mealybug coating stems in white waxy fluff
- Size
- Length: 2–5 mm
- Lifespan
- 1–2 years
- Diet
- Herbivorous: feeds on plant sap using piercing-sucking mouthparts. Excretes honeydew which attracts ants and promotes sooty mould growth. Some species are pests in greenhouses and on houseplants.
- Habitat
- Warm, sheltered crevices of plants, under bark, in leaf axils or on roots. The waxy hermits of the garden and greenhouse.
- Range
- Throughout North and South Islands in gardens, greenhouses and native forests. Most common in warm, sheltered environments with diverse host plants for feeding and reproduction.
- Endemism
- Native
- Main Threats
- None significant. Native species are widespread and common. Some species considered pests in greenhouses and on houseplants but face no conservation threats in natural habitats.
- Population
- New Zealand has many native species, including some that live exclusively on roots of native grasses or within leaf sheaths of flax (harakeke).
- Conservation Status
- Not Threatened
A specialised suit of white, filamentous wax resembling a dusting of flour. The mealybug is the dusted resident of the New Zealand botanical world. Unlike their close relatives, the armoured scales, mealybugs retain their legs throughout their life cycle, allowing them to remain mobile crevice seekers that tuck themselves into the tightest axils, leaf sheaths and underside of bark.
This soft defence is a sophisticated biological shield. The hydrophobic, powdery meal acts as a waterproof barrier against the elements and serves as a sticky deterrent for predatory ladybirds and lacewings that find a mouthful of waxy fuzz unpalatable. These flour-dusted crawlers represent a state of sheltered abundance, utilising a piercing-sucking rostrum to drain nutrient-rich sap while remaining hidden in the shadows of their host plants.
As they feed, they excrete a sticky, sugar-rich honeydew that often attracts farming ants, which in turn protect the mealybug colony from natural enemies in a classic example of mutualism. This life cycle is a definitive sign of hidden life within the New Zealand garden and bush, reminding us that a simple shift of a leaf can reveal a thriving community of waxy pioneers.
Their presence indicates a micro-environment where the humidity is stable and the botanical architecture provides ample refugia for slow-moving, sedentary residents to flourish undisturbed. Not threatened, mealybugs are a foundational part of the invertebrate community, though they can become significant horticultural challenges when their natural predators are absent.
The females lay their eggs in a white, cottony mass that protects them from predators and desiccation. The nymphs, called crawlers, are mobile and disperse to find new feeding sites before settling down to begin feeding.
To encounter a mealybug is to witness a survivor that has mastered the art of soft defence. A delicate, flour-dusted appearance can be a highly effective suit of armour in a predatory world.