Biosecurity research projects and reports

This page lists recently published biosecurity research and reports.

The Spotted Lanternfly (SLF) is considered a significant threat to kiwifruit and is not yet present in New Zealand. It has spread rapidly outside its native range of China, into South Korea, Japan and more recently the USA.

From translating Chinese literature, SLF was identified as a ‘major pest’ of kiwifruit, although the level of impact remains somewhat unknown. To help address this uncertainty, this project sought to provide a better understanding of the seasonal occurrence of SLF in kiwifruit and potential impacts.

The study was undertaken in China on organically grown green (Hayward) and yellow (Nongda Jinmi) kiwifruit varieties. Weekly inspections were undertaken and all life stages were found in kiwifruit, however SLF appeared more abundant in the yellow variety. A single generation was observed from mid-April till late-September. This study presented no evidence for SLF feeding damage or sooty mold production on those kiwifruit blocks studied.

It us important to note that the research was done in its native range and on a small scale so may not fully represent impact of SLF if an incursion was to occur in New Zealand.

Read the report here.

Objective 2: This project aimed to test the pathogenicity of three species/groups of the most prevalent Fusarium species identified in Objective 1. The project demonstrated that the Fusarium solani complex was the most pathogenic to kiwifruit, of those species tested. Although the other two species were able to establish in the vines, they did not move far from the inoculation site, and it was unclear whether these species are primary pathogens in kiwifruit. These tests validate what is being observed on-orchard, where Fusarium solani is being isolated from a greater proportion of Kiwifruit Trunk Disease symptoms than many other organisms.

Objective 3: A literature review was completed to identify potential management options for Fusarium to support and inform management decisions by growers. There is no published information on control options for Fusarium solani in kiwifruit vines and little for other hosts. So, most of the management is centered around good biosecurity practices on-orchard which reduce inoculum and spread of the pathogen.

Read the report here.

Below is a summary of the research completed from our most recent research programme for Ceratocystis fimbriata, which is looking to improve kiwifruit industry preparedness through enhancing our management practices and knowledge of this organism.

Read the summary here.

This project aimed to gather information from different kiwifruit growing communities, focussing on how well they understand biosecurity and engage with biosecurity resources, training, and practices, and what barriers affect this engagement.

A summary of the report can be found here.

This report summarises the 2020-2021 Brown Marmorated Stink Bug (BMSB) surveillance project, which set out with the aim to establish a trapping network to identify whether BMSB is present or enters the Bay of Plenty during active monitoring. The project also sought to provide appropriate identification, trapping, and monitoring training for kiwifruit industry members.

The Bay of Plenty region has been included in the national BMSB surveillance programme twice now, with 24 traps set at 12 locations across the region in November 2020. BMSB was not detected by any traps or monitoring activities associated with the Bay of Plenty surveillance network within the 2020-21 year.

Read the report here or view an industry BMSB monitoring video here.

KVH and Zespri have initiated a large research programme looking to better understand Kiwifruit Trunk Diseases (KTDs) in New Zealand kiwifruit.

While relatively early on in our research programme, it is becoming clear that no single pathogen is responsible for KTDs but rather it is a complex of fungal pathogens that are associated with these vine decline symptoms in kiwifruit. One of the groups of organisms that appears to be involved are a fungal group called the Ilyonectria species group. Species of Ilyonectria cause root rots of a wide range of plants including kiwifruit. In other countries infection of kiwifruit by these pathogens causes leaf wilting, black and necrotic lesions on woody tissues of both the rootstock and roots, and death of the trees.

Prior to this research, we did not know much about Ilyonectria and its presence in kiwifruit. This project aimed to clarify the species of Ilyonectria associated with kiwifruit in New Zealand and establish whether they were pathogenic (disease causing). We discovered four species within the Ilyonectria group in New Zealand but we did not understand if they were causing disease, or simply secondary invaders. As such, we set out to understand the pathogenicity of these four species that make up this complex. From this report, we now understand that these species are capable of causing disease in inoculated roots which suggests that they are pathogenic to kiwifruit. Further work on these species in whole plants would aid in confirming their association with the disease symptoms we are seeing from diseased vines.

Read the report here.

It was acknowledged there is little information known on the ability of pollen that transmit pathogens. To address this gap, an extensive literature review was undertaken on pollen and associated floral debris as a means of pathogen (viruses, oomycetes, fungi and bacteria) spread. This work will help inform KVH’s proposed Pathway Management Plan to ensure appropriate measures are implemented to manage the level of risk associated with pollen.  Key findings from the report include:

- That pollen is a substrate that can transmit pathogens, but there a few pathogens present in NZ that are known to be pollen transmissible and;
- The pollen review confirms that the existing pollen protocols are adequate for managing current known risks.

Read the report here or view a summary presentation here.

This project aimed to understand which members of the fungal group Nectriaceae are associated with kiwifruit trunk disease. A survey of three kiwifruit orchards (two in the Bay of Plenty, one in Motueka), with a history of disease, took place in early 2019. In each orchard, fungal isolations were made from bark at the crown and from woody trunk cores taken from symptomatic and asymptomatic vines. This report is the first objective of a larger piece of work.

Read the report here or view a summary presentation, including management advice here.

This literature review used Chinese and English databases in order to pull out publications about YSSB and kiwifruit. The report describes the lifecycle of YSSB, its impacts on kiwifruit and other crops, and potential control options.

Read the report here.

The taxonomy of Psa has been evolving rapidly in recent years. This report reviews the nomenclature associated with Psa and the virulence of the different biovars of Psa.  It outlines the phylogenetic relationship of the five biovars, before reviewing the evolution of the Psa taxonomy. The ability of a few strains of different biovars to multiply on or in kiwifruit tissues has been reported but as of today there is no study which demonstrates that strains of some biovars are more virulent than strains of others.

Read the report here.

Xylella fastidiosa, a deadly bacterial pathogen, is currently having devastating impact across horticultural industries in both Europe and the USA. This pathogen can infect many different plants, both natives and important crops, but we did not know the full scale of potential damage if it got into New Zealand. The Xylella Action Group (XAG) of which KVH is a member, was assembled with the purpose to collaborate and improve New Zealand’s readiness should Xylella fastidiosa be detected on our shores.

Through the Zespri Innovation funding we contributed, alongside other potentially impacted industries and stakeholders, towards a literature review to better understand the impacts of an incursion to New Zealand. While the report highlighted that Xylella fastidiosa has an incredibly wide host range comprising more than 350 species, the good news is that there are no reports of it affecting kiwifruit. However, there is still much uncertainty, particularly around our vector status, and thus our future potential host status.

Read the report here.

SLF is native to Asia and has recently spread to the United States causing damage to a number of valued crop and tree species. SLF has not established in New Zealand but is considered a significant biosecurity threat to valued crop species including kiwifruit. English sourced references about SLF damage to kiwifruit are very sparse, likely due to only recently being invasive outside of its native range. This report provides a collation of the translation of six Chinese publications on the SLF on kiwifruit in China. It highlights the impacts of SLF on kiwifruit and control methods they use to manage it on-orchard.

Read the report here.

A literature review presenting detailed information on the potential threat posed by Phytophthora species to kiwifruit production in New Zealand. As well as providing an overview of Phytophthora in kiwifruit, a further three case studies on well-studied horticultural crops help to highlight the general principles of spread, management and control of Phytophthora.

Read the report here.

This review looked at the biology, distribution, impacts and management of White Peach Scale. It also provided information of potential control options for kiwifruit growers in New Zealand.

Read the report here.

This review looked at the biology, distribution, impacts and management of Spotted Lanternfly. It also provided information of potential control options for kiwifruit growers in New Zealand.

Read the report here.

This review looked at the biology, distribution, impacts and management of South American fruit fly. It also provided information of potential control options for kiwifruit growers in New Zealand.

Read the report here.

This review looked at the biology, distribution, impacts and management of BMSB. It also provided information of potential control options for kiwifruit growers in New Zealand.

Read the report here.

This review looked at the biology, distribution, impacts and management of fruit piercing moth. It also provided information of potential control options for kiwifruit growers in New Zealand.

Read the report here.