The latest in designer backyards is being blamed for the arrival of an alien pest that may have spread further than the popular Auckland gardens it was detected in.
Auckland's Wintergardens were closed two months ago when the Florida red scale (Chrysomphalus aonidum) was detected in threeglasshouses.
But the Ministry of Agriculture and Forestry believes the tiny bug, a pest to citrus and fruit-growing industries, found its way here on dracaena plants, a favoured ornamental for barbecue, deck and pool areas.
"We strongly believe this organism will have distributed around a large chunk of New Zealand," said MAF scientist Dr Barney Stephenson, "but the climate will probably deal with it. It doesn't like colder climates."
Trying to find out where it had spread would "be like looking for the proverbial needle in a haystack".
Florida red scale is a citrus pest in some parts of the world and widespread in tropical and subtropical regions, including Asia, Africa, the Pacific and Australia.
The chief executive of the Fruitgrowers Federation, Peter Silcock, said growers were concerned.
"We don't really know how this thing is going to behave. The last thing we want is further pests here."
Dr Stephenson said MAF had talked with plant nurseries and importers of dracaenas and sent out pamphlets to "advise people of their obligations".
Citrus grower Andrew Harty of Kerikeri said Florida red scale was not a big problem for commercial growers and a new export agreement with the United States had not been affected by detection of the bug because it was native to the United States.
Meanwhile, the Wintergardens look set to remain closed for another month while MAF switches to a different spray treatment.
Dr Stephenson said an insecticide used to wipe out the scale but that did not damage exotic plants in the Victorian-era glasshouses would be replaced by an oil-based treatment which would kill all lifestages of the pest.
Auckland City Council wanted the gardens opened by spring.
Dracaenas, as well as other spiky plants such as palms and yuccas, have grown in popularity in recent years.
They are imported in bulk as dry trunks which can be propagated to grow new plants.
