Assessing the influence of inflorescence traits on the susceptibility of grape to vine moths

In north‐eastern Italy during 1994–2006, studies were carried out on the susceptibility of grapevine cultivars to the first generations of the European vine moth [Lobesia botrana (Den. and Shiff.); Lep., Tortricidae] and the European grape berry moth [Eupoecilia ambiguella (Hb.); Lep., Cochylidae]. In five different years, the larval population density of both moth species and the larval age composition of L. botrana were recorded on 11 grapevine cultivars (Cabernet Sauvignon, Carmenère, Chardonnay, Pinot Gris, Merlot, Refosco dal Peduncolo Rosso, Rhine Riesling, Sauvignon Blanc, Terrano, Tocai Friulano, Verduzzo Friulano), grown in the same vineyard. The influence of inflorescence traits on these demographic parameters was also evaluated. On a 5‐year average, L. botrana significantly prevailed over E. ambiguella in nine of the 11 cultivars. Chardonnay and Pinot Gris were the most infested cultivars. Age composition of L. botrana larvae varied with cultivar type, being older on Chardonnay and Tocai Friulano than the other cultivars. Inflorescence earliness and hairiness explained the majority of the variability in cultivar susceptibility. In particular, the larval population level of the two vine moths was positively correlated with inflorescence earliness and negatively correlated with inflorescence hairiness. Lobesia botrana larval age composition was negatively correlated with inflorescence hairiness. Inflorescence earliness and hairiness could be used to predict in each grape‐growing area which cultivars are potentially more infested in the first generation. Inflorescences without pubescence, favouring an older age composition of first generation larvae, could induce an earlier second generation.     

Defense strategies used by two sympatric vineyard moth pests

Natural enemies including parasitoids are the major biological cause of mortality among phytophagous insects. In response to parasitism, these insects have evolved a set of defenses to protect themselves, including behavioral, morphological, physiological and immunological barriers. According to life history theory, resources are partitioned to various functions including defense, implying trade-offs among defense mechanisms. In this study we characterized the relative investment in behavioral, physical and immunological defense systems in two sympatric species of Tortricidae (Eupoecilia ambiguella, Lobesia botrana) which are important grapevine moth pests. We also estimated the parasitism by parasitoids in natural populations of both species, to infer the relative success of the investment strategies used by each moth. We demonstrated that larvae invest differently in defense systems according to the species. Relative to L. botrana, E. ambiguella larvae invested more into morphological defenses and less into behavioral defenses, and exhibited lower basal levels of immune defense but strongly responded to immune challenge. L. botrana larvae in a natural population were more heavily parasitized by various parasitoid species than E. ambiguella, suggesting that the efficacy of defense strategies against parasitoids is not equal among species. These results have implications for understanding of regulation in communities, and in the development of biological control strategies for these two grapevine pests.     

葡萄花翅小卷蛾抗药性研究进展

葡萄花翅小卷蛾是葡萄上的重要害虫,具有多食性、多化性等生物学特点,抗逆能力极强。该虫起源于欧洲,现已入侵全球多个国家。葡萄花翅小卷蛾主要以幼虫取食葡萄花序、幼果和成熟果实,给葡萄生产造成重大损失;其危害有利于真菌的侵入,导致灰霉病、白粉病等病害大量发生,从而造成葡萄腐烂。由于该虫入侵风险极高,已被我国列为重要的进境检疫性有害生物。国外对葡萄花翅小卷蛾的防治主要采用化学杀虫剂,由于长期大量且不合理地使用化学杀虫剂,葡萄花翅小卷蛾已对多种不同类型的杀虫剂产生了抗药性。本研究总结了葡萄花翅小卷蛾的抗性测定方法、抗性现状及其抗性机理,同时结合国外葡萄花翅小卷蛾抗性和防治相关研究,提出该虫抗性治理策略,并对我国预防该虫的入侵提出建议。     

Relative performance of European grapevine moth (<Emphasis Type="Italic">Lobesia botrana</Emphasis>) on grapes and other hosts

The European grapevine moth, Lobesia botrana is a major grapevine pest, but despite the abundance of vineyards it is a generalist and uses either grapes or alternative species. Given the abundance and predictability of grape, L. botrana could be expected to have evolved towards monophagy. In order to understand why this species remains polyphagous, we hypothesized that larvae reared on rare wild host plants should have higher fitness than those reared on the more abundant grape host. For this, we compared larval performance and several life history traits on three alternative host plants (Daphne gnidium, Olea europaea, Tanacetum vulgare) and three Vitaceae (Vitis vinifera), two cultivars and one wild species (Ampelopsis brevipedunculata), and two control groups raised on either a low or a high nutritive value medium. Alternative hosts are more suitable than Vitaceae for the reproductive performance of L. botrana: larval mortality and development time was reduced, while pupal weight, growth rate, female longevity, female fecundity, duration of laying and mating success were increased. High quality food ingested by larvae promotes higher adult body weight and enhances female reproductive output. This suggests that alternative hosts provide greater nutritional value for L. botrana than Vitaceae. The use of alternative host plants could thus be maintained in the host range because they offer L. botrana a better fitness than on the Vitaceae. This could typically represent an advantage for moths behaving in plant diversity grape landscapes.     

Wolbachia is present in the European grapevine moth

The European grapevine moth, Lobesia botrana, has high economic impact on grapevines being one of the most harmful pests of vineyards worldwide. Wolbachia infection has not yet been reported for this moth. We systematically look for Wolbachia presence in L. botrana from three areas within the viticultural region of Alentejo (Portugal), via wsp gene specific PCR, and consistently found its presence. The interaction between the grapevine, its associated moth pest and the Wolbachia needs to be further explored, towards its potential in the development of symbiosis-based pest management strategies.     

Identification of host‐plant chemical stimuli for the European grape berry moth Eupoecilia ambiguella

Olfaction is of major importance for survival and reproduction in moths. Males possess highly specific and sensitive olfactory receptor neurones to detect female sex pheromones. However, the capacity of male moths to respond to host‐plant volatiles is relatively neglected and the role that such responses could play in the sensory ecology of moths is still not fully understood. The present study aims to identify host‐plant stimuli for the European grape berry moth Eupoecilia ambiguella Hb. (Tortricidae, Lepidoptera), a major pest of vine in Europe. Headspace volatiles from Vitis vinifera L. cv. Pinot Noir, Vitis vinifera subsp. sylvestris and five other host‐plant species comprising five different families are analyzed by gas chromatography linked to electroantennogram (EAG) recording from male E. ambiguella antennae and by gas chromatography‐mass spectrometry. This procedure identifies 32 EAG‐active compounds, among them the aliphatic compounds 1‐hexanol, (Z)‐3‐hexenol, (Z)‐3‐hexenyl acetate and 1‐octen‐3‐ol; the terpenes limonene, β‐caryophyllene and (E)‐4,8‐dimethyl‐1,3,7‐nonatriene; and the aromatic compounds benzaldehyde and methyl salicylate. Male and female E. ambiguella show similar EAG response amplitudes to individual chemical stimuli and also to mixtures of plant volatiles, as represented by essential oils from ten other plant species. This possibly indicates a common role for plant compounds in the sensory ecology of the two sexes of E. ambiguella.     

Isolation and characterization of polymorphic microsatellite loci in Lobesia botrana Den. & Schiff. (Lepidoptera: Tortricidae)

The tortricid moth Lobesia botrana is considered to be an important pest of the cultivated grapevine (Vitis vinifera, Vitaceae). It feeds on young flower buds and young fruits, and is the primary vector of the ‘noble mould’ fungus (Botrytis cinerea). In order to study the population dynamics and genetic structure of this species in space and time, we developed seven polymorphic microsatellite markers (three to 12 alleles). Although the presence of null alleles is suspected, these polymorphic loci are likely to provide information on the population genetics of L. botrana, and could help in the development of an efficient control strategy against this pest.     

Climate warming effects on grape and grapevine moth (Lobesia botrana) in the Palearctic region

相似文献   

Prospective analysis of the invasive potential of the European grapevine moth Lobesia botrana (Den. & Schiff.) in California

• 1 The polyphagous European grapevine moth Lobesia botrana (Den. & Schiff.) is the principal native pest of grape berries in the Palearctic region. It was found in Napa County, California, in 2009, and it has subsequently been recorded in an additional nine counties, despite an ongoing eradication programme. The present study aimed to assess prospectively its potential geographical distribution and relative abundance in California and the continental U.S.A. A subsidiary goal was to provide explanation for timing control measures.
• 2 Data from the European literature were used to formulate and parameterize a holistic physiologically‐based demographic model for L. botrana. This model was linked to an extant mechanistic model of grapevine phenology, growth and development that provides the bottom‐up effects of fruiting phenology, age and abundance on L. botrana dynamics. Fruit age affects larval developmental rates, and has carryover effects on pupal development and adult fecundity. Also included in the model were the effects of temperature on developmental, survival and fecundity rates.
• 3 Observed daily weather data were used to simulate the potential distribution of the moth in California, and the continental U.S.A. The relative total number of pupae per vine per year was used as the metric of favourability at all locations. The simulation data were mapped using grass gis ( http://grass.osgeo.org/ ).
• 4 The model predicts L. botrana can spread statewide with the highest populations expected in the hotter regions of southern California and the lower half of the Central Valley. In the U.S.A., areas of highest favourability include south Texas, and much of the southeast U.S.A.
• 5 The effects of a warmer climate on pest abundance were explored by increasing observed mean temperatures 2° and 3 °C. L. botrana abundance is expected to increase in northern California and in the agriculturally rich Central Valley but to decrease in the hot deserts of southern California where summer temperatures would approach its upper thermal limit.
• 6 Analysis of the timing of mating disruption pheromone for control of L. botrana suggests the greatest benefit would accrue by targeting adults emerging from winter diapause pupae and the flight of first summer adults.

     

Natal insect experience with Arabidopsis thaliana plant genotypes influences plasticity in oviposition behavior

Previous studies have shown that insect experience with secondary chemicals present in different plant species can induce behavioral changes in female oviposition preferences. However, there is a lack of information on whether insect experience with intraspecific plant variation may influence oviposition behavior. The prediction that experience with plant genotypes would affect the oviposition behavior of two crucifer insect pests was tested using a wild ecotype of Arabidopsis thaliana (L.) Heynh. (Brassicaceae) (Col‐0) and two of its genetically modified lines (35S:ESP and tgg1 tgg2), which differ in their glucosinolate hydrolysis profiles. Choice oviposition assays were performed using both naïve and experienced females of the specialist Plutella xylostella (L.) (Lepidoptera: Plutellidae) and the generalist Trichoplusia ni (Hübner) (Lepidoptera: Noctuidae). In addition to oviposition preferences, the effect of plant genetic lines was assessed on insect traits related to development, growth, survival, and fecundity. Experience with different natal treatments (i.e., artificial diet and plant genotypes) led to changes in oviposition behavior of the diamondback moth P. xylostella; however, this effect was dependent on the specific genetic lines included in dual‐choice oviposition assays. In addition, for both moth species, experience led to female oviposition choices that would have maximized fitness of their offspring. In summary, this article suggests that insect experience with plant genotypes varying in their secondary metabolites can influence subsequent oviposition behavior. This outcome may have implications for plant‐insect coevolution and integrated pest management.     

Differences in nutritional quality of parts of Vitis vinifera berries affect fitness of the European grapevine moth

The European grapevine moth, Lobesia botrana (Denis & Schiffermüller) (Lepidoptera: Tortricidae), is a major grapevine pest in Europe. The larva is polyphagous and able to develop on more than 25 plant species, several of them being more suitable than Vitaceae for the fitness of L. botrana. Larvae normally eat the pulp of the berry, but may also consume the seeds according to the development stage of the berry and the larval density per bunch. Understanding the effect on individual fitness of such feeding behaviour is important to assess how suitable the different berry tissues are for this insect. We offered to the larvae either entire berries, seeds, or pulp with skin of the variety Vitis vinifera cv. ‘Cabernet Sauvignon’ as larval food in order to assess several life history traits from egg hatching to adult death. Two control groups were raised on semisynthetic diets, offering a low (no plant material) or a higher (with corn flour) nutritive value medium. The larvae performed differently when fed on diets containing different parts of berries. The larvae fed on a diet containing grape berry seeds had a prolonged development time and showed higher mortality. The females emerging from these larvae had a lower fecundity and mating success than the females emerging from larvae fed on diets containing other parts of the berries. However, their longevity was greater in comparison to the other groups. We conclude that seeds of Cabernet Sauvignon are not toxic to larvae but affect the reproductive life history traits in L. botrana.     

Volatiles that encode host-plant quality in the grapevine moth

Plant volatiles are signals used by herbivorous insects to locate host plants and select oviposition sites. Whether such volatiles are used as indicators of plant quality by adult insects in search of host plants has been rarely tested. We tested whether volatiles indicate plant quality by studying the oviposition of the grapevine moth Lobesia botrana on the grapevine plant Vitis vinifera. Host plants were infected with a variety of microorganisms, and larval fitness was correlated to the infected state of the substrate. Our results show an oviposition preference for volatiles that is significantly correlated with the fitness of the substrate. The chemical profiles of the bouquets from each V. vinifera–microorganism system are clearly differentiated in a PCA analysis. Both the volatile signal and the quality of the plant as larval food were affected by the introduction of microorganisms. Our study represents a broad approach to the study of plant–insect interactions by considering not only the direct effect of the plant but also the effect of plant–microorganism interactions on insect population dynamics.     

世界性害虫葡萄花翅小卷蛾入侵我国的风险分析

【目的】葡萄花翅小卷蛾是我国禁止进境的检疫性害虫,一旦入侵我国,将会给葡萄产业和林果业造成严重损失。开展葡萄花翅小卷蛾入侵我国的风险分析可为该虫的检疫和预警提供依据。【方法】介绍了葡萄花翅小卷蛾的形态特征和生物学特性,并参照通用的有害生物风险评估方法,从该虫在国内外的发生情况、潜在的经济危害性、受害作物的经济重要性、传播扩散的可能性及风险管理的难度等方面,对其入侵风险进行了定性和定量分析。【结果】葡萄花翅小卷蛾是一种对我国有很大潜在威胁的有害生物,其风险值为2.14,属高度危险性有害生物。【结论】建议新疆等口岸比较多的省、自治区口岸检疫部门加强对该害虫的检疫力度,杜绝其传入我国。     

Response of the European grapevine moth Lobesia botrana to somatosensory‐active volatiles emitted by the non‐host plant Perilla frutescens

The European grapevine moth Lobesia botrana Denis & Schiffermüller (Lepidoptera: Tortricidae) is a major pest on grapes worldwide. Attempts to develop control methods for this pest based on grape kairomones demonstrate limited success and studies indicate that a major limiting factor is overlap between synthetic kairomones and background odours in the vineyard. Behaviourally active compounds from non‐host plants may thus represent an effective alternative for monitoring and control methods. Extracts from food plants (i.e. from capsicum, garlic and peppermint, which elicit the so‐called somatosensory sensation) are traditionally used in agriculture for the control of pest insects. Among those plants, Perilla frutescens L. (Lamiales: Lamiaceae), native of Asia, contains compounds activating sensory ion channels in mammals, which are known to be involved in the perception of somatosensory compounds and are expressed in tortricid moth antennae. In the present study, in search of non‐host volatiles with potential application in pest control, essential oil metabolites isolated from P. frutescens are screened for biological activity on the olfactory system of L. botrana. The compounds (S)‐(?)‐perillaldehyde and isoegomaketone, which are released from different P. frutescens varieties, are identified by gas chromatography‐coupled electroantennographic detection. In a dual‐choice oviposition test, females show a preference for a combination of host odours and perillaldehyde, preferring this over a host‐plant odour bouquet alone. In Y‐tube olfactometer assays, virgin males show a higher level of activity in the presence of isoegomaketone, even if not significantly responsive to the compound.     

Mutualism between a phytopathogenic fungus (Botrytis cinerea) and a vineyard pest (Lobesia botrana). Positive effects on insect development and oviposition behaviour

In vineyards, larvae of the grape berry moth (Lobesia botrana) favour the development of the grey mould fungus Botrytis cinerea. To study the possibility of a mutualistic relationship between these organisms, we investigated the effects of the fungus on the development and oviposition behaviour of the insect. Larvae were reared on whole plants infected or uninfected with the fungus, or on an artificial diet containing either infected grape berries or the mycelium. The presence of the fungus consistently led to a reduction in the duration of insect development (4–6 d) and mortality (20–67 %). The fecundity increased from 12 to 76 %. Moreover, the fact that the females laid eggs preferentially on fungus-infected grape berries confirms the mutualistic association between these organisms. The fungus alone contributed to the positive effects. We showed the existence of a mutualistic relationship between the two organisms which are both damaging to vineyards.     

Global warming affects phenology and voltinism of Lobesia botrana in Spain

• 1 Climate change is promoting alterations of a very diverse nature in the life cycle of an array of insect species, including changes in phenology and voltinism. In Spain, there is observational evidence that the moth Lobesia botrana Den. & Schiff. (Lep.: Tortricidae), a key vine pest that is usually trivoltine in Mediterranean latitudes, tends to advance spring emergence, displaying a partial fourth additional flight, a fact that is potentially attributable to global warming.
• 2 To verify this hypothesis, local temperatures were correlated with L. botrana phenology in six vine‐growing areas of southwestern Spain during the last two decades (1984–2006) by exploiting the database of flight curves obtained with sexual pheromone traps. The dates of second and third flight peaks of the moth were calculated for each area and year and then correlated with both time (years) and local temperatures.
• 3 The results obtained demonstrated a noteworthy trend towards local warming (as a result of global warming) in the last two decades, with mean increases in annual and spring temperatures of 0.9 and 3.0°C, respectively. Therefore, L. botrana phenology has significantly advanced by more than 12 days. Moreover, the phenological advance contributed to increased moth voltinism in 2006 by promoting a complete fourth additional flight, a fact that has never been reported previously to our knowledge in the Iberian Peninsula.
• 4 The potential impact of an earlier phenology and increased voltinism in L. botrana is discussed from an agro‐ecological perspective.

     

Inconsistent effects of local and landscape factors on two key pests in Israeli vineyards

An ecoinformatics approach was used to test how two noxious species in grapevines with varying host preferences and movement characteristics: the European grapevine moth (Lobesia botrana), and a parasitic fungus, the grape powdery mildew (Uncinula necator), are affected by local and landscape variables. Data were collected from 202 vineyards during four seasons: 2013, 2014, 2016 and 2017 and analysed using generalized mixed models. We hypothesized that the European grapevine moth would be affected most by the landscape variables, while the grape powdery mildew would be affected most by local ones. We found that the number of sprayings during the season was an important variable explaining variation in infestation levels between vineyards for both species. At the landscape scale, we found larger variations in the relationship between the studied variables and the two pests, but both were also affected by the surrounding land use including areas of deciduous orchards. Understanding the factors that affect the occurrence of various pests in the same environment might improve farmers' decision-making.     

Efficacy of Trichogramma evanescens in controlling the grape berry moth Lobesia botrana in grape farms in Egypt

Abstract

The present work was conducted to evaluate the efficacy of Trichogramma evanescens (Westwood) in controlling the grape berry moth Lobesia botrana (Schiff) in two grape farms, in El-Beheira and El-Gharbia Governorates, northern Egypt during 2004 and 2005 seasons. T. evanescens was mass produced on Sitotroga cerealella (Olivier) eggs in the National Research Centre in Egypt. The horizontal and vertical searching activity of T. evanescens was studied to determine the proper way of distributing the Trichogramma cards in vineyards. Field experiments were also conducted to evaluate T. evanescens efficacy to control L. botrana on a large scale. Parasitism by T. evanescens on L. botrana eggs was greatly affected with the horizontal or vertical distance from the release points as well as with the rate of release. Parasitism reached over 97% and the percentage of reduction in damage caused by the pest reached 96.8% in treated plots. A significant increase in the crop was achieved in treated plots. T. evanescens could be a potential candidate for biological control of the grape moth in vineyards.     

Pine volatiles mediate host selection for oviposition by Thaumetopoea pityocampa (Lep., Notodontidae)

The oviposition behaviour and host selection by females of the pine processionary moth, Thaumetopoea pityocampa, was studied under two conditions: in a field insectary and in a pine stand. An oviposition choice test was conducted in an insectary cage, using artificial Christmas trees (ACTs) baited with extracts from four pine species: Pinus pinea, Pinus pinaster, Pinus halepensis and Pinus brutia, plus a control. Females oviposited significantly more egg batches on the ACT baited with a P. brutia extract, while no oviposition occurred on the control ACT. In a large P. pinea stand, two groups of randomly selected trees were marked and baited respectively with an extract of P. brutia, which was the preferred species under insectary conditions and with a solvent, to act as control. Results showed that oviposition in the field followed an aggregated pattern, fitting a negative binomial distribution and that trees baited with P. brutia extracts, received a significantly larger number of egg‐batches than control trees. In parallel, the volatiles emitted by all pine extracts tested where analysed by gas chromatography and mass spectrometry (GC‐MS), coupled to a time‐of‐flight (TOF) mass analyser after solid phase microextraction (SPME), resulting in the identification of 26 compounds. Comparative chromatograms showed qualitative differences among the pine species used, some compounds being present in one of them only. Findings demonstrate for the first time that: (i) T. pityocampa females discriminate among bouquets extracted from different host pine species and exhibit oviposition preferences; and (ii) olfactory cues play an important role in mediating the selection process.     

Food-mediated modulation of immunity in a phytophagous insect: An effect of nutrition rather than parasitic contamination

Inherent to the cost of immunity, the immune system itself can exhibit tradeoffs between its arms. Phytophagous insects face a wide range of microbial and eukaryotic parasites, each activating different immune pathways that could compromise the activity of the others. Feeding larvae are primarily exposed to microbes, which growth is controlled by antibiotic secondary metabolites produced by the host plant. The resulting variation in abundance of microbes on plants is expected to differentially stimulate the insect antimicrobial immune defenses. Under the above tradeoff hypothesis, stimulation of the insect antimicrobial defenses is expected to compromise immune activity against eukaryote parasites. In the European grape berry moth, Eupoecilia ambiguella, immune effectors directed towards microbes are negatively correlated to those directed towards eukaryotic parasites among host plants. Here, we hypothesize this relationship is caused by a variable control of the microbial community among host plants by their antibiotic metabolites. To test this hypothesis, we first quantified antimicrobial activity in berries of several grape varieties. We then measured immune defenses of E. ambiguella larvae raised on artificial diets in which we mimicked levels of antimicrobial activity of grape berries using tetracycline to control the abundance of growing microbes. Another group of larvae was raised on artificial diets made of berry extracts only to control for the effect of nutrition. We found that controlling microbe abundance with tetracycline in diets did not explain variation in the immune function whereas the presence of berry extracts did. This suggests that variation in immune defenses of E. ambiguella among grape varieties is caused by nutritional difference among host plants rather than microbe abundance. Further study of the effects of berry compounds on larval immune parameters will be needed to explain the observed tradeoff among immune system components.