Black Orange-Spot House Spiders or Redback Spiders

Redback spiders (Latrodectus hasselti) are found in Australia. They have been found in all parts of the country. These spiders are found primarily in arid regions and make their homes in sheds, woodpiles, outdoor furniture, machinery and garages. These spiders may also appear near rocks and tree bark.

Redback spiders are most commonly jet black in color and can be identified by an orange or faded red stripe on the upper side of the abdomen. Red or orange hourglass-shaped marking is present on the underside of the abdomen. Young spiderlings and adult males have brown bodies mottled with white. Female redback spiders are larger than males and can reach lengths up to 15 mm.

Redback spiders are members of the “Widow” spiders, along with the black widow spiders that are found in the United States. Although redback spiders usually bite only when provoked, their venom is dangerous. Symptoms of redback spider bites include nausea, fever, vomiting, heart palpitations, sweating, weakness and convulsions.