Redback spider is one of the poisonous spider. Their origin is Australia and they have a strong poison. They have red spots on their back. So they are called "redback" spider.

1. Professor ： Christopher YUKNA
8/01/2014
Masahiro Yakeya
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2. Contents
What is Redback Spider
Habitats
Their figure
Their lifecycle
Venom
Symptom
Treatment and care
Conclusion
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3. What is Redback Spider?
The redback spider (Latrodectus
hasseltii), also known as the jockey
spider, is a species of poisonous spider
indigenous to Australia.
Adult female
The redback is one of the few spider
species that can be seriously harmful to
humans, and its preferred habitat has
led it to being responsible for the large
majority of serious spider bite in
Australia.
Adult male
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4. Habitats
Distribution
Areas
Japan
Australia
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5. Color and shape
Red pattern also stomach
Red pattern on the back
Fang
(0.7mm)
Even if bitten from
the top of the clothes,
it does not reach the
skin.
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6. Size
Female
Male : 3~5mm
Female : 10~15mm
Male
Female only has a
poison, there is no
poison in the male.
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7. Where does Redback Spider Live?
• Sunny, warm place
• Where there is plenty of food, such as insects or small animals
• Where there is a suitable gap to put the nest
The back of groove
Fence
Under the planter
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8. What does Redback Spider eat?
They can survive for 100 days
without any food.
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9. Lifecycle of Redback Spider
Eggs
Adult
Egg sac
Internal sac of one egg : 100~200
Juvenile
They work in June-September
Male : 58~75 days
Female : 75~104 days
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10. Their venom
Venom is produced by glands in the cephalothorax, and expelled
venom travels through paired ducts from the cephalothorax, exiting
through the tip of the spider's hollow fangs.
Venom
gland
Venom protein
Fang
Fang and venom gland of
redback spider
Muscular layer
Microstructure of venom gland
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of redback spider

11. Component of the venom
Name : α-latrotoxin (neurotoxin)
Features of α-latrotoxin
 The only toxic to vertebrate
 Toxin which is effective in the presynaptic membrane
 Toxic effect of promoting the depolarization of the
central nervous system of vertebrates
TOXICITY (Comparison of LD50)
King Cobra : 1.75mg/kg
Redback Spider : 0.59mg/kg
Their poison is stronger than snake’s it. 11

12. Actions of α-latrotoxin
α-latrotoxin is allowed to
flow to force the Ca ion by
acting from outside the
neuron to calcium channels
of axon terminals.
Neurotransmitter is
released all and we
provoke such seizures
abnormally excited the
muscle fibers or neurons
Information
transmission
function of the
nervous system is
paralyzed.
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13. Symptom
Immediately after being bitten
When redback spider bites, almost no pain topical immediately after being bitten and
only feel a slight pain at a site bitten even. In some cases, stab mouth is found one or two.
5~60 minutes after being bitten
Local symptoms appear, pain will increase gradually.
60 minutes~ after being bitten
Pain bitten over time spread to the entire limb. Local sweating also occur, warmth,
itching also often associated with. However, the greatest feature of the local
symptoms is pain.
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14. If we are bitten…
If the treatment is delayed, we cause muscle paralysis or skin rot.
However…
We don’t die by their poison because injection
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amount of their poison is a little.

15. Bite treatment and care
 If we are bitten by redback spider, we have to wash the area
of the bite with soap and water.
 Even if there is bleeding, it is not necessary to the
tourniquet and bandage.
 Chilled on ice the wound, to go to the hospital.
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16. How to remove
If you found a redback spider, you must not touch it with
bare hands.
Spraying
Stomping
Burning
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17. Conclusion
The adult female redback spider has a round body about
1 cm long, with long, slender legs. The body is a deep
black (occasionally brownish), with a red (sometimes
orange) longitudinal stripe on the upper abdomen.
The poison that they have is very strong to the vertebrate.
However, if you do not do anything for them, they will
not bite.
If we are bitten by them, appropriate care is necessary.
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18. Thank you!!
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20. History of Redback spider①
 1870 : Swedish aracheologist Tamerlan Thorell described the
redback spider from specimens collected in Rockhampton and
Bowen in central Queensland
He named it Latrodectus hasselti in honour of collegue A.W.M van
Hasselt.
 1902 :German arachnologist Friedrich Dahl revised the genus and
named L.ancorifer from New Guinea, which was later regarded as
a subspecies of the redback.
 1911 : Another subspecies , L. h. aruensis , was described by
Norwegian entomologist Embrik Strand.
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21. History of Redback spider②
 1959 : Arachnologist Herbert Walter Levi revised the genus
Lactrodectus.
He focused on differences in the morphology of the female sexual
organs, he reclassified the genus reducing the number of
recognized species from 22 to 6.
 ~Recently : More reliable genetic studies have split the genus
into about 30 species, and the redback has no recognized
subspecies in modern classifications.
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22. Nest of Redback spider
The nest that they build is
irregular and have a threedimensional structure strung
complicated.
Nest area
Capture area
Mucus of capturing is
attached to the thread.
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23. Fatal case
Redback spider bites rarely cause chronic morbidity , and
deaths are even more rare. Throughout the history, at least 14
deaths from redbacks have been recorded. Children, the
elderly, or those with serious medical conditions are at much
higher risk of severe effects and death resulting from a bite.
Dangerous
Dangerous
Dangerous
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24. Relationship with humans
Their net is used to cross line of optical instruments surveying
instruments, rangefinder, microscope, bombsight, such as
telescopic sight.
The study that made full use of genetic engineering, and a
thread of this spider is produced to bacteria is going by the fund
of the United States Army.
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25. Japanese spider
Chiracanthium japonicum
(kabakikomachigumo)
Latrodectus mactans
(kurogokegumo)
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