodies and are uniformly brown
Brown
Brown is a color term, denoting a range of composite colors produced by a mixture of orange, red, rose, or yellow with black or gray. The term is from Old English brún, in origin for any dusky or dark shade of color....
, unlike the brown recluse. The females are dark brown or black and more compact. Both sexes may grow to be roughly 2 inches (5.1 cm) across (legs extended), with the males typically having longer legs, and the females often having larger, bulbous bodies. The abdomen
Abdomen
In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
of the southern house spider is covered with fine velvet
Velvet
Velvet is a type of woven tufted fabric in which the cut threads are evenly distributed,with a short dense pile, giving it a distinctive feel.The word 'velvety' is used as an adjective to mean -"smooth like velvet".-Composition:...
y light gray hair.
Female southern house spiders are rarely seen, as they build radial webs
Spider web
A spider web, spiderweb, spider's web or cobweb is a device built by a spider out of proteinaceous spider silk extruded from its spinnerets....
around crevices, for which reason their family (Filistatidae) is called crevice weaver
Crevice weaver
The crevice weaver spiders contain primitive cribellate. They are haplogyne weavers of funnel or tube webs. The family contains 17 genera and more than hundred described species worldwide. One of the most abundant members of this family in the Americas is the Southern house spider...
s. Females seldom move except to capture prey caught in their webs. Males, on the other hand, typically wander in search of insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s and females to mate with, having no particular territory.
The southern house spider is a cribellate spider. That is, its spinnerets do not produce adhesive
Adhesive
An adhesive, or glue, is a mixture in a liquid or semi-liquid state that adheres or bonds items together. Adhesives may come from either natural or synthetic sources. The types of materials that can be bonded are vast but they are especially useful for bonding thin materials...
webbing. Instead, to capture prey the spider uses its legs to comb webbing across its cribellum
Cribellum
The cribellum is a silk spinning organ found in certain spiders. Unlike normal spinnerets, the cribellum consists of one or more plates covered in thousands of tiny spigots. These spigots produce extremely fine fibers which are combed out by the spider's calamistrum, producing silk with a wooly...
, a spiked plate near the spinnerets. This combing action frays and tangles the strands, producing a fine, velcro
Velcro
Velcro is the brand name of the first commercially marketed fabric hook-and-loop fastener, invented in 1948 by the Swiss electrical engineer George de Mestral...
-like netting that ensnares insect legs.
Male southern house spiders sometimes appear aggressive, but they do not bite
Spider bite
A spider bite is an injury resulting from the bites of spiders or other closely related arachnids.Spiders are active hunters and rely heavily on their bites to paralyze and kill their prey before consuming it. They also bite in self defense...
unless trapped, and their mouthparts are too small to easily penetrate human skin. They do, however, have an unnerving tendency to crawl across anything in their path regardless of whether it is alive. This is not aggression; these spiders are simply nearly blind and cannot see larger animals. Indeed, these spiders instinctively play dead if they feel threatened (a tactic which is effective against their common predators).
Southern house spiders are capable of crawling through crevices as narrow as 1/4 in (0.66 cm) due to their elongated bodies and compact legs.
Reproduction
The southern house spider mating ritualMating ritual
Mating rituals may refer to:*Mating, for mating rituals in the animal kingdom*Courtship, for mating rituals in human culture...
is a lengthy (over an hour) and elaborate process with long periods during which neither the male nor the female moves considerably. When the wandering male encounters a female's web, there may be an initial confrontation where each scares the other. Upon recovering, the male then constructs a large web around the female's crevice. When this web is complete, the male pulls on its strands continuously to draw the female out of her hole, which may take several minutes. Following her emergence, each spider will tap at the other in an effort to grasp the other by the forelegs, with the male remaining suspended in his web.
External links
- South house spider pictures and info
- Picture of K. hibernalis (free for noncommercial use)
- southern house spider on the UFUniversity of FloridaThe University of Florida is an American public land-grant, sea-grant, and space-grant research university located on a campus in Gainesville, Florida. The university traces its historical origins to 1853, and has operated continuously on its present Gainesville campus since September 1906...
/ IFASInstitute of Food and Agricultural SciencesThe University of Florida’s Institute of Food and Agricultural Sciences is a federal-state-county partnership dedicated to developing knowledge in agriculture, human and natural resources, and the life sciences, and enhancing and sustaining the quality of human life by making that information...
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