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SpidersSpidersProjectProject

By Rebecca

Redbacks

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DescriptionDescription

Redback spiders, “latrodetus hasselti”,are almost too familiar to need description.Mature female redbacks are jets black spiders with a variable a red stripe on the back of their spherical adbomen.

Size:1 cm (female); 3mm-4mm(male)

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Description Description Immature females are smaller,usually

brown with whitish marking.Their tough,untidy webs are usually near the ground with the spiders hiding in a shelter tucked in a corner,often guarding her round woolly egg sacs. Male redback spiders are rarely seen.

They are small and brown with red and white markings.

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FoodFood

Redbacks spiders feed mainly on ground-living insects that blunder into their webs ,but small vertebrates such as lizard and even mice can fall victim.

Also eaten-after mating-are the tiny male redbacks.

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Habitat Habitat

Redbacks are found throughout Australia, in drier habitats and built-up areas.They are common in a place around buildings,outdoor furniture,machinery and stacked materials.

In bush, Redback spiders nest under logs and rocks.There is some evidence to suggest that redbacks are not native to Australia.

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Their web Their web A female spider can produce eggs for up to

two years after a single mating. Eggs are enclosed in a 3-5 –white whoolly, spherical egg sacs suspended in the retreat of the web and guarded by the female

Spidersling emerge after about 14 days and disperese on the wind as soon as conditions are right.This is how redback spiders turn up in new places or quickly areas from which they have previously been removed.

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Life cycleLife cycle Once the female has mated, she can store

sperm and use it over a period of up to 2 years to lay several batches of eggs. Each sac contains around 250 eggs and only one to three weeks need to pass before more eggs can be laid.

The females became mature in about 4 months. The smaller male matures in about 90 days. Females live for 2 to 3 years, on the other hand males only live for about 6 to 7months.

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Their bite-venomTheir bite-venomThis type of spiders are not

aggressive,and rarely leave the web. But we still have to be cautious because their bite is very poisonous and could kill children or elderly people.

More likely in summer months.

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Their bite-venomTheir bite-venom After the bite,the onset of pain may be

delayed for five minutes then increase in intensity.Subsequent symptoms vary but have included:nausea,vomiting,abdominal or generalised pain, sweating, restlessness, weakness, muscle spasms and fever.

Redback spider bites normally occur when part of the body comes in direct contact with the spider or its web.

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Interesting informationInteresting information

Anyone bitten by a redback should seek medical attention.

Do not bandage the bite but apply iced water and take simple painkillers.An antivenene is available and very effective.

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Interesting informationInteresting information

Manage redback spiders by learning to recognise their webs and the kinds of places they live.

Always take care when gardening or moving objects where redbacks spiders might be hiding.

Fumigation has only temporary effects on redbacks spider numbers and kills its natural enemies.

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ReferenceReference

Australian museum webpageWikipediaGoogle “redback spiders

fact”09/07/09