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IOBC-WPRS Bulletin Vol. 128, 2017

 

IOBC-WPRS Bulletin Vol. 128, 2017

Working Group "Integrated Protection and Production in Viticulture"
Proceedings of the meeting at Vienna (Austria), 20th - 23rd October, 2015
Edited by Agnès Calonnec, Mauro Jermini, Carlo Duso & Andrea Lucchi
ISBN 978-92-9067-313-2 [X + 147 pp]

 

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Effect of covering vine rows on pest and disease incidence, pesticide residue and fresh grape quality
F. Özlem Altındişli, N. Mukerrem Celiker, Fatma Özsemerci, Ahmet Altındişli, Oguz Asciogul, Ahmet U. Duru

Abstract: Vine rows of table grapes vineyards in Turkey are covered with polypropylene sheets after veraison. This practice allows growers to postpone maturation and harvest period, and to prevent berry cracking due to rainfall as happened in recent years. The effect of covering on population density of insect and mites, incidence of diseases, degradation period of pesticides sprayed and fresh grape quality parameters were investigated in the study. The experiment was conducted in a 2 ha-Sultana Seedless vineyard in Sarıgöl District of Manisa Province in 2012 and 2013. In early August after veraison, rows were covered individually by UV added white colour polypropylene canvas sheets at 2-m-width and 75 cm above the trellising poles. Three rows were left uncovered in the vineyard for comparison. Diseases, insects and mites were checked on 100 bunches visually and 30 leaves under stereo-microscope from early July until harvest weekly. Fresh grapes were sampled from covered and uncovered vines at harvest for quality and residue analysis. The experiment has ended on 1st October 2012 and 23rd October 2013 at harvest. Higher values of relative humidity were recorded in the canopy of covered vines in both years. Most of the pesticide residues were lower than EU and national maximum residue levels in covered and uncovered plots in 2012 and 2013. Covering had no important or statistically significant effect on quality parameters of fresh grape except firmness in berry flesh. Generally, quality parameters were better in uncovered grapes than covered ones. It was proved that covering did not affect the population density of insects and mites and incidence of diseases, and did not cause residue problem by prolonging degradation period of pesticides.

1-8

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Reducing primary inoculum sources of grapevine powdery mildew by the hyperparasite Ampelomyces quisqualis
Dario Angeli, Franca Valentini, Chiara Masiero, Oscar Giovannini, and Ilaria Pertot

Abstract: The present study addresses the occurrence of artificial parasitism of grapevine powdery mildew chasmothecia by Ampelomyces quisqualis and aims to explore new methods for managing powdery mildew infections under field conditions. Conidia of the hyperparasite were rarely detected in mature chasmothecia with fully developed appendages. In contrast, the large number of fully developed chasmothecia without asci and ascopores were considered to be parasitized by the mycoparasite. Infested chasmothecia do not reach the stage of maturity, do not form appendages nor ascospores, which is linked with the reduction of the source of primary infections. To conclude this study underlines a good effectiveness of this hyperparasite in terms of reduction of overwintering chasmothecia in its natural environment.

9-12

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Repellency of aromatic plant essential oils against Drosophila suzukii
S. Bedini, G. Flamini, F. Cosci, R. Ascrizzi, P. L. Cioni, C. Ioriatti, B. Conti, and A. Lucchi

Abstract: The Spotted Wing Drosophila (SWD), Drosophila suzukii Matsumura (Diptera: Drosophilidae), is causing severe economic losses to various fruit crops, grapes included. Due to its relatively short life cycle, D. suzukii is able to complete several generations per year, so that frequent applications of insecticides are needed for its control and more eco-friendly control methods against this pest are expected. Essential oils (EOs) represent a very promising alternative to conventional insecticides because of their low environmental and mammalian toxicity. Here we evaluated the repellency of mandarin Citrus reticolata Blanco, and tea tree Melaleuca alternifolia (Maiden & Betche) Cheel EOs against adults of SWD. The chemical composition of the two EOs was assessed by GC-MS analysis. EOs were tested by two-choice still-air arena bioassays. Results showed a negative chemotaxis of SWD adults to both the essential oils at 1 and 10%. Tea tree EO exerted a stronger repellent activity in comparison with the mandarin EO.

13-17

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Epidemiology of Botrytis bunch rot in Bordeaux vineyards and alternative control strategies
C. Calvo-Garrido, C. Pañitrur-De la Fuente, L. Davidou, N. Aveline, S. Cestaret, J. Roudet, H. Valdés-Gómez & M. Fermaud

Abstract: Botrytis bunch rot (BBR) is a major fungal disease of grapevine worldwide caused by Botrytis cinerea. The pathogen presents a complex life cycle in the vineyard with a great genetic variability, multiple biological forms and various infection pathways highly dependent on meteorological conditions. Losses at harvest can be very important quantitatively as well as qualitatively by modifying wine quality from 5% of rotted berries upwards.
Extensive research on BBR epidemiology has been carried out at INRA Bordeaux-Aquitaine evaluating and developing disease risk indicators. An interesting case of study is the B. cinerea floral calyptras infection rate as a potential early indicator of disease development and losses at harvest. From 2011 to 2015, B. cinerea infection of calyptras from an experimental Bordeaux vineyard (cv. Merlot) was evaluated at the end of flowering. The potential relationships between the infection on calyptras and the climatic conditions are analysed and discussed. However, no significant correlation was observed between the indicator and BBR disease incidence or severity.
Additionally, alternative strategies to chemical fungicides have been evaluated in different Bordeaux organic vineyards in 2015. Natural products, already commercialized for their use in organic viticulture, were applied at key phenological stages or following a disease risk index. Results indicated the reduced interest of a wicker tea product, whereas potassium bicarbonate, kaolin and a fatty acid products showed BBR reduction and may be good candidates as alternative strategies for BBR control.

18-27

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Geographical area extension of Drosophila suzukii (Diptera: Drosophilidae) in Bordeaux vineyards
Lionel Delbac, Raphaël Rouzes, Adrien Rusch, Denis Thiéry

Abstract: The invasive fruit fly Drosophila suzukii (Diptera: Drosophilidae) was recorded for the first time in 2011 in the Bordeaux vineyard through a trap network located in the Sauternes subregion (south of Bordeaux). This species is now regularly present in our food traps surveys. In 2013, we observed complete reproductive cycles of this species on grapes in vineyards located on the left bank of the Garonne river both in the Sauternes (South) and the Médoc (North) subregions (ca. 70 km from the 2011 first observation). In 2014, almost all the Bordeaux vineyard was affected by D. suzukii and this was concomitant with unusual widespread development of sour rot. This was particularly the case for black cultivars (Merlot and Cabernet-Sauvignon). This invasive drosophila is now considered as part of the regular drosophila community on grapes. Ongoing studies examine the variability of behavioral traits of D. suzukii on different cultivars, the damages induced by this species, and the evolution in space and time of fruit flies communities on grapes.

28-36

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Lobesia botrana (Lepidoptera: Tortricidae) larval population assessment by damage to grape flowers: could empty larval nests monitoring be useful?
Lionel Delbac, Denis Thiéry

Abstract: A correct accurate determination of the population size is the basis of successful pest management procedures and is of primary importance in the protection against the European grapevine moth (EGVM, Lobesia botrana). During three consecutive years, we quantified the time course of larval damage to grape flower buds and the presence of the different larval instars of EGVM in an experimental vineyard (INRA Bordeaux Aquitaine research center). From a total of 1003 so called larval damage (glomerula), 704 living larvae were obtained. We determined the larval instars of all samples. There was a significant correlation between damage per larva and larval population densities. Intra-specific competition between larvae and avoidance of larval parasitism are the most probable causes of empty glomerulae, and of the relation we observed. We assume that grape damage could efficiently be quantified also by estimating the number of empty glomerulae as a good indicator of larval density.

37-44

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PHYLLI – an international database for grape phylloxera (Daktulosphaira vitifoliae Fitch)
A. Forneck, V. Dockner, R. Mammerler, K. S. Powell, L. Kocsis, D. Papura, J. Fahrentrapp, S. Riaz, M. A. Walker

Abstract: PHYLLI is a database of standardized microsatellite reference alleles to manage phylloxera genotypes. Protocols for the aspects of analysis (DNA extraction, PCR methods, visualization and allele description) are presented with appropriate flexibility. The open database is a major step towards developing strategies and devising measures to control aggressive phylloxera strains. This is the first report to introduce the PHYLLI database and discuss its advantages for both vineyard management and academic research.

45-51

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Dreams versus accomplished facts in pheromone technologies as exemplified in recent viticultural applications towards sustainable Lobesia management
Hans E. Hummel, Simone S. Langner, Michael Breuer, Detlef F. Hein, Andreas Greiner, Christoph Hellmann, Günter Leithold

Abstract: Developing Lobesia IPM from humble beginnings to todays' state of the art was a laborious process extending over a period of 75 years. Eight identifiable technological steps along this arduous path to success can be distinguished: (1) first observations by Götz (1939) in vineyards established a method for quantitative measurement of Lobesia presence in vineyards by luring male Lobesia to crude extracts of virgin female Lobesia moths. (2) Butenandt (1939) envisioned a theoretical future of insect management by applying the principles of vertebrate hormone physiology to invertebrates. (3) Butenandt et al. (1959 and 1961) identified and then synthesized volatile exogenic emanations of "pheromones" in the silk moth Bombyx mori and first demonstrated the lipid nature of such pheromones as by-products of cell metabolism. This major discovery spawned explosive developments of pheromone physiology and application in IPM for dozens of problematic pest insect species all over the world, including the identification of the Lobesia sex pheromone by Roelofs et al. (1973) and Buser et al. (1974) as (E,Z)-7,9-dodecadienyl acetate. (4) Suitable polymeric dispenser materials for extended volatilization of pheromones were developed in the US by Leonhardt and Beroza (1982), in Europe (Neumann, 1990), and in Japan (Shin-Etsu Company). (5) Greiner and Wendorff (2007) developed electrospun organic biodegradable nanofibers/mesofibers and showed their ability for use in various technical applications. Seven patents by U.S., EU, and German patent offices were granted between 2011 and 2013. (6) Hummel et al. (2010-2012; 2014 a, b) and Hummel and Langner (2013) provided proof for pheromone inclusion into such fibers dispensers and their ability to serve as disruptants under field conditions. (7) Hummel et al. (2010 a, b), Hellmann et al. (2011) and Breuer et al. (2012; 2013) compared mesofiber dispensers with non-biodegradable commercial dispensers and found them to be competitive. (8) Lastly, Hummel et al. (2013; 2014 a, b) showed that these mesofiber dispensers could be mechanically deployed by existing vineyard machinery, thus saving time, application costs and resources.
In conclusion, 75 years of basic and technical achievements in various fields of entomology, microanalytical and polymer chemistry, and technical engineering finally are merging into a mature and coherent IPM procedure satisfying most needs for viticultural (but also horticultural) requirement for insect IPM in row crops. The scope of applicabilities is by no means exhausted.

52-65

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Modeling spatial and temporal spread of Flavescence dorée in two Austrian vine growing areas
Ian Kopacka, Robert Steffek, Gudrun Strauß, Helga Reisenzein

Abstract: A Monte Carlo model to simulate the natural spread of Flavescence dorée [FD] and of its vector Scaphoideus titanus was developed using the statistical software R. Simulations were run for two model domains with demarcated areas for FD, which differ in the average acreage of vineyards and the abundance of amenity grapevines in arbours and hedges that act as vector and disease reservoir. The model incorporates biological characteristics, the topography and different scenarios regarding the initial disease and vector infestation and can hence be used as a decision support tool for risk reduction options in specific outbreaks. The results confirm the vital importance of surveillance to detect outbreaks at an early stage and show that the main factors affecting the spread of FD are the initial disease and vector infestation, the abundance of untreated grapevines and the applied pest control measures: in locations with a high density of untreated amenity grapevines and severe initial outbreaks, the spread of FD within the region is only contained using strict phytosanitary measures that include vector treatments of larvae and adults in vineyards and amenity grapevines. In cases where outbreaks are limited to single plants the spread of FD can be contained using application against larval stages only, particularly in areas where amenity grapevines are rare.

66-74

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Vineyards and natural habitats: a useful combination for biocontrol agents
Augusto Loni, Gianluca Vannini, Giovanni Burgio, Daniele Sommaggio, Andrea Lucchi

Abstract: The quantification of spatial scale interaction is crucial in understanding the relationship between the structure of the environment and the responses of insect communities. In this study we investigated the occurrence of Hymenoptera: Braconidae and Diptera: Syrphidae in a wine-growing area, in relation to various environmental indices measured at different spatial scales. Positive correlations emerged between the biodiversity of Braconid subfamilies and the environmental sub-class “wild-herbaceous” at a spatial scale of 100 meters. Syrphid biodiversity was correlated with the class “wild” and sub-class “wild herbaceous” at a spatial scale of 100 meters, and with the class "wild” at a spatial scale of 250 meters.

75-78

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Area-wide Cariñena DO mating disruption for controlling the European grapevine moth
A. Lucchi, P. Sambado, A. B. Juan Royo, A. Narvaiza Martínez, B. Bagnoli

Abstract: Mating disruption is known to be a reliable and effective tool for the control of Lobesia botrana when applied as part of an area-wide pest management strategy (AWPM). The Cariñena project has involved more than 500 farmers and 92% of the DO Cariñena vine surface (13,200 hectares) in just four years. This was possible thanks to the efforts of the main wineries and farmers, under the coordination of a technical working group. The results achieved are encouraging in terms of the satisfactory pest control obtained and the important reduction in the use of insecticides.

79-83

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Pests in the wild: life history and behaviour of Lobesia botrana on Daphne gnidium in a natural environment
A. Lucchi, A. Loni, L. Gandini, P. L. Scaramozzino

Abstract: We studied the phenology of the European grapevine moth, Lobesia botrana (Den. & Schiff.), on Daphne gnidium L. in the Natural Reserve of San Rossore-Migliarino-Massaciuccoli (Pisa – Tuscany). D. gnidium is regarded by many as the original host plant of EGVM and the aim was to understand the real trophic relationships of EGVM with D. gnidium in a natural ecosystem where the grapevine is not present.

84-88

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New formulations for the control of Lobesia botrana (Lepidoptera Tortricidae) by mating disruption
Andrea Lucchi, Edith Ladurner, Francesco Savino, Luca Gandini, Stefano Di Blasi, Andrea Iodice

Abstract: Two new mating disruption (MD) products for the control of Lobesia botrana in vineyards were developed by Shin-Etsu Chemical Co. and CBC (Europe) S.r.l. Both products consist of two parallel capillary tubes (twin tubes) filled with L. botrana synthetic pheromone, and joined and sealed at the ends. Thanks to the gap in the middle, twin tube dispensers are applied easier and faster than conventional single tube dispensers, such as the reference product Isonet® L. The trials carried out in Tuscany (Italy) in 2014 and 2015 on two different grapevine varieties evidenced that both new products are valuable tools for L. botrana control. In fact, efficacy values were always comparable to those of the reference product Isonet® L.

89-93

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Influence of cover crop management systems on the development of the vine mealybug, Planococcus ficus, in a Mediterranean vineyard
Enrico Muscas, Arturo Cocco, Alessandra Mura, Andrea Lentini, Luca Mercenaro, Giovanni Nieddu

Abstract: The vine mealybug, Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae), has become a serious pest in grape-growing areas in southern Europe and its development is affected by nitrogen fertilization. Cover crops are common cultural techniques in vineyards to manage soil fertility and plant vigour. The influence of different total ground cover crops on selected life-history parameters of the vine mealybugs (survival, development time, fecundity and fertility) was investigated in a multi-year interdisciplinary project. The soil management systems tested were: natural covering, grass and legume cover crops and soil tillage. To evaluate the vine response to ground management, crop yield and total soluble solids (sugar content) were recorded. The nitrogen content on grape leaves was indirectly assessed using a SPAD meter.
Ground covers affected development time, fecundity and fertility of P. ficus in both years of observations. Enhanced reproductive and development parameters (i.e. lower development time and higher fecundity and fertility) were observed in tillage and legume covering plots. With regard to the grapevine response to soil management systems, in both years soil management significantly affected nitrogen concentration on plants, as SPAD values were higher in plants managed with tillage and legume covering. Cover crops modified the physiology of grapevines thereby affecting the development of the vine mealybug. The investigated ground covers also affected crop yield and quality of must. In particular, grass cover crops reduced the quantitative production and increased the concentration of sugar in the must. In conclusion, ground covers play an important role in vineyards and should also be considered when planning pest management programs.

94-101

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Control of vine mealybug, Planococcus ficus, in wine grapes using new reduced-risk insecticides in a pest management program
Ruth A. Poliakon, Robert A. Van Steenwyk, Alyssa M. Hernandez, Benjamin J. Wong and Paul S. Verdegaal

Abstract: Vine mealybug, Planococcus ficus (Signoret), is a significant pest of grapes in many major grape-growing regions and is the most damaging of all the mealybug pests of grape in California, USA. Control of vine mealybug has relied on repeated applications of a number of insecticides including spirotetramat, imidacloprid, acetamiprid, thiamethoxam, clothianidin, dinotefuran, buprofezin and chlorpyrifos. Two new reduced-risk insecticides (sulfoxaflor and flupyradifurone) were integrated into pest management programs for vine mealybug and reported here. Three test plots were established in two vineyards with moderate to high vine mealybug populations in San Joaquin County in northern California. Each plot tested various pest management programs consisting of combinations of spirotetramat, imidacloprid, acetamiprid, buprofezin, chlorpyrifos, sulfoxaflor and/or flupyradifurone. The efficacy of the pest management programs that integrate these two new reduced-risk insecticides will be reported.

102-109

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Study of the variability of a vineyard sensitivity to the main fungus diseases: a priori zoning of Physiological Behavior Units (PBU)
Marc Raynal, Benoit Delfour, Christian Debord, Marc Vergnes, Amine Bennnabi, Michael Georges, Remy Fulchic, Jonathan Servant

Abstract: The systemic analysis of the performance of a vineyard at the scale of a wine-making exploitation is made possible by the use of sensors stemming from so called precision techniques, which allow precise and exhaustive geo-located measures.
The aim of our study is to exploit this kind of data and evaluate their information using geographical information systems (GIS) and crossing different layers representing characteristic and independent variables of the production system. The goal is then to elaborate an à priori zoning, likely to explain variations of the physiological development of vines and possible differences of the plants susceptibility to fungus diseases. The study is based on the combination of two maps established on the property of Chateau Léoville Las Cases in the Medoc area of the Bordeaux vineyard (France). These maps represent the behavior of the two compartments, soil and plant, respectively determined by means of electric resistivity (R) and biomass index (B) measures. Three levels – low, medium, high – are defined for each type of data. The combination of these indicators allows the elaboration of 9 classes of islets, named Physiological Behavior Units (PBU), whose distribution is bounded by the GIS on the whole vineyard.
Six of these nine PBU were selected by exclusion of the medium class of the biomass index. Each PBU is replicated twice, thus establishing an observation device of 12 PBU likely to identify differences in terms of physiological development and disease susceptibility. For this purpose, treated and non-treated zones were delimited for each PBU, and a weekly monitoring of these areas has been performed during the 2014 and 2015 crop years. The first years’ results of the study show that the PBU concept proposed seem to correlate with some of the significant variations observed for physiological and sanitary criterions.

110-125

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Ricania speculum (Walker) (Homoptera Ricaniidae): the next destructive planthopper of grapevine in Europe?
Elisabetta Rossi, Andrea Lucchi

Abstract: Ricania speculum is a new polyphagous planthopper to Europe, detected for the first time in 2014, near Genoa (Liguria, Italy). One year later it was found near La Spezia, where it was observed on many cultivated and wild plants. The eggs are inserted by the female inside the leaf midribs or in the young twigs, frequently leading to the death of the tissues in which they are released. The juveniles produce abundant wax secretions. The adults have large anterior brown wings, with five characteristic transparent spots. Eggs, juveniles and adults were observed on American and European grapevines. The eggs were laid in alternate rows, in several plant tissues. As yet, the species does not represent a real problem but it is spreading and the size of its populations is also increasing. Its possible role as a pathogen vector in grapevine should be investigated.

126-129

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Who's who in the nests molded by Lobesia botrana on Daphne gnidium?
P. L. Scaramozzino, A. Loni, L. Gandini, A. Lucchi

Abstract: In 2014 and 2015 we studied the ecology and behavior of Lobesia botrana (EGVM) on its wild host plant Daphne gnidium (DG), in the Natural Reserve of Migliarino-San Rossore-Massaciuccoli (Pisa, Italy). EGVM larvae build nests, which they live in, by rolling together the top leaves of the DG sprouts. In or around these nests we found about fifty species of herbivorous and carnivorous arthropods. EGVM is the most common among Lepidoptera, followed by Cryptoblabes gnidiella, Cacoecimorpha pronubana, Gymnoscelis rufifasciata and Phyllobrostis fregenella. The juvenile stages of these moths were parasitized by two species of Diptera and 17 species of Hymenoptera. In 2014 the total percentage of parasitization was 14.7%. EGVM and Campoplex capitator, the main larval parasitoid, accounted for 86.5% of the individuals obtained in our rearing programme. The rate of parasitization of C. capitator on L. botrana was about 12.2%. Moreover, Ancistrocerus auctus (Vespidae: Eumeninae) was repeatedly observed inspecting nests and trying to catch larvae inhabiting them.

130-134

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Effect of insecticides on generalist predatory mites released in vineyards
P. Tirello, A. Stedile, A. Pozzebon, N. Mori, C. Duso

Abstract: Generalist predatory mites belonging to the Phytoseiidae family are considered key biocontrol agents of phytophagous mites in European vineyards. In IPM strategies, inoculative releases of predatory mites are effective tools against phytophagous mites. However, the activity of predatory mites can be limited by the use of non-selective pesticides. Here, in three field experiments we evaluated the effect of insecticides applied in vineyards on the releases of Kampimodromus aberrans. The effects of insecticides and K. aberrans releases on naturally occurring predatory mites and phytophagous mites were also considered. In the first experiment the insecticides thiamethoxam, buprofezin, etofenprox and indoxacarb were applied to control grape leafhoppers. In the second experiment the insecticides Bacillus thuringiensis, emamectin benzoate, methoxyfenozide and chlorantraniliprole were applied against grape berry moths. In the third experiment releases were performed on two grapevine varieties characterized by different levels of leaf hairiness. Two insecticides were tested, i.e. B. thuringiensis and chlorantraniliprole, targeted at grape berry moths’ control. In all release treatments K. aberrans was the predominant predatory mite species. K. aberrans abundance was reduced by etofenprox and buprofezin in the first experiment while none of insecticides used in the second were associated to a detrimental effect on predatory mite. In the third experiment K. aberrans abundance differed between grapevine varieties and no effect of insecticides was observed. The implications on interspecific interactions among predatory mites and biological control of phytophagous mites in vineyards are discussed.

135-138

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Update on the Lobesia botrana Program in California
Lucia G. Varela, Monica L. Cooper, Andrea Lucchi

Abstract: Lobesia botrana (Denis & Schiffermüller), European grapevine moth, was discovered for the first time in North America towards the end of the 2009 growing season in Napa County, California. Upon confirmation of the first detection, the United States Department of Agriculture Animal and Plant Health Inspection Service established a regulatory program. To delimit the area of the infestation, the program deployed pheromone-baited traps at densities of 3 to 10 traps per km2 in vineyards and high-risk urban areas throughout California. When 2 or more moths within 4.8 km of each other or any other life stage were detected, an 8-kilometer-radius quarantine area surrounding the find was established; the radius was decreased to 5-kilometers in 2012. Moths were detected in 11 California counties, 10 of which were regulated. The largest population was in Napa County where 100,831 moths were trapped in 2010, compared to 128 total moths in the remaining counties. The treatment programs targeted all vineyard acreage within 200 m (Napa) or 1000 m (all other counties) of detections in 2010; subsequently the treatment area was standardized to 500 m. In 2010, insecticide applications were recommended for all three generations and thereafter for the first two generations. At least one application of a conventional insecticide or two applications of an organic insecticide were timed based on degree-day accumulations (and vine phenology). Isomate Shin-Etsu pheromone dispensers were used in Napa County in 2010 through 2014 and other select counties in 2011. Mating disruption was not used in areas of California that were attempting to be released from quarantine regulations. After 2013, insecticide treatments were recommended for vines within 500 m of all finds from the previous two years. In urban areas within 500 m of a detection, property owners with grapevines were given the choice of flower and fruit removal or applications of Bacillus thuringiensis during the first two generations. All control measures in urban areas were performed by the California Department of Food and Agriculture. Areas that met the following requirements were deregulated: no moth captured during five consecutive generations; insecticide was applied to the first two larval generations; during the final two full generations mating disruption dispensers were not deployed and trapping density increased to 39 traps per km2. Peak quarantine area of 6048 km2 across portions of 10 California counties occurred in 2011. Four counties were deregulated in early 2012 and five additional counties were deregulated partially or in full at the end of 2012. The quarantine area in 2013 was reduced to include most of Napa County (1434 km2) and areas of two neighboring counties within 5 km of Napa traps that caught adult moths. One moth was caught in 2014 and no moths were caught in 2015. Monitoring of vineyard acreage outside the quarantine continues without detections. Ongoing surveys of host plants cited in the literature have not identified any alternate hosts of consequence in California.

139-147

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