Mating disruption for the control of Aonidiella aurantii Maskell (Hemiptera: Diaspididae) may contribute to increased effectiveness of natural enemies

BACKGROUND: New directives on sustainable use of pesticides have encouraged research on efficient alternative pest control methods. In the case of the California red scale (CRS), Aonidiella aurantii (Maskell), this imperative, along with the many difficulties in controlling this pest, have led to the investigation of new approaches. Previously developed mating disruption (MD) dispensers, together with the augmentative releases of the parasitoid Aphytis melinus DeBach, are here considered as a combined strategy for use against A. aurantii. RESULTS: Efficacy of MD was demonstrated by a mean reduction of 80% in CRS male catches and a mean fruit damage reduction of 83% compared with the control. A delay in the development of A. aurantii instars was observed in the MD plot. This delay increased the period of exposure of the susceptible instars to natural enemies, which resulted in higher predation and parasitism levels in the MD plot. Under laboratory conditions, A. melinus mating behaviour and effects on A. aurantii were not significantly altered in a CRS-pheromone-saturated environment. CONCLUSION: Mating disruption pheromone did not affect the behaviour or level of parasitism by A. melinus or the incidence of other generalist predators. Therefore, A. aurantii pheromone appears to be compatible with augmentative releases and biological control, making its use a good strategy for CRS management. Copyright © 2011 Society of Chemical Industry     

Mating disruption of California red scale,Aonidiella aurantii Maskell (Homoptera: Diaspididae), using biodegradable mesoporous pheromone dispensers

BACKGROUND: The control of California red scale, Aonidiella aurantii (Maskell), has encountered many difficulties, which has raised interest in alternative control methods. Up to now, the A. aurantii sex pheromone has been used only for monitoring. In a previous work the authors described a biodegradable mesoporous pheromone dispenser for mating disruption. To verify the efficacy of these dispensers, three field trials were conducted, and the results are shown in this paper. RESULTS: The study of the release profile of these dispensers revealed a mean pheromone emission value of 269 µg day^?1 and levels of residual pheromone of 10% at the end of 250 days. During the second flight, an A. aurantii male catch reduction of 98% was achieved in the mating disruption plot of trial 1, 93.5% in trial 2 and 76.7% in trial 3. During the third flight, reductions were 94.1, 82.9 and 68.1% in trials 1, 2 and 3 respectively. Considering damaged fruit with more than five scales, reductions of about 80 and 60% were obtained in the mating disruption plots of trials 2 and 3, respectively, compared with an untreated plot, and a reduction of about 70% in trial 1 compared with an oil‐treated plot. CONCLUSION: Mating disruption has been found to be an efficient technique to control this pest, working equally well to a correctly sprayed oil treatment. Further studies are needed to improve the determination of the time of dispenser application and evaluate the effects of the pheromone on natural enemies. Copyright © 2010 Society of Chemical Industry     

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     

Studies on the development of a mating disruption system to control the tomato leafminer, Tuta absoluta Povolny (Lepidoptera: Gelechiidae)

BACKGROUND: The tomato leafminer (Tuta absoluta Povolny) has rapidly colonised the whole Mediterranean and South‐Atlantic coasts of Spain, and it has become a key problem in both outdoor and greenhouse crops. New control methods compatible with biological control are required, and mating disruption appears to be a perfect method in current agriculture, as it is an environmentally friendly and residue‐free technique. IPM packages tested have included the use of pheromones to detect populations, but there has not been much previous research on mating disruption of T. absoluta. In this work, pheromone doses varying from 10 to 40 g ha^?1, emitted at a constant rate over 4 months, were tested in greenhouses with different levels of containment in order to evaluate the efficacy of mating disruption on T. absoluta. RESULTS: Trials on containment level revealed that the flight of T. absoluta was satisfactorily disrupted with an initial pheromone dose of 30 g ha^?1, and levels of damage did not significantly differ from those in reference plots with insecticide treatments. Later efficacy trials confirmed previous experiences, and release studies showed that control of damage and flight disruption were taking place when releasing at least 85 mg pheromone per ha per day. CONCLUSION: Effective control using pheromone application against T. absoluta can be achieved, in greenhouses with high containment levels, for 4 months, with initial doses of 30 g ha^?1. Further research must be conducted in order to evaluate the prospect of outdoor application of mating disruption systems. Copyright © 2011 Society of Chemical Industry     

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     

Regional differences in pheromone responses of diamondback moth in Indonesia

Trap captures with two‐ and three‐component blends of synthetic sex pheromone for the diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae), were assessed in Indonesia. In West Java, the two‐component blend containing 10g of (Z)‐11‐hexadecen‐1‐ol acetate and (Z)‐11‐hexadecena| in a 4:6 ratio captured the greatest number of diamondback moths. Three and five virgin females were more attractive than the two‐component lures, which were as attractive as lures that also contained (Z)‐9‐tetradecen‐1‐ol acetate. In North Sulawesi, a 100 g dose of the two‐component blend attracted more males than the 10 g dose but was not significantly more potent than five virgin females. These results suggests that pheromone production and bioactivity should be assessed in separate populations prior to attempts to develop pheromone‐based monitoring or mating disruption programmes.     

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     

Effects of reservoir dispenser height on efficacy of mating disruption of codling moth (Lepidoptera: Tortricidae) in apple

BACKGROUND: The effect of varying the height of reservoir dispensers for mating disruption of codling moth, Cydia pomonella (L.), was investigated. The goal was to improve the effectiveness of C. pomonella mating disruption through improved understanding of adult distribution within the tree canopy and the impact of pheromone dispenser placement on disruption. Two dispensers per tree were placed at 2 m and 4 m and/or one dispenser at each height on the tree at a label rate of 1000 units ha^?1. Monitoring traps and tethered female moths were deployed in plots at 2 and 4 m heights to assess treatment effects by catches or matings respectively. RESULTS: Fewest male moths were captured with all dispensers placed at 4 m. Female mating was lowest, and with least variation between females tethered at 2 and 4 m, when dispensers were placed simultaneously at 2 and 4 m (28% mated). Mating was 32% with both dispensers at 4 m, 38% with both dispensers at 2 m and 46% in the no disruption control. Mating was highest across treatments when females were tethered at 2 m and dispensers placed at 4 m (40%), and when females were tethered at 4 m with dispensers placed at 2 m (46%). CONCLUSION: Traps at 4 m in trees captured more male moths than traps at 2 m, regardless of disruption dispenser positioning. Female mating was lowest when dispensers were placed simultaneously at 2 and 4 m, suggesting that current recommendations for placement of reservoir dispensers in tree crowns may be suboptimal. Copyright © 2011 Society of Chemical Industry     

Development of single-dispenser pheromone suppression of Epiphyas postvittana, Planotortrix octo and Ctenopseustis obliquana in New Zealand stone fruit orchards

BACKGROUND: Pheromones of two native leafrollers of economic importance to the New Zealand horticulture industry, Planotortrix octo [(Z)‐8‐tetradecenyl acetate and tetradecyl acetate] and Ctenopseustis obliquana [(Z)‐5‐tetradecenyl acetate and (Z)‐8‐tetradecenyl acetate], were reinvestigated and combined with pheromone of Epiphyas postvittana [light‐brown apple moth, (E)‐11‐tetradecenyl actetate and (E, E)‐9,11‐tetradecen‐1‐yl acetate] to develop a single dispenser for mating disruption of three pest species for integrated pest management. RESULTS: Additional compounds identified from pheromone gland extracts were characterised as repellents for P. octo. However, for C. obliquana from Central Otago, a change in ratio of (Z)‐5‐tetradecenyl acetate and (Z)‐8‐tetradecenyl acetate and the addition of three compounds found in the gland (dodecyl acetate, tetradecyl acetate and hexadecanal) led to a significant improvement in catch over previous lures. Males from Central Otago showed antennal electrophysiological responses to hexadecanal, unlike C. obliquana from Auckland, which did not. Three multiple‐species disruption blends were devised in a single dispenser to target E. postvittana, P. octo and C. obliquana. Disruption of traps was recorded in single‐tree replicates with all three blends, but the five‐component blend was overall most effective at disruption and was deployed area wide in commercial orchard plots. CONCLUSIONS: Deployment of single dispensers into commercial stone fruit orchards led to disruption of trapping for the three species and measurable reductions in insecticide use in cherries, peaches and nectarines without increased fruit damage (assessed in apricots). Copyright © 2011 Society of Chemical Industry     

Control of the codling moth (cydia pomonella) in apple and pear orchards in Israel by mating disruption

Control of the codling moth,Cydia pomonella (L.) (Lepidoptera: Tortricidae), by pheromone-mediated mating disruption, was studied in Israel using two types of dispensers: Shin-Etsu twist-tie (normal and long-life) and TNO matrix formulation (square wafers). Factors affecting mating disruption: initial pest population density, timing of the pheromone application, early season insecticide treatments and monitoring of the pest, were evaluated. Efficacy of mating disruption was assessed by comparing catch of males in pheromone traps located in pheromone-treated and chemically sprayed control plots. Fruit infestation during the season and at picking time was the major criterion to assess mating disruption. The preferred time for pheromone application was before the first flight of the moth. When pheromones were applied at a later stage, one or two early insecticide sprays had to be used to reduce the initial level of the codling moth population. In all tests, trap catch in pheromone-treated plots was drastically reduced as compared with respective control plots. In pheromone-treated plots where total seasonal trap catch (after pheromone application) was less than 12 males/trap, fruit infestation was less than 1.5%; zero trap catch resulted in 0.1-0.3% infestation. At high population levels, mating disruption was ineffective, with the rate of infestation at picking-time being similar in pheromone-treated and control plots. All the field tests indicated that mating disruption with either Shin-Etsu ropes or TNO squares can control codling moth infestations in apple and pear orchards, at relatively low densities of the pest, as efficiently as commercial insecticide sprays.     

Night observations on the cotton leafworm,Spodoptera littoralis: Reliability of pheromone traps for population assessment and efficacy of widely separated pheromone dispensers for mating disruption

Night observations on the cotton leafworm,Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae), were conducted in pheromone-treated and untreated plots in which males, females, mating pairs on plants, and males caught in traps were collected. Results indicated that emergence of a new population was rapid (8-9 days) and that the number of virgin females and of mating pairs on plants reached a peak 5–6 days prior to that of males captured in pheromone traps. Males responded to pheromone traps most actively when the actual virgin female popution had already declined considerably. Dispensers adsorbed with(Z,E)-9,11-tetradecadienyl acetate and located 25 m apart, effectively reduced male captures in traps. However, the number of native mating pairs observed in the treated field during the night was not reduced. Few releasers at wide spacing, even with high amounts of the major pheromonal component, were ineffective in causing mating disruption ofSpodoptera littoralis.     

Influence of pheromone emission on the attraction of California red scale males in citrus orchards

Attraction of California red scale males, Aonidiella aurantii (Maskell), to different release rates of the sex pheromone compound 3-methyl-6-isopropenyl-9-decen-1-yl acetate was evaluated in field trials. This study was aimed to study pheromone emission-response correlations and the existence of an optimum release rate that maximizes trapping efficacy. Release profiles of the pheromone dispensers deployed were determined by gas chromatography to estimate the various emission rates tested. The results reveal that the mean number of A. aurantii males caught correlates with the daily pheromone release rates by means of a quadratic model. The obtained model indicates the existence of a relative maximum of the captures corresponding to an optimum release rate of ca. 300 μg/day. Higher emission rates (up to 1 g/day) resulted in lower captures. Implications for the mating disruption technique are discussed.     

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。     

Control of three major bollworm pests of cotton in Pakistan by a single application of their combined sex pheromones

Abstract

In the Punjab province of Pakistan, cotton is subject to attack by three major bollworm pests: Pectinophora gossypiella, Earias vittella and £ insulana. Because of the difficulty of controlling these pests once their larvae have penetrated the bolls, early season control is essential. A non‐toxic method is desirable if beneficial insects are not to be destroyed. Tests with a Mitsubishi ‘twist‐tie’ pheromone formulation containing the major components of Pectinophora and the two Earias spp. achieved almost complete trap suppression of all three species for up to eight weeks duration following a single application at the pin‐square stage. Visual observations confirmed a complete lack of moth activity indicating that control by mating disruption was attainable.     

Recovery of non-target plants affected by airborne bromoxynil-octanoate and metribuzin

The present study was conducted to evaluate the recovery potential of non‐target plants affected by two airborne herbicides. Sunflower at the two‐leaf stage was used as a test plant and exposed for 24 h in a wind tunnel to a range of concentrations of airborne bromoxynil‐octanoate and metribuzin. Quantum yield (φ_PSII) of exposed leaves and of the second leaf pair developed after exposure was determined at a particular time up to 16 days following exposure. Maximum depression in quantum yield of exposed leaves from which a complete recovery occurred within 16 days was 63% for bromoxynil‐octanoate and 60% for metribuzin respectively. The corresponding maximum concentrations were 1.310 and 0.390 μg m^?3 respectively. The second leaf pair was also affected and showed a similar recovery potential. From the results it can be concluded that the significance of airborne bromoxynil‐octanoate and metribuzin must not be overestimated, as sunflower and non‐target plants with a similar sensitivity are likely to recover from air concentrations of both herbicides reported under field conditions.     

Aerosol delivery of trail pheromone disrupts the foraging of the red imported fire ant,Solenopsis invicta

BACKGROUND: The fire ant, Solenopsis invicta, is one of the most aggressive and invasive species in the world. The trail pheromone Z,E‐α‐farnesene (91% purity) was prepared, and disruption of worker trail orientation was tested using an ethanol‐based aerosol formulation presenting a single puff of this compound by airbrush and compressed air. Trail‐following behaviour was recorded by overhead webcam and ants digitised before and after presentation of the aerosol treatment at four rates (1.6, 16, 160 and 1600 ng cm^?2). RESULTS: Ants preferred 110 ng cm^?1 over 11, 1.1 and 0.11 ng cm^?1 for trail following. Within seconds of presentation of 1600 ng cm^?2, the highest dose tested, trail disruption was observed. Disruption was evident as reduced arrival success and reduction in the trail integrity statistic (r²), as well as increased deviation from the trail (deg). The distribution of walking track angles was also flattened. CONCLUSIONS: The feasibility of using aerosol for delivery of trail pheromone was demonstrated, but the need for high purity combined with the difficulty of commercial supply makes this technique impractical. However, the commercial production of Z,E‐α‐farnesene of high purity by industrial biotechnology or from (E)‐nerolidol may be possible in future, which would facilitate further development of trail pheromone disruption of S. invicta. Copyright © 2012 Society of Chemical Industry     

Efficacy of mating disruption technique against carob moth,Apomyelois ceratoniae Zeller (Lepidoptera: Pyralidae) in pomegranate orchards in Southeast Turkey (Şanlıurfa)

Carob moth, Apomyelois (=Ectomyelois) ceratoniae Zeller (Lepidoptera: Pyralidae) is a key pest in pomegranate orchards in Southeast of Turkey. The pest causes significant damage and reduces marketability of fruits, and is difficult to control with insecticides. Therefore, it is imperative to develop environmentally sound effective alternative management approaches. In this study, we aimed to evaluate the mating disruption technique and determine the appropriate application dose for the management of the pest. The study was carried out in Central and Suruç districts of ?anl?urfa province (Turkey) in 2011 and 2012. SPLAT EC (Specialized Pheromone-Lure Application Technology) trade named dispenser containing 2% Z7, E9-11-dodecatrienyl formate pheromone mimic was applied at 500, 625 and 750 g/ha in three pomegranate orchards in each district. Results indicated that mating disruption technique significantly reduced the pest populations. But effectiveness of the method was less in terms of the damage rate on fruits. Pheromone applied at 500 g/ha was not effective. However, application at 625 g/ha reduced the pest populations to an acceptable level. Thus, the concentration could be considered an appropriate dose for the less abundant pest population within integrated pest management while higher population would require combining the mating disruption method with a bio-insecticide.     

苹果蠹蛾不同防治方法的控害效应比较

为了及时地在苹果蠹蛾Cydia pomonella(L.)入侵地实施有效的防控策略,通过评价活雌蛾诱捕器诱捕雄蛾数量、在树干上化蛹或越冬的幼虫数量以及对苹果果实的为害程度,比较性信息素诱杀技术、迷向技术和化学防治技术对苹果蠹蛾的控害效应。结果显示,采用迷向法控制苹果蠹蛾的防治效果与化学防治相当,其中在第1代幼虫为害盛末期,蛀果率可控制在1%以下,在第2代幼虫为害盛末期,可控制在2%左右;而诱捕区与对照区(无处理)的蛀果率相当,几乎无控制效应。     

Semiochemicals of the common bed bug,Cimex lectularius L. (Hemiptera: Cimicidae), and their potential for use in monitoring and control

The recent resurgence of the common bed bug, Cimex lectularius L., has driven an increase in research into the biology and behaviour of this pest. Current control is reliant on the application of insecticides, but, owing to the development of insecticide resistance, there is a need for new tools and techniques. Semiochemicals (behaviour‐ and physiology‐modifying chemicals) could be exploited for management of bed bugs. The aim of this review was to evaluate studies undertaken in bed bug chemical ecology to date, with particular reference to how the research could be exploited for monitoring and control. Bed bugs, like many other insects, have a complex olfactory system. Recent studies have characterised the olfactory sensilla, located on the terminal segment of the antennae, to functional classes by electrophysiological screening. Behavioural studies have revealed the presence of an alarm pheromone and potential airborne aggregation semiochemicals, but it is not yet understood if bed bugs use a sex pheromone during mating. Host location cues have been investigated, and carbon dioxide has been found to be highly attractive both in laboratory and in field studies. Recent field trials have tested blends of other potential kairomones, which have been shown to have an additive effect when used in a heated bed bug trap with carbon dioxide. The trap, which combines heat and kairomones, is the only trap currently available with proven efficacy in the field. In order for semiochemicals to be useful for bed bug management, an increased knowledge and understanding of the biology, behaviour and chemical ecology of this insect is essential. Copyright © 2010 Society of Chemical Industry     

我国昆虫性信息素技术的研发与应用进展

昆虫性信息素是昆虫性成熟后求偶时所分泌的能引诱同种异性个体以进行交尾的微量挥发性化学物质,具有种的特异性,因此广泛应用于害虫的监测与防治。近年来,我国在昆虫性信息素的工业化合成、纯化、稳定,缓释生产工艺的改进和完善,各种干式诱捕器的开发研制,智能化性诱测报技术研发,以及多种害虫田间性诱实用技术试验示范方面取得了一系列进展,极大地促进了重大害虫的监测预报和绿色防控。本文详细介绍和比较了群集诱杀技术的诱芯、诱捕器种类及其应用特点,交配干扰技术的释放器及其智能化的原理、种类和应用特点;系统总结了求偶与交配之间的关系、性信息素引诱力和专一性,以及生物和非生物因子对群集诱杀和交配干扰效果的影响;总结了群集诱杀和交配干扰技术在水稻、玉米、蔬菜、果树、棉花等作物重要害虫中的应用进展。最后,分析了当前性信息素技术研发与推广应用中仍存在的问题,并提出了改进对策及建议。