Potential for controlling codling moth Cydia pomonella (Linnaeus) (Lepidoptera: Tortricidae) in Argentina using the sterile insect technique and egg parasitoids

Codling moth is the main pest affecting apples and pears worldwide. Most pest control strategies used against this insect have relied on the use of broad‐spectrum insecticides which have led to non‐desirable effects like pesticide resistance, residues in the environment, human health concerns and the reduction of access to international markets. Therefore, alternative pest control strategies that would result in sustainable fruit production systems while taking care of the environment are strongly promoted. The use of the sterile insect technique has proven to be a valuable pest control tactic within area‐wide integrated pest management strategies, and its synergistic effect for Lepidoptera pests when combined with other biological control tactics such as parasitoids has been documented. The purposes of this research were to evaluate the response of an Argentinean codling moth strain to a sub‐sterilizing radiation dose of 100 Gy and to assess the acceptability and suitability of sterile codling moth eggs by the egg parasitoids, Trichogramma cacoeciae (Marchal) and Trichogramma nerudai (Pintureau and Gerding). Irradiated female moths survived better than irradiated male moths and non‐irradiated male and female moths. Also, the fecundity of irradiated female moths was reduced by more than 30% as compared to non‐irradiated ones whereas their fertility was close to zero. The F₁ generation was male biased with a lower fertility (inherited sterility) than the parental generation. Trichogramma cacoeciae and T. nerudai parasitized both fertile and sterile eggs. However, there was a significant reduction in acceptability for sterile eggs. Trichogramma nerudai parasitized more eggs than T. cacoeciae, but egg acceptability for this species was proportionally lower than for T. cacoeciae especially on eggs oviposited by irradiated females. Development to adult of both parasitoids species was not substantially affected by the origin of the eggs and the wasps had acceptable levels of adult emergence, survival and fecundity. These results provided useful information on the potential for controlling the codling moth using egg parasitoids and the sterile insect technique in Argentina.     

Pheromone trap and population model-based control of the codling moth, Cydia pomonella L., in Romanian apple culture

Like in most parts of the world, the codling moth, Cydia pomonello (L.), is one of the most important pests in apple orchards in the Romanian Banat region. There, the control of this pest is often inadequate and the damage and economic losses are therefore enormous. This lack of control is caused by structural problems such as the absence of an advanced distribution network for phytopharmaceutical products, obsolete spraying equipment and the insufficient exchange of knowledge and expertise of those products and the pest itself between the local research facilities and the apple growers. The purpose of this research project is rather demonstrative, because a change in the Romanian pome culture's attitude is urgently needed. Pheromone trapping and the computerized population model RIMpro Cydia, which predicts important phenological events such as adult flight and egg hatch, were used to determine the optimal spray timing. These modern pest management techniques would not only minimize pressure on the environment, but also on the income of the Romanian apple grower, for whom phytopharmaceuticals are a high-priced investment. In July 2006 a comparative study between the supervised pest control program using Calypso, Runner and Reldan, all easily obtainable and commercially available insecticides in the region, and a conventional Romanian management programme was conducted. The control plot and the two test plots were all three located in a high codling moth pressure orchard in Timi?oara. In the control plot 9,44 % of the fruits were damaged by codling moth larvae. In the plot containing the trees that were treated according to the traditional Romanian management programme 5,56 % damage was recorded, while the supervised management plot showed only 1,1% damage. Additionally damage was measured in another orchard in Periam, about 60 km away from the other plots. There, an intensive control program using Reldan, Calypso, Actare, Karate and Insegar was applied and damage measured only 0.2%. While at first glance that approach seems most efficient, it has to be noticed that it used twice as much insecticide treatments as were used in the supervised control program. Furthermore, 1 % damage is suggested by most references as being the economical threshold for treatments. The results of this comparative study clearly show that supervised codling moth control proofs to be the most profitable. Starting from August the same year, all of the control programmes in Timi?oara were stopped. Therefore the second and possibly the third generation of codling moth larvae could develop freely. In the plot which was earlier sprayed according to the warnings of RIMpro Cydia and the pheromone trap this resulted in 27.5% damaged fruits during harvest in September. In the control plot damage reached 60.95%. These results highlight the necessity of the development of an efficient codling moth control program. Once that program is fine-tuned it should be presented to the local apple growers in order to give the Romanian pome culture a boost.     

Naturally occurring Trichogramma species in olive farms in Egypt

A survey of two-year studies (2001-2003) was carried out in two olive groves sited at two representative olive growing areas, namely Paradise Park (arid area) and Burg E1-Arab farm (semi-arid area) to monitor the frequency of endemic Trichogramma species on olive moth (Prays oleae) and jasmine moth (Palpita unionalis). The suspended host bait traps were found to be a more practical and effective tool for collecting Trichogramma wasps than the attached ones. Four naturally occurring Trichogramma species were collected for the first time in Egypt from the olive groves, where releases have never been conducted. T.bourarachae was collected exclusively from Burg El-Arab farm. It seems that this wasp species adapts well to the semi-arid area. Three species, namely T. cordubensis, T. nr.pretiosum and T. cacociae were isolated from Paradise Park farm. All of these wasps were also bred from naturally parasitized host eggs during favorable and even at unfavorable temperature conditions of June-August. However, these endemic species did not occur naturally in sufficient numbers to keep the pest populations from reaching damaging levels.The excessive usage of insecticides and the oophagous predators (e.g., ants and lacewing larvae) are some factors that affect the performance of Trichogramma wasps in olive farms.The presence of warm weather wasp strains suggests the existence of well-adapted wasp species or swains which may be appropriate candidates for the control of target pests in olive groves. Additional study is required to determine the best “habitat-specific” species/strains of Trichogramma for augmentative release of naturally occurring wasps and to incorporate them into integrated pest management programs. Efforts should be made to conserve these endemic species from oophagous predators, hot weather and insecticides.The olive and jasmine moth-larvae and pupae found under tree canopies were bred and emerged parasitoids were listed.     

Composite asymmetry as an indicator of quality in the beneficial wasp Trichogramma nr. brassicae (Hymenoptera: Trichogrammatidae)

Trichogramma are egg parasitoids that are widely cultured for the control of moth pests in commercial insectaries. Stock quality is often maintained by releasing wasps from a mass culture in an area with target host eggs and initiating fresh stocks from parasitized eggs. Here we test if variability among individuals as measured by fluctuating asymmetry can be used as an additional method of quality control in Trichogramma nr. brassicae by comparing fluctuating asymmetry levels between a random sample of wasps before release and wasps that successfully reach host eggs. Although the asymmetry of individual traits was not associated with wasp fitness, a total asymmetry measure based on combining the uncorrelated asymmetries of nine traits did predict the ability of wasps to reach the eggs.     

Evaluating dispensers loaded with codlemone and pear ester for disruption of codling moth (Lepidoptera: Tortricidae)

Polyvinyl chloride polymer (PVC) dispensers loaded with ethyl (E,Z)-2,4-decadienoate (pear ester) plus the sex pheromone, (E,E)-8,10-dodecadien-1-ol (codlemone) of codling moth, Cydia pomonella (L.), were compared with PVC dispensers and a commercial dispenser (Isomate-C Plus) loaded with codlemone. Evaluations were conducted in replicated plots (0.1-0.2 ha) in apple, Malus domestica (Borkhausen) during both generations of codling moth from 2007 to 2009. Dispensers were applied at 1,000 ha(-1). Male captures in traps baited with virgin female moths and codlemone lures were recorded. Residual analysis of field-aged dispensers over both moth generations was conducted. Dispensers exhibited linear declines in release rates of both attractants, and pear ester was released at a significantly higher rate than codlemone during both time periods. The proportion of virgin female-baited traps catching males was significantly lower with combo dispenser TRE24 (45/110, mg codlemone/mg pear ester) during the second generation in 2007 and the combo dispensers TRE144 (45/75) and TRE145 (75/45) during the first generation in 2008 compared with Isomate-C Plus. Similarly, male catches in female-baited traps in plots treated with the combo dispensers TRE144 during the first generation in 2008 and TRE23 (75/110) during the second generation, in 2007 were significantly lower than in plots treated with Isomate-C Plus. No significant differences were found for male catches in codlemone-baited traps in plots treated with Isomate-C Plus and any of the combo dispensers. However, male catches were significantly lower in plots treated with Cidetrak CM (codlemone-only dispenser) than the combo TRE144 dispenser during both generations in 2009.     

The possible role of entomophagous insects in the genetic control of the codling moth,with special reference toTrichogramma

The release of sterilized codling moth enriches the animal community of the orchard. This enrichment leads to new situations also for the entomophagous species and may provide special possibilities in the use of entomophaga. Codling moth control by the sterility principle may provide certain entomophagous species with an extra food source, namely, the released moth and, possibly more important, the sterile eggs laid by these moths. This extra food may be detrimental to the sterility control because of certain predators of the adult codling moths (e.g.Vespula maculata L., other predatory insects and entomophagous birds). On the other hand, the extra food source may be advantageous. For example, sterilized moths, at the rate of release currently used in control programs, should deposit up to 5 to 10 million eggs per hectare per season. These eggs may produce 2,5 to 5 million adultTrichogramma parasites, assuming 2Trichogramma per egg and 75 % parasite mortality. Both inviable eggs of sterilized moths and gamma sterilized eggs proved to be reasonably satisfactory food for the larvae ofTrichogramma evanescens Westw. This parasite also attacked and developed in normal eggs ofAdoxophyes reticulana.Hbn. These results suggest that release of limited numbers ofTrichogramma parasites could be combined with release of sterile codling moths to provide improved control of this pest and to aid in the biological suppression of other injurious tortricids.

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Résumé Lors de l'emploi des males stériles dans la lutte contre les insectes, la population du verger est enrichie par le lacher de Carpocapses. Les prédateurs peuvent diminuer le nombre des adultes lachés, mais les œufs stériles pondus par ces derniers sont aptes à enrichir la population de Trichogrammes, comme nous l'avons montré par nos expériences en laboratoire. Cette population peut être un complément à l'utilisation des males stériles dans la lutte contre le Carpocapse. Elle peut surtout être efficace dans la lutte biologique contre d'autres Tortricides.

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This paper was read at the 3rd meeting of the IOBC working group on genetic control of Codling Moth andAdoxophyes at Montfavet, France, November 24–26, 1971.     

我国启动重大入侵害虫苹果蠹蛾基因组测序

苹果蠹蛾Cydia pomonella (L.)属鳞翅目卷蛾科,具有极强的适应性和抗逆能力,是仁果类果树的毁灭性害虫。1953年首次在我国新疆库尔勒发现,并迅速扩散危害,1987年随旅客携带物传入甘肃敦煌,造成了重大经济损失,是我国重点防控的检疫对象。近日,由中国农业科学院植物保护研究所、南京农业大学等科研单位联合启动了苹果蠹蛾的基因组测序工作。研究团队对苹果蠹蛾进行了10余代的纯化,建立了纯化品系。利用流式细胞分析和小片段文库前期测序等方法,对苹果蠹蛾基因组进行了初步的基因组前期分析。结果显示,苹果蠹蛾基因组大小约为650 Mb, 17-mer和SNP分析显示杂合度大约在0.3%-0.6%之间。经协商拟定了详细的全基因组鸟枪法测序方案后,基因组测序已经全面启动。苹果蠹蛾的基因组测序,对阐明其入侵机制、抗逆机理及防控等研究具有重要的推动意义。     

Adjusting the phenology model of codling moth (lepidoptera: tortricidae) in Washington State apple orchards

Studies were conducted with codling moth, Cydia pomonella L., to fit cumulative curves for the occurrence of injured fruits and male moth catches in sex pheromone-baited traps as a function of accumulated degree-days after the start of moth flight. Twelve data sets were collected from seven apple, Malus domestica Bordhausen, orchards in Washington State from 2003 to 2006. Cumulative data were grouped across years for orchards either treated with sex pheromone dispensers or untreated and fit to logistic equations for both the first and second generation. No significant differences were found for the cumulative curves of moth flight or egg hatch between pheromone-treated and untreated orchards; thus, these data were combined. These new logistic models for moth flight and egg hatch were compared with a widely used distributed-delay model originally developed in Michigan. The cumulative flight curves for the logistic and distributed-delay models were statistically different (slopes) for the first but not the second generation. Cumulative egg hatch in the logistic model was significantly different from the distributed-delay model (intercepts and slopes) for both generations. Most strikingly, the timing of 50% egg hatch during the first generation was delayed 100 DD in the logistic model. The potential impact of this change in the characterization of codling moth's phenology on the effectiveness of insecticide programs targeting eggs and newly eclosed larvae was examined. Possible explanations for this significant difference between the models are discussed.     

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.     

陕西省苹果蠹蛾阻截防控实践与入侵路径分析

苹果蠹蛾是威胁果业生产的检疫性有害生物,已在新疆、甘肃、宁夏、内蒙古、黑龙江、辽宁、吉林等7个省发生分布。陕西省是我国主要的苹果优质产区,阻截苹果蠹蛾向陕西扩散是保护陕西乃至全国果业生产的重要举措。通过对陕西苹果蠹蛾入侵风险、阻截防控过程取得的数据进行分析,明确了入侵路径,探讨防控策略。由新疆、甘肃、宁夏等地果汁加工原料果携带幼虫远距离方式传入陕西的风险较大;由甘肃、宁夏等地经过陕西西部果区自然传播方式进入陕西的风险加剧。提出加强果汁企业监管,拒绝携带苹果蠹蛾果品进入非疫区,是防止远距离传播的最有效措施;做好自然传播的防控策略与措施研究,已迫在眉睫。     

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.     

Mortality factors affecting immature stages of codling moth,Cydia pomonella (Lepidoptera: Tortricidae), and the impact of parasitoid complex

Codling moth, Cydia pomonella Linnaeus (Lepidoptera: Tortricidae), is a serious pest of apples worldwide. This study aimed to evaluate the mortality rate of codling moth eggs, larvae and pupae in the field in commercial and neglected apple and walnut orchards over two years, and to investigate the biodiversity and intensity of parasitoids associated with codling moth in the orchards. Five patches of wax paper containing 1-day-old codling moth eggs were placed in a neglected orchard in order to evaluate parasitism rates. Corrugated cardboard bands were placed around the trunk of 15 trees during late spring and the beginning of summer through to fruiting season to capture and measure parasitism of codling moth larvae. 5285 larvae in total were collected during this study. Mortality rate (egg?+?larvae?+?pupae) varied between the commercial and neglected orchards, reaching a maximum of (42.89% and 66.67%) in neglected apple orchards and (61.03% and 74.76%) in the neglected walnut orchard in 2003 and 2004, respectively. Trichogramma cacoeciae (Hymenoptera: Tichogrammatidae) was the only egg parasitoid recorded. Eight hymenopteran larval and pupal parasitoids belonging to several subfamilies were recorded: Cheloninae, Agathidinae, Cremastinae, Haltichellinae, Chalcidinae, Anomalinae, and Pteromalinae and one dipteran belonging to Tachininae. In conclusion, mortality factors, mainly by parasitoids, are contributing to a general reduction in codling moth larvae populations particularly in neglected orchards. The hymenopteran Ascogaster quadridentata and the dipteran Neoplectops pomonellae can contribute to biological control programmes against codling moth in the coastal region and other regions.     

Climate change effects on walnut pests in California

Increasing temperatures are likely to impact ectothermic pests of fruits and nuts. This paper aims to assess changes to pest pressure in California's US$0.7 billion walnut industry due to recent historic and projected future temperature changes. For two past (1950 and 2000) and 18 future climate scenarios (2041–2060 and 2080–2099; each for three General Circulation Models and three greenhouse gas emissions scenarios), 100 years of hourly temperature were generated for 205 locations. Degree‐day models were used to project mean generation numbers for codling moth (Cydia pomonella L.), navel orangeworm (Amyelois transitella Walker), two‐spotted spider mite (Tetranychus urticae Koch), and European red mite (Panonychus ulmi Koch). In the Central Valley, the number of codling moth generations predicted for degree days accumulated between April 1 and October 1 rose from 2–4 in 1950 to 3–5 among all future scenarios. Generation numbers increased from 10–18 to 14–24 for two‐spotted spider mite, from 9–14 to 14–20 for European red mite, and from 2–4 to up to 5 for navel orangeworm. Overall pest pressure can thus be expected to increase substantially. Our study did not include the possibility of higher winter survival rates, leading to higher initial pest counts in spring, or of extended pest development times in the summer, factors that are likely to exacerbate future pest pressure. On the other hand, initiation of diapause may prevent an extension of the season length for arthropods, and higher incidence of heat death in summer may constrain pest population sizes. More information on the impact of climate change on complex agroecological food webs and on the response of pests to high temperatures is needed for improving the reliability of projections.     

Net enclosures disrupt codling moth dispersal not establishment

1. Apple growers have pursued the use of exclusion netting to reduce pesticide inputs and maintain control of codling moth.
2. It is uncertain if these nets provide a physical or behavioural behaviour, and if they prevent codling moth establishment.
3. To address this, we conducted field trials testing the ability of commercial netting to exclude codling moth using small (3 trees) and large (48 trees) cages. Experiments were conducted to evaluate both the permeability by releasing marked sterile moths either inside or outside the small cages, and the establishment of wild codling moth in the large cages.
4. Results from the small cage study showed that netting reduced codling moth movement out of the netted plots, but virtually prevented codling moth dispersal into the plots. Codling moth capture inside the large cage plots was significantly less than in uncaged plots, but no differences were found in codling moth damage at harvest.
5. These results indicate that the netting is physically permeable to codling moth adults; however, it acts as a behavioural barrier to moth immigration. These outcomes agree with existing literature that net enclosures can provide a non-insecticidal tool to improve codling moth management, although it may not be a stand-alone technique.

     

甘肃苹果蠹蛾的发生现状与研究进展

苹果蠹蛾是果园最重要的害虫之一,1987年入侵甘肃敦煌,2005年苹果蠹蛾在河西地区严重发生。各地先后开展了一系列的防控与监测工作,并对苹果蠹蛾的发生规律及防治技术进行了大量的研究。本文就甘肃苹果蠹蛾的发生历史、为害与防控现状及其生物学、生态学及防治技术方面的研究进展进行概述,以期为全国苹果蠹蛾的防控提供参考。     

Quality of mass-reared codling moth (Lepidoptera: Tortricidae) after long-distance transportation: 1. Logistics of shipping procedures and quality parameters as measured in the laboratory

The sterile insect technique (SIT) is a proven effective control tactic against lepidopteran pests when applied in an areawide integrated pest management program. The construction of insect mass-rearing facilities requires considerable investment and moth control strategies that include the use of sterile insects could be made more cost-effective through the importation of sterile moths produced in other production centers. For codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), this is an attractive option because mating studies have confirmed the absence of mating barriers between codling moth populations from geographically different areas. To assess the feasibility of long-distance transportation of codling moths, pupae and adult moths were transported in 2004 from Canada to South Africa in four shipments by using normal commercial transport routes. The total transport time remained below 67 h in three of the consignments, but it was 89 h in the fourth consignment. Temperature in the shipping boxes was fairly constant and remained between -0.61 and 0.16 degrees C for 76.8-85.7% of the time. The data presented indicate that transporting codling moths as adults and pupae from Canada to South Africa had little effect on moth emergence, longevity, and ability to mate, as assessed in the laboratory. These results provide support to the suggestion that the STT for codling moth in pome fruit production areas might be evaluated and implemented by the importation of irradiated moths from rearing facilities in a different country or hemisphere.     

Selecting effective parasitoids for biological control introductions: Codling moth as a case study

Codling moth is a notorious fruit-boring pest that has been neglected as a target for biological control introductions. Nonetheless, it is a suitable target as it is an exotic species in the western U.S., on an exotic crop plant, in a relatively undisturbed environment, and has a lower level of abundance in its region of origin in Central Asia. In contrast, it belongs to the Olethreutidae, a family of pests with a very poor history of past successes in the biological control record. From an analysis of a stage-structured model for codling moth, the second instar and cocoon are identified as the most vulnerable life stages in terms of the potential for additional parasitism-based mortality to reduce the intrinsic rate of increase of codling moth populations. Criteria used in the selection of effective parasitoids for introduction to the western U.S. from Central Asia were the absence of antagonistic interactions between parasitoid species, greater than 30% parasitism observed in the region or origin, and parasitoids targeting the second instar and cocoon stages. Three species selected for introduction were the larval parasitoid Bassus rufipes, and two cocoon parasitoids Liotryphon caudatus and Mastrus ridibundus. Of these, M. ridibundus also exhibits three attributes considered to be of value from a theoretical perspective, a positive response to patches of higher host density, a shorter generation time, and production of a greater number of female offspring per host attacked.     

Effect of anti‐hail nets on Cydia pomonella behavior in apple orchards

Over the last 10 years, the use of nets to protect pome fruit from hailstorms has increased. In this study, we investigated the effect of these nets on the behavior of the codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), a major pest of apple, Malus domestica Borkh. (Rosaceae). Experiments were carried out in net‐covered and uncovered apple orchards treated with conventional insecticides. The number of codling moth males caught in pheromone‐ and virgin female‐baited traps was significantly reduced in net‐covered compared to uncovered plots. In addition, inhibition of mating by the net was demonstrated by significant reductions in mating of tethered virgin females. Fruit injury was consistently lower in net‐covered plots vs. uncovered plots. Because of the reductions in male trap catch, the reduced female mating frequency, and the lower level of damage, we conclude that flat anti‐hail nets have a disruptive effect on the reproductive behavior of the codling moth.     

Monitoring codling moth (Lepidoptera: Tortricidae) with passive interception traps in sex pheromone-treated apple orchards

Male and female codling moth, Cydia pomonella (L.), were monitored with passive interception traps (PI-traps) in apple orchards treated with sex pheromone dispensers. The proportion of mated females recaptured by PI-traps was significantly higher than the proportion released after the release of both sexes into a codling moth-infested orchard. However, no significant difference occurred between the proportion of mated females recaptured and released when only females were released into uninfested orchards. Replicated nine-tree apple plots situated either on the edge or in the center ofpheromone-treated apple orchards were monitored with PI-traps during first moth flight in 1995 and during both flights in 1996. Moths caught on PI-traps were predominately males. The first male moths were captured 7-10 d before females during the first flight in both years. Initial capture of virgin and mated females on PI-traps coincided in 1995. Mated females were captured 14 d after the first virgin females in 1996. The mean proportion of females that were mated ranged from 32 to 55% during the first flight and 85 to 92% during the second flight. Moth catch and fruit injury were significantly higher in the edge versus the center plots. The numbers of total and female moths caught with PI-traps were significantly correlated with fruit injury for each generation. The percentage of female moths caught on PI-traps that were mated was 32% lower and the mean oocyte load of all females was 42% higher in a pheromone-treated apple orchard than in the untreated crabapple grove monitored during May and June 1997.     

Population genetic structure of codling moth (Lepidoptera: Tortricidae) from apple orchards in central Chile

Codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), is the main pest of pome fruits worldwide. Despite its economic importance, little is known about the genetic structure and patterns of dispersal at the local and regional scale, which are important aspects for establishing a control strategy for this pest. An analysis of genetic variability using microsatellites was performed for 11 codling moth populations in the two major apple (Malus domestica Borkh) cropping regions in central Chile. Despite the geographical distances between some populations (approximately 185 km), there was low genetic differentiation among populations (F(ST) = 0.002176), with only slight isolation by distance. Only approximately 0.2% of the genetic variability was found among the populations. Geographically structured genetic variation was independent of apple orchard management (production or abandoned). These results suggest a high genetic exchange of codling moth between orchards, possibly mediated by human activities related to fruit production.