Farm Forestry New Zealand
PESTS AND DISEASES OF FORESTRY IN NEW ZEALAND
Siphoninus phillyreae (Ash Whitefly) established in New Zealand
Scion is the leading provider of forest-related knowledge in New Zealand
Formerly known as the Forest Research Institute, Scion has been a leader in research relating to forest health for over 50 years. The Rotorua-based Crown Research Institute continues to provide science that will protect all forests from damage caused by insect pests, pathogens and weeds. The information presented below arises from these research activities.
From Forest Health News No. 43, June 1995.
On 5 May 1995 a Devonport resident submitted some insect specimens found on a pomegranate to the Lynfield Plant Protection Centre (MAF Quality Management) for diagnosis. They were identified as Siphoninus phillyreae (Haliday) (Homoptera: Aleyrodidae). This is the first record of this species in New Zealand. Whiteflies are sap-sucking insects related to aphids and scale insects. The adults are generally 1-2 mm long, have four wings and are covered with a snowy white powder. The nymphs resemble scale insects but never have shell-like coverings rather they are naked or covered with waxy material. The nymphs also excrete honeydew that becomes blackened by mould. They feed on leaves and hosts are almost exclusively woody flowering plants. Siphoninus phillyreae is a European species and has been introduced into California. Overseas it has been recorded on a wide range of shrubs and trees including ash (Fraxinus), pear, apple and hawthorn. As yet I have not been able to determine how long it has been present in California but I do know that it has caused severe damage to ash in Sacramento and that a few years ago Clitostethus arcuatus (Coleoptera: Coccinellidae) and Encarsia partenopea (Hymenoptera: Aphelinidae), a predator and parasitoid respectively, were introduced and are apparently controlling the pest well (Ruth Frampton, MAF Regulatory Authority, pers. comm.).
As requested by the MAF Regulatory Authority, survey work undertaken by MAF Quality Management has revealed that S.phillyreae is well established on the North Shore including the suburbs of Devonport, Milford and Takapuna. It has also been found in Remuera. In addition to the original find on pomegranate, specimens have been found on ash, pear and hawthorn. According to Richard Baker (MAF, Lynfield) ash street trees in Devonport are heavily infested. MAF have concluded that eradication is not feasible.
John Bain, FRI
This information is intended for general interest only. It is not intended to be a substitute for specific specialist advice on any matter and should not be relied on for that purpose. Scion will not be liable for any direct, indirect, incidental, special, consequential or exemplary damages, loss of profits, or any other intangible losses that result from using the information provided on this site.
(Scion is the trading name of the New Zealand Forest Research Institute Limited.)
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