Pest Guides

Lesser Grain Borer

Rhyzopertha dominica

Appearance

Lesser Grain Borer Beetle | Rentokil Pest Control Australia
  • Adult – 1/8" long. They have a roughened dark brown or black colouring.

Lifecycle

  • The female lays between 300 and 500 eggs, singly or in clusters, in loose grain.
  • The eggs hatch in a few days and the larvae bore into damaged kernels to continue growing. After pupating, the adults bite their way out.
  • The life cycle takes between one and two months depending on temperature.

Habits

  • Originally native to the tropics, they have spread to all parts of the world but are more common in “dirty” grain, i.e. grain dust, cracked kernels.
  • The damage caused by the adult lesser grain borers may facilitate infestation by secondary pests or diseases.
  • It is a strong flyer and can easily migrate to begin new infestations elsewhere.