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Australian Spider Beetle (Ptinus tectus)

The Australian spider beetle, endemic to Australia, has a cosmopolitan distribution at present. It mainly infests stored food alongside museum specimens, causing severe damage. Though Ptinus tectus is its commonly used species name, it is synonymously referred to as Ptinus ocellus Brown, 1929 even at present.

Australian Spider Beetle

Scientific Classification

  • Family: Ptinidae
  • Genus: Ptinus
  • Scientific name: Ptinus tectus

Physical Description and Identification

Adult

Size: 2.5–4 mm (0.1 -0.15 in)

Color: They have a dark brown body.

Other physical features: Their heavy bodies with six thin, long legs make them closely resemble a spider. Besides biting mouthparts, the adults even have a prominent thorax and an eleven-segmented antenna.

Ptinus tectus

Larva

The cream-colored larvae are fleshy, hairy, and curved, measuring 3.175 mm (0.125 in), rolling into a ball if disturbed or threatened. They develop in around six weeks, molting 4 to 5 times during that phase.

Australian Spider Beetle Larva

Pupa

They pupate inside a spherical, thin-walled cocoon, with the adults emerging between 20 and 30 days. The adults take shelter in the cocoon up to three weeks post-emergence.

Egg

The eggs are pearly and sticky, with food and other materials getting attached to them. Around 100 of these are laid at a time, over 3-4 weeks. They hatch at 20-25 °C, within 16 days.

Quick Facts

Lifespan1 year
DistributionNative: Australia
Invasive: In Europe, and other parts of the world
HabitatIn homes mostly in dark and damp areas like drop ceiling, and wall void, and even bird’s nest  
Common PredatorsNot recorded
Seasons activeOctober to January
Diet of larvae and adultsLarvae: Corn, grains, flour, herbs, cocoa, and spices
Adults: Insect remains, rodent guano

Identifying the Damage Caused by Them

It is considered a massive pest to museums, warehouses, and grain mills. The larvae and adults can cause enormous damage to stored food, cellophane, cardboard boxes, and wood, making the items unfit for use or consumption.

Following proper hygiene measures, sealing food containers tightly, and even spraying areas near walls with insecticides regularly would help control their infestation to a certain extent. Removing and destroying old bird’s nests in gardens or near homes is also a mandate since it is a preferred dwelling place for these beetles.

Did You Know

  • In the United Kingdom, these beetles have infested about 55 museums and historic establishments.
Australian Spider Beetle Picture

Image Source: whatseatingyourcollection.com, bugguide.net, api.sodapdf.com

The Australian spider beetle, endemic to Australia, has a cosmopolitan distribution at present. It mainly infests stored food alongside museum specimens, causing severe damage. Though Ptinus tectus is its commonly used species name, it is synonymously referred to as Ptinus ocellus Brown, 1929 even at present.

Australian Spider Beetle

Physical Description and Identification

Adult

Size: 2.5–4 mm (0.1 -0.15 in)

Color: They have a dark brown body.

Other physical features: Their heavy bodies with six thin, long legs make them closely resemble a spider. Besides biting mouthparts, the adults even have a prominent thorax and an eleven-segmented antenna.

Ptinus tectus

Larva

The cream-colored larvae are fleshy, hairy, and curved, measuring 3.175 mm (0.125 in), rolling into a ball if disturbed or threatened. They develop in around six weeks, molting 4 to 5 times during that phase.

Australian Spider Beetle Larva

Pupa

They pupate inside a spherical, thin-walled cocoon, with the adults emerging between 20 and 30 days. The adults take shelter in the cocoon up to three weeks post-emergence.

Egg

The eggs are pearly and sticky, with food and other materials getting attached to them. Around 100 of these are laid at a time, over 3-4 weeks. They hatch at 20-25 °C, within 16 days.

Quick Facts

Lifespan1 year
DistributionNative: Australia
Invasive: In Europe, and other parts of the world
HabitatIn homes mostly in dark and damp areas like drop ceiling, and wall void, and even bird’s nest  
Common PredatorsNot recorded
Seasons activeOctober to January
Diet of larvae and adultsLarvae: Corn, grains, flour, herbs, cocoa, and spices
Adults: Insect remains, rodent guano

Identifying the Damage Caused by Them

It is considered a massive pest to museums, warehouses, and grain mills. The larvae and adults can cause enormous damage to stored food, cellophane, cardboard boxes, and wood, making the items unfit for use or consumption.

Following proper hygiene measures, sealing food containers tightly, and even spraying areas near walls with insecticides regularly would help control their infestation to a certain extent. Removing and destroying old bird’s nests in gardens or near homes is also a mandate since it is a preferred dwelling place for these beetles.

Did You Know

  • In the United Kingdom, these beetles have infested about 55 museums and historic establishments.
Australian Spider Beetle Picture

Image Source: whatseatingyourcollection.com, bugguide.net, api.sodapdf.com

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