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Puriri erineum mite - Acalitus australis

By N A Martin (2018)

Classification

Phylum:
Arthropoda
Class:
Arachnida
Subclass:
Acari
Order:
Trombidiformes
Suborder:
Prostigmata
Superfamily:
Eriophyoidea
Family:
Eriophyidae
Subfamily:
Eriophyinae
Tribe:
Aceriini
Scientific Name:
Acalitus australis (Lamb, 1952)
  • Drawing of side view of Puriri erineum mite, Acalitus australis (Acari: Eriophyidae). The adult mite is very tiny, 0.114-0.174 mm long. Image: Dave Manson © Image by Dave Manson Drawing published in Fauna of New Zealand 1984, vol. 5, fig. 1.
    Drawing of side view of Puriri erineum mite, Acalitus australis (Acari: Eriophyidae). The adult mite is very tiny, 0.114-0.174 mm long. Image: Dave Manson © Image by Dave Manson Drawing published in Fauna of New Zealand 1984, vol. 5, fig. 1.
  • White erineum on the underside of a leaflet of Puriri, Vitex lucens (Labiatae) induced by Puriri erineum mite, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
    White erineum on the underside of a leaflet of Puriri, Vitex lucens (Labiatae) induced by Puriri erineum mite, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
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Common Names

Puriri erineum mite, Puriri leaf mite
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Synonyms

Aceria australis Lamb, 1952
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Biostatus and Distribution

is endemic gall mite is found in the North Island of New Zealand where its host plant, Puriri, Vitex lucens (Labiatae) grows. Feeding by the mites induces white hairs (erineum) on the underside of leaves.

Conservation status: Present in the North Island where Puriri trees grow.

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Life Stages and Annual Cycle

This gall mite is very tiny. Adult mites are about 0.114-0.174 mm long. The adult mite is like a tiny white cow’s horn with two pairs of legs at the wide end of the horn. Adult female mites lay tiny spherical eggs. The larva that hatches from an egg looks like a tiny adult. The mite larva moults (changes skin) into a nymph. There is one nymphal stage that also looks like a small adult. The last juvenile stage moults into an adult mite. There are males and females.

Walking
The mite uses its legs for walking, but it can also hold on to the plant with the tip of its abdomen, which acts as a sucker.

Feeding and inducing the gall
The mites have pointed mouth parts that puncture the surface cells on the underside of young leaves and gall tissue from which they suck up the cell sap. During feeding, the mites may inject saliva into the plant. When mites feed on the underside of a young leaf, plant cells in the immediate area multiply forming a white hairy tissue (erineum) in which the mites live and breed. The erineum protects the gall mites from predators and adverse weather.

Dispersal to new leaves and new trees
When the plant grows new shoots, adult female mites disperse to the new leaves and their feeding induces the formation of new galls, erineum. It is presumed that mites walk from the old erineum to young leaves suitable for the initiation of new erineum.

When this gall mite colonises new plants or branches, it is unlikely that mites walk all the way. It is believed that most mites are dispersed by wind. Some species of mite climb to prominent places on plants and stand waiting for a gust of wind to take them away.

  • White erineum on the underside of a leaflet of Puriri, Vitex lucens (Labiatae) induced by Puriri erineum mite, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
    White erineum on the underside of a leaflet of Puriri, Vitex lucens (Labiatae) induced by Puriri erineum mite, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
  • Chlorotic (pale) bulges on the upper side of a leaf of Puriri, Vitex lucens (Labiatae) induced by feeding on the underside of the leaf by Puriri erineum mites, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
    Chlorotic (pale) bulges on the upper side of a leaf of Puriri, Vitex lucens (Labiatae) induced by feeding on the underside of the leaf by Puriri erineum mites, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
  • White erineum on the underside of a leaflet of Puriri, Vitex lucens (Labiatae) induced by Puriri erineum mite, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
    White erineum on the underside of a leaflet of Puriri, Vitex lucens (Labiatae) induced by Puriri erineum mite, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
  • A section through the white erineum on the underside of a leaflet of Puriri, Vitex lucens (Labiatae). The erineum is induced by Puriri erineum mite, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
    A section through the white erineum on the underside of a leaflet of Puriri, Vitex lucens (Labiatae). The erineum is induced by Puriri erineum mite, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
  • Old brown erineum on the underside of a leaflet of Puriri, Vitex lucens (Labiatae) induced by Puriri erineum mite, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
    Old brown erineum on the underside of a leaflet of Puriri, Vitex lucens (Labiatae) induced by Puriri erineum mite, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
  • Old brown erineum on the underside of a leaflet of Puriri, Vitex lucens (Labiatae) induced by Puriri erineum mite, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
    Old brown erineum on the underside of a leaflet of Puriri, Vitex lucens (Labiatae) induced by Puriri erineum mite, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
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Recognition

This mite requires special procedures and taxonomic knowledge to identify specimens. However, its presence on a plant can be recognised by plant damage symptoms. This species of mite is the only one known to induce erineum on leaves of Puriri, Vitex lucens (Labiatae). The upper surface of the leaf above areas of erineum, bulge upwards and may be chlorotic (coloured yellow). The erineum on older leaves turns brown.

  • Chlorotic (pale) bulges on the upper side of a leaf of Puriri, Vitex lucens (Labiatae) induced by feeding on the underside of the leaf by Puriri erineum mites, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
    Chlorotic (pale) bulges on the upper side of a leaf of Puriri, Vitex lucens (Labiatae) induced by feeding on the underside of the leaf by Puriri erineum mites, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
  • White erineum on the underside of a leaflet of Puriri, Vitex lucens (Labiatae) induced by Puriri erineum mite, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
    White erineum on the underside of a leaflet of Puriri, Vitex lucens (Labiatae) induced by Puriri erineum mite, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
  • Erineum on the underside of a leaflet of Puriri, Vitex lucens (Labiatae) induced by Puriri erineum mite, Acalitus australis (Acari: Eriophyidae): note that the erineum has started to turn brown. Image: Nicholas A. Martin © Plant & Food Research
    Erineum on the underside of a leaflet of Puriri, Vitex lucens (Labiatae) induced by Puriri erineum mite, Acalitus australis (Acari: Eriophyidae): note that the erineum has started to turn brown. Image: Nicholas A. Martin © Plant & Food Research
  • Old brown erineum on the underside of a leaflet of Puriri, Vitex lucens (Labiatae) induced by Puriri erineum mite, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
    Old brown erineum on the underside of a leaflet of Puriri, Vitex lucens (Labiatae) induced by Puriri erineum mite, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
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Natural Enemies

One predatory mite, Agistemus longisetus Gonzalez-Rodriguez, 1963 (Acari: Raphignathoidea: Stigmaeidae) has been found on Puriri leaves in association with leaf erineum. It is presumed that this predator feeds on the Puriri erineum mite. Other predatory mites and predatory insects may also feed on these gall mites.

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Host Plants

Puriri, Vitex lucens (Labiatae) is the only host plant of the Puriri erineum mite. The mite feeds on the underside young leaves. When mites feed on the underside of a young leaf, plant cells in the immediate area multiply forming a white hairy tissue (erineum) in which the mites live and breed.

  • Chlorotic (pale) bulges on the upper side of a leaf of Puriri, Vitex lucens (Labiatae) induced by feeding on the underside of the leaf by Puriri erineum mites, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
    Chlorotic (pale) bulges on the upper side of a leaf of Puriri, Vitex lucens (Labiatae) induced by feeding on the underside of the leaf by Puriri erineum mites, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
  • White erineum on the underside of a leaflet of Puriri, Vitex lucens (Labiatae) induced by Puriri erineum mite, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
    White erineum on the underside of a leaflet of Puriri, Vitex lucens (Labiatae) induced by Puriri erineum mite, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
  • White erineum on the underside of a leaflet of Puriri, Vitex lucens (Labiatae) induced by Puriri erineum mite, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
    White erineum on the underside of a leaflet of Puriri, Vitex lucens (Labiatae) induced by Puriri erineum mite, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
  • Old brown erineum on the underside of a leaflet of Puriri, Vitex lucens (Labiatae) induced by Puriri erineum mite, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
    Old brown erineum on the underside of a leaflet of Puriri, Vitex lucens (Labiatae) induced by Puriri erineum mite, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
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Additional Information

Eriophyid gall mites belong to the super family Eryiophyoidea. These mites have several unusual features. For example, though most mites have four pairs of legs like spiders, Eriophyoid mites have only two pairs of legs. Many of these mites can induce host plants to form galls, some of which may be very complex. Some species of these mites can transmit plant viruses that may cause plant diseases and plant death.

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Information Sources

Manson DCM 1984. Eriophyinae (Arachnida: Acari: Eriophyoidea). Fauna of New Zealand 5: 1-123.

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Acknowledgements

The New Zealand Plant & Food Research Institute Limited (Plant & Food Research) for permission to use photographs.

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Other Images

  • Hatched eggs of an unknown arthropod embedded in old brown erineum on the underside of a leaflet of Puriri, Vitex lucens (Labiatae) induced by Puriri erineum mite, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
    Hatched eggs of an unknown arthropod embedded in old brown erineum on the underside of a leaflet of Puriri, Vitex lucens (Labiatae) induced by Puriri erineum mite, Acalitus australis (Acari: Eriophyidae). Image: Nicholas A. Martin © Plant & Food Research
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Suggested Citation

Martin NA. 2018. Puriri erineum mite - Acalitus australis. Interesting Insects and other Invertebrates. New Zealand Arthropod Factsheet Series Number 143. http://nzacfactsheets.landcareresearch.co.nz/Index.html. Date Accessed. ISSN 1179-643X.

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