"The threat to our primary industries is significant and the implications are huge. It could damage our economy to the tune of hundreds of millions."
The scenario was effectively akin to the Foot and Mouth disease of the crop world. It makes arable and horticulture farmers very nervous and we have to trust in our biosecurity measures, he said.
Ministry for Primary Industries (MPI) confirmed BMSB was not established in New Zealand, but it was a sneaky pest that has been caught at the border many times, hitch-hiking on passengers and in imported goods.
BMSB, which is known to feed heavily on a wide variety of plant species, would attack grapes, kiwifruit, apples, citrus and stone fruit, corn and many other valuable crops if it settled in New Zealand.
MPI manager central and south for border clearance services Andrew Spelman said a full-time quarantine officer in Timaru was on the case, ensuring everything that came into port, from containers to vehicles and stock food, were inspected.
"We check goods there and we undertake clearances [of] vessels when they arrive [including] stock food and palm kernel."
From "time to time" live pests have been found during quarantine at the port, he said.
Those discoveries, referred to as "hitchhiking pests" by MPI, have been found among machinery and general cargo. Mr Spelman said MPI deals with any discoveries case by case.
"It depends on what the case is, [but it generally involves] containing it, directing it for treatment and fumigation."
Measures to protect Timaru shores also involves cleaning containers and taking samples from bulk cargo and stock foods in search of anything live.
"All goods coming through the port...they are putting them through assessment risk coming through," Mr Spelman said.
He said there were a lot of BMSB coming out of Italy and Japan, but all efforts were made to keep it away.