Mating disruption barriers in pome fruit for improved control of oriental fruit moth Grapholita molesta Busck (Lep., Tortricidae) in stone fruit under mating disruption

Oriental fruit moth (OFM) Grapholita molesta Busck (Lep., Tortricidae) is a very important pest in commercial orchards in Victoria, Australia. Pheromone‐mediated mating disruption (MD) applied in stone fruit orchards successfully controlled OFM populations for many years, but damage to shoot tips and fruit at the edge of peach blocks located adjacent to pear blocks under insecticide treatments has become problematic. To improve protection of stone fruit against edge damage and outbreaks of OFM, all orchards were treated with sex pheromone dispensers for MD on an area‐wide basis. Area‐wide MD treatment, including all pome and stone fruit orchards in a discrete area, successfully controlled edge infestations of OFM, but was expensive. To reduce the cost of OFM control, sex pheromone dispensers for MD were applied as barrier treatments to 54–60 m of neighbouring pears adjacent to peaches under MD. Detailed monitoring of the OFM population, shoot tip and fruit damage assessments indicated that application of MD barriers on pears during two consecutive seasons provided sufficient control of OFM on peaches. This MD barrier treatment was able to reduce the number of OFM caught in all experimental peach blocks, with damage to shoot tips and fruit giving similar results to MD treatment of the whole neighbouring pear block. Extending the MD treatment area for 54–60 m into the neighbouring pear block significantly reduced the edge damage in MD‐treated peaches in the first season and almost eliminated OFM damage in the second season.     

Sprayable microencapsulated sex pheromone formulation for mating disruption of oriental fruit moth (Lepidoptera: Tortricidae) in Australian peach and pear orchards

Areawide mating disruption treatments have been effective in controlling infestation of oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae), in Australian pome and stone fruit orchards. Although successful, the areawide mating disruption program has been an expensive approach by using hand-applied Isomate dispensers. Sprayable microencapsulated (MEC) pheromone formulations that can be applied with standard spray equipment could substantially reduce the cost of application. Field trials conducted during two consecutive seasons (2002-2004) demonstrated that monthly applications of MEC-OFM phase V (3M Canada, London, Ontario, Canada) at a rate of 125 ml/ha (37.1 g [AI]/ha) in replicated 2-ha blocks of both peaches and pears reduced oriental fruit moth shoot tip and fruit damage as effectively as a single application of Isomate OFM Rosso hand-applied dispensers (500 dispensers per ha) and as or more effectively than standard broad-spectrum insecticide sprays. Fruit protection was achieved despite high oriental fruit moth population densities in both crops as measured by moth catches in terpinyl acetate food and pheromone traps. Similar numbers of oriental fruit moths were captured among all treatments in food traps but captures of males in pheromone traps were disrupted (96-99%) in pheromone-treated blocks relative to controls. The results of this study suggest that microencapsulated formulations of pheromone could be effectively used in areawide mating disruption programs for oriental fruit moth in Australia as a cost-saving alternative to reservoir-style dispensers requiring labor-intensive hand application.     

Efficacy of pheromonal control of peachtree borer (Synanthedon exitiosa (Say)) in small‐scale orchards

The efficacy of pheromone‐based mating disruption for control of the peachtree borer Synanthedon exitiosa (Say) in small‐scale peach orchards (<0.1 ha) was evaluated in a total of six blocks at two locations in New Mexico, USA, from 2010 to 2015. In treated orchards, commercial pheromone dispensers were deployed at rates of approximately 500 or 600 per ha. Pheromone‐based monitoring traps were installed in each block (treated and untreated), and catches of male moths were recorded throughout each growing season to assess the effectiveness of pheromone treatments and to determine the pest's seasonal flight activity. Levels of larval trunk infestation were assessed twice yearly by inspecting all trees at and below soil level. Infestation levels in an unreplicated block of mature peaches at one site (Los Lunas) declined from 57.5% to 8.4% while under pheromone treatment (2010–2011). Pheromone treatments in this block were discontinued in 2012, and infestation levels subsequently increased to 16.9% by spring 2015. In a replicated study in four other peach blocks at the same site, annual application of pheromones from 2012 to 2014 resulted in a significant difference in larval infestations in treated blocks compared to untreated blocks. In addition, when a single block of infested peaches at a second site (Alcalde) was treated with pheromone dispensers for three consecutive years, trunk infestation levels declined significantly, but were not completely eliminated. These results indicate that mating disruption can help protect even very small orchards from damage by S. exitiosa. However, the technique is likely to be more effective where such orchards are relatively isolated and/or where the surrounding pest pressure is moderate or low.     

番石榴实蝇寄主选择性试验

番石榴实蝇Bactrocera correcta(Bezzi)是一种为害多种水果的害虫,近年来在云南的元江暴发成灾。本试验选择番石榴实蝇的常见寄主:梨、芒果、苹果、桃、橙及芒果的不同品种进行室内试验,比较番石榴实蝇雌虫产卵对寄主的选择性及不同寄主对番石榴实蝇生长发育的影响。结果显示,番石榴实蝇雌虫对5种供试水果的寄生选择性大小依次为桃>梨>芒果>橙>苹果;番石榴实蝇对芒果不同品种的寄生选择性为三年芒>台农行1号>虎豹牙>胭脂芒>鹰嘴芒;番石榴实蝇在不同寄主上的蛀果期(卵及幼虫的历期)具有极显著的差异,以寄生桃和芒果的最短;从梨和苹果上饲养出的蛹最轻,且极显著低于其它寄主上饲养出来的蛹重;苹果上寄生的番石榴实蝇蛹重与蛀果期呈显著的正相关,而寄生梨的番石榴实蝇蛹重与蛀果期呈极显著的负相关。结果表明,番石榴实蝇雌虫产卵对不同寄主或同一寄主不同品种有明显的选择性,且该选择行为与其后代的生长发育有关。     

Volatile compounds from young peach shoots attract males of oriental fruit moth in the field

Abstract

The oriental fruit moth (OFM) is one of the most serious pests of commercial fruit orchards worldwide. Newly planted peach trees in particular, can be very attractive for mated OFM females for oviposition. Samples of airborne host plant volatiles from intact young peach shoot tips and old leaves of the same potted plants were collected and analyzed with a gas chromatograph-mass spectrometer. Chemicals present in young shoot tips, but not in old leaves, were used for field trials. Moth capture by traps with the synthetic chemicals was compared to that of the standard terpinyl acetate (TA) food trap. The TA food trap caught OFM males and mated females, but tested synthetic chemicals trapped only OFM males. We observed that the mixture of (Z)-3-hexenyl acetate: (E)-β-ocimene: (E)-β-farnesene in proportion 1:2:2 attracted OFM males. Further, 1 mg of (E)-β-ocimene, and that of (E)-β-farnesene also attracted OFM males.     

Dual pheromone dispenser for combined control of codling moth Cydia pomonella L. and oriental fruit moth Grapholita molesta (Busck) (Lep., Tortricidae) in pears

Codling moth (CM) and oriental fruit moth (OFM) are very important orchard pests worldwide, and particularly in Victoria, Australia, where both species damage pome fruit. Individually CM and OFM have been controlled successfully by pheromone‐mediated mating disruption, but treatment of pome fruit with full registered rates of two individual hand‐applied dispensers for CM and OFM could be uneconomical for growers. Field trials conducted over three seasons in plots sprayed with insecticides consistently demonstrated that dual Isomate C/OFM TT dispensers, designed to disrupt both CM and OFM, were as effective as Isomate CTT and Isomate OFM Rosso dispensers applied individually in pears for control of CM and OFM respectively. The dual‐ and individual‐species dispensers reduced moth catches and fruit damage to a similar degree. The results suggest that combined control of CM and OFM in pears by applying dual Isomate C/OFM TT dispensers at the full‐recommended rate of 500 dispensers per hectare will be more economical than use of individual species dispensers, because the price and application cost of dual dispenser is about half that for individual dispensers.     

Efficacy of a physical method for control of direct pests of apples and peaches

Two studies were conducted to test the feasibility and efficacy of using physical barriers (Maggot Barrier^® nylon mesh bags) for control of three internal pests of tree fruit (codling moth (Cydia pomonella L.), apple maggot (Rhagoletis pomonella (Walsh)) and peach twig borer (Anarsia lineatella Zeller)) and three groups of external direct pests (stink bugs (Pentatomidae), plant bugs (Miridae) and birds). Two types of Maggot Barrier^® were tested (regular and heavy duty), and two methods of securing the bags: knotting the bag on itself (‘self‐ties’) and using plastic‐coated wire ‘twist‐ties’. Bags were applied to eight cultivars of both apples and peaches, selected to give a range of maturity dates. Apples were bagged when fruit was approximately 27 mm in diameter, and peaches when the fruit was approximately 36 mm in diameter. Unbagged fruits served as controls. On apples, bagging had no effect on damage due to birds, stink bugs or apple maggot (which was present only in very low numbers), but reduced codling moth damage by 20–25% compared with unbagged controls; there were no significant differences due to bag type or tie type. In apples, a significantly higher proportion of the heavy duty bags were reusable after harvest, but on peaches, which were bagged for a shorter time, there was no difference between bag types in this respect. Bagging significantly reduced the percentage of peach fruits damaged by twig borer, birds and stink bugs, but increased the percentage of fruit with skin marks; there were no significant differences between bag or tie types. In peaches, there were significant effects on the time taken to apply bags due to both tying method and differences between individual operators. Cultivar affected pest‐related damage in both fruit types, underlining the importance of appropriate cultivar choice in pest management, particularly for organic growers and home gardeners.     

Factors influencing adult male Grapholita molesta dispersal in commercial Malus and Prunus host crops

The oriental fruit moth (OFM), Grapholita molesta (Busck) (Lepidoptera: Tortricidae), has been an economic pest of apples (Malus spp.) and peaches (Prunus spp.; both Rosaceae) in the eastern USA since the 1930s. Successful management of G. molesta with insecticides requires careful timing of these products based on sex‐pheromone trap captures of male moths. In Pennsylvania, apple and peach orchards are often planted adjacently. Factors such as trap distance from release points, host crop, and wind were considered in relation to male moth movement within and between hosts. Our practical objective was to understand male G. molesta dispersal within and between these two hosts to achieve better management. Recapture of moths decreased over distance; the majority of moths were recaptured 50–100 m from the release point regardless of crop type. Male G. molesta released into commercial apple and peach orchards were most likely to remain in the crop of release and to not exhibit host shifts over the season, even after peach fruit were harvested. Our analyses of wind direction data with respect to recapture showed that the likelihood of recapture was similar regardless of the orientation of the traps relative to the mean wind direction at peak flight times. The apple and peach host crops appeared to affect male G. molesta dispersal to the extent that wind in orchards affects their perception of pheromone. Crop effects were most likely due to the traps closest to the release points being in the same crop as the release points.     

Comparative content of some bioactive compounds in apples,peaches and pears and their influence on lipids and antioxidant capacity in rats

The aim of this study was to compare some bioactive compounds in apples, peaches and pears and their influence on lipids and antioxidant capacity in rats. The content of total polyphenols (g/100g) was 0.23 +/- 0.03; 0.22 +/- 0.03 and 0.68 +/- 0.1 in peeled fruits and 0.48 +/- 0.04, 0.47 +/- 0.04 and 1.2 +/- 0.12 in peels of peaches, pears and apples, respectively. Caffeic, p-coumaric and ferulic acids and the total radical-trapping antioxidative potential (TRAP) values in peeled apples and their peels were significantly higher than in peaches and pears, respectively. Contrarary, no significant differences in the content of dietary fiber among the studied fruits were found. The content of all studied indices in peels was significantly higher than peeled fruits (p < 0.05 ). A good correlation between the total polyphenols and the TRAP values was found in all fruits. Diets supplemented with apples and to a less extent with peaches and pears have improved lipid metabolism and increased the plasma antioxidant potential especially in rats fed with added cholesterol. The highest content of biologically active compounds and the best results in the experiment on rats makes apple preferable for dietary prevention of atherosclerosis and other diseases.     

Comparison of a sprayable pheromone formulation and two hand-applied pheromone dispensers foruse in the integrated control of oriental fruit moth (Lepidoptera: Tortricidae)

The efficacy of integrated programs using a sprayable pheromone formulation or one of two hand-applied pheromone dispensers, and a conventional oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae) control program, was compared using 4-5-ha blocks of peach orchard at three Niagara Peninsula farms during 2000-2002. In the integrated programs, chlorpyrifos and mating disruption with 3M Sprayable Pheromone, Isomate OFM Rosso, or Rak 5 hand-applied dispensers were used to control first-generation larvae, and mating disruption alone was used to control second- and third-generation larvae. In the conventional program, chlorpyrifos was used to control first-generation larvae, and pyrethroid insecticides were used to control larvae of the later generations. All programs were effective at maintaining fruit infestation by G. molesta below the industry tolerance level of 1%. An integrated program using sprayable pheromone required the use of more supplementary insecticide applications to control second- and third-generation larvae than a program using hand-applied dispensers. The elimination of insecticide sprays from integrated program blocks did not result in an increase in damage by plant bugs, Lygus spp. (Hemiptera: Miridae) or by the plum curculio, Conotrachelus nenuphar (Herbst) (Coleoptera: Curculionidae).     

Suppression of leopard moth (Lepidoptera: Cossidae) populations in olive trees in Egypt through mating disruption

The leopard moth, Zeuzera pyrina (L.) (Lepidoptera: Cossidae), is a damaging pest for many fruit trees (e.g., apple [Malus spp.], pear [Pyrus spp.] peach [Prunus spp.], and olive [Olea]). Recently, it caused serious yield losses in newly established olive orchards in Egypt, including the death of young trees. Chemical and biological control have shown limited efficiency against this pest. Field tests were conducted in 2005 and 2006 to evaluate mating disruption (MD) for the control of the leopard moth, on heavily infested, densely planted olive plots (336 trees per ha). The binary blend of the pheromone components (E,Z)-2,13-octadecenyl acetate and (E,Z)-3,13-octadecenyl acetate (95:5) was dispensed from polyethylene vials. Efficacy was measured considering reduction of catches in pheromone traps, reduction of active galleries of leopard moth per tree and fruit yield in the pheromone-treated plots (MD) compared with control plots (CO). Male captures in MD plots were reduced by 89.3% in 2005 and 82.9% in 2006, during a trapping period of 14 and 13 wk, respectively. Application of MD over two consecutive years progressively reduced the number of active galleries per tree in the third year where no sex pheromone was applied. In all years, larval galleries outnumbered moth captures. Fruit yield from trees where sex pheromone had been applied in 2005 and 2006 increased significantly in 2006 (98.8 +/- 2.9 kg per tree) and 2007 (23 +/- 1.3 kg per tree) compared with control ones (61.0 +/- 3.9 and 10.0 +/- 0.6 kg per tree, respectively). Mating disruption shows promising for suppressing leopard moth infestation in olives.     

蔷薇科植物果实花青苷积累研究进展

蔷薇科植物是植物界重要组成成员,除了观赏类植物月季、玫瑰等,还包含苹果、梨和桃等食用类果树。蔷薇科果实因为富含花青苷而具有丰富多彩的颜色,深受消费者喜爱。近年来,果树学家们围绕果实花青苷积累进行了较为深入的研究,主要探究环境因素或激素信号参与花青苷积累的分子机制。综述了蔷薇科果实着色的分子调控机制,对如何提高果实花青苷积累进行了思考总结,旨为提高蔷薇科果实的商品性和内在品质作出理论支持。     

How does winter pruning affect peach tree–Myzus persicae interactions?

Winter tree pruning is a cultural practice known to modify vegetative growth, which is likely to affect the development of pests. However, it has been poorly addressed as a cultural control method for diminishing the population levels of the green peach aphid, Myzus persicae (Sulzer) (Homoptera: Aphididae), in peach [ Prunus persica (L.) Batsch (Rosaceae)] orchards. In this study, we conducted a 2-year, on-station experiment to evaluate how winter pruning affects peach– M. persicae interactions, by examining tree vegetative growth, aphid population dynamics, and crop yield and fruit quality. We collected data under an insect-proof shelter on adult peach trees submitted to various levels of pruning and artificially infested with aphids. Our results showed that pruning enhanced shoot growth due to the proportion of growing shoots, which increased exponentially (10–60%), whereas the growth rate of growing shoots was not affected. The degree of infestation of peach trees increased with increasing pruning intensity. This effect was mainly due to the increase of the proportion of growing shoots, on which aphids developed better than on rosettes. In turn, the higher the aphid infestation, the higher the aphid-induced shoot-tip damage, leaf curling, and leaf fall that disturbed the growth of growing shoots. However, aphids did not considerably reduce fruit quality at harvest. They did not affect fresh fruit weight, and the refractometric index (indicator of sugar content) was reduced by only 3–4%. The relevance of winter pruning as a cultural method for pest control in orchards conducted under integrated fruit production guidelines is discussed.     

Species of Aspergillus causing post-harvest fruit decay in Israel

Five species ofAspergillus were isolated from post-harvest decays of pears, apples, peaches, grapes, strawberries, melons and tomatoes.A. niger was the most common species and was isolated from all types of fruits. Next in frequency wasA. flavus, which was infrequently isolated from stored grapes, tomatoes and peaches.A. wentii, A. ochraceus andA. tamarii were each cultured from only one type of stored fruit.All the fruit-decay Aspergilli were typical inhabitants of the atmospheres of store-rooms. Of these,A. niger was by far the most ubiquitous species, comprising about 80% of the total airborne Aspergilli. Each of the four other pathogenic Aspergilli comprised 0.2–0.4% of the total. However, some of the most common airborne Aspergilli such asA. versicolor (6.6% of the total), have never been isolated from any fruit decay and were also very limited in their potential pathogenicity.The highest potential pathogenicity was attributed toA. niger, which was capable of infecting all inoculated fruits except eggplants, followed by a 2–3-day incubation period. The other Aspergilli cultured, pathogenic as well as airborne, showed selective potential pathogenicity when artificially inoculated into the fruit. Fruit tissues of apples, pears and tomatoes, followed by those of peaches and grapes, were found the most suitable for Aspergilli development, whereas strawberries and, more so, eggplants were mostly resistant to infection.     

Size of orchard trees as a factor affecting behavioural control of apple maggot flies (Dipt., Tephritidae) by traps

Over a 3-year period (1997–1999), we examined the influence of tree size on effectiveness of traps for behaviourally controlling apple maggot flies, Rhagoletis pomonella (Walsh), in small blocks of trees in Massachusetts commercial apple orchards. Traps were red spheres coated with Tangletrap and baited with an attractive synthetic host fruit odour (butyl hexanoate). Traps were placed 6 m apart on perimeter apple trees of each block and were designed to intercept apple maggot flies immigrating into blocks from unmanaged host trees. Based on captures of adults by unbaited red spheres placed near the centre of each block to monitor degree of adult penetration into the interior and on percentages of fruit injured by apple maggot, traps surrounding blocks of small trees (1.5 m canopy diameter) planted at high density were more effective in controlling apple maggot flies (relative to control obtained by insecticide sprays used in comparison blocks) than were traps surrounding blocks of large trees (3.7 m canopy diameter) planted at low density, with traps surrounding blocks of medium-size trees (2.5 m canopy diameter) planted at medium density generally providing an intermediate level of control.     

Fungicide residues in pears, apples and grapes after post harvest treatments by thermonebulization

In the context of trials conducted in cold store, in order to investigate efficacy of fruit protection applying agrochemicals, the fate during the storage of two active ingredients (a.i.): pyrimethanil and imazalil, have been studied. The experimental trials were done on eight varieties of apples and pears and two of grapes. Only field use of named pesticides was already authorised on fruits and maximum residue limits (MRL) fixed. In the present biennial experimentation (apples and pears in the first year; grapes in the second one). Two fungicides formulations were applied and treatments have been executed by thermonebulization technique. The storage cell, had a volume of 110 m3 filled up with the fruits until 80% of its capacity. Each fruit variety constituted one thesis of 4 replicates. For each trial, only one treatment was performed at the beginning of conservation period (72 days for pears and apples, and 57 days for grapes). In order to estimate fungicides persistence, residues determinations have been carried out. From results obtained especially on grape, not homogenous residues distribution on treated commodities was observed. For all theses, residue level has not evidenced statistically significant decrement as function of time, behaviour not as observed in field tests. The following average values of residues have been determined: in apples and pears, 0.7 mg/kg of imazalil much lower than 5 mg/kg (RML fixed for field use), and 1.2 mg/kg of pyrimethanil little higher than 1 mg/kg (RML fixed for field use); in grapes 0.5 mg/kg pyrimethanil much lower than 3 mg/kg (RML fixed for field use).     

Effects of orchard host plants (apple and peach) on development of oriental fruit moth (Lepidoptera: Tortricidae)

Studies were designed to examine the effects of host plants (apple, Malus domestica Borkh., and peach, Prunus persica L.) on the development of oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae). Oriental fruit moth larvae developed faster on peach than on apple, both on fruit as well as on growing terminal shoots. On fruit, these differences were shown to cause significant changes in both the rate (approximately 20-60 degree-days earlier emergence on peach than on apple) and patterns of adult emergence among several cultivars of peaches and apples. Slopes of female emergence plots varied by host in 2003, with emergence occurring over a longer period on peach cultivars than on apple cultivars (with one exception). Slopes of male emergence curves did not differ by cultivar in 2003. These host-driven effects could impact the efficacy of traditional pest management approaches and probably complicate efforts to predictively model G. molesta populations in mixed cultivar orchards. Such developmental effects may help to explain previously observed differences in patterns of pheromone trap captures in peach versus apple orchards. Host-associated effects should be incorporated into future models to develop more realistic predictive tools and thus improve integrated pest management efforts.     

A comparison of various mating disruption technologies for control of two internally feeding Lepidoptera in apples

Sex pheromone mating disruption (MD) is an approach used to control several moth pest species of pome fruit by disrupting the ability of the males to find females and consequently prevent mating. The following experiments were performed to determine the effectiveness of several new and experimental sex pheromone MD technologies, and dispenser densities for simultaneous control of the codling moth (CM), Cydia pomonella (L.), and the oriental fruit moth (OFM), Grapholita molesta (Busck) (both Lepidoptera: Tortricidae), in Pennsylvania apple orchards. In one study, three MD approaches to control CM and oriental fruit moth – CM and OFM Disrupt Micro‐Flakes, Isomate CM/OFM TT, and both a CideTrak OFM and a CideTrak CM dispenser containing both codlemone and pear ester – and an insecticides‐only treatment were compared over the course of 2 years. In the other studies, the efficacy of several CheckMate Duel dispenser densities (i.e., 250, 375, 425, and 500 dispensers ha^?1) were compared against Isomate CM/OFM TT, and an insecticides‐only treatment. The CideTrak CM/pear ester combination and Isomate CM/OFM TT treatments both substantially reduced CM captures in traps in 2007 and 2008. Meanwhile, OFM trap shutdown was highest in the CheckMate Duel densities of 375 (99.9 ± 0.08%) and 500 dispensers ha^?1 (98.9 ± 0.07%) and the Isomate CM/OFM TT treatment (98.0 ± 1.13%), and lowest in the 250 dispensers ha^?1 density treatment (94.3 ± 3.23%). In orchards where OFM is the dominant pest species, a CheckMate Duel dispenser density of 375 ha^?1 is necessary for effective control, whereas higher densities are needed to control CM.     

Population dynamics of Epicoccum nigrum, a biocontrol agent against brown rot in stone fruit

Aims:  To study the population dynamics of Epicoccum nigrum on peaches and nectarines and to enhance its colonization on fruit surfaces to improve its biocontrol efficacy against brown rot.
Methods and Results:  Twelve surveys were performed to study E. nigrum populations and their effect on the number of the pathogenic Monilinia spp. conidia in peach orchards in Spain and Italy between 2002 and 2005. Fresh conidia and five different formulations of E. nigrum conidia were applied three to six times to peach and nectarine trees from full flowering to harvest. The size of the E. nigrum populations was determined from the number of colony-forming units and conidial numbers per flower or fruit. Treatment with all conidial formulations increased the size of the indigenous conidial population on peach surfaces.
Conclusions:  Formulations of E. nigrum having high viability are most effective against conidia of the pathogen when applied at pit hardening and during the month immediately before fruit harvest.
Significance and Impact of the Study:  Application of an E. nigrum conidial formulation decreased the number of conidia of Monilinia spp. on fruit surfaces during the growing season to the same extent as fungicides.