Mating disruption of Lobesia botrana (Lepidoptera: Tortricidae): effect of pheromone formulations and concentrations

The reluctance of Israeli vine growers to adopt the mating disruption technique to control the moth Lobesia botrana Den. & Schiff. has been attributed to the high cost of this method compared with that of traditional insecticide control. In this study, we tested the possibility of reducing the cost, first by testing different pheromone formulations (and thus open the market for competition) and second by reducing the pheromone concentration used in vineyards. Comparisons were made between two pheromone formulations--Shin-Etsu (Tokyo, Japan) at 165 g/ha and Concep (Sutera, Bend, OR) at 150 g/ha--and between two concentrations of Shin-Etsu, 165 and 110 g/ha. Pheromone dispensers were placed at the onset of the second moth generation. Comparison of the numbers of clusters infested with eggs and larvae of L. botrana showed no significant differences in the performance, either between the two formulations, or between the two tested concentrations. The results suggest that 1) the two formulations are equally effective, and 2) a low pheromone concentration is sufficient to maintain good control of small populations of L. botrana. However, when the population is high, pest control efficacy is not improved by increasing the pheromone concentration. Therefore, in the interest of reducing the relatively high cost of mating disruption, we emphasize that increasing the pheromone concentration does not provide improved control of high populations of L. botrana. The cost of mating disruption can be diminished by reducing the applied pheromone concentration and by using the least expensive pheromone formulations     

Spatial analysis of Lobesia botrana (Lepidoptera: Tortricidae) male population in a mediterranean agricultural landscape in central Italy

The results obtained from the spatial analysis of pheromone-baited trap catch data of Lobesia botrana (Denis and Schiffermüller) males are reported. The research was undertaken in the Abruzzo region of central Italy. In the study area, vineyards (of Vitis vinifera L.) are the predominant cultivation, surrounded by hedgerows and small woodlots, and interspersed with cereal crops and olive groves. The main purpose of the study was to investigate the spatio-temporal dynamics of L. botrana, inside and outside vineyards, and to evaluate the effect of the landscape elements on pest distribution. A trend orientation over the experimental area was observed along the direction from northwest to southeast. Correlograms fitted using a spherical model showed in all cases an aggregated distribution and an estimated range having a mean of 174 m in 2005 and 116 m in 2006. Contour maps highlighted that spatial distribution of L. botrana was not limited to vineyards, but its presence is high particularly inside olive groves. The adult distribution on the experimental area changed during the season: hot spots of flight I were positioned inside olive groves; during flights II and III, they were concentrated in vineyards. L. botrana males were also captured in uncultivated fields, but never in high densities. Our results showed that a large proportion of the adult population of L. botrana inhabits areas outside those usually targeted by pest management programs. Thus, in Mediterranean agro-ecosystems, it is highly recommended to consider the whole landscape, with particular attention to olive crops.     

Delayed mating reduces reproductive output of female European grapevine moth,Lobesia botrana (Lepidoptera: Tortricidae)

Virgin females of Lobesia botrana Denis & Schiffermüller were mated at ages of 1, 3, 5, 8, 12 and 16 days and the effect of mating delay on reproductive output assessed. Delayed mating did not affect female mating success but fertilization was reduced in 16-day-old females. Increased mating delays substantially affected daily oviposition pattern and resulted in a significant reduction of both fecundity and fertility, so that mean number of viable eggs laid decreased from 150 to 22 in 1- and 16-day-old mated females, respectively. Heavier females were more constrained than lighter ones by mating delays and female reproductive efficiency (no. viable eggs/female body weight) was also significantly reduced. Female longevity significantly increased and oviposition period gradually declined with mating delay. The number of viable eggs was positively correlated with both female weight and oviposition period; female longevity and female weight were also significantly correlated. However, the significance of these correlations declined with increased mating delay. Results overall indicated that mating delay drastically reduces female L. botrana reproductive output. The implications of delayed mating of females are discussed from an ecological perspective in relation to L. botrana control using mating disruption.     

Organic nanofibers containing insect pheromone disruptants: a novel technical approach to controlled release dispensers with potential for process mechanization

Beginning fifty years ago, the search for suitable dispensers containing insect pheromones grew with the availability of these synthetic biotechnical tools. Many economic entomologists and application engineers dearly wish they had the "smart, intelligent and ideal dispenser". More or less suitable approximations are available commercially, but none so far meets all demands. Under economic strictures, novel inexpensive systems would be advantageous with release characteristics tailored to the specific life histories of pest insects, the plants considered and the numerous requirements of growers alike. Simultaneously, their field distribution should be mechanizable and be accomplished by one (or very few) application runs. The dispensers should be biodegradable, biocompatible, sustainably applicable, and they should be based on renewable resources. This report presents first results of a novel organic, electrospun nanofiber dispenser with dimensions in the upper nanometer range. Its load of pheromone can be adjusted to be sufficient for 7 weeks of constant disruptive action in vineyards and can be directed against the European Grape Vine Moth Lobesia botrana (Lepidoptera: Tortricidae) which here serves as a readily available model. Mating disruption in L. botrana and the related Eupoecilia ambiguella is a well studied and developed engineering process. Equally, nanofiber production by electrospinning (for a comprehensive review see Greiner and Wendorff, 2007A, B) is well known and already has numerous applications in filtration technology, air conditioning, and medical wound dressing. Our goal was to bring together and successfully mate these (partly incompatible) technologies via technical tricks of a proprietary nature. Even though the lifetime and effectiveness of currently available nanofibers still must be doubled, the rather complicated system of their production and analysis is known well enough to identify the parameters that need future adjustment. Another challenge is the mechanical distribution of the fibers in the vineyards by suitable machinery. Also, in this respect, certain technical leads are available for future development.     

Comparison of three dispenser distribution patterns for pheromone mating disruption of Paralobesia viteana (Lepidoptera: Tortricidae) in vineyards

Over two growing seasons, Isomate GBM-Plus tube-type dispensers releasing the major pheromone component of grape berry moth, Paralobesia viteana (Clemens) (Lepidoptera: Tortricidae), were evaluated in vineyards (Vitis spp.) in Michigan, New York, and Pennsylvania. Dispensers were deployed in three different density-arrangement treatments: 124 dispensers per ha, 494 dispensers per ha, and a combined treatment with 124 dispensers per ha in the vineyard interior and 988 dispensers per ha at the vineyard border, equivalent to an overall density of 494 dispensers per ha. Moth captures and cluster infestation levels were compared at the perimeter and interior of vineyards receiving these different pheromone treatments and in vineyards receiving no pheromone. Orientation of male moths to pheromone-baited traps positioned at the perimeter and interior of vineyards was reduced as a result of mating disruption treatments compared with the nontreated control. These findings were consistent over both years of the study. Disruption of male moth captures in traps varied from 93 to 100% in treated vineyards, with the 494 dispensers per ha application rates providing significantly higher level of disruption than the 124 dispensers per ha rate, but only in 2007. Measurements of percentage of cluster infestation indicated much higher infestation at perimeters than in the interior of the vineyards in all three regions, but in both sample positions there was no significant effect of dispenser density on cluster infestation levels in either year. The contrasting results of high disruption of moth orientation to traps in vineyards that also had low levels of crop protection from this pheromone treatment are discussed in the context of strategies to improve mating disruption of this tortricid pest.     

Control of Lobesia botrana (Lepidoptera: Tortricidae) by biodegradable ecodian sex pheromone dispensers

Mating disruption with a high density of sex pheromone dispensers is a new strategy recently developed for the control of the moth Lobesia botrana (Denis & Schiffermüller) (Lepidoptera: Tortricidae). Ecodian LB dispensers, made of low-cost biodegradable material, were formulated with 10 mg of (E,Z) -7,9-dodecadienyl acetate and placed at a rate of 1,600 dispensers per ha. Seasonal dispenser performances were studied using different methods. The female attractiveness disruption and the efficacy of the method were evaluated in the field. The release rates of field-aged Ecodian LB dispensers, measured directly by solid phase microextraction, was comparable with that of the standard monitoring lure after 50-60 d of field exposure and significantly lower beyond 60 d; however, at the end of the season, it was approximately 46 times higher than that of a calling L. botrana female. Electroantennographic recordings showed that dispensers of different field age strongly stimulated male antennae. In a wind tunnel test, dispensers elicited close-range approaches and direct source contacts irrespective of their age. In fields treated with Ecodian dispensers the attractiveness of traps lured with calling females and monitoring baits was significantly reduced. Our data suggest that Ecodian dispensers are active sources of pheromone throughout the season. The efficacy of Ecodian strategy for L. botrana control was comparable with standard mating disruption and curative insecticides.     

Effects of sex pheromone in electrostatic powder on mating behaviour by Lobesia botrana males

Abstract:  In laboratory trials, mating behaviour of males of Lobesia botrana Den. and Schiff. (Lep., Tortricidae) was investigated after treatment with an electrostatically chargeable powder, Entostat^TM. Male moths were powdered with either blank Entostat or Entostat containing sex pheromone. Significantly more Entostat adhered to L. botrana males when sex pheromone was added to the powder compared with blank Entostat. Powdering male moths with Entostat, with or without sex pheromone, caused a significant reduction in antennal response when antennae were placed 2 cm away in downwind direction, while there was little effect when antennae were placed 25–100 cm from the EAG in downwind direction. In a flight study, powdering males of L. botrana caused significant increase in time before flight initiation and reduction in proportion of males making contact with calling females compared with untreated males. In a mating experiment in Petri dishes (to minimize required search time to locate female), significantly fewer females mated successfully (based on dissection of bursa copulatrix) when males had been treated with pheromone-loaded powder. Overall, powdering males of L. botrana caused considerable suppression of mating behaviour on various levels, and these suppressing effects were increased after adding sex pheromone to Entostat.     

Oviposition by Lobesia botrana is stimulated by sugars detected by contact chemoreceptors

Abstract.  The influence of glucose, fructose and sucrose on oviposition site selection by Lobesia botrana is studied by combining behavioural and electrophysiological experiments. Oviposition choice assays, using surrogate grapes treated with grape berry surface extracts of Vitis vinifera cv. Merlot at different development stages, show that L. botrana females are most stimulated by extracts of mature berries containing the highest concentrations of glucose and fructose. Choice assays reveal that the oviposition response to these sugars is dose-dependant (with a threshold of the applied solution = 10 m m and a maximum stimulation at 1  m ) and that females are more sensitive to fructose than to glucose. Tarsal contact-chemoreceptor sensilla are unresponsive to stimulation with sugars but the ovipositor sensilla contain at least one neurone most sensitive to fructose and sucrose with a threshold of approximately 0.5 m m . Corresponding to the behavioural data, glucose is significantly less stimulatory to sensilla than fructose or sucrose. It is argued that fructose may be of special importance for herbivorous insects exploiting fruit as an oviposition site.     

Overwintering of codling moth (Lepidoptera: Tortricidae) larvae in apple harvest bins and subsequent moth emergence.

Codling moths, Cydia pomonella (L.), have long been suspected of emerging from stacks of harvest bins in the spring and causing damage to nearby apple and pear orchards. With increased use of mating disruption for codling moth control, outside sources of infestation have become more of a concern for growers using pheromone based mating disruption systems. Studies were designed to provide information on bins as a source of codling moth and the pattern of codling moth emergence from stacks of bins. In these studies, codling moth larvae colonized wood harvest bins at a much higher frequency than harvest bins made of injection molded plastic (189 moths emerged from wood compared with five from plastic). There was no statistical difference in the number of moths infesting bins that had been filled with infested fruit compared with bins left empty at harvest. This suggests that codling moth enter the bins during the time that the bins are in the orchard before harvest. Emergence of laboratory reared adult codling moth from wood bins placed in stacks was found to be prolonged compared with field populations. Temperature differences within the bin stacks accounted for this attenuated emergence pattern. Covering bin stacks with clear plastic accelerated codling moth development in the upper levels of the stack. Codling moth emergence patterns from plastic-covered stacks more closely coincided with male flight in field populations. This information could be important in developing a technique for neutralizing codling moth-infested bins, and in understanding how infested bins may influence pest management in fruit orchards that are located near bin piles. Implications for control of codling moth in conventional orchards and in those using mating disruption as the principal component of an integrated pest management system include increased numbers of treatments directed at areas affected by infested bins.     

Efficiency of spreading maize in the garrigues to reduce wild boar (<Emphasis Type="Italic">Sus scrofa</Emphasis>) damage to Mediterranean vineyards

The aim of this work was to assess the efficiency of dissuasive spreading of maize to reduce the level of wild boar damage to vines in a Mediterranean area (Puéchabon, southern France). The 50 wine growers of Puéchabon were all questioned about the annual losses caused by the wild boar in each vineyard of the study area between 1990 and 1992. We also studied the distribution of the damage on a smaller scale, by mapping the damaged vines within two vineyards. In summer 1993, we distributed 4.7 tons of maize in the woods , and then questioned the wine growers about the losses in each vineyard for 1993. During 1990–1992, on both large and small scales, the damage had a patchy distribution, with more patches of damage occurring close to the woods. Moreover, the later the vines ripened, the less frequent the damage. The severity of the damage was only affected by the distance of the vineyard from woods. In total, the wild boar consumed 20,049 kg of grapes each year between 1990–1992 (193 kg/ha), and 63% of the vineyards were damaged. In 1993, both the density and the compensation paid in the département increased threefold. However, in our study area, both the proportion of damaged vineyards (36%) and the level of damage in the vineyards (151 kg/ha) were reduced, saving more than 60% in compensation. The dissuasive spreading of maize is therefore an efficient tool to reduce the level of damage to vineyards.     

Evaluation of two visual birdscarers,the Peaceful Pyramid® and an eye‐spot balloon,in two vineyards

Abstract

The effectiveness of a visual birdscarer, the Peaceful Pyramid®, relative to a much‐cheaper eye‐spot balloon was investigated experimentally in two vineyards in Canterbury, New Zealand. Monitoring of bird damage to natural bunches of Riesling grapes within vineyard blocks showed that the rate of starling (Sturnus vulgaris) damage to the crop was reduced significantly by the balloon relative to pyramid and control plots. Nevertheless, after 24 days of monitoring, birds in the balloon plot had damaged 75% of the grapes, respectively (cf. 84% in the pyramid plot). In a second trial, clusters of table grapes were attached to vineyard wire at a Lincoln vineyard. The balloon and pyramid both reduced bird damage to clusters within 15 m of the device, but had no measurable effect on clusters further away. We conclude that neither device would provide growers with any economically significant reduction in grape damage. This study highlights the importance of undertaking quantitative assessments of the numerous bird‐scaring technologies presently available to growers.     

Improvement of the sterile insect technique for codling moth Cydia pomonella (Linnaeus) (Lepidoptera Tortricidae) to facilitate expansion of field application

The codling moth Cydia pomonella (L.) (Lepidoptera Tortricidae) is a key pest of pome fruit (apple, pear and quince) and walnut orchards in most temperate regions of the world. Efforts to control the codling moth in the past mostly relied on the use of broad spectrum insecticide sprays, which has resulted in the development of insecticide resistance, and the disruption of the control of secondary pests. In addition, the frequent reliance and use of these insecticides are a constant threat to the environment and human health. Consequently, there have been increased demands from the growers for the development of codling moth control tactics that are not only effective but also friendly to the environment. In that respect, the sterile insect technique (SIT) and its derivative, inherited sterility (IS), are, together with mating disruption and granulosis virus, among the options that offer great potential as cost‐effective additions to available control tactics for integration in area‐wide integrated pest‐management approaches. In support of the further development of the SIT/IS for codling moth control, the Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture implemented a 5‐year Coordinated Research Project (CRP) entitled ‘Improvement of codling moth SIT to facilitate expansion of field application’. Research focussed on sterile codling moth quality and management (e.g. mobility and life‐history traits in relation to rearing strategy, dispersal, flight ability, radiosensitivity and mating compatibility) and a better understanding of the basic genetics of codling moth to assist the development of genetic sexing strains (e.g. cytogenetics, the development of dominant conditional lethal mutations, molecular characterization of the sex chromosomes, sex identification in embryos and cytogenetic markers). The results of the CRP are presented in this special issue.     

Physiological factors regulating polyandry in Lobesia botrana (Lepidoptera: Tortricidae)

Abstract. The effects of several physiological factors related to female multiple mating in the monandrous Lobesia botrana Denis and Schiffermuller (Lepidoptera: Tortricidae) were studied under laboratory conditions. Polyandry was assessed observing the induction of re-calling in previously once-mated females. Female age at first mating had no effect on induction of re-calling during practically the whole of the female lifetime, but in older females it was significantly lower. The percentage of re-calling was negatively correlated with the volume of the spermatophore received, ranging from ≅ 23% with the largest spermatophores to ≅ 75% with the smallest ones. Furthermore, the smaller the spermatophore volume, the earlier the re-calling was induced, significantly reducing die female refractory period after the first mating. Heavy females showed a significantly higher rate of re-calling (52.8%) than light ones (37.0%), but no differences were observed when females received only small spermatophores. This finding was explained by die allometric relationship between me female weight and the size of its reproductive system that affects relative replenishment by the spermatophore. Females with a supply of water displayed a significantly higher rate of re-calling (41.2%) than control females (22.8%), highlighting the effect of adult feeding (or drinking) status on the re-calling behaviour. The short-distance presence of virgin males with once-mated females promoted a re-calling rate (and subsequent matings) close to 37%, significantly higher than that of isolated females (20%). It is concluded mat re-calling and polyandry in L. botrana are controlled, as expected, by a number of mating-derived stimuli, but also to a great extent by other physiological stimuli unrelated to mating. The reproductive strategies in relation to polyandry and the mechanisms controlling female sexual inhibition are discussed.     

Grape variety affects larval performance and also female reproductive performance of the European grapevine moth Lobesia botrana (Lepidoptera: Tortricidae)

For insect herbivores, the quality of the larval host plant is a key determinant of fitness. Therefore, insect populations are supposed to be positively correlated with the nutritional quality of their host plant. This study aimed to determine if and how different varieties of grapes (including the wild grape Lambrusque) affect both larval and adult performance of the polyphagous European grapevine moth Lobesia botrana (Denis & Schiffermüller). Significant differences were found in larval development time, but not in pupal mass, adult emergence rate, or sex ratio. Although the fecundity of females is not different among varieties, females fed on some varieties produced eggs of different sizes which are correlated to their fertility. Thus, females adapt resource allocation to eggs depending on their diet as larvae. Using a fitness index, the average reproductive output was found to be highest for females reared on cv. Chardonnay. Females reared on wild grape produced a fitness index identical to the cultivated grapes. However, Lambrusque and Gewurztraminer separate themselves from the cultivated varieties according to our discriminant analyses. It is emphasized, through this study, that cultivars fed on by larvae should be considered in the population dynamics of L. botrana and that egg number is insufficient to determine host plant quality.     

Pheromone-based mating disruption of Planococcus ficus (Hemiptera: Pseudococcidae) in California vineyards

Experiments were conducted to test a mating disruption program for the mealybug Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae) in California vineyards. The sprayable, microencapsulated formulation of the racemic sex pheromone lavandulyl senecioate was applied with an air-blast sprayer, using three and four applications in 2003 and 2004, respectively. Mating disruption was combined with an application of buprofezin (2004) in June. Compared with a no-pheromone control, there were significantly lower season-long trap catches of adult males, season-long mealybug densities (2003 only), and crop damage in mating disruption plots. The amount of mealybug reduction and mechanisms that resulted in lower crop damage in mating disruption plots is discussed. In samples taken during the growing season (April to September), mealybug density was only 12.0 +/- 15.6 and 31.1 +/- 11.6% lower in the mating disruption plots than in control plots in 2003 and 2004, respectively. In the mating disruption treatment, mealybug egg production was significantly lower (2003 only), as were the proportion of ovisacs and crawlers produced. There was no treatment impact on percentage of parasitism. Mealybug density influenced treatment impact. In 2004, vines were categorized as having low, medium, or high mealybug densities during a preapplication survey. After treatment application, mealybug density was reduced by 86.3 +/- 6.3% on vines in the low mealybug density category, but it was unchanged on vines in the high density category. Another factor that reduced treatment impact was the relatively short effective lifetime of the sprayable formulation.     

Current and potential management strategies against Harmonia axyridis

This paper reviews the current and potential methods to control the harlequin ladybird, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), an Asian predatory beetle invasive in Europe and the Americas where it has become a human nuisance, a grape and wine pest and a threat to native biodiversity. Current methods to manage this invasive species include: techniques to mechanically prevent adult beetles from entering buildings in autumn or to remove aggregates of beetles inside buildings, e.g. using various trapping methods; the use of insecticides on buildings or in vineyards to prevent aggregation in houses or on grapes; cultivation practices in vineyards to lower the impact of the ladybird on grape production and wine quality; remedial treatments for wine tainted by the ladybird. Other methods are presently being developed or considered. Semiochemicals could be used as deterrents or as attractants to develop more efficient trapping systems in buildings and open fields. Natural enemies include pathogens, parasitoids, predators and a parasitic mite but few of them show potential as biological control agents. While management methods presently used or under development may eventually solve the problems caused by beetles aggregating in buildings or vineyards, the issue of H. axyridis populations outcompeting native species is much more challenging. Only the sudden adaptation of a native natural enemy or the importation of a natural enemy from the area of origin of the ladybird may ultimately lower population densities. The problems linked to the importation of an Asian natural enemy of H. axyridis are discussed.     

Effectiveness of insecticides in controlling the first and second generations of the Lobesia botrana (Lepidoptera: Tortricidae) in table grapes

The moth Lobesia botrana (Denis & Schiffermüller) (Lepidoptera: Tortricidae) is a key pest of table and wine grape (Vitis spp.) varieties in Cyprus. Many different insecticide combinations were applied for three consecutive years (2006-2008) in a Sultana seedless table grape vineyard, aimed at controlling the first and second generations of this pest under warm and dry Mediterranean climatic conditions. In Cyprus, Sultana is the main early maturing table grape variety grown in the country. L. botrana has two generations and a partial third on this export variety, of which the first two generations are the most destructive. Applications were made according to pheromone trap captures of males. One application was used against the first and two applications against the second generation of L. botrana. A high rate of bunch damage was observed in the untreated rows during all years, reaching 56.7, 62.5, and 69.2% in 2006, 2007, and 2008, respectively. Differences between insecticide treatments and the untreated control were statistically significant. The treatment combination of lufenuron, spinosad, and indoxacarb as well as the combination of chlorpyrifos, spinosa and indoxacarb, used against the first and second generations of L. botrana, were the most effective compared with the untreated control. Satisfactory control of the pest also was observed with other combinations such as lufenuron, cypermethrin, and Bacillus thuringiensis; chlorpyrifos, cypermethrin, and B. thuringiensis; and lufenuron, deltamethrin, and azadirachtin.     

Study of the relationship between sex pheromone trap catches of Lobesia botrana (Den. & Schiff.) (Lep., Tortricidae) and the accumulation of degree-days in Sherry vineyards (SW of Spain)

The relationship between temperature accumulations and pheromone trap captures of the males of Lobesia botrana (Den. & Schiff.) (Lep., Tortricidae) in the Sherry vineyards (SW of Spain) presents a statistically acceptable linear behaviour through conveniently transforming the variables. Data series ranging from 1990 to 1995 were used to compute the linear correlations. The reliability of the forecasts based on the resulting log-probit lines have shown to be acceptable in order to be considered as an useful tool to improve the effectiveness of the integrated pest management in the area.     

The genetic structure of fermentative vineyard-associated <Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis> populations revealed by microsatellite analysis

From the analysis of six polymorphic microsatellite loci performed in 361 Saccharomyces cerevisiae isolates, 93 alleles were identified, 52 of them being described for the first time. All these isolates have a distinct mtDNA RFLP pattern. They are derived from a pool of 1620 isolates obtained from spontaneous fermentations of grapes collected in three vineyards of the Vinho Verde Region in Portugal, during the 2001–2003 harvest seasons. For all loci analyzed, observed heterozygosity was 3–4 times lower than the expected value supposing a Hardy–Weinberg equilibrium (random mating and no evolutionary mechanisms acting), indicating a clonal structure and strong populational substructuring. Genetic differences among S. cerevisiae populations were apparent mainly from gradations in allele frequencies rather than from distinctive “diagnostic” genotypes, and the accumulation of small allele-frequency differences across six loci allowed the identification of population structures. Genetic differentiation in the same vineyard in consecutive years was of the same order of magnitude as the differences verified among the different vineyards. Correlation of genetic differentiation with the distance between sampling points within a vineyard suggested a pattern of isolation-by-distance, where genetic divergence in a vineyard increased with size. The continuous use of commercial yeasts has a limited influence on the autochthonous fermentative yeast population collected from grapes and may just slightly change populational structures of strains isolated from sites very close to the winery where they have been used. The present work is the first large-scale approach using microsatellite typing allowing a very fine resolution of indigenous S. cerevisiae populations isolated from vineyards.