PEST
 
   NAME
     Large Citrus Butterfly
     Princeps aegeus
 
   ORDER
     Lepidoptera
 
   FAMILY
     Papilionidae

Description of the Pest
The adult butterflies have a wingspan of up to 120m; they have siphoning mouth-parts. Butterflies are black with yellow markings; males have a single red spot on the lower wings, while females have many red spots. Eggs are laid singly on citrus branches. Young larvae are mottled white and brown, resembling bird droppings; mature larvae are olive-coloured, with brown, three white-outlined diagonal stripes down the sides of the body, and grow up to 65mm in length. Larvae protrude two red “horns” from behind their heads when disturbed, exuding an offensive, concentrated citrus odour.

Appearance and Distribution of the Pest
This native pest is found throughout Australia, rarely in  Western Australia; larvae appear on the new growth in spring.

Life Cycle
These insects have a Holometabolous life cycle, ie. When metamorphosis is observed during the pupal stage.
The pupal stage appears as a chrysalis attached to the host plant by a silk pad; adults emerge after 2-3 weeks during the warmest months, but may pupate through winter and not emerge until spring.

Period of Activity
Spring to autumn; larvae are most active from late summer onward.

Damage Caused
Larvae eat leaves. Small plants may be seriously damaged by larvae.

Susceptible Plants
ManyCitrus species and other members of the Rutaceae family such as Choisya ternata are attacked.

Cultural Control
Remove manually, with small infestations, using gloves.

Biological Control
The parasitic wasp is a natural predator, as are predatious bugs.

Chemical Control
Larvae may be controlled with Maldison, or Carbaryl.
Note
Always read the label for registration details and direction of use prior to application of any chemicals.