There is currently little knowledge about the dynamics of invertebrates in Australian viticultural ecosystems. This study was conducted in Coonawarra vineyards over three seasons (years) and has focused on identifying natural enemies, their seasonal phenology, multiple species interactions, and potential for the suppression of the pest lepidopteran Epiphyas postvittana (Tortricidae). The work presented in this thesis shows that endemic natural enemies have far greater potential to control E. postvittana than has been realised. An initial survey identified a diverse and abundant range of potential natural enemies. Of these, the species most likely to attack E. postvittana include a predatory mite Anystis baccarum and a number of hymenopteran parasitoids. The most abundant parasitoid in the vineyards was a braconid, Dolichogenidea tasmanica. Understanding the characteristic behaviour of parasitoids in response to host density can help to gauge their potential for pest suppression. The results of large-scale field experiments showed that the response of D. tasmanica to the density of E. postvittana was inversely density-dependent, and that parasitism was consistently higher in Cabernet Sauvignon compared with Chardonnay varieties. Despite the fact that interactions among multiple species of natural enemies can increase or decrease pest suppression, particularly when they share a common prey/host, few multispecies interactions have been investigated. Laboratory studies identified a novel interaction between the predatory mite A. baccarum an abundant predator in the vine canopy, the parasitoid D. tasmanica and host E. postvittana larvae. Although A. baccarum readily ate E. postvittana eggs and free roaming larvae, they could not access larva in their silk leaf rolls. However, the addition of D. tasmanica significantly increased predation of E. postvittana larvae, by altering the behaviour of host larvae and increasing their vulnerability to the mite. Experiments conducted at a landscape level in the Coonawarra showed that D. tasmanica was also present in habitat other than vineyards including native vegetation. However, it was not present in highly disturbed habitats. Although the exact mechanism for this remains unknown, results indicate that viticultural practices and resources in the surrounding landscape can influence the presence of parasitoids. Together, the findings presented in this thesis make a significant contribution towards developing sustainable pest management in Australian viticulture. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1320930 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2008

There is currently little knowledge about the dynamics of invertebrates in Australian viticultural ecosystems. This study was conducted in Coonawarra vineyards over three seasons (years) and has focused on identifying natural enemies, their seasonal phenology, multiple species interactions, and potential for the suppression of the pest lepidopteran Epiphyas postvittana (Tortricidae). The work presented in this thesis shows that endemic natural enemies have far greater potential to control E. postvittana than has been realised. An initial survey identified a diverse and abundant range of potential natural enemies. Of these, the species most likely to attack E. postvittana include a predatory mite Anystis baccarum and a number of hymenopteran parasitoids. The most abundant parasitoid in the vineyards was a braconid, Dolichogenidea tasmanica. Understanding the characteristic behaviour of parasitoids in response to host density can help to gauge their potential for pest suppression. The results of large-scale field experiments showed that the response of D. tasmanica to the density of E. postvittana was inversely density-dependent, and that parasitism was consistently higher in Cabernet Sauvignon compared with Chardonnay varieties. Despite the fact that interactions among multiple species of natural enemies can increase or decrease pest suppression, particularly when they share a common prey/host, few multispecies interactions have been investigated. Laboratory studies identified a novel interaction between the predatory mite A. baccarum an abundant predator in the vine canopy, the parasitoid D. tasmanica and host E. postvittana larvae. Although A. baccarum readily ate E. postvittana eggs and free roaming larvae, they could not access larva in their silk leaf rolls. However, the addition of D. tasmanica significantly increased predation of E. postvittana larvae, by altering the behaviour of host larvae and increasing their vulnerability to the mite. Experiments conducted at a landscape level in the Coonawarra showed that D. tasmanica was also present in habitat other than vineyards including native vegetation. However, it was not present in highly disturbed habitats. Although the exact mechanism for this remains unknown, results indicate that viticultural practices and resources in the surrounding landscape can influence the presence of parasitoids. Together, the findings presented in this thesis make a significant contribution towards developing sustainable pest management in Australian viticulture. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1320930 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2008

Thesis (MSc (Genetics))--University of Stellenbosch, 2005. / An infectious clone of a viral RNA genome is one that can be used, either as an in vitro transcript or as cDNA, to produce an infection in a susceptible plant. Infectious clones serve as a tool to study viral RNA genomes at a molecular level to gain deeper insight into genome organization, viral gene function, presence of regulatory sequences and gene expression. In the Western Cape (and elsewhere) a new crippling grapevine disease, known as Shiraz disease, is emerging of which the aetiology and pathogenic agents involved are not yet fully understood. Grapevine virus A (GVA), genus Vitivirus, family Flexiviridae, is thought to be the associated with this disease. The aim of this study was to construct a full-length infectious cDNA clone of GVA, which will aid in the molecular study of the viral genome. This clone could ultimately be used to investigate GVA’s involvement in Shiraz disease, which could lead to the unravelling of the aetiology and control of the disease. A full-length clone of GVA, named GVA-IC2/T7-2972-3, was constructed in several steps using restriction digestion/ligation and primer overlap extension PCR. Grapevine virus A cDNA fragments were obtained from GVAinfected Nicotiana benthamiana and Vitis vinifera plants using three different techniques, of which the Rapid direct-one-tube RT-PCR was most successful. A 5’ T7 promoter and a 3’ poly-A tail were incorporated and the full-length clone was cloned into pBluescript II SK (+). Full-length sequencing of the clone, revealed two significant frameshift mutations. The first mutation was a single base pair insertion (one G) in a slippery site of 6 G’s at position 1380 – 1385 in open reading frame one (ORF 1) of the viral genome. This mutation was corrected by PCR-based site-directed mutagenesis, which resulted in pSK-GVA-mutagen-3 and pSK-GVA-mutagen-4. The second mutation was a single base pair deletion (one G) at position 6959 in ORF4, which coded for the coat protein (CP). Several techniques were attempted to correct this mutation, but none were successful. Even though the second mutation could not be corrected, in vitro transcriptions were performed on three clones followed by subsequent infections of N. benthamiana plants. The three clones included pSK-GVA-mutagen-3, pSKGVA- mutagen-4 (both hosting the mutation at position 6959) and GVA-IC2/T7-2972-3 (hosting both mutations). At 21 days post-inoculation no significant visual symptoms were observed in plants infected with in vitro RNA or in plants infected with wild type GVA. Rapid direct-one-tube RT-PCR results revealed the presence of viral RNA in infected leaves and apical leaves of infected plants, and provided preliminary evidence that the mutated clones were still capable of systemic infection and viral movement. These results are still inconclusive, and several post-infection studies will have to be performed to confirm these findings. Koch's postulates will also have to be proved in order to confirm the infectious nature of the clones. The effect of the two mutations in the constructed clones will be investigated further and post-infection analysis performed to deduce whether the viral progeny are devoid of the mutations. Three full-length GVA cDNA clones (hosting mutations) seemingly capable of systemic infection in N. benthamiana plants were constructed in this study and have laid the foundation for molecular and mutational analysis of the GVA genome. This could lead to the study of pathogen-host interactions in order to unravel the aetiology of Shiraz disease in the future.

Thesis (MScAgric)--University of Stellenbosch, 2005. / ENGLISH ABSTRACT: Various studies revealed that Botrytis cinerea, the causal pathogen of Botrytis bunch rot, is mostly associated with pedicels, rachises, laterals and berry bases, and not with berry skins as previously understood. Provided that sufficient coverage of inner bunch parts was achieved, laboratory studies have shown that fungicides can effectively reduce the amount of B. cinerea at the various positions in bunches, and prevent infection and symptom expression at all growth stages. The same efficacy was, however, not achieved with the same fungicides when using conventional spraying methods in vineyards. Poor disease control on fruit and leaves in vineyards is attributed to inappropriate timing of fungicide applications and/or insufficient coverage of susceptible tissue. Previously, spray coverage evaluations in South Africa were based on the use of water-sensitive cards. A variety of other methods have been used to assess spray coverage in vineyards, but none of these methods could assess spray deposits on a very small, three-dimensional area of interest such as the susceptible grape bunch parts. The methods were furthermore dependent on human objectivity, which lacks quantitative measuring and speed of measurement. Suitable technology to determine spray coverage on susceptible bunch parts is, therefore, not available. The aim of this study was to develop a protocol to visualise and quantify spray deposits in grape bunches, specifically on the inner bunch parts and to use the protocol to determine the effect of different levels of spray cover on artificially inoculated B. cinerea grape bunches, in order to facilitate future determination of minimum effective coverage levels for effective B. cinerea control. A spray coverage assessment protocol using fluorometry, photomicrography and digital image analyses was developed to measure spray coverage on susceptible grape bunch parts. Among several fluorescent pigments tested, a yellow fluorescent pigment (SARDI Fluorescent Pigment) from Australia was selected on the basis of its small particle size (2.45 - 4.90 μm). Bunches were sprayed at pea size and bunch closure with different volumes of a mixture of fenhexamid and the yellow fluorescent pigment. Sprayed parts from bunches were illuminated under black light (UV-A light in the 365 nm region) and visualised under a stereo microscope at 20 x magnification. Photos of the berry skin, pedicel and rachis were taken with a digital camera (Nikon DMX 1200). Image analysis of photos was done with Image- Pro Discovery version 4.5 for Windows (Media Cybernetics) software. The total area of deposited pigment in selected areas of interest (AOI) was calculated. The percentage area covered was subsequently calculated for each AOI. Good correlation was evident between the parameters, sum of objects and percentage area covered. Bunch parts at pea size generally had higher coverage values than at bunch closure. Spray applications earlier in the season would therefore result in higher and more effective spray coverage of the susceptible bunch parts. Similar deposition trends were observed on the inner bunch parts (pedicel and rachis). These were, however, significantly different from berry skins, which had significantly higher levels of spray deposits than the inner bunch parts. The variance component analysis indicated that the highest variance was observed for berries and bunches, and substantially less for image readings. For the same accuracy, means for percentage coverage values of at least 10 bunches per treatment (1 part per bunch and 3 readings per part) will be sufficient. In order to determine the biological efficacy of different levels of spray coverage on B. cinerea incidence on grape bunches, bunches were sprayed at pea size and bunch closure with different volumes of a mixture of fenhexamid and a yellow fluorescent pigment and the percentage fluorescent pigment coverage on pedicels was determine. Bunches were subsequently dusted with dry airborne conidia of B. cinerea in a settling tower and incubated for 24 h at high relative humidity (98%). Infection was determined by estimating the amount of B. cinerea infections occurring on sprayed bunch parts with isolations on to paraquat and Kerssies mediums. Linear regressions for the part x stage combinations of percentage B. cinerea incidence on different bunch parts were fitted on mean coverage levels. An increase in spray cover caused linear reductions in levels of B. cinerea on susceptible bunch parts. Higher B. cinerea incidences were recorded at pea size. Furthermore, higher B. cinerea incidences were found on paraquat medium for both stages, than on Kerrsies medium. The information gathered from this study will be used to facilitate future determination of minimum effective coverage levels for effective B. cinerea control in grape bunches. In these validation experiments, the results clearly showed that the protocol can be used to determine the effect of different levels of spray coverage on B. cinerea incidence and that an increase in spray coverage will decrease B. cinerea incidence. The information gathered from this study will be used to facilitate future determination of minimum effective coverage levels for effective B. cinerea control in grape bunches and subsequently be used as benchmarks to evaluate spray application in vineyards. / AFRIKAANSE OPSOMMING: Vaalvrot by wingerde word veroorsaak deur Botrytis cinerea. Verskeie studies het getoon/gewys dat die oorsaaklike patogeen meestal geassosieer word met die pedisel, ragis, laterale en die korrelbasis, en nie met die korrelskil soos voorheen beweer nie. Laboratorium studies het getoon dat swamdoders wel effektief is om B. cinerea by alle trosdele te verminder en simptoomontwikkeling te voorkom tydens alle groeistadia, mits die binne-trosdele voldoende spuit bedekking ontvang het. Dieselfde effektiwiteit is egter nie gevind in wingerde met konvensionele spuittegnieke nie. Onvoldoende siektebeheer van vrugte en blare van wingerde kan toegeskryf word aan verkeerde spuit skedulering en/of swak spuitbedekking van vatbare gasheerweefsel. Evaluering van spuitbedekking is voorheen in Suid Afrika deur middel van water-sensitiewe papier gedoen. Verskeie ander metodes is al gebruik om spuitbedekking te evalueer in wingerde, maar nie een van hierdie metodes kan gebruik word om spuitbedekking op ’n baie klein, drie-dimensionele oppervlak, soos die vatbare trosdele, te evalueer nie. Verder was die tegnieke afhanklik van menslike objektiwiteit, en gevolglik ontbreek kwantitatiewe meting en metingspoed. Daar is dus nie geskikte tegnologie vir die evaluering van spuitbedekking op vatbare trosdele nie. Die doel van hierdie studie was die ontwikkeling van ‘n protokol vir die visualisering en kwantifisering van spuitbedekking op spesifiek die binne-tros dele en om die protokol dan te gebruik om die effek van verskillende vlakke van spuitbedekking op B. cinereageinokuleerde druiwetrosse te bepaal, Protokol vir evaluasie van spuitbedekking op vatbare druifdele is ontwikkel deur gebruik te maak van fluorometrie, fotomikrografie en digitale beeldanalise. Van die verskillende fluoresensie pigmente wat getoets is, is ‘n geel flouresensie pigment (SARDI Flourescent Pigment) van Australië gekies op grond van sy klein partikelgrootte (2.45 - 4.90 μm). Druiwetrosse is gespuit tydens ertjie- en trostoemaakstadia met verskillende volumes van ’n mengsel van fenheksamied en die geel fluorosensie pigment. Die gespuite druifdele is dan verlig onder swartlig buise (UV-A lig in die 365 nm spektrum) en gevisualiseer deur ’n stereo mikroskoop by 20x vergroting. Foto’s van die korrelskil, pedisel en ragis is met ‘n digitale kamera (Nikon DMX 1200) geneem. Beeldanalise is gedoen met ImagePro Discovery weergawe 4.5 vir Windows (Media Cybernetics) sagteware. Die totale area neerslag van die pigment is in geselekteerde areas bereken. Die presentasie area bedek is bereken vir elkeen van hierdie areas. Goeie korrelasie is gevind tussen die parameters aantal fluoresserende partikels en die persentasie bedekte area. Trosdele tydens ertjie-stadium het in die algemeen hoër waardes gehad as by trostoemaak. Dit blyk dus dat spuittoediening vroeg in die seisoen meer effektief sal wees vir die bedekking van vatbare trosdele. Soortgelyke bedekkings patrone is gevind by die binne trosdele (pedisel en ragis). Dit het egter betekenisvol verskil van die korrelskil, wat betekenisvol meer spuitbedekking as die binne trosdele gehad het. ’n Variasie komponent analise het getoon dat die meeste variasie gevind is tussen korrels en trosse, en heelwat minder vir die beeld analise lesings. Om dieselfde akkuraatheid te behou, is ten minste 10 trosse per behandeling (1 deel per tros en 3 lesings per deel) nodig. Vir die bepaling van biologiese effektiwiteit van verskillende vlakke van spuitbedekking op B. cinerea voorkoms op druiwe, is druiwe gespuit tydens ertjie- en trostoemaak-stadia met verskillende volumes van ’n mengsel van fenheksamied en die geel fluorosensie pigment. Die persentasie fluoresensie pigment is bepaal op die pedisels. Trosse is vervolgens geinokuleer met droë luggedraagde konidia van B. cinerea in ’n inokulasietoring en geïnkubeer vir 24 h by hoë relatiewe humiditeit (98%). Die voorkoms van B. cinerea infeksie op gespuite tros dele is bepaal deur middel van isolasies op paraquat en Kerssies medium. Liniêre regressies vir trosdeel x stadium kombinasies van persentasie B. cinerea voorkoms op verskillende trosdele is gepas vir gemiddelde bedekkings waardes. ’n Verhoging in spuit bedekking het ‘n liniêre vermindering van B. cinerea voorkoms op vatbare trosdele veroorsaak. Verder is hoër vlakke van B. cinerea op paraquat medium as op Kerssies medium vir beide die groeistadia gevind. Die kennis wat verkry is uit hierdie studie sal gebruik word om minimum effektiewe spuitbedekkingsvlakke vir die beheer van B. cinerea op druiwetrosse te bepaal.

Thesis (MScAgric.)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: Phomopsis cane and leaf spot disease of grapevine is an economically important disease in many of the vine-growing areas of the world. Four different Phomopsis spp. have previously been associated with this disease. The present study investigates the taxonomic significance of the different taxa found on grapevines in South Africa, as well as the endophytic growth and fungicide sensitivity of Phomopsis viticola isolates. The thesis is compiled of several different parts, which deal with specific, but related topics, and hence some duplication has been unavoidable. Understanding the epidemiology of a disease is important for the correct timing of disease control. To investigate the endophytic growth of P. viticola, asymptomatic shoots were collected at eight different growth stages. Nodes, internodes, leaf petioles, leaves, tendrils and bunch peduncles were investigated. Two Phomopsis spp., taxon 1 and 2 were identified in this study. The Phomopsis viticola-complex had a relative importance of 9% and accounted for 3% of the isolations. P. viticola (taxon 2) is mainly isolated from the nodes and internodes. Inoculations of healthy, young vine tissue confirmed taxon 2 to be a virulent pathogen, suggesting that it is a latent pathogen rather than an endophyte. In contrast, taxon 1 appeared to be a true endophyte, and did not seem to be an important pathogen on vines. The true identity of the causal organism of Phomopsis cane and leaf spot disease was investigated by collecting samples from 58 different vineyards in the grapevine growing areas of the Western Cape. P. viiicola occurred in grapevine material collected from Lutzville to Swellendam, but was not found in the Oudtshoorn and Orange River grapevine areas. Diaporthe perjuncta (taxon 1), P. vutcola (taxon 2), taxon 3 and a Phomopsis species commonly associated with shoot blight of peaches in the U.S.A., P. amygdali, were identified among the South African grapevine isolates. Examination of the Australian culture designated as taxon 4 found it to be a species of Libertella, thus excluding it from the P. viticola-complex. An Italian isolate was found to represent a species of Phomopsis not previously known from grapevines, and this was subsequently described as taxon 5. Species delimitation was based on morphological and cultural characteristics, stem inoculations and the formation of the teleomorph in vitro. The identity of each morphological taxon was confirmed by means of phylogenetic analyses of the nuclear ribosomal DNA internal transcribed spacers (ITS 1 and ITS2) and the 5' end partial sequence of the mitochondrial small subunit (mtSSU). P. amygdali, associated with peach shoot blight in the U.S.A., was isolated once only and appeared to be of lesser importance in this disease complex. Furthermore, taxa 1 (Diaporthe perjuncta) and 3 were also rarely encountered and proved to be non-pathogenic, indicating their non-functional role in Phomopsis cane and leaf spot disease. Taxon 2 (Phomopsis viticolas was common and widely distributed in diseased vineyards. This taxon was associated with the typical disease symptoms and proved to be pathogenic. Morphologically taxon 2 corresponded best with P. viticola, which was also neotypified in this study. Taxon 2 was mostly isolated from buds and nodes, indicating that these are important sites in which the fungus survives during winter. Molecular data indicated that taxon 3 and P. amygdali were not host specific to grapevine. The currently used foliar fungicides were compared to the new strobilurin fungicides. The effects of nine fungicides (azoxystrobin, flusilazole, folpet, fosetyl- Al+mancozeb, kresoxim-methyl, mancozeb, penconazole, spiroxamine and trifloxystrobin) were tested in vitro on inhibition of mycelial growth. The following EC50 (ug/ml) values were obtained: azoxystrobin (0.350), flusilazole (0.007), folpet (4.489), fosetyl-Al+mancozeb (3.925), kresoxim-methyl (1.665), mancozeb (2.891), penconazole (0.023), spiroxamine (0.321) and trifloxystrobin (0.051). Additionally, azoxystrobin, folpet, kresoxim-methyl, mancozeb, propineb and trifloxystrobin were tested for their ability to inhibit spore germination in vitro. The subsequent EC50 (ug/ml) values were obtained: azoxystrobin 0.123), folpet (0.510), kresoxim-methyl (0.0037), mancozeb (0.250), propineb (0.156) and trifloxystrobin (0.003). The results reported in part 4 showed that the strobilurin fungicides inhibited the mycelial growth and spore germination of P. viticola. However, further trials need to be conducted to verify these findings under field conditions. In the present study taxa 1, 3 and P. amygdali were infrequently isolated, suggesting that they played a less prominent role in the P. viticolacomplex. / AFRIKAANSE OPSOMMING: Streepvleksiekte van wingerd is 'n ekonomies belangrike siekte wat in die meeste wingerdproduserende gebiede van die wêreld voorkom. Vier Phomopsis spesies is in die verlede met dié siekte geassosieer. Hierdie studie ondersoek die taksonomiese belangrikheid van die verskillende taksa wat op wingerd in Suid Afrika gevind word, asook die endofietiese groei en fungisiedsensitiwiteit van die Phomopsis vitico/a isolate. Hierdie tesis bestaan uit verskeie dele met spesifieke, maar verwante onderwerpe wat tot onafwendbare duplisering lei. Dit is belangrik om die epidemiologie van 'n siekte te verstaan sodat korrekte en tydsberekende siektebeheer toegepas kan word. Die endofietiese groei van P. vitico/a is ondersoek deur simptoomlose lote by agt verskillende groei stadiums te versamel. Nodusse, internodusse, blaarstele, blare, rankies en trosstele is ondersoek. Twee Phomopsis spp., takson 1 en 2 is geïdentifiseer. Die Phomopsis vitico/a-kompleks het 3% van die isolasies uitgemaak en 'n relatiewe belangrikheid van 9% getoon. P. vitico/a (takson 2) is meestal uit die nodus en internodus geïsoleer. lnokulasies van gesonde, jong wingerdweefsel het bevestig dat takson 2 'n virulente patogeen is en dat die takson eerder 'n latente patogeen as 'n endofiet is. In teenstelling hiermee is takson 1 'n ware endofiet en 'n onbelangrike patogeen op wingerd. Die ware identiteit van die veroorsakende organisme van streepvlek is ondersoek deur plantmateriaal vanaf 58 verskillende wingerde in die wingerproduserende gebiede van die Wes-Kaap te versamel. P. vitico/a is in wingerdmateriaal vanaf Lutzville tot Swellendam aangetref, maar nie in die Oudtshoorn en Oranjerivier wingerd produserende gebiede nie. Diaporthe perjuncta (takson 1), P. vitico/a (takson 2), takson 3 en P. amygdali is in die Suid Afrikaanse wingerdisolate geïdentifiseer. P. amygdali word met lootverskroeiing van perske bome in die V.S.A. geassosieer. Die Australiese isolaat wat benoem is as takson 4, is met die huidige ondersoek gevind om 'n spesie van Libertella te wees. Takson 4 is daarvolgens uit die P. vitico/a-kompleks gelaat. 'n Italiaanse isolaat het 'n nuwe spesie van Phomopsis op wingerd verteenwoordig en is vervolgens as takson 5 beskryf. Spesie-onderskeiding is op morfologiese en kulturele eienskappe, staminokulasies en die vorming van die teleomorf in vitro gebaseer. Die identiteit vanelke morfologiese takson is met behulp van filogenetiese analises van die nukleêre ribosomale DNS intern transkriberende spasieerders (ITS 1 en ITS2) en die 5' punt gedeeltelike nukleotied volgorde van die mitochondriale klein subeenheid (mtSSU) bevestig. P. amygdali is slegs een keer geïsoleer en blyk van minder belang in die siektekompleks te wees. Takson 1 (Diaporthe perjuneta) en takson 3 het ook min voorgekom en is nie-patogenies, wat hul nie-funksionele rol in streepvleksiekte aandui. Takson 2 (P. viticola) is algemeen geïsoleer en kom wyd verspreid voor. Hierdie takson is geassosieer met die tipiese siektesimptome en is ook patogenies. Morfologies stem takson 2 met P. viiicola ooreen en is ook geneotipifiseer in hierdie studie. Takson 2 is meestal vanaf die ogies en nodusse geïsoleer, wat daarop dui dat hierdie belangrike setels is waar die swam tydens die winter oorleef. Die molekulêre data toon aan dat takson 3 en P. amygdali nie gasheerspesifiek tot wingerd is nie. Die swamdoders wat tans teen streepvlek gebruik word, is met die nuwe strobilurin swamdoders vergelyk. Die effek van nege swamdoders (azoksistrobin, flusilasool, folpet, fosetyl-Al + mancozeb, kresoxirn-metiel, mankozeb, penconasool, spiroksamien en trifloksistrobin) is in vitro op die inhibisie van miseliumgroei getoets. Die volgende EKso-waardes (g/ml) is verkry: azoxystrobin (0.350), flusilasool (0.007), folpet (4.489), fosetiel-Al + mankozeb (3.925), kresoxirn-metiel (l.665), mankozeb (2.891), penkonasool (0.023), spiroksamien (0.321) en trifloxystrobin (0.051). Azoxystrobin, folpet, kresoxim-rnetiel, mankozeb, propineb en trifloksistrobin is ook in vitro getoets vir hul inhibisie op spoorontkieming. Die volgende EKso-waardes is verkry: azoxystrobin (0.123), folpet (0.510), kresoxim-metiel (0.0037), mankozeb (0.250), propineb (0.156) en trifloxystrobin (0.003). Die resultate vervat in deel 4 toon dat die strobilurin swamdoders die miseliumgroei en spoorontkieming van P. viticola inhibeer. Toetsing in die veld word egter benodig om die effektiwiteit van die middels te bevestig. In hierdie studie is taksa I, 3 en P. amygdali selde geïsoleer, wat aangedui het dat hierdie taksa 'n minder belangrike rol in die P. viticola-kompleks speel.

Thesis (PhD(Agric))--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Despite adherence to fungicide spray schedules and label recommendations, table and wine grape producers invariably suffer crop losses when environmental conditions are conducive to fruit and foliar pathogens. Registered fungicides are effective and poor control is often attributed to: 1) improper spray timing, 2) reduced sensitivity to fungicides in the pathogen populations, and 3) poor spray deposition. Spray timing, management of fungicide resistance and the epidemiology of Botrytis cinerea have been thoroughly researched under South African conditions on grape crops. However, limited research regarding spray deposition exists in South Africa, probably due to a lack of proper spray deposition assessment protocols. To determine minimum spray deposition quantity and quality levels needed for effective B. cinerea control, bunches and leaves of table (Waltham Cross) and wine grapes (Chenin blanc) were sprayed at various stages using different volumes with a precision spray gun. A deposition assessment protocol using fluorometry, photomicrography and digital image analyses was improved. Deposition values correlated favourably with Botrytis infection. Increasing spray volume increased spray deposition; however, at a certain point, deposition quality remained constant and B. cinerea infections did not decrease significantly with increasing spray volume, indicating the importance of both spray deposition quantity and quality. Fluorescent pigment area that effected 75% control of B. cinerea infection (FPC75 values) was calculated for leaves, pedicels and receptacles at different growth stages. The FPC75 values obtained in this study can be used as benchmarks to evaluate future spray application. In order to study the optimisation of spray deposition with existing application technology (air blast and air shear sprayers) in commercial vineyards, spray deposition quantity and quality values were assessed from leaves and structural bunch parts of wine (Chenin blanc) and table grapes (Waltham Cross) and compared with FPC75 values. Spray trials were conducted at different growth stages at current best-practice recommendations, and with a range of spray volumes but with spray mixture concentration amended accordingly (i.e. fixed dosage per hectare). Spray trails indicated that deposition levels following current best-practice spray application were sub-optimal to control B. cinerea infections on bunches and leaves. Deposition values between air blast and air shear sprayers were generally similar. The air blast sprayer resulted in higher deposition levels with diluted spraying and increased spray volume; however, when dosage per hectare was kept constant, no significant differences were calculated between spray volumes (250-1000 L/ha), indicating that this sprayer can as effectively but more efficiently be used at lower spray volume. The air shear were not as efficient at higher spray volumes (>500 L/ha), but was superior at low volume concentrate application (≈250 L/ha at 4× concentration). This study clearly demonstrated the efficacy and cost-saving potential in optimising spray application with respect to application technology. / AFRIKAANSE OPSOMMING: Wingerdprodusente kan oesverliese ondervind indien omgewingstoestande bevorderlik is vir swampatogene. Siektes word onvoldoende beheer ten spyte van die nakoming van korrekte swamdoder aanbevelings. Geregistreerde swamdoders is effektief, mits die vatbare plantdele voldoende spuitbedekking ontvang. Onvoldoende siekte beheer kan gewoonlik toegeskryf word aan: 1) verkeerde spuit tydsberekening, 2) vermindere sensitiwiteit in patogeen-populasies teen swamdoders, en 3) swak spuitbedekking. Spuit tydsberekening, die bestuur van weerstand teen swamdoders en die epidemiologie van Botrytis cinerea is deeglik onder Suid-Afrikaanse toestande nagevors. Nietemin is daar beperkte navorsing oor spuitbedekking, waarskynlik weens 'n gebrek aan behoorlike spuitbedekking assesseringsprotokol. Om te bepaal hoeveel spuitbedekking (% area bedek deur fluoresserende pigment) nodig is om 75% van B. cinerea infeksies (FPC75 waardes) op vatbare wingerddele te beheer, is druiwetrosse en blare van tafel- en wyndruiwe (Waltham Cross en Chenin blanc, onderskeidelik) op verskillende groei stadiums en spuitvolumes in die laboratorium gespuit. ‘n Assesseringsprotokol van spuitbedekking op vatbare druifdele en blare is ontwikkel deur gebruik te maak van fluorometrie, fotomikrografie en digitale beeldanalise. Spuitbedekking het goed met Botrytis infeksies gekorreleer. Toenemende spuitvolume het bedekking laat toeneem, maar egter net tot 'n sekere punt, waar die kwantiteit van die bedekking nog toegeneem het, maar die kwaliteit van bedekking en B. cinerea infeksies nie beduidend toegeneem het nie. Dit is ‘n aanduiding van die belangrikheid van beide die kwantiteit en kwaliteit van spuitbedekking. Die FPC75 waardes wat in hierdie studie verkry is, kan as drempelwaardes om toekomstige spuittoediening te evalueer, gebruik word. Ten einde spuitbedekking met bestaande tegnologie (druk en waaierpomp spuitmasjiene) te optimiseer, is kommersiële wyn- en tafeldruiwe (Chenin blanc en Waltham Cross, onderskeidelik), volgens huidige spuit aanbevelings vir wingerde tydens verskillende groeistadiums en met ‘n reeks van verskillende spuitvolumes gespuit. Die konsentrasie van die spuitmengsel is dienooreenkomstig gewysig, i.t.v. ‘n vaste dosis per hektaar ongeag die spuitvolume. Bedekkingswaardes is met FPC75 waardes vergelyk en het aangedui dat kommersiële spuit aanbevelings aan produsente sal lei tot sub-optimale beheer van B. cinerea op beide blare en druiwetrosse. In die algemeen was bedekkingswaardes vir beide druk- en waaierpomp spuitmasjiene soortgelyk. Vir die waaierpomp teen verskillende spuitvolumes en aanbevole konsentrasie het ‘n toename in spuitvolumes tot hoër beddekingswaardes gelei, maar indien die dosis per hektaar van die spuitmengsel konstant behou is, is geen betekenisvolle verskille tussen spuitvolumes (250-1000 L/ha) voorspel nie. Hierdie dui aan dat die waaierpomp net so doeltreffend, maar meer effektief teen laer spuitvolumes gebruik kan word. Die drukpomp was nie so doeltreffend teen hoër spuitvolumes (> 500 L/ha) nie, maar was aansienlik beter by lae volume konsentraat toediening (≈ 250 L/ha op 4 × konsentrasie). Die studie toon duidelik die doeltreffendheid en moontlike kostebesparing moontlikhede deur bespuiting relatief tot bespuitingstegnologie te optimiseer. / Department of Plant Pathology, National Research Foundation, THRIP, Deciduous Fruit Producers’ Trust, Winetech, Bayer, BASF, Dow Agrosciences, DuPont, Syngenta, Nexus, Terason, UAP and Wenkem for financial assistance

Dissertation (PhD)--University of Stellenbosch, 2003. / ENGLISH ABSTRACT: A survey was conducted in the Western Cape Province during the 1999/2000 and 2000/2001 seasons on mealybugs occurring in vineyards. P/anococcus ficus (Signoret) was the dominant mealybug in vineyards during this time. During this study P. ficus was recorded for the first time on roots of grapevines, which has far reaching implications for the control of this important vine leafroll virus vector as control actions were focused on above ground control. Other mealybugs presently recorded in local vineyards included Pseudococcus /ongispinus (Targioni) and Ferrisia ma/vastra (McDaniel). Pseudococcus viburni (Maskell) and Ps. so/ani Ferris were found on weeds in vineyards. Natural enemies of P. ficus recorded most frequently were species of Nephus predatory beetles, and the parasitaids Coccidoxenoides peregrinus (Timberlake), Anagyrus sp. and Leptomastix dacty/opii (Howard). Developmental studies on P. ficus and C. peregrinus indicated that the intrinsic rate of increase (rm) was similar, peaking at 25°C (rm = 0.169 for P. ficus; rm = 0.149 for C. peregrinus). The net replacement rate (Ra) was higher for P. ficus than for C. peregrinus at all five temperatures tested. The Ra for P. ficus reached a maximum at 21°C (308.87) and C. peregrinus at 25°C for C. peregrinus (69.94). The lower and upper thresholds for development of P. ficus were estimated at 16.59 and 35.61°C respectively. The lower threshold for development of C. peregrinus was 8.85°C. These parameters indicated that both insects were well adapted to temperatures in the Western Cape Province. The lower minimum threshold temperature of C. peregrinus in relation to that of P. ficus suggests that C. peregrinus should be more active during winter and early spring than P. ficus. A central systematic presence-absence sampling system was developed for P. ficus. Monitoring three different plant parts on the vine indicated that new growth areas on vines adjacent to the main stem could serve as an early warning system for pending P. ficus bunch infestations. Intervention should be planned when 2 % of the stems are infested with P. ficus when using this system. Seasonal population studies of P. ficus and its natural enemies showed that stem infestation by P. ficus reached peak levels during January in Robertson and Stellenbosch and during February in the Hex River Valley. Vine mealybugs colonised new growth early in the season, followed by the leaves and eventually the bunches towards the end of the season. High stem infestations early in the season resulted in high bunch infestation levels at harvest. A density dependent relationship was evident between P. ficus populations and parasitoid populations, suggesting that the parasitoids played a mayor role in the biological control of P. ficus populations. Biological control was however only achieved towards the end of the season when damage to the crop had already occurred. Mass releases of C. peregrinus on P. ficus populations were done in order to augment biological control as an alternative to chemical control. Between five and six releases of 20 000 C. peregrinus per release were done at monthly intervals in three grapegrowing areas. Mass released C. peregrinus controlled P. ficus adequately in the Hex River Valley. Control of P. ficus using this approach was no worse than using chemical control in Robertson and Stellenbosch. C. peregrinus is commercially available and can therefore be used as an alternative to chemical control by producers. Degree day estimation was used to predict development of P. ficus populations. This information was used as an input in a P. ficus pest management model. Data acquired from P. ficus and ant monitoring were used as components to construct a decision chart. This chart can be used by producers to optimise the control of P. ficus populations using either chemical control or mass releases of C. peregrinus. / AFRIKAANSE OPSOMMING: "n Studie is gedurende die 1999/2000 en 2000/2001 seisoene gedoen met die doelom die witluisspesies wat in wingerde voorkom, te identifiseer. Planococcus ficus (Signoret) is tans die dominante witluisspesie in wingerde in die Wes Kaap Provinsie. P. ficus kolonies is op wingerdwortels gevind. Dié bevinding kan verreikende gevolge hê vir die beheer van dié plaag as "n belangrike rolbladvirus vektor aangesien beheer tot dusver gefokus het op bogrondse gedeeltes. Ander witluisspesies wat in wingerde gevind is, sluit in Pseudococcus /ongispinus (Targioni) en Ferrisia malvastra (McDaniel). Pseudococcus vibumi (Maskell) en Ps. so/ani Ferris is op onkruide in wingerde gevind. Dominante natuurlike vyande van P. ficus sluit predatoriese kewertjies van verskeie Nephus spp. en die parasitoïede Coccidoxenoides peregrinus (Timberlake), Anagyrus sp. en Leptomastix dacty/opii (Howard) in. Ontwikkelingstudies op P. ficus en C. peregrinus het aangetoon dat die inhirente voortplantingstempo (rm) soortgelyk was vir beide insekte met "n maksimum by 25°C (0.169 vir P. ficus, 0.149 vir C. peregrinus). Die netto vervangingstempo (Ra) was in vergelyking met C. peregrinus hoër vir P. ficus by al vyf temperature getoets. Die Ra van P. ficus het "n maksimum bereik teen 21°C (308.87) en die van e. peregrinus by 25°C (69.94). Die teoretiese hoër en laer drempels vir ontwikkeling van P. ficus was onderskeidelik 16.59 en 35.61 oe. Die teoretiese laer drempelwaarde van ontwikkeling vir e. peregrinus was 8.85°e. Hierdie parameters dui aan dat beide insekte goed aangepas is by temperature in die Wes Kaap Provinsie. Die laer minimum drempel vir ontwikkeling van C. peregrinus in verhouding tot P. ficus impliseer dat C. peregrinus in die winter en vroeë lente meer aktief sal wees as P. ficus. 'n Sentrale sistematiese aan-afwesig moniteringsisteem met bekende vlakke van steekproefnemingsfout is ontwikkel in kommersiële wingerde vir P. ficus. Monitering van drie verskillende dele op die wingerdstok het aangedui dat die nuwe groei areas kan dien as 'n vroeë waarskuwing vir latere P. ficus trosinfestasies. Dié sisteem sal produsente in staat stelom te bepaal wanneer optrede noodsaaklik is. Daar word voorgestel dat optrede noodsaaklik is by 'n P. ficus besmettingsvlak van 2 % op die nuwe groei areas op stokke. Stambesmetting deur P. ficus het in Januarie piekvlakke bereik in Stellenbosch en Robertson, en in Februarie in die Hex Rivier Vallei. P. ficus koloniseer nuwe groei vroeg in die seisoen waarna blare en trosse aan die einde van die seisoen gekoloniseer word. Dié data dui aan dat P. ficus besmetting op nuwe groei vroeg in die seisoen 'n aanduiding kan gee van hoë trosbesmetting aan die einde van die seisoen. 'n Digtheidsafhanklike verwantskap was waarneembaar tussen P. ficus plaagpopulasies en parasitoïed populasies. Dié verwantskap dui aan dat parasitoïede die belangrikste rol speel in biologiese beheer van P. ficus populasies. Biologiese beheer van witluis is egter eers aan die einde van die seisoen bereik toe die oes reeds beskadig was. Massavrylatings van C. peregrinus is in P. ficus besmette blokke gedoen om biologiese beheer aan te help en sodoende as alternatief tot chemiese beheer te dien. Tussen vyf en ses vrylatings met 20 000 C. peregrinus is een keer per maand gedurende die seisoen gedoen. Die vrygelate C. peregrinus het P. ficus populasies voldoende beheer in die Hex Rivier Vallei. Beheer van P. ficus deur massavrylatings van C. peregrinus was soortgelyk as chemiese beheer in Robertson en Stellenbosch. C. peregrinus is kommersieel beskikbaar en kan om hierdie rede as alternatief tot chemiese beheer gebruik word. Graaddag bepaling is gebruik om die ontwikkeling van P. ficus populasies te voorspel. Hierdie inligting is gebruik as 'n verdere hulpmiddel in die P. ficus plaagbeheermodel. Inligting verkry vanuit P. ficus en mier monitering is gebruik as komponente in die opstel van 'n besluitnemingstabel. Hierdie tabel kan gebruik word deur produsente om beheer van P. ficus plaagpopulasies te optimaliseer deur chemiese beheer of massavrylatings van C. peregrinus.

Thesis (MSc (Genetics))--Stellenbosch University, 2008. / The vine mealybug, Planococcus ficus (Signoret), is a severe pest of grapevine in many grape and wine producing countries around the world. It is renowned not only for the considerable damage it infers to grapevine of its own accord, but in particular for its role in transmitting deleterious viral diseases such as grapevine leafroll disease, Kober stem grooving, Shiraz disease and corky bark. Incidentally, it is an exceptionally tenacious antagonist of grapevine, being resistant to both chemical and biological control mechanisms. As a result, finding an effective strategy for P. ficus control has become a main priority of viticultural industries worldwide. Possible implementation of biotechnological approaches to pest management has resulted in a need for P. ficus genetic data - of which there are currently very little available. The transcribed genes of an organism can be captured in a cDNA library, and the sequences of the various transcripts can then be characterized. In this study altogether five cDNA libraries were constructed from the transcribed sequences of Planococcus ficus (Signoret). Instrumental to their construction was the identification of an RNA extraction protocol that provided large quantities of high quality RNA from mealybugs. The five cDNA libraries were the result of a set of modifications to the Creator™ SMART™ cDNA Library Construction Kit (used for Primary Library construction), and differed mainly with regards to range of insert sizes they contain. Whereas an abundance of short fragments were found in the Primary Library (42% of screened inserts 60.5 kb, and 20% >1 kb), the Fractionated Libraries contained inserts of specific size ranges that were more-or-less equally represented. The broadest size range was found in Fractionated Library 4, for which a uniform distribution over the range 0.25 kb - 4 kb was observed. Average insert sizes of Fractionated Libraries 1 to 4 were estimated at 0.25 kb, 0.5 kb, 1 kb and 2 kb respectively. These results demonstrated the importance of using a protocol designed to circumvent the bias towards incorporation of shorter transcripts in cDNA libraries. Although the libraries were not exhaustively analyzed, the outcome of a pilot investigation indicated that 41% of the submitted sequences had matches in the non-redundant database of the National Center for Biotechnology Information (NCBI, E-value 6 10-5), and that approximately 82% of these were of insect origin. Moreover, two potential targets for an RNAi-mediated approach to P. ficus pest control were identified. With one exception, these sequences seemed to be unique to arthropods. Future research needs to investigate the efficiency by which these sequences are able to constrain P. ficus proliferation, and their suitability for grapevine transformation.

Thesis (PhD (Agric) (Conservation Ecology and Entomology))--University of Stellenbosch, 2006. / A study was performed to develop a generic pest monitoring system for sampling the main table grape pests in vineyards in the Hex River Valley, Western Cape Province of South Africa. The presence of phytophagous and predatory mites on cover crop plants was also investigated as this may contribute to biological control of the phytophagous mites in vines. Life table studies for Epichoristodes acerbella (Walker), an important phytosanitary pest, were conducted to determine whether or not this pest was sensitive to high temperatures. Information gained from the latter can also be used for breeding purposes in the possible future development of a sterile insect technique (SIT) programme to control this pest. The sampling system consisted of inspecting 20 plots of five vines per plot per one to two hectares. The top fork of each of the five vines per plot was examined for Planococcus ficus (Signoret) to a distance of within 30 cm of the stem, as well as the distal 15 cm of one cane per vine for the presence of P. ficus and damage caused by Phlyctinus callosus Boh. One bunch per vine was examined for insect damage or presence, and one leaf per vine for the presence of leaf infesting arthropods, such as Tetranychus urticae Koch, P. ficus and Frankliniella occidentalis (Pergande). Corrugated cardboard bands, tied around the stem of one vine per plot, were used to monitor activity of P. callosus. Blue sticky traps, at a density of four to five traps per one to two hectares, were used to monitor activity of F. occidentalis. Pheromone traps, at a density of one trap per one to two hectares, were used to monitor activity of P. ficus, E. acerbella and Helicoverpa armigera (Hübner). All the above-mentioned inspections were done at two-weekly intervals, except traps for E. acerbella and H. armigera, which were inspected weekly. In each of the rows in which the sample plots were situated, one leaf of each of the cover crop plant species was examined for the presence of phytophagous mites and their predators. The abundance and distribution of cover crop plants were determined using a co-ordinate sampling system. Cover crop sampling was done at monthly intervals. The current threshold for P. ficus is 2% stem infestation, which is reached when more than 65 males per pheromone trap are recorded. Counting mealybugs on the sticky pads in the pheromone traps is time consuming. However, the number of grid blocks on the sticky pad with males present can be counted. When P. ficus males are found in 27 blocks on the sticky pad, stem inspections should commence. Due to the spatial association between P. ficus bunch and stem infestation, stem infestation could give an indication of where bunch infestation could be expected. The use of blue sticky traps for predicting halo spot damage, caused by F. occidentalis, is not recommended. The presence of thrips on the vine leaves could not give an indication of where to expect bunch damage, since thrips on the leaves and halo spot damage were not spatially associated. A suitable sampling method for F. occidentalis still needs to be developed. The monitoring system described here can only provide information on the infestation status of the vineyard. For E. acerbella, H. armigera and P. callosus, the traps and cardboard bands could be used to identify vineyards where these pests are present and therefore, where phytosanitary problems may arise. The presence of P. callosus under the bands was spatially associated with P. callosus damage and could be used as an indicator of the latter. The presence of drosophilid flies in the bunches could not be used as an indicator of the presence of E. acerbella in the bunches. If 5% bunch damage is used as an economic threshold for E. acerbella and P. callosus, there will be a good chance of not under spraying if control measures are applied at 1% bunch damage. Epichoristodes acerbella favoured more moderate constant temperatures, with constant temperatures of 28°C and above being unfavourable for development. The economic threshold for Tetranychus urticae Koch is six mites per leaf, or if presence-absence sampling is used, 11 to 29% leaf infestation. Three important predatory mites, that kept T. urticae under control, were found in the Hex River Valley, namely Euseius addoensis (Van der Merwe & Ryke), Neoseiulus californicus (McGregor) and an undescribed phytoseiid in the genus Typhlodromus. Various cover crop plants served as hosts for T. urticae and predatory mites. The presence of these plants created suitable conditions for the survival of these mites and may have influenced their presence on the vine leaves. In the case of phytosanitary pests, both field and pack shed inspections can be used to conclude with a 99% degree of certainty that infestation levels in the pack shed will be 10% or less, since similar results for both methods were obtained. However, more than 20 plots will have to be inspected.

Thesis (MScAgric (Conservation Ecology and Entomology)--University of Stellenbosch, 2005. / The South African table grape industry exports approximately 60% of the table grapes produced. A major threat to the export of these grapes is the phytosanitary risk that insect pests pose. This study was conducted in the Hex River Valley, South Africa’s main table grape producing area. The aim of this study was to reduce the number of phytosanitary rejections from insects on table grapes from the Hex River Valley. Thus the main objectives of the study were to identify the most important phytosanitary pests in the Hex River Valley; the determination of their presence in the vineyards with possible means to control them; and to assess the possibility of using postharvest quarantine treatments in the Western Cape. Further aims were to determine the effect of different colour harvesting crates on the phytosanitary pests and whether the phytosanitary pests infested the grapes via packhouses. The most important phytosanitary pests of table grapes of the Hex River Valley are in order of importance: Phlyctinus callosus (Schonherr) (Coleoptera: Curculionidae), Epichoristodes acerbella Walker (Lepidoptera: Tortricidae), Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae), Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), Gonocephalum simplex Fabricius (Coleoptera: Tenebrionidae) and Dysdercus fasciatus Signoret (Hemiptera: Pyrrhocoridae). 12.71% of rejections were from species that were not identified, while a further 33% of the rejections were possibly identified incorrectly. Phytosanitary control of P. callosus appeared to be far more effective using Plantex® than pesticides. Weather conditions appeared to affect the abundance of P. callosus, especially warm weather, while bunches harboured less P. callosus later in the day. Control of E. acerbella with DiPel® (Bacillus thuringiensis var. kurstaki) appeared to at least reduce the population within the vineyards, and so its use is recommended. P. ficus is a non-actionable species for the USA market and is not listed as a phytosanitary pest for the Israeli market and so should not be causing any phytosanitary rejections. C. capitata appeared to be successfully controlled by the fruit fly sterile release program and the cold sterilisation it currently undergoes. G. simplex caused few rejections. It is still unclear where this pest infests the grapes, as it was found in both the field and in the packhouses. D. fasciatus occurrence on grapes was probably accidental. It was shown that picking during the early and late parts of the day, when this species was less active, reduced its occurrence in bunches. Gryllus bimaculatus (De Geer) (Orthoptera: Gryllidae), although not reported as a reason for rejections in table grapes for the past two years, was an actionable species that was present in large numbers in the Hex River Valley. There was a strong correlation between increasing quantities of pesticides and higher abundances of G. bimaculatus. It appeared to be an indicator of the overuse of pesticides. Results of this study showed that infestation by the phytosanitary pests came from neighbouring vineyards. The creation of barriers to prevent the movement of these pests between vineyards is suggested. Methyl bromide is the most commonly used postharvest quarantine treatment. Owing to the ozone-depleting properties of methyl bromide, it is scheduled to be outlawed in many countries from 2005. Alternative postharvest treatments are irradiation, extreme temperatures, forced air, vapour-heat treatments and the use of controlled atmospheres. Irradiation treatments appeared to control the pests at doses that do not damage the grapes. Controlled atmosphere treatments also have a high probability of success, although more research is required on this treatment. Low temperature treatments are relatively cheap as most exported fruit already undergoes cold storage, and appears to control species in the families Pseudococcidae and Tephritidae, although further research is required for the other pest. Colour or location of the harvesting crates in the vineyards appeared not to influence the number of phytosanitary pests collected, as they were not attracted to these crates.