hides in the damp garden shadows

Size
Body: 4–6 cm
Lifespan
1–2 years
Diet
Herbivorous: feeds on decaying plant material, fungi and living plants including seedlings, vegetables and garden ornamentals. Particularly troublesome in nurseries and vegetable gardens.
Habitat
Damp cellars, under paving stones, greenhouses and moist garden beds. The shadows of the damp world, avoiding light and dryness at all costs.
Range
Throughout North and South Islands in gardens, greenhouses, nurseries and agricultural areas. Most common in lowland regions with mild, wet winters and sheltered, damp conditions.
Endemism
Introduced
Main Threats
None. This introduced pest is widespread and abundant. Controlled using baits, barriers and biological controls in gardens, but remains a persistent pest in wet conditions.
Population
A pervasive introduced pest from Europe, found throughout New Zealand. Particularly troublesome in nurseries and vegetable gardens, where they can decimate seedlings overnight. Populations boom in wet, mild winters.
Conservation Status
Introduced
Human Risk
caution
Handling Note
introduced pest, potential disease vector do not handle
Conservation Note
Introduced slug; common agricultural pest not subject to conservation assessment.
Te Ao Māori
Like the garden snail, the grey field slug is an introduced species with no lineage in Māori tradition. It is a creature of the new New Zealand, a symbol of the damp, cool climates that European plants and pests brought with them. In the modern garden, it represents the constant battle between cultivation and nature's scavengers.
Rain falls. The air turns damp. The grey field slug emerges. Without a shell to weigh it down or protect it, it is pure, exposed muscle, a soft, grey-brown torpedo that can squeeze through gaps no snail could ever manage. It is a creature of extreme vulnerability, which is why it lives life in the shadows. The moment the sun comes out or the air turns dry, it retreats into the deepest cracks of the cellar, under flower pots or into the soil, secreting a thick layer of mucus to prevent desiccation. But when the rain falls and the night descends, it emerges to graze with a voracious appetite. Unlike the snail, which rasps slowly, the slug is a relentless feeder. It moves with a fluid, undulating motion, leaving a silver trail of slime that marks its path like a guilty secret. It possesses a unique pore on its right side called the pneumostome, which opens and closes rhythmically as it breathes, a tiny, pulsing detail visible only if you look closely at its flank. Its diet is indiscriminate. It will eat living plants, decaying matter, fungi and even the eggs of other slugs. In a bad infestation, they can strip a garden bed bare in a single wet week. Their defence mechanism is purely chemical and textual. When threatened, they contract their bodies into a tight lump and release a distasteful, sticky mucus that gums up the mouths of predators like beetles or birds. Some can even detach parts of their skin to escape a grasp. The grey field slug is a hermaphrodite, like all slugs and snails. Each individual has both male and female reproductive organs. When two slugs meet, they exchange sperm, then both lay eggs. The eggs are laid in clusters of up to fifty, hidden in damp soil or under debris. The young hatch as miniature versions of the adults, already capable of feeding and defending themselves. They grow rapidly in warm, wet conditions, reaching maturity in a few months. A single slug can produce hundreds of offspring in a year, which is why populations can explode so quickly. Populations boom in wet, mild winters. Like the garden snail, the grey field slug is an introduced species with no lineage in Māori tradition. It is a creature of the new New Zealand, a symbol of the damp, cool climates that European plants and pests brought with them. In the modern garden, it represents the constant battle between cultivation and nature's scavengers.