Latin: Ptinus tectus
The Australian spider beetle originates from Australia as the name imply. But the beetle also goes by its Latin name Ptinus tectus. The beetle came to Europe around 1900 and has since also found its way to Denmark, where it is to this day a common guest in Danish households.
The Australian spider beetle belongs to a whole family of beetles, which in Denmark amount to around 40 different species. The spider beetle family goes by the common name Ptinus in Latin and in addition to the Australian spider beetle also counts family members such as the common thief beetle (Ptinus fur) and the brass thief (Niptus hololeucus), both of which are common pest in Denmark.
Appearance
While the Australian spider beetle is still a larva, it can grow between 3 to 5 millimeters long. The larva has a curved shape with quite small legs and a dark head, while the rest of its body has a yellowish white hue.
A fully developed Australian spider beetle is approximately 3 to 4 millimeters long. And unlike in its larval stage, the fully developed beetle has rather long legs and long antennae. The beetle’s wing cover is covered with small hairs, and the body has a reddish-brown hue and is slender and elongated, which contrasts with the fellow brass thief and the common thief beetle.
Biology and behavior
The Australian spider beetle belongs to the woodboring beetle family (Anobiidae) and to the subfamily thief beetles (Ptininae). The Australian spider beetle is a diligent small size that can lay up to 1,000 eggs in its lifetime. The eggs have a unique texture that makes them stick to surfaces. The female lays her eggs individually or in small groups. She places her eggs in carefully selected and protected areas where the small, hatched larvae can feed on the surrounding material.
Here the larvae have every opportunity to develop. The small larvae spin their own whitish cocoon in which they pupate. The cocoon has an almost tissue-paper-like appearance, and the webs of the larva can be seen as thin threads and spun cocoons in the infested area. The development from larva to fully adult thief beetle lasts about 3 to 4 months if the larva has good conditions e.g., at room temperature.
When the larvae are fully developed, they most often leave this safe area. This means that they sometimes have to climb obstacles such as packaging in kitchen cabinets or through soft wood. If you have had a visit from an Australian thief beetle, you will hardly be in doubt. It will leave visible circular holes as a sign of its stay.
However, you will hardly encounter the Australian spider beetle during the day. It is nocturnal and prefers to be active at night. Both larvae and the adult beetles all eat dried foods such as grains and bread products, cocoa, dried fruits, seeds, nuts, feathers, animal skin and dead insects. In heated houses, the beetles can have two to three generations in a year.
Damage
The Australian spider beetle can be an annoying guest to have in the home. Not only does it go into the cabbage and the contents of your kitchen cabinets – where it loves to go on board in your dry goods – but the fully grown beetle can also break loose in your wardrobe and mash itself in the textiles. It can therefore do great damage in your home.
But it is not just in the family home that the beetle gets loose. It can also settle on ceilings, where it feeds on excrement from mice and rats as well as remains from insects.
Prevention and pest control
If you want to keep the Australian spider beetle out of your kitchen cabinets, you can advantageously store your dry goods in tight-fitting containers. In addition, you should keep your items as cool as possible.
It can be an advantage to find the hearth for the development of the larvae. In this way you can get rid of new attacks. But it may be difficult to find the right place, as the beetles are not stagnant.
Be thorough with your vacuuming and general cleaning and pay extra attention to areas where there are collections of hair, or where dead insects gather. For example, in cracks and crevices, behind panels or in corners. A bird’s nest in the attic can also be the reason to an outbreak. If the Australian thief beetle has settled in your food, discard them, and clean the area thoroughly. You may want to supplement infested areas with a coat of insect repellent.
Heat treatment can also be used – objects to be heat treated must reach a core temperature of over 50 degrees for at least 30 minutes.
"Pests in House and Home"
"Bed Bugs - Bites, Stings and Itches"
"Food Pests"
"Husets dyreliv" (Insects Around the House - Only danish)
"Skadedyr i træ" (Timber Pests - Only danish)
"Stuefluen" (Common Housefly - Only danish)