Have you seen African citrus psyllid?
Be on the lookout for symptoms and report them to Biosecurity Queensland.
Early detection and reporting are the key elements in controlling the pest.
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General information
Like the Asian citrus psyllid (Diaphorina citri Kuwayama), the African citrus psyllid (Trioza erytreae del Guercio) is a sap-sucking insect that can transmit the lethal citrus disease, huanglongbing-also known as 'citrus greening'.
While the insect itself is a minor citrus pest, huanglongbing is a serious threat to citrus-producing areas worldwide. The African citrus psyllid, Asian citrus psyllid and huanglongbing are not known to occur in Australia.
Overview
Symptoms | As African citrus psyllid nymphs feed, they can cause distinctive cup-shaped or pit-like galls to form in leaves, particularly in the lower leaf surface of immature leaves. These are often visible as bumps in the upper leaf surface. They can cause severe leaf distortion, curling, stunting and leaf yellowing. The psyllids excrete pellets of honeydew that look like tiny, white eggs. The ground or vegetation under a badly infested tree can look like it has been dusted with white powder (the excreted pellets). |
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Appearance | Adults
Nymphs
Eggs
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Distribution | Asia (restricted), Africa, and in some European countries. |
Lifecycle | A female psyllid lays eggs over the course of a 4-7 week period on the margins of new leaf. Eggs hatch after 7-14 days and the first-instar nymphs start to feed on the underside of the leaves where they begin to form galls. The nymphs moult 5 times before becoming winged adults. The nymphal development stage lasts between 20-40 days depending on temperature. |
Crops affected | All citrus cultivars are a host for African citrus psyllids (e.g. orange, lemon, lime, grapefruit, mandarin, kumquat, tangelo, pomelo, native citrus and citrus rootstock). |
Hosts | Atalantia buxifolia, Balsamocitrus dawei, Casimiroa edulis (white sapote), Citrus, Citrus aurantiifolia (lime), Citrus jambhiri (rough lemon), Citrus limon (lemon), Citrus maxima (pummelo), Citrus nobilis (tangor), Citrus sinensis (navel orange), Clausena indica, Clausena lansium (wampi), Limonia acidissima (elephant apple), Microcitrus australasica, Triphasia trifolia (limeberry). Native and exotic mock orange/orange jasmine (Murraya spp.), white ironwood (Vepris lanceolata), lime berry (Triphasia trifolia) and horsewood (Clausena anisata) are also hosts of the African citrus psyllid. They can also feed on Cape chestnut (Calodendrum capense), orange-climber or forest-pepper (Toddalia asiatica) and small knobwood (Zanthoxylum capense). |
Impacts | The main economic importance of T. erytreae is as the vector of the very serious citrus huanglongbing (greening) disease caused by Liberibacter species. Heavy infestations of T. erytreae also cause severe leaf distortion and the development of conspicuous pits on the leaf surface. |
Spread of pest | The African citrus psyllid prefers cooler, moist climates. It is very sensitive to extremes of hot, dry weather. It occurs throughout sub-Saharan Africa; Saudi Arabia; Yemen; the Indian Ocean islands of Madagascar, Mauritius and Reunion; and the Atlantic Ocean islands of Saint Helena, Madeira, Porto Santo, Tenerife and Gomera. Long-distance spread most commonly occurs via movement of plant material infested with psyllids. Short-distance dispersal can be wind-assisted for these short-distance fliers. Like the Asian citrus psyllid, the African citrus psyllid and huanglongbing could be introduced into Australia through illegal imports of host plants. The Australian Quarantine and Inspection Service (AQIS) closely regulates approved importation of plant material and monitors for illegal plant movement. |
Risk period | Vegetative growing stage of hosts, when high populations of this pest are noticed on the underside of new leaves. |
Monitoring and action | Regularly monitor common host plants, such as citrus:
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Control | There are simple steps you can take to protect your farm:
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Quarantine restrictions | The Department of Agriculture and Water Resources closely regulates approved importation of plant material and monitors for illegal plant movement. |
Management and quarantine | Regularly monitor common host plants, such as citrus:
There are simple steps you can take to protect your farm:
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Reference and acknowledgement | African citrus psyllid fact sheet (PDF, 238 kB) (PDF, 232.7KB) Tim Grout (Citrus Research International, South Africa), Andrew Beattie (University of Western Sydney), David Astridge (Department of Agriculture and Fisheries, Queensland) and Ceri Pearce (Biosecurity Queensland, Department of Agriculture and Fisheries). |