Biosecurity NZ ramps up hunt for yellow-legged hornet on Auckland’s North Shore
Biosecurity New Zealand is intensifying its campaign to locate and eliminate the invasive yellow-legged hornet, following confirmed detections on Auckland's North Shore.
The insect feeds on over 300 species – including significant crops such as apples, corn, wine grapes, kiwifruit, and a range of stone fruit varieties causing severe damage to flowers, stems, leaves and fruit of host plants.
Although not yet established in New Zealand, stink bugs present a major threat to New Zealand’s horticulture industry. In the United States, the first reported sighting was in Pennsylvania in 2001 and in just 20 years they are now found in 46 states. The bugs have been known to cause millions of dollars in crop damage, sometimes with upwards of 90% of crop being rendered unsaleable.
Jointly funded by Biosecurity New Zealand and industry members of the BMSB Council, the summer campaign will run from November to March, targeting local gardeners and online shoppers who receive goods from overseas.
“There is ongoing monitoring of the threat posed by countries that have known BMSB populations,” says Biosecurity New Zealand deputy director-general Stuart Anderson.
“Officers target passengers, craft and goods that could be contaminated with BMSB. Monitoring of countries with known BMSB populations and targeting of passengers and goods have been effective to date, with no evidence of any established BMSB population in New Zealand.”
A Biosecurity New Zealand quarantine officer detected a single live BMSB at an airport search bench on 8 October while processing passengers arriving from the United States. A second bug was found on an 18 October flight from South Korea prior to passengers leaving the plane, with officers detecting a further 286 dead BMSB on arriving vessels and cargo.
Biosecurity New Zealand says the number of live interceptions has dropped considerably over the last few years. It believes this is largely due to the introduction of strict import rules that make it harder for live BMSB to enter New Zealand on risky cargo such as vehicles, machinery and parts.
Improved reporting and monitoring has also allowed officers to better target risk goods, with a greater focus on air cargo during the 2021/22 season following increased BMSB detections in this pathway.
Anderson says that Biosecurity New Zealand has seen high levels of engagement from the shipping industry in the past and wants this positive relationship to continue.
“Accurate reporting of detections by crew helps Biosecurity New Zealand target its surveillance and other actions. We ask international travellers to be understanding of the need to protect New Zealand and our economy as they get their bags checked or are required to answer questions from our frontline staff.”
Anyone who thinks they’ve found BMSB are asked to catch it, take a photo and report it. The find can be reported online (https:// report.mpi.govt.nz/pest/) or via Biosecurity New Zealand’s hotline ( 0800 80 99 66).
Nasty Buggers
Approximately 1.7cm long and forming a distinctive shield shape (leading to their alternate name of shield bugs), stinkbugs use their piercing mouthparts to pierce through the outer skin of fruit and consume the flesh within.
A combination of the inner flesh exposure to air and germs in the stinkbugs cause the flesh around the bite area to rot and decay rendering the fruit unfit for human consumption.
BMSB lay 28 (on average) small, light green eggs per brood on the underside of leaves with an incubation period of 3-5 days. Tests carried out in the US in which stinkbugs were tethered to a freely rotating measuring device have shown that stinkbugs are capable of flying up to 5km per day. Although precise details are difficult to ascertain, depending on climate BMSB have been known to produce multiple generations per year.
