Pheromone-based communication disruption ofAdoxophyes orana on peach using the new RAK 3+4 dispensers and their effect on development of fruit rot diseases

The effectiveness of the pheromone-based communication disruption method was examined against the summerfruit tortrix,Adoxophyes orana F.v.R. (Lepidoptera: Tortricidae), a pest of peach trees, using the new RAK 3+4 dispenser (BASF). NoA. orana males were captured in pheromone traps inside the experimental orchards, which were saturated with the RAK 3+4 dispensers. The percent of damaged leaves was practically zero, while the level of damaged fruits was 0–6% in pheromone-treated orchards. The percentage of fruit rot caused byMonilinia laxa was lower in pheromone-based communication disruption orchards than in the control. It was concluded that the RAK 3+4 dispenser could be used againstA. orana as an economical and environmentally friendly method.     

信息素迷向法规模化防治梨小食心虫

梨小食心虫是梨树和桃树上一种重要的蛀食性害虫,为了推动果园害虫的无公害防治,2010年在山东省莱阳市的桃园和梨园应用信息素散发器对梨小食心虫进行了迷向防治研究。在应用信息素散发器的桃园与梨园中,梨小食心虫发生数量明显低于对照园,使用密度增加,梨小食心虫的发生数量降低,迷向率增加。每公顷施用信息素散发器450、900、1350根的桃园,对梨小食心虫的迷向率分别为67.80%、80.14%、89.29%,而梨园中对梨小食心虫的迷向率分别为84.17%、93.41%、98.17%。桃园与梨园施用信息素散发器后,梨小食心虫的蛀果率明显低于对照园,桃园与梨园对梨小食心虫的防治效果分别在40.34%～73.57%和54.24%～92.38%之间。研究表明,梨园中信息素散发器对梨小食心虫的防治效果高于桃园。     

桃小食心虫成虫种群动态监测与防治指标

为明确桃小食心虫Carposina sasakii Matsumura成虫的种群动态变化,2002—2014年在陕西省礼泉县当地具有代表性的苹果园中,采用性诱剂诱捕器对桃小食心虫成虫的种群动态进行系统监测,并于2010年和2011年的7—8月桃小食心虫成虫盛发期,系统调查了成虫发生量与苹果着卵量的关系,建立基于性诱剂监测的桃小食心虫成虫防治指标。结果显示,苹果园桃小食心虫成虫的种群动态、始见期和终见期在年度之间差异很大,每年主要集中在6—8月发生;桃小食心虫成虫每年出现多次无规律的高峰,但第1代成虫高峰期发生的早晚与越冬代成虫高峰期出现的早晚有密切联系,即越冬代成虫高峰期出现早,则第1代成虫高峰期出现也就相对较早,且越冬代成虫发生量明显多于第1代成虫。性诱剂诱捕的成虫与卵果率之间呈极显著的对数关系,当以卵果率1%或2%为防治指标时,性诱剂诱捕器诱蛾量为8.3头/诱捕器·日或30.0头/诱捕器·日。     

Distribution and damage caused by Halyomorpha halys in Italy

Since the first occurrence of Halyomorpha halys (Heteroptera: Pentatomidae) in Italy in 2012, the pest has spread in the Po Valley causing severe damage in summer 2015, particularly in pear orchards. At present, populations of H. halys have been reported in the regions of Emilia‐Romagna (Modena, Reggio Emilia and Bologna provinces), Piedmont, Lombardy, Veneto and Friuli. The damage caused by H. halys is typical of pentatomids and is aggravated by the pest's polyphagy and by the behaviour of adults which move continuously from plant to plant, from hedges or herbaceous crops to fruit orchards. The unpredictability of H. halys’ movements, along with the effect of the aggregating pheromone that concentrates the pest in certain areas of the orchards, therefore making chemical spraying complicated.     

Phenology modelling of major insect pests in fruit orchards from biological basics to decision support: the forecasting tool SOPRA*

The forecasting tool SOPRA has been developed with the objective of optimizing timing of monitoring, management and control measures of insect pests in fruit orchards in Switzerland. Applying time‐varying distributed delay approaches, phenology‐models were developed driven by solar radiation, air temperature and soil temperature on hourly basis. Relationships between temperature and stage‐specific development rates for relevant stages of the life cycles were established under controlled laboratory conditions for Dysaphis plantaginea, Hoplocampa testudinea, Cydia pomonella, Grapholita lobarzewskii, Cacopsylla pyri, Rhagoletis cerasi, Anthonomus pomorum and Adoxophyes orana. The implementation of body temperatures in the models is based on habitat selection and biophysical modelling of habitat conditions. In order to validate modelling, phenology predictions were compared with several years of independent field observations. On the basis of local weather data, the age structure of the pest populations is simulated and crucial events for management activities are announced. Through a web interface, the simulation results are made available to consultants and growers ( http://www.sopra.info ) and the latter can be applied as a decision support system for the eight major insect pests of fruit orchards in the alpine valleys and north of the Alps on local and regional scale.     

糖醋酒液对桃园和苹果园中桃蛀螟的诱捕效果分析

为研究桃园和苹果园中桃蛀螟Conogethes punctiferalis成虫的发生动态,探讨糖醋酒液对桃蛀螟的诱捕效果,于2015—2016年利用糖醋酒液和性信息素对泰安市郊区桃园和苹果园中桃蛀螟成虫的全年发生动态进行监测,并比较糖醋酒液诱捕器在不同悬挂高度0、1.0、1.5、2.0和2.5 m下对桃蛀螟雌、雄成虫的诱捕效果。结果显示,2015—2016年,泰安市郊区桃园和苹果园中桃蛀螟成虫田间始发期为4月下旬至5月中旬,发生末期均为10月上旬。糖醋酒液和性信息素诱捕器监测结果均显示,桃蛀螟成虫群体数量发生高峰期为9月上旬—10月上旬,且在此期间二者的诱捕量无显著差异。糖醋酒液能够同时诱捕桃蛀螟雌、雄成虫,且以雄成虫为主,在桃园和苹果园中,2016年的雄成虫诱捕量分别占总诱捕量的87.62%和88.29%。糖醋酒液诱捕器在地上0～2.5 m悬挂高度均能诱捕到桃蛀螟成虫,其中诱捕器悬挂于地上2.5 m高度时诱捕量最多,显著高于其它悬挂高度处理。表明糖醋酒液可以通过有效诱捕桃蛀螟成虫来准确监测其群体发生动态。     

Trapping Cryptophlebia illepida and C. ombrodelta (Lepidoptera: Tortricidae) in macadamia in Hawaii

Abstract

Two species of Cryptophlebia found in Hawaii's macadamia orchards are active in different parts of a tree canopy. C. illepida (Butler) males were mostly caught in traps hung 1·5 m to 9.1 m from the ground; whereas C. ombrodelta (Lower) males were caught from 9.1 m to 15.2 m. A plastic, cylindrical sticky trap caught equal numbers of C. illepida males as Pherocon 1C traps but more than delta traps. A synthetic pheromone blend of 93% (Z)‐8‐dodecenyl acetate, 4% (E)‐8‐dodecenyl acetate, 1% (Z)‐8‐dodecenol, and 2% (2)‐7‐dedecenyl acetate attracted more males than other blends. No significant differences were detected between the two Cryptophlebia species in their response to the four‐component pheromone blend when traps were hung 4.6 m from the ground.     

Phenological forecasting model for Cydia funebrana*

A simulation model of the phenology of Cydia funebrana (plum fruit moth) is presented. The Logan function was used to determine the temperature‐dependent developmental rates of the eggs, larvae and pupae; a linear equation was used for the ageing rate of females. The mean fecundity of females as a function of age was expressed by a modified Bieri's function. In order to simulate the stochastic process, a time‐distributed delay model was used. Results from the validation of the model in northern Italy (1995 and 1997) are reported. Catches of male moths in pheromone traps and oviposition activity were monitored in orchards of mid‐ and late‐ripening plum cultivars. The model was then run using temperature data from each farm. When the oviposition activity forecast by the model was compared with that actually observed in the orchards, good correlations between actual and forecast oviposition were obtained. The model is already available for technicians in Emilia‐Romagna and is a valuable tool in integrated fruit production; it gives an indication of the right moment to apply insecticides or to carry out further monitoring activity to assess the risk of C. funebrana damage (e.g. by sampling actual oviposition on just a single occasion).     

Mobile mating disruption of light-brown apple moths using pheromone-treated sterile Mediterranean fruit flies

BACKGROUND: Public opposition to aerial application of sex pheromone for mating disruption of light‐brown apple moth (LBAM), Epiphyas postvittana (Walk.), in California stopped its further use in the ca $ 74 million eradication programme in 2008, underscoring the need for other eradication tactics. It is demonstrated that pheromone‐treated sterile Mediterranean fruit flies (medflies), Ceratitis capitata Wied., can disrupt communication in male moths. RESULTS: Medflies topically dosed with moth pheromone (E)‐11‐tetradecenyl acetate showed a no observed effect level (NOEL) of ～10 µg fly^?1, with increasing toxicity from 30 to 100 µg fly^?1. Greater potency and longevity of attraction and lower mortality were achieved using microencapsulated pheromone. Releases of 1000 pheromone‐treated medflies ha^?1 prevented male moth catch to synthetic lures in treated 4 ha plots for 1 day in suburban Perth, Australia. Releases of ca 3000 pheromone‐treated medflies ha^?1 disrupted catch to single female moths in delta traps, and to synthetic pheromone lures. Percentage disruption on the first four nights was 95, 91, 82 and 85%. CONCLUSIONS: Disruption of moth catch using pheromone‐treated medflies is a novel development that, with future improvement, might provide a socially acceptable approach for application of the insect mating disruption technique to control invasive insects in urban environments. Adequacy of payload and other issues require resolution. Copyright © 2011 Society of Chemical Industry     

Effects of pheromone loading, dispenser age, and trap height on pheromone trap catches of the oriental fruit moth in apple orchards

The effects of field aging (0–28 days) and pheromone loading rate on the longevity of red rubber septa loaded with the sex pheromone blend of the oriental fruit mothGrapholita molesta (Busck), were evaluated in North Carolina apple orchards in 2002. Separate field tests examined the influence of trap height and pheromone loading rate of rubber septa on trap catches of adultG. molesta males in an abandoned orchard. The loss of the major pheromone component, (Z)-8-dodecenyl acetate (Z8–12:OAc), from red rubber septa over a 4-week period exhibited a relatively constant release rate with 30, 100 and 300 μg pheromone. Trap catch was significantly higher in pheromone traps placed in the upper canopy than in those in the lower canopy. Pheromone traps baited with 100μg lures caught more moths compared with those loaded with 300 μg. There was no apparent relationship between pheromone trap catch and septa age, with trap catch appearing to be primarily a function ofG. molesta population density. http://www.phytoparasitica.org posting May 14, 2006.     

Agricultural factors affecting Verticillium wilt in olive orchards in Spain

In recent years, the spread of Verticillium wilt in olive orchards, caused by the soil-borne pathogen Verticillium dahliae, is often related to intensive modern farming of highly productive cultivars, planted at high densities, usually irrigated, and under a mechanised system. The effects of agricultural factors associated with olive orchards were investigated in an important olive-growing area in southern Spain, as tools in predicting outbreaks of the disease. A stratified double-sampling technique was designed to determine the number of olive orchards needed to survey. A sampling survey was conducted from 2002 to 2005 in 873 olive orchards randomly selected, the owners were interviewed for details of agronomic factors, and orchards were inspected for the presence or absence of the disease. Polymerase chain reaction assays were carried out for identifying V. dahliae pathotypes. Pathogen prevalence showed a significant linear correlation with the mean plant density (r ² = 0.93), associated predominantly with a less virulent non-defoliating pathotype (r ² = 0.96). Overall, irrigation × high density caused disease incidence to peak in super-high-density olive-tree-planting systems. Olive orchards that had V. dahliae, however, did not differ in pathogen prevalence regardless of the olive cultivars. Young olive orchards were significantly more affected by V. dahliae than were old ones, particularly orchards with trees 8 to 12 years old. Irrigation increased pathogen prevalence and disease incidence in very young orchards (<7 years old). The prevalence of the non-defoliating pathotype was statistically high in young orchards whereas the prevalence of a highly virulent defoliating pathotype was high in old orchards.     

Effects of application rate and interval on the efficacy of sprayable pheromone for mating disruption of the oriental fruit mothGrapholita molesta

The efficacy of microencapsulated sprayable pheromone was evaluated at different application rates and intervals for mating disruption of the oriental fruit moth,Grapholita molesta (Busck), in apple orchards during 2002. The following treatments were arranged in a randomized complete block design with three replications: (i) a low rate of pheromone (6.2 g a.i. ha⁻¹) applied at 14-day intervals, (ii) a medium rate of pheromone (12.4 g a.i. ha⁻¹) applied at 28-day intervals, (iii) a high rate of pheromone (24.7 g a.i. ha⁻¹) applied at 28- day intervals, and (iv) a non-pheromone control (insecticides only). The combination of a single insecticide application against first generationG. molesta at petal fall with one pheromone application each for the second, third and fourth generations at 12.4–24.7 g a.i. ha⁻¹ successfully controlled low populations. Pheromone-treated blocks. had significantly lower trap catches than those in the insecticide-treated control blocks. Among pheromone treatments, significantly more moths were caught in the 6.2 g compared with the 12.4 and 24.7 g rates. Fruit damage was <1% at harvest and there were no significant differences among treatments. Low rate frequent applications of sprayable formulation appeared to be effective under low pest pressure but efficacy declined with increasing populations. Further studies are needed to demonstrate the effectiveness of this approach under higher pest pressure. http://www.phytoparasitica.org posting July 13, 2005.     

Studies on the sterile male technique as a means of control of Adoxophyes orana (Lepidoptera,Tortricidae). 5. Release trials

In release trials with sterile males ofAdoxophyes orana in an apple orchard of 1.4 ha in 1971 and in an other orchard of 1.9 ha in 1973 and 1974 a marked decrease in the population ofA. orana was observed. Release of sterile males seemed to cause the effect. Immigration of moths, usually not more than a few hundreds, did not disturb the programme but would obviously prevent eradication and control at low level. Other tortricids increased in the absence of chemical control but less competition fromA. orana might also offer some explanation. The other tortricids were responsible for up to 9% damage among apples. Consequently the sterile male method specifically against one pest does not result in an important reduction in the number of sprays and a specific control method is not always the solution to pest problems in integrated control.Samenvatting Twee loslaatproeven met steriele mannetjes ter bestrijding van de vruchtbladrollerAdoxophyes orana worden beschreven.In de eerste, uitgevoerd in 1971 bij Overberg, werden 41000, met 25 krad gamma-stralen gesteriliseerde mannetjes bij de eerste vlucht, en 56000 tijdens de tweede vlucht losgelaten. In geen van de proeven werden de mannetjes van de wijfjes gescheiden. De sexe verhouding was circa 11. Alle losgelaten motten waren gemerkt met Calco Red Oil D. Terugvangsten met vanglampen gaven een verhouding tussen losgelaten en wilde motten van 41 in de eerste vlucht en 131 in de tweede vlucht (Tabel 3). Tellingen van de aantallen larven, door het afzoeken van hele bomen, wezen op teruggang van het aantal rupsen (Tabel 4). De vangst aan wilde mannetjes in de vanglamp wijst op een duidelijke immigratie uit de omgeving (Tabel 3). Het aantal andere bladrollersoorten bleek sterk toe te nemen (Tabel 4).In de tweede proef, uitgevoerd in 1973 en 1974 bij Lienden, werden tijdens de eerste en tweede vlucht van 1973 resp. 17000 en 37000 mannetjes losgelaten en in 1974 resp. 55000 en 26000. De bestralingsdosis bedroeg 25 krad. De wijfjes werden in gelijke aantallen mee losgelaten. De motten waren gemerkt met Rotor kleurstoffen en werden teruggevangen in feromoonvallen. De terugvangverhouding bedroeg in 1973 tijdens de eerste vlucht 91 (Tabel 3). In 1974 was deze resp. 91 en 211. De larvetellingen (Tabel 4) wezen weer op sterke teruggang vanA. orana. Ook hier bleken andere soorten sterk in aantal toe te nemen (Tabel 5) zodat toch nog een vrij belangrijke bladrollerschade in de oogst ontstond.Hoewel de populatiedaling in beide proeven zeer duidelijk was, kan toch nog niet met zekerheid tot succes van de methode worden geconcludeerd omdat in de laatste jaren de betekenis vanA. orana in geïntegreerd bestreden percelen afnam. Een belangrijke moeilijkheid blijkt ook de statistische bewerking van de tellingen te zijn, daarA. orana zeer sterk pleksgewijs voorkomt. Het verdelingstype kon niet altijd worden vastgesteld maar leek soms op dat van een negatieve binomiaal met k-waarden keliner dan 1 (Tabel 6).Ook in deze proef werden aanwijzingen voor immigratie gevonden (Tabel 8). Deze is niet zo sterk dat het loslaatprogramma werd verstoord maar zou wel een uitvoerige campagne in de weg staan.Door het toenemend optreden van andere bladrollersoorten wordt het doel van de specifieke bestrijding vanA. orana verijdeld, daar toch nog chemische bestrijding noodzakelijk blijft. De specifieke bestrijdingsmethode hoeft dus niet altijd een oplossing van een plaagprobleem in de geïntegreerde bestrijding te geven.     

Evaluating sex-pheromone- and kairomone-based lures for attracting codling moth adults in mating disruption versus conventionally managed apple orchards in Pennsylvania

BACKGROUND: Effectiveness of different types of commercial sex‐pheromone‐ and kairomone‐based lures for attracting codling moth adults may vary under different pest management practices. The attractiveness of four types of codling moth (CM) lures (CM L2 Long‐Life^®, CM 10X Megalure^®, Pherocon CM DA^® and Pherocon CM‐DA Combo^®) was evaluated in commercial apple orchards either treated with sex pheromone mating disruption (MD) or only conventional insecticides (non‐MD) in Adams County, Pennsylvania, in 2006 and 2007. RESULTS: CM DA Combo lure was most effective in terms of mean seasonal weekly moth capture as well as mean cumulative moth capture in MD orchards. In both years, the CM L2 lure was as attractive to adult moths as the CM DA Combo lure in non‐MD orchards. The CM DA and CM 10X lures caught significantly fewer moths in both MD and non‐MD orchards compared with the CM DA Combo lure. CONCLUSIONS: ON the basis of mean seasonal weekly moth capture as well as mean cumulative moth capture, the CM DA Combo and CM L2 lures were found to be significantly more effective for monitoring CM adults in both MD and non‐MD orchards. In contrast, the CM DA and CM 10X lures were not as effective in either type of orchard. Copyright © 2011 Society of Chemical Industry     

三种果园中实蝇粘虫板对橘小实蝇及天敌的诱杀作用

为减少实蝇粘虫板对天敌的诱杀作用,完善实蝇粘虫板在果园的使用方法,于2018年和2019年分别在湖南省农业科学院园艺研究所橘园、桃园、梨园悬挂实蝇粘虫板,调查其诱杀的橘小实蝇、其他害虫和天敌数量。结果表明,橘园、梨园和桃园共诱杀到15个种、4个科和9个类群,包括靶标害虫橘小实蝇、其他害虫和天敌。3种果园中粘虫板诱杀的昆虫种、科或类群数量有差异,其中梨园中诱杀的昆虫总数最多,为13 653头,其次是桃园,橘园中诱杀的昆虫总数最少。在橘园、梨园和桃园中,橘小实蝇的相对丰富度分别为5.90%、23.45%和21.73%,最早出现时间均为6月;在橘园中橘小实蝇诱杀量高峰期在8月下旬至10月上旬,下半年天敌诱杀量高峰期略滞后于橘小实蝇的诱杀量高峰期,在梨园和桃园中橘小实蝇诱杀量高峰期主要集中在7月中下旬至10月中旬,橘小实蝇诱杀量高峰期与天敌诱杀量高峰期无明显相关性;3种果园中粘虫板诱杀的主要天敌有瓢虫、食蚜蝇、草蛉、寄生蜂,桃园和梨园中诱杀的草蛉较多,橘园中诱杀的瓢虫和寄生蜂较多。应用实蝇粘虫板防控橘小实蝇时,梨园和桃园应从6月上旬开始悬挂,橘园应从8月上旬开始悬挂,先少量悬挂,根据诱杀橘小实蝇数量,再逐渐增加粘虫板。     

Plant volatile compounds shorten reaction time and enhance attraction of the codling moth (Cydia pomonella) to codlemone

BACKGROUND: The codling moth is the most serious pest of deciduous tree fruit (apples, pears, crabapples, walnuts, quince) worldwide. The high frequency of insecticide treatments per season has resulted in breakdown of codling moth control owing to insecticide resistance. As an alternative, integrated pest management includes mating disruption to achieve population suppression in orchards. Under this scheme, the sex pheromone of the codling moth, (E, E)‐8,10‐dodecadien‐1‐ol (codlemone), is released from dispensers in crops to hinder mating by luring males. Increasing the attractiveness of codlemone formulations to codling moth males can be regarded as a key to increasing the efficacy of mating disruption. With this aim, the effects of adding plant volatiles on the behavioural responses of codling moth males to codlemone were tested. RESULTS: Adding R(+)‐limonene, linalool, (E)‐β‐farnesene or ethyl (E, Z)‐2,4‐decadienoate to codlemone significantly increases the proportion of males flying to the pheromone source in a wind tunnel. The response level is equivalent to that of males responding to females releasing codlemone. Using real‐time recordings, it is shown how these four plant products also shorten the response time of males to codlemone under the behavioural criteria time to activation, time till upwind flight is induced and time to pheromone source contact. CONCLUSION: Shortening the response time and increasing source location by males of dispensers releasing codlemone with R(+)‐limonene, linalool, (E)‐β‐farnesene or ethyl (E, Z)‐2,4‐decadienoate added would enhance mating disruption through better engagement of males with dispensers, to the detriment of females. Copyright © 2011 Society of Chemical Industry     

Field evaluation of synthetic sex pheromone traps for the cocoa mirid Sahlbergella singularis (Hemiptera: Miridae)

BACKGROUND: Field trapping experiments were conducted to evaluate the attractiveness of five different pheromone blends as well as the impact of trap design on attractiveness towards cocoa mirids, Sahlbergella singularis Hagl. and Distantiella theobroma (Dist.), in Cameroon. RESULTS: A total of 361 adults of S. singularis (359 males and two females) were caught. The highest numbers of mirids were found in traps with pheromone blends that combined a monoester and a diester, compared with traps with the diester or the monoester individually and control traps with no pheromone. Rectangular traps caught significantly more mirids compared with delta traps. The mean number of 5.1 mirids trap^?1 year^?1 caught in rectangular traps was significantly higher compared with the 1.8 mirids trap^?1 year^?1 for the delta traps. CONCLUSION: The data revealed that rectangular traps containing pheromone blends combining both the monoester and the diester have a good potential to lure and trap adult males of S. singularis on cocoa farms. The pheromone blends used were specific for S. singularis, and the use of pheromone traps appears to be a promising strategy for incorporation into integrated pest management strategies for the monitoring or even the control of S. singularis in cocoa plantations. Copyright © 2011 Society of Chemical Industry     

Spatial analysis of pheromone trap catches of codling moth (<Emphasis Type="Italic">Cydia pomonella</Emphasis>) in two heterogeneous agro-ecosystems,using geostatistical techniques

From 2000 to 2002, local distribution and dispersion patterns of the codling moth,Cydia pomonella (L.) (Lepidoptera: Tortricidae), captured in pheromone traps were investigated in two heterogeneous agro-ecosystems (A and B) of the Molise region, in central Italy. The main objectives of this study were to determine the temporal and spatial variations in distribution and abundance of codling moth inside and outside apple orchards located in these study areas, and to evaluate the importance of the presence of several host plants in relation to the observed distribution. Trap catches of male moths were clumped during almost all sampling weeks. Spatial characterizations obtained by means of geostatistical methods illustrate that the high trap capture foci were confined to the productive apple orchards for both agro-ecosystems or in small groups of apple trees, and in the case of study area B, in a zone containing pear trees, service trees and walnut trees. Occasionally moths were found in traps installed outside these zones. Furthermore, the position of high male population foci seems not to change during a single flight period. The results obtained are discussed with respect to the improvement of Integrated Pest Management programs employed in apple orchards situated in heterogeneous landscapes. http://www.phytoparasitica.org posting July 14, 2004.     

Dynamics of post‐harvest pathogens Neofabraea spp. and Cadophora spp. in plant residues in Dutch apple and pear orchards

Post‐harvest diseases of apple and pear cause significant losses. Neofabraea spp. and Cadophora spp. infect fruits during the growing season and remain quiescent until disease symptoms occur after several months in storage. Epidemiological knowledge of these diseases is limited. TaqMan PCR assays were developed for quantification of N. alba, N. perennans, C. malorum and C. luteo‐olivacea in environmental samples. Various host tissues, dead weeds and grasses, soil and applied composts were collected in 10 apple and 10 pear orchards in May 2012. Neofabraea alba was detected in 73% of samples from apple orchards and 48% from pear orchards. Neofabraea perennans was present in a few samples. Cadophora luteo‐olivacea was detected in 99% of samples from apple orchards and 93% from pear orchards, whilst C. malorum was not detected in any sample. In apple orchards, highest concentrations of N. alba were found in apple leaf litter, cankers and mummies, and of C. luteo‐olivacea in apple leaf litter, mummies and dead weeds. In pear orchards, N. alba and C. luteo‐olivacea were found in highest concentrations in pear leaf litter and in dead weeds. Substrate colonization varied considerably between orchards. The temporal dynamics of pathogens was followed in four apple orchards and four pear orchards. In apple orchards the colonization by pathogens decreased from April until August and increased from September until December. This pattern was less pronounced in pear. Knowledge on population dynamics is essential for the development of preventative measures to reduce risks of fruit infections during the growing season.     

Occurrence and pathogenicity of Armillaria tabescens on almond in Greece 1

Armillaria tabescens was detected in almond orchards in three different localities of central Greece (Fthiotis county). Mycelial fans of the fungus were observed in the roots and the base of the trunk of dead or dying trees. Symptoms of gummosis were also evident on the bark of infected trees. One of the orchards had been established on land cleared of a Quercus coccifera forest. A. tabescens was identified from basidiocarps developed in vitro, as well as in haploid–haploid mating tests with testers from France. This is the first report of A. tabescens on almond in Europe. Although the fungus has been characterized as a weak parasite or even non-pathogenic to other hosts, it caused considerable damage in almond orchards. In inoculation trials, it was shown that one-year-old almond trees were susceptible to three Armillaria species tested: A. mellea, A. gallica and A. tabescens. The most virulent species in these tests was A. mellea while the least virulent was A. tabescens. The pathogenicity tests verified the ability of A. tabescens to be pathogenic to almond.