New Zealand Plant Protection

Termites belong to the infraorder Isoptera, which contains almost 3,000 described species worldwide. These social insects cause substantial damage globally leading to billions of dollars of losses annually. Damage can occur to timber, wooden goods, paper, cotton, certain plastics, trees and many crops. Consequently, termite control and management is a major sector in the global pest-control industry. However, economic losses due to termite damage have not been quantified in the Fiji Islands to date. A review of published literature was conducted to assess the geographic range of Asian subterranean termites that occur in the Fiji Islands and to identify existing and potential control measures. The most common termite species that is known to cause millions of dollars of damage each year in the Fiji Islands is Coptotermes gestroi. This species is currently controlled primarily using the chemical fipronil but integrated termite management is the preferred long-term solution. Other poss...

Developing decision support models to evaluate biosecurity risks objectively helps decision makers manage the associated risks with importation of goods We report on the development of a prototype generic risk assessment model to determine the probability and consequences of a plant pest establishment and spread event for an infection point given the biosecurity risk organism arrives via various pathways The model has a number of submodels including entry pathway which models the ratio of infested units coming from any pathway supplying the infection point; establishment and spread which models the chance of an establishment and spread event occuring at an infection point; and consequences which models the consequences of any establishment or spread event occurring at the site Future research is planned to develop a generic input interface to generate a support tool to allow a user to investigate the impacts of alternative whatif scenarios and to test the model on realworld plant pe...

Phytophthora agathidicida is a highly virulent pathogen of kauri (Agathis australis) and the causal agent of dieback disease in New Zealand’s kauri forests. This study aimed to identify microbial isolates isolated from kauri forest soils that inhibited the growth of P. agathidicida. Three different forms of in vitro bioassays were used to assess the inhibition of each isolate on the mycelial growth of P. agathidicida. Furthermore, head space (HS) solid-phase micro-extraction coupled with gas chromatography-mass spectrometry (SPME-GCMS) was performed to identify if the microbial isolates emitted volatile organic compounds (VOCs), which may be contributing to inhibition. This research identified several bacterial isolates belonging to the genus Burkholderia that inhibited the mycelial growth of P. agathidicida. Furthermore, several VOCs produced by these isolates were putatively identified, which may be responsible for the inhibition observed in the bioassays. Several isolates of Peni...

Abstract Ten years ago there were no known foliar diseases caused by Phytophthora on pine trees worldwide. Since then two significant Phytophthora diseases have emerged on radiata pine, one of which is only known in New Zealand. Red needle cast is a disease caused by the pathogen Phytophthora pluvialis, which is thought to have originated from northwestern USA. This paper reviews the challenges the New Zealand forestry industry faces when dealing with this disease and evaluates the management options, such as chemical control, biological control and breeding programmes, being investigated to minimise its effect on forest production. The distribution of the pathogen in New Zealand and research that shows bark, logs and wood are free of the pathogen and are unlikely to pose biosecurity threats through trade in these products are also outlined.

Argentine stem weevil (ASW) Listronotus bonariensis is a well known pest of grass species in New Zealand pasture Less well known is its pest status in amenity turf especially golf courses in New Zealand and Australia ASW infests Poa annua and browntop which are common grasses on New Zealand golf courses Larval damage initially appears as chlorotic turf then turns strawcoloured which can be confused as dormant (dry) or diseased turf While many aspects of the biology of ASW in pasture have been elucidated little is known about the biology or behaviour of the insect on golf courses A preliminary study was carried out from mid September 2010 to early February 2011 at Pleasant Point Golf Club (South Canterbury) where ASW has caused significant damage in recent years The study looked at the relative number of ASW adults collected from the fairway and rough and their reproductive condition The study also tracked the presence and stage of development of larvae in the fairway throughout the ...

This study compared four methods to quantitatively sample adult Listronotus bonariensis and Sitona lepidus (both Coleoptera Curculionidae) in dairy pasture with a view of determining an appropriate sampling method for accurate population estimation in terms of weevils/m2 Collections were made by one of three vacuum methods a vacuum cleaner to take 12 02 m2 quadrats a Vortis (24 16 cm diameter 002 m2) or blowervac (30 m ca 11 cm diameter 327 m2) to suck the weevils from the soil surface; or by taking turf cores (48 10 cm diameter 000785 m2) with extraction of weevils using a Berlesse funnel The sampling was carried out on three occasions and the four methods compared for each occasion Overall for both weevil species coring or the vacuum cleaner generally indicated significantly higher densities compared to the Vortis or blower vac and are concluded to be the most accurate methods for measuring adult density However the blowervac is a convenient tool for mass collection of weevils and...

Insect phenology models are widely used for decision support in pest management and more recently in risk assessments. During the last two decades, numerous linear and nonlinear models have been used to describe insect development rates and estimate various critical temperatures (CT) including optimal development temperature (Topt), maximum development temperature (Tmax), minimum development temperature (Tmin) and thermal constant (K) (e.g. day degree requirements to complete development). Using a database comprising more than 600 species from laboratory and field experiments, the relationship between CT for the six main insect orders, Coleoptera, Diptera, Hymenoptera, Lepidoptera, Homoptera and Hemiptera, was compared. There were no significant differences (P>0.05) between ToptandTmax for all orders, but Tmin and Kshowed significant (P<0.001) differences between orders, with Hemiptera and Coleoptera having the highest and Homoptera the lowest Tmin for egg to adult development...

Vulpia species (silver grasses), including V. bromoides and V. myuros, are native to the Mediterranean, Middle East and Eurasia, but have become dispersed worldwide. These two species reduce the grazing quality of pastures, frequently co-occur and are often associated with poor-quality acidic soils. This study investigated two species, Vulpia bromoides and V. myuros. Germination trials tested the effects of seasonal temperature, light,pH, moisture, salinity, pre-germination heat shock and smoke, and seed burial depth. Vulpia bromoides germinated well regardless of temperature or light (>80%, all conditions), whereas V. myuros preferred lower temperatures and absence of light (97%, 7/17oC in 24-h dark). Under different culture conditions, the two species germinated well across the pH range 4 to 10 (>85%). Reduced moisture, pre-germination heat shock and smoke, and increased burial depth reduced germination and emergence of both species. Preventing germination of these species i...

Bacillus megaterium is a beneficial bacterium that is used as a biological control agent (BCA) against the fungi Rhizoctonia solani, Fusarium sacchari and Curvularia lunata, which attack rice plants. However, the cost of preparing the bacterium using standard nutrient broth is prohibitively expensive on a large scale. Therefore, a low-cost product (seasoning cube, a common ingredient for cooking) was examined as an alternative nutrient medium. Bacillus megaterium was cultured in either nutrient broth or in dissolved seasoning cube. These cultures were evaluated for their effect on the growth of rice seedlings in the laboratory and to suppress grain discoloration of rice in small-scale field trials. Bacillus megaterium cultured with a seasoning cube was as effective as standard nutrient broth for the growth of rice seedlings in the laboratory. It also suppressed grain discoloration disease of rice in small-scale field trials. Use of a seasoning cube is suitable for culturing B. megat...

The potential of Lycosa hilaris as a bioindicator of organophosphate contamination was assessed experimentally in a crop of beans (Phaseolus vulgaris) in Canterbury New Zealand Although the numbers of L hilaris caught in pitfall traps fluctuated significantly as the crop aged there were no differences (P>005) in L hilaris abundance in plots sprayed with diazinon or chlorpyrifos compared with plots of beans sprayed with water The abundances of other beneficial arthropod predators (linyphiid spiders harvestmen centipedes) were also not affected by insecticide application (P>005) Although L hilaris may not represent a good bioindicator the use of this species as a laboratory bioassay organism should be further investigated especially with respect to sublethal physiological responses

European canker (EC), caused by Neonectria ditissima, is an important disease in apple-producing regions in New Zealand. In order to improve plant protection, Geographic Information Systems (GIS) can be used to map plant disease location and severity in agricultural settings. Data were compiled from apple growers in Tasman, New Zealand, to investigate EC distribution over 4 years, for the period 2015–2018. ArcGIS software, including the Spatial Analyst, Interpolation and Geospatial statistics toolboxes, was used to map EC incidence at the spatial scale of orchard blocks, which allowed the identification of disease hot-spots. A clustered spatial pattern of disease was detected every year and areas with higher risk of EC were identified within the region. The spatial patterns detected were related to disease pressure over time for different apple cultivars. The use of GIS provides a platform for analysing and visually communicating disease patterns over time. Investigating disease spa...

A laboratory study was conducted to: (1) advance earlier work to determine the susceptibility of Listronotus bonariensis (Argentine stem weevil) to its parasitoid biological control agent, Microctonus hyperodae, in the presence of diploid ryegrasses such as Lolium multiflorum or Lolium perenne; and (2) determine whether or not plant orientation (i.e. horizontal vs. vertical) had any effect on parasitism rates. No significant differences in parasitism rates were found in the Listronotus bonariensis populations in the two grasses. However, combining and analysing these data with those from an earlier experiment conducted in the same way showed that parasitism rates were significantly lower in diploid Lolium multiflorum cultivars than in tetraploid Lolium multiflorum. This is the first clear evidence of a ploidy effect on parasitism rates in the presence of Lolium multiflorum. Tetraploid Lolium multiflorum has fewer, more robust and larger tillers than the diploid Lolium spp. so higher...

The biological control programme against Sitona lepidus (Gyllenhal) (Coleoptera Braconidae) commenced in 1998 with the first parasitised weevils imported into New Zealand quarantine in 2000 Extensive collections in Europe confirmed that the solitary endoparasitoid Microctonus aethiopoides Loan (Hymenoptera Braconidae) was the principal natural enemy of adult S lepidus With one exception all M aethiopoides reared from S lepidus collected in Europe have been arrhenotokous All M aethiopoides collected from Ireland are thelytokous which obviates the risk of hybridisation with an arrhenotokous Moroccan strain already established in New Zealand Levels of parasitism in S lepidus fieldcollected from Ireland were low (lt;8) and overall averaged 07 Rates of parasitism of S lepidus in New Zealand quarantine have averaged 25 but ranged from 0 to 95 Aspects relating to the rearing and management of Irish M aethiopoides are discussed including possible reasons for low rates of parasitism in quara...

Biopesticides can provide effective control of existing and invasive invertebrate pests and diseases impacting on New Zealands primary sector production and combat new pests emerging as a result of landuse change farming intensification and climate change While the international biopesticide market is undergoing rapid growth at present assisted by regulatory environments favourable to biopesticide registration and uptake biopesticides are not widely used in New Zealand The number of biopesticides registered under the Agriculture Compounds and Veterinary Medicines Act (Ministry for Primary Industries MPI) has slowly increased from 11 products in 1991 to 33 in 2010 with 49 registered in 2015 However only a limited number of these products are actively marketed and used by growers at present To play an increasing role in New Zealands sustainable production systems next generation biopesticides will need to have levels of efficacy comparable to currently available controls and will be a...

Responses of adult Argentine stem weevil (ASW) to meadow fescue infected with the endophyte Neotyphodium uncinatum and to two loline alkaloids produced by the fungus were investigated Endophyte in two different meadow fescue seedlines did not affect adult ASW feeding scores but reduced oviposition compared with endophytefree controls In a nochoice experiment adult ASW were given artificial diets containing Nformyl loline (NFL) or Nacetyl norloline (NANL) at three concentrations or a control diet with no lolines Mortality was significantly higher at the highest rate of NFL than for lower rates and the control For NANL mortality was increased at both the lowest and the highest concentrations Feeding scores were higher on control than loline diets but only after 4 weeks In a choice experiment NFL appeared to have no effect on ASW feeding preference whereas there was less feeding at the highest concentration of NANL compared with the control diet

Viability and germination of conidia of three Botryosphaeriaceae species which are important grapevine pathogens were significantly affected by exposure to different levels of sunlight and relative humidity (RH) After 7 h exposure to nonfiltered sunlight (UV) filtered sunlight (UV) and shade germination differed between light levels being 35 57 and 81 respectively and after 70 h exposure it was 0 21 and 65 respectively Nongerminated conidia were unable to germinate when placed in a moist environment indicating that they had been killed High RH favoured germination since 91 and 70 respectively germinated after 3 h in 100 and 97 RH However in 93 RH only 44 germinated by 24 h and in 84 RH no conidia germinated The inhibition of germination was temporary since replacement in a moist environment caused conidia to germinate Light and RH effects were similar for the three species

Analysis of microbial communities associated with plants insects and soil has been a significant challenge for plant protection researchers because of the lack of techniques with which to access these populations A new molecular community profiling technique 16S rRNA genebased PCR followed by denaturing gradient gel electrophoresis (DGGE) has been used to analyse microbial communities in a number of environments and has many potential uses in plant protection research The technique is currently being used for the analysis of insect gut microflora characterisation of phylloplane and rhizosphere microbial populations and in environmental assessment of the effects of biopesticides and new technologies on indigenous soil microbes

Analysis of microbial communities associated with plants insects and soil has been a significant challenge for plant protection researchers because of the lack of techniques with which to access these populations A new molecular community profiling technique 16S rRNA genebased PCR followed by denaturing gradient gel electrophoresis (DGGE) has been used to analyse microbial communities in a number of environments and has many potential uses in plant protection research The technique is currently being used for the analysis of insect gut microflora characterisation of phylloplane and rhizosphere microbial populations and in environmental assessment of the effects of biopesticides and new technologies on indigenous soil microbes

Current management options for grapevine trunk diseases are focused on ameliorating symptoms once they have occurred In grapevines and other crops plant stress has been observed to increase symptom expression for different pathogens depending on timing and type of stress This research aimed to establish whether stress to vines at the time of wounding enhances colonisation by fungi associated with trunk disease Potted plants were wounded and inoculated with two grapevine trunk fungi Eutypa lata and Botryosphaeria lutea Stress treatments (leaf removal and girdling) were applied to the vines immediately prior to inoculation Lesion size at the wound site and infection confirmed by reisolation of the pathogen were measured In these experiments stress did not induce greater infection incidence or larger lesions at the site of wounding Some difficulties in using potted plants to simulate responses of mature vines in the field are discussed

The folivorous beetle Cassida rubiginosa was introduced to New Zealand to control the weed, Californian thistle (Cirsium arvense). Although Californian thistle is the primary host, many other thistles are accepted hosts. The objective of this study was to test if the beetle can reduce the fitness of marsh thistle (Cirsium palustre). A potted plant experiment was established with four treatments (0, 50, 100, and 200 larvae/plant). Plant growth (width, height, and number of branches) and reproductive performance (number of flowers, seeds, seed weight and percent germination) parameters were measured. No significant differences were found for any of the measured parameters, except percent germination. Higher larval densities (100 and 200) resulted in approximately 10% less germination compared with lower densities (0 and 50). Under these experimental conditions, C. rubiginosa had minimal impact on the performance of marsh thistle. For the beetle to have an impact, it would likely need ...

Moth plant, Araujia sericifera, is an environmental weed in northern regions of New Zealand. Due to its rapid spread, its ability to cause substantial damage to natural ecosystems and the increasing cost of conventional control methods, a biological control programme was initiated. A survey of the plant in New Zealand found that damage attributed to either disease or insect herbivory was minimal with little biocontrol potential. Botanical, pathogen and insect surveys were subsequently initiated in the native South American range to locate and identify potential agents for classical biocontrol. Potential agents associated with plant damage were collected. Damage was mostly due to pathogenic attack with 90% of moth plant populations showing disease symptoms. To date, eight fungal pathogens have been associated with plant die back, leaf necroses and a severe fruit rot. At least two mosaic (virus) diseases were also found, frequently associated with colonies of the aphid, Aphis nerii.

Apple Futures was a research implementation project designed to produce export quality ultralow residue apples while meeting the phytosanitary requirements of over 60 countries In 3 years from 2007/08 to 2009/10 seasons it was successfully implemented on 65 of New Zealands export apple crop with a benefitcost ratio of 30 times the value of the investment The process of developing and implementing Apple Futures is the subject of a case study on coinnovation an approach to solving complex problems that engages multiple stakeholders throughout research and extension initiatives to enhance adoption and impact A new innovation system analysis framework was used to identify key coinnovation learnings These included the importance of trust amongst participants learning together a clear agenda for change and monitoring and evaluating progress towards that change agenda Findings are discussed in the context of maximising impact in innovation projects in New Zealands primary sector