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Phaeomoniella chlamydospora is a fungal pathogen of woody grapevine tissue that causes Petri disease As one potential source of inoculum is infested soil a SDS/phenol/chloroform DNA extraction method and PCR assay utilising speciesspecific primers were evaluated for the ability to detect P chlamydospora in grapevine nursery soil Using a nested PCR approach the assay was able to detect 102 conidia/ml when a spore suspension was added to sterilised soil samples and 50 fg when P chlamydospora genomic DNA was added directly to the reaction In this process preamplification of a 600 bp region of the ribosomal DNA was followed by amplification with primers Pch 1 and Pch 2 to produce a 360 bp speciesspecific product This highly sensitive diagnostic tool will be used in future studies to determine if pathogen propagules are present in soils collected from New Zealand grapevine nurseries

A European biotype of Microctonus aethiopoides was identified as the best candidate biocontrol agent for Sitona lepidus a serious New Zealand pasture pest A Moroccan biotype was already present throughout the country and hence there was no requirement to obtain Hazardous Substances and New Organisms (HSNO) Act approval to release new biotypes However as research had shown mating between the two biotypes produced hybrids with poor efficacy against target hosts and that the Moroccan biotype attacked several native weevil genera serious reservations were held about introducing the European biotype Concerns were overcome with the identification of a parthenogenetic strain of European M aethiopoides from Ireland which has little risk of hybridisation and a narrower host range than the Moroccan biotype Following regulation of M aethiopoides as a risk species this strain was considered to be a new organism Approval was sought and gained under the HSNO Act to release the strain

A range of bacteria were screened to identify potential antagonists against Botrytis cinerea on grape tissue (Vitis vinifera L.). From dual culture tests, 13 isolates were selected which exhibited antagonism towards B. cinerea mycelial growth. Inhibition zones ranged between 3 and 12 mm. These isolates were screened in a grape leaf bioassay. Irradiated leaf discs were inoculated with 5. cinerea (1 × 10 4 spores/ml) then challenged with bacteria applied at 1 × 10 8 colony forming units (cfu)/ml in tryptic soya broth (TSB). Sporulation of B. cinerea was significantly (P = 0.05) reduced on leaf discs treated with Serratia liquefaciens isolates B47 and 171B by 62 and 57% respectively, 7 days after application. In a second leaf bioassay, B47 applied in TSB significantly (P = 0.05) reduced B. cinerea sporulation by 65% after 21 days compared to a 39% suppression achieved with isolate 171B (applied in TSB) and the fungicide, iprodione. However, when applied in Ringers solution, both isolates failed to reduce B. cinerea sporulation. This research has identified two isolates of S. liquefaciens able to suppress sporulation of B. cinerea on grape tissue and has shown that bacterial application solution can strongly influence the degree of suppression achieved. H98022

The parasitoid Tamarixia triozae (Burks) (Hymenoptera Eulophidae) has been imported from Mexico into containment in New Zealand as a potential biological control agent for the tomato/potato psyllid Bactericera cockerelli (Sulk) (Hemiptera Triozidae) The tomato/potato psyllid is a North American pest that was first reported in New Zealand in 2006 This psyllid has been found to vector the bacterial disease Candidatus Liberibacter solanacearum or psyllarous and has now become a major pest on both greenhouse and outdoor solanaceous crops Inundative releases of T triozae have been used to control the tomato/potato psyllid in greenhouse crops in North America In New Zealand this parasitoid may also have potential for the classical biological control of this psyllid Data to support an application for the full release of this parasitoid will be obtained by comparing the efficacy of T triozae and an undescribed species of Tamarixia found in New Zealand in 1997; establishing the ability of T triozae to parasitise the tomato/potato psyllid on capsicums tomatoes and potatoes; and undertaking host specificity testing using indigenous psyllids Approval to import T triozae was obtained under the HSNO Act 1996 and HSNO Order 1998 (ERMA Approval Code NOC00253039) and the Biosecurity Act 1993 (MAF Biosecurity Permit to Import Live Animals 2008035896)