Ant finds linked to Pacific wood

New Zealand's biosecurity authorities are surveying "high risk" timber yards looking for unwanted colonies of crazy ants.

Ministry of Agriculture and Forestry contractors are targeting timber yards and timber treatment sites in the Northland, Auckland and Tauranga regions that receive relatively large volumes of timber from the South Pacific.

A pest-risk analysis has shown it was possible that crazy ant colonies recently found on Auckland and Mt Maunganui wharves had arrived in New Zealand on sawn timber imported from the Solomon Islands, Fiji and Papua New Guinea.

The analysis also indicated that the insects could escape from the yards or treatment facilities that first receive the imported timber.

The survey is designed to find any crazy ant colonies that have established in New Zealand from past shipments of sawn timber from the South Pacific.

The ministry has already set new conditions on importing, but the measures are expected only to reduce the risk of colonies to "acceptable levels".

Its staff killed crazy ants at two sites at Auckland's port early last year during intensive surveillance work for another, nastier species - the red fire ant - which was found at Auckland Airport in 2001.

The ministry said last year that the crazy ant finds occurred in an area where recently imported goods were stored before being given biosecurity clearance.

The crazy ant (Paratrechina longicornis) and yellow crazy ant (Anoplolepis gracilipes) cause severe irritation on humans and animals. When disturbed, they run erratically in large numbers.

Australian scientists have warned that their country's tropical and subtropical farms and bush could be overrun by crazy ants, which are capable of causing billions of dollars' worth of environmental and agricultural devastation.

An initially small population of the African ants has built up super-colonies in the northeast area of Arnhem Land.

The formic acid that the ants spit into the eyes of their prey can blind a person who touched it and then rubbed his or her eyes.

Crazy ants

* Occur in two varieties: crazy ant (Paratrechina longicornis) and yellow crazy ant (Anoplolepis gracilipes)

* Get their name because they run erratically when disturbed.

* Cause severe irritation on humans and animals.

* Could overrun Australia's tropical and subtropical farms and bush, say scientists, causing billions of dollars' worth of damage.

- NZPA