Risk analysis of Halyomorpha halys - Biosecurity New Zealand

prior to delivery, or be delivered to a transitional facility (MAFBNZ 1998). However,
border clearance of containers may occur some time after arrival in New Zealand and
any H. halys arriving on these items may escape and find a host plant prior to
biosecurity clearance.
Some transitional facilities are located many kilometers distance from the port of
arrival increasing the likelihood of exposure prior to inspection. The likelihood of
exposure is lower for those containers devanned at the port or airport and then
removed from the country; however, items within the containers could also harbour
H. halys and be transported throughout the country. Even for those containers present
only briefly in New Zealand the flight behavior of H. halys may provide the
opportunity for successful exposure if suitable host plants are present in the vicinity of
the port or airport.
Given that:
some containers may travel anywhere within New Zealand;
containers devanned at the port or airport present less opportunity for
exposure;
sea containers may travel some distance to transitional facilities prior to
inspection;
most air containers never move beyond airside and are present in New Zealand
only briefly;
adults may fly some distance when disturbed;
The likelihood of exposure from sea containers is considered to be moderate
The likelihood of exposure from air containers is considered to be low
4.5.3 Fresh produce and cut flowers
Adult H. halys are highly mobile, and adults and nymphs are easily disturbed. Routine
handling will disturb these lifestages and cause them to seek new host plants. It is the
location in which they leave the infested commodity which will determine the
likelihood of exposure to the New Zealand environment. If disturbed off the
commodity in a closed environment such as a warehouse or supermarket the
opportunities of finding a new host plant are greatly reduced. However, as H. halys
commonly overwinter in indoor environments adults may be able to leave an indoor
environment and locate a suitable host plant.
The majority of discarded produce or cut flowers will be sent to land-fill with limited
opportunity for exposure. In a study by Hogg et al. (2010) it was reported that New
Zealanders discard around 400,000 tonnes of kitchen waste each year; of this 67% is
sent to landfill, 12.5% of this is composted, another 12.5% discarded in an in-sink
disposal and 7% is collected by councils for composting.
Compost bins are likely to be in a garden setting in close proximity to suitable host
plants. Halyomorpha halys is highly polyphagous, feeding on plants in 45 different
families, many of which are common in New Zealand; therefore suitable host plants
are likely to be present in a home garden environment. Adults and nymphs are easily
disturbed and adults can fly some distance, therefore if they are disturbed they may
well find a host plant.
Ministry for Primary Industries Risk Analysis: Halyomorpha halys 27