Climate change is likely to increase New Zealand’s potential exposure to the impact of further agricultural and horticultural pests, including the brown marmorated stink bug – should it arrive here.
Ground-breaking research by scientists at Unitec is adding to the current knowledge to enable the optimum management of this pest species, if it is established, and help stem potentially significant damage to New Zealand’s export economy.
The recent significant find of this species on board a cargo ship indicates that the risk to New Zealand is extremely high and that any related information available to MPI and the public in support of the management of this species is vital for the New Zealand economy.
The Brown Marmorated Stink Bug (Halyomorpha halys) is an agricultural pest that originated in Asia and is now found in countries including Canada, Switzerland, Germany, Italy and France. It has aggressively invaded the US and at present, while it has not established here, it is regarded by the New Zealand horticulture industry as one of the top six pests of concern.
The insect feeds on more than 300 hosts, primarily fruit trees and woody ornamentals but also field crops. Targets include pipfruit, stonefruit, berries, grapes, asparagus, sweetcorn, hibiscus and roses. It severely disfigures fruit and renders it unmarketable, with damage resulting in significant economic loss. Dollar damage to the 2010 apple crop in the mid-Atlantic regions of the US was estimated at approximately $37 million with up to 90% loss of some stone fruit crops. The export value of NZ horticultural products totalled NZ$5,187 million in the year ending 30 June 2016. Even with conservative production losses, the severe potential economic and social impact of the organism to New Zealand is obvious.
It’s not just the prevalence of the species during crop-producing months that is of concern. The adult stink bug naturally tends towards cracks and crevices to shelter from the environment during winter months and may find its way into loaded containers for import into New Zealand. The species’ overwintering behaviour of swarming in buildings will be a significant nuisance to the public if the stink bug becomes established. When disturbed or crushed, the stink bug emits its weapon of choice: A characteristic, unpleasant and long-lasting odour.
Staff at Unitec’s Environmental and Animal Sciences (EAS) department have modelled the species under future conditions of climate change as a way of understanding the range of potential risk. Guided by EAS Senior Lecturers Dr Diane Fraser and Dr Glenn Aguilar, Unitec student Shivani Kumar modeled algorithms to map which areas of the world -- and within New Zealand -- are most environmentally suitable for the bug. Dr Aguilar then helped her expand these models to include low and high trajectories of future climate change. The results of the study show that, under current climatic conditions, large areas of New Zealand are suitable for the establishment of this pest. The projected modeling of the impact of climate change shows a southerly range shift of the species over time.
The trio co-published the results in the prestigious online journal, ‘Climate’ last September; the first time research of this nature has been published.
The modeling exercise provides information on the environmental suitability of New Zealand to host the pest under current and future projected environmental conditions, and helps arm both national and regional authorities with an indication as to the severity and impact that would be expected in their respective areas. In addition, this information will be invaluable for producers to increase awareness and vigilance for detection of this species, the potential impacts and likely spread through New Zealand.
For further information on the brown marmorated stink bug, see MPI link:
For any suspected sightings or concerns about BMSB, contact the MPI Pests and Diseases Hotline on 0800 80 99 66
Find out more about studying Environmental and Animal Sciences at Unitec: