Citrophilus mealybug: declared pest

Page last updated: Friday, 16 June 2023 - 8:13am

Citrophilus mealybug (Pseudococcus calceolariae) is a serious pest of many horticultural industries that can downgrade fruit quality and affect fruit production. This pest is absent from and has never been recorded in Western Australia. Early detection and reporting of citrophilus mealybug will improve chances of eradication and containment to help protect the state’s horticultural industries.

What plants are affected?

  • Fruit and vegetables: blackberry, carrot, citrus, European grape, fig, pea, peanut, pear, potato, quince, raspberry, stone fruit and walnut are common hosts.

  • Trees and ornamentals: grevillea, hibiscus, Monterey pine, oleander, rhododendron and roses are also common host plants.

What do I look for?

  • When poked, citrophilus mealybugs will excrete dark red honeydew whereas typical mealybug species excrete pale yellow honeydew.
  • Adult females are slow moving, oval-shaped insects about 3–4mm long with a covering of white, mealy wax.
  • Adult males are small, delicate, winged insects with long tail filaments. They survive only a few days to mate and do not feed.
  • Nymphal stages include multiple instars (phases between moults). Initial female instars are mobile and look like small adults with minimal wax covering. With subsequent moults they become increasingly sessile and have greater wax covering.
Citrophilus mealybugs secrete red liquid when disturbed
Citrophylus mealybugs secrete a red droplets when disturbed
Late stage nymphs and adults of mealybugs overwinter under bark on deciduous fruit tree crops
Late stage nymphs and adults overwinter under bark on deciduous fruit trees

How does the pest survive and spread?

  • Eggs are laid in groups of up to 500 in egg sacs that may be attached to leaves, bark, fruit or branches.
  • There can be 3-4 generations throughout a year.
  • Late-stage instars and adult mealybugs overwinter under bark of deciduous fruit trees.
  • Nymphs are the main means of citrophilus mealybug spread within a property as they may disperse by wind or by hitchhiking on animals and people.
  • New infestations on properties may be caused by moving infested fruit and nursery stock, or as insects hitchhiking on animals and people.

What damage can this pest cause?

  • Citrophilus mealybugs extract sap from plants which reduces the plants’ vigour and production.
  • Citrophilus mealybugs secrete large amounts of honeydew which encourages development of sooty mould. High concentration sooty mould can reduce photosynthesis of affected plants.
  • Presence of honeydew and sooty mould in fruit downgrades the quality and severe infestations may render fruit unmarketable.
  • Mealybugs generally are vectors of grapevine leafroll associated viruses, banana streak virus and pineapple mealybug wilt-associated virus.

Status in Western Australia

Citrophilus mealybug (Pseudococcus calceolariae) is absent from Western Australia and is a quarantine pest. It is a prohibited organism under section 12 of the Biosecurity and Agriculture Management Act 2007.

Western Australia's Pest Freedom for citrophilus mealybug is supported by general surveillance and import requirements to prevent its entry.  A person who finds or suspects the presence of citrophilus mealybug in orchards, nurseries, urban areas or in loose fruit must report it to DPIRD.

What do I do if I find it?

It is important that any suspect citrophilus mealybug infestations are reported. Early detection and eradication will help protect the Western Australian horticulture industry. If you find or suspect plants with citrophilus mealybug, please make a report using MyPestGuide® Reporter or contact the Pest and Disease Information Service (PaDIS) to report this pest.

MyPestGuide® reporter logo

MyPestGuide® Reporter
Via app or online

Pest and Disease Information Service
(08) 9368 3080

Contact information

Pest and Disease Information Service (PaDIS)
+61 (0)8 9368 3080
Technical support - MyPestGuide®