Australian Spider Beetle

The Australian spider beetle (Pictus tectus) measures 2.5–4 mm in length and is coloured dark brown. The adults have biting mouthparts, a well developed thorax and 11-segmented antennae. Characteristics which give them a spider-like appearance include a stout body, pronounced constriction of the neck shield and 6 long thin legs with 5-segmented tarsi.

The female Australian spider beetle lays 100–120 sticky eggs over a period of 4–5 weeks in early summer, either singly or in small batches. At 20–25 °C the eggs hatch in 3–16 days, producing larvae which are fleshy, curved, covered with fine hairs and relatively immobile. Larval development takes at least 6 weeks, during which time the larvae moult 4 or 5 times. When mature, they wander in search of a pupation site where they spin a cocoon cell in which to pupate. Adults emerge after 20 to 30 days and will live for as long 12 months. At 70% R.H. development of Ptinus tectus from egg laying to emergence from the cocoon takes an average of about 62 days at 23–25 °C; at 15 °C the time taken is about 130 days. The minimum temperature at which complete development can occur is 10 °C and the maximum is between 28 and 30 °C. Considerable mortality occurs in eggs and larvae at 28 °C.