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Mealybug Host Plants

Practical biological control, IPM and environmental pest-management knowledge.

Mealybug Host Plants

Overview

Mealybugs attack a wide range of ornamental, fruit and protected crops.

They are especially difficult in plants with:

  • dense foliage
  • sheltered stem junctions
  • woody growth
  • overlapping leaves
  • fruit clusters
  • long production cycles

Host plants currently linked in Biopredator

Fruit crops

Ornamental crops

These plant records also show the other pests commonly associated with each crop.


High-risk crop types

Mealybug risk is often greatest in:

  • tropical ornamentals
  • foliage plants
  • poinsettia
  • citrus
  • vines
  • succulents
  • long-season pot plants
  • stock plants
  • mother plants

Why long-season crops are vulnerable

Long-season crops give mealybugs time to:

  1. establish in hidden plant areas
  2. produce multiple generations
  3. spread through crawler movement
  4. build waxy colonies
  5. escape occasional treatments
  6. contaminate surrounding plants

Infestations may persist from one crop cycle to the next.


Imported and incoming plants

Incoming plant material is a major risk route.

Inspect:

  • stem bases
  • leaf axils
  • pot rims
  • support stakes
  • plant labels
  • packaging
  • drainage holes
  • root systems where root mealybug is suspected

Suspect plants should be isolated before entering the main crop.


Symptoms by crop type

Crop Typical warning signs
Citrus Colonies around fruit, stems and leaf joints
Grapevine Hidden colonies beneath bark and around fruit clusters
Fig Honeydew, sooty mould and sheltered stem colonies
Poinsettia Colonies in dense canopy and stem junctions
Ornamentals Cosmetic contamination and reduced vigour
Pot plants Persistent colonies and root-zone reservoirs

Plant inspection strategy

Prioritise:

  • newly delivered plants
  • stock plants
  • crop edges
  • warm sheltered bays
  • plants with honeydew
  • plants attended by ants
  • dense or difficult-to-spray canopies
  • plants with previous infestation history

Reducing host-plant risk

Useful actions include:

  • quarantining incoming stock
  • removing heavily infested plants
  • pruning inaccessible hotspots
  • cleaning benches and supports
  • controlling ants
  • avoiding movement of contaminated tools
  • maintaining biological-control continuity
  • checking root zones where symptoms remain unexplained

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