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•Larger motile predators, chrysopids and syrphids, were excluded from netted plots.•Aphelinus mali densities were 5-fold greater in the netted plots.•Woolly apple aphid densities were ...100-fold greater in the net exclusion plots.•Lack of full predator complex likely released aphids from top-down control.•Codling moth densities and feeding were significantly lower in the netted plots.
Exclusion cages can quantitatively demonstrate the value of natural enemies and the biological control services they provide. Currently, in Washington State, enclosing orchards in netting is being evaluated as a pest control method, but these enclosures may also serve as an exclusion cage to natural enemies, thereby disrupting biological control. To test the effects of net enclosures on apple arthropod communities, we conducted a two-year study comparing apple herbivore, predator, and parasitoid densities in caged and uncaged plots (both receiving insecticides) to an untreated check. Effects on the various groups were influenced by size and motility. Densities of larger motile arthropods, including codling moth (Cydia pomonella (L.)), chrysopids, and syrphids, were lower in the caged plots, demonstrating exclusion. Woolly apple aphid (Eriosoma lanigerum (Hausmann)) and its parasitoid Aphelinus mali (Haldeman) densities in the caged plots were over 100-fold greater and 5-fold greater, respectively, than the other treatments. European earwig (Forficula auricularia (L.)), a generalist predator, was more abundant in the caged plots in 2016 but not in 2017. Spider mites were more abundant in the cage treatments for both years, while predatory mites had higher densities in the cages in 2017 only. These outcomes show that net enclosures change the composition of apple arthropod communities through exclusion of certain herbivores and natural enemies. In the case of some pest herbivores (e.g., codling moth), this exclusion is beneficial, but in the case of predators, it is detrimental. This study further demonstrated that exclusion of only part of the natural enemy complex may be sufficient to cause herbivore outbreaks.
•Degree-day models are often used to time the activity of key pest life stages.•Farmers also often collect pest data as counts that are not easily interpretable.•Our model predicts pest abundance ...based on field data and phenology models.•This model will allow for more informed pest management decision-making.
Sustainable pest management in crop systems requires that producers target control tactics to key periods of pest activity. To accomplish this, producers often sample pests to estimate abundance and use degree-day models to predict timing of discrete pest phenology events. However, there are few examples of management tools that link phenology models with sampling data to make predictions of pest abundance. Here, we propose a method to predict pest captures by linking trap count data collected in-season with models that predict the cumulative emergence of insects from heat accumulation. Specifically, we used a 20-year dataset of codling moth Cydia pomonella (L.) pheromone trap captures to build and validate a model that produces a prediction band of cumulative captures until the end of the overwintering generation, assuming constant sampling and no migration or controls. Uncertainty was calculated as a function of the predicted mean, sample size, prediction length, and model variance. Model validation revealed that > 75 % of the tested moth capture trajectories fell within prediction bands when they were produced at or after 350 degree-days. The model provides a tool for codling moth management that integrates sampling data with an established phenology model to produce sound within-season population predictions. Producers can use such tools to make decisions on pesticide applications that are both timed to the proper pest life stage and informed by population dynamics predictions.
The codling moth Cydia pomonella (L.) (Lepidoptera: Tortricidae) is a destructive pest of apple (Malus domestica (Rosales: Rosaceae)), pear (Pyrus spp. (Rosales: Rosaceae)), and other pome tree ...fruits; outbreaks cause significant ecological and economic losses. In this study, we used CLIMEX model to predict and evaluate the global risk of C. pomonella based on historical climate data (1989-2018) and simulated future climate data (2071-2100) under the RCP4.5 scenarios. Cydia pomonella exhibited a wide distribution under both historical and future climate conditions. Climate change is predicted to expand the northern boundary of the potential distribution from approximately 60degreesN to 75degreesN. Temperature was the most dominant factor in climatic suitability for the pest. Combinations of multiple meteorological factors (relative humidity and precipitation) associated with a failure to break diapause in certain regions also affect suitability, particularly in northern South America and central Africa. Irrigation only had a slight impact on species favorability in some areas.The projections established in our study present insight into the global potential suitability of C. pomonella under climate change scenarios by the end of the 21st century. Farmers should be aware of the risk associated with the pest based on the results, which would provide guidance for quarantine agencies and trade negotiators worldwide.
California is a global leader in production and supply of walnuts and almonds, and the state is the largest producer of peaches in the U.S. These crops have an important contribution to the ...California's agricultural economy. Damages to these crops from lepidopteran pests, mainly from Codling moth (Cydia pomonella) (family: Tortricidae), Peach twig borer (Anarsia lineatella) (family: Gelechiidae) and Oriental fruit moth (Grapholita molesta) (family: Tortricidae), are still high, despite the improvement in pest management activities. Given that temperature increase can directly impact the rate of growth and development of these pests, it is important to understand to what extent dynamics of these pests will change in future in California. The objective of this study was to quantify changes in the biofix, lifecycle length, and number of generations for these pests for the entire Central Valley of California. Using a well-established growing-degree days (GDD) model calibrated and validated using observations from orchards of California, and climate change projections from the Coupled Model Intercomparison Project phases 5 and 6 (CMIP5 and CMIP6) General Circulation Models, we found that biofix dates of these pests are expected to shift earlier by up to 28 days, and length of generations is expected to be shortened by up to 19 days, and up to 1.4 extra generations of these pests can be added by the end of the century depending on the scenario. Results from this work would enable industries to prioritize development of practices that are more effective in the long run, such as developing better cultural and biological pest solutions and insect tolerant varieties. Growers and researchers can take proactive actions to minimize future risks associated with these damaging pests. This work can be scalable to other pests and regions to understand regional dynamics of damaging agricultural pests under climate change.
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•Climate change will increase pest pressure in high value agriculture in California.•Earlier onset and rapid completion of insect lifecycle under climate change•Results can serve as a guide for managing pest risks under future climate.•Results are relevant globally and methods scalable to other regions and pests.
The false codling moth (FCM), Thaumatotibia leucotreta (Meyrick), is a major pest of citrus fruits and other plants and is defined as a quarantine pest in several countries. Supervision and visual ...monitoring are crucial for the detection of eggs and larvae. There is a growing need to implement alternative pest control strategies and early detection methodologies in the packing house before shipping. Biosensors may provide a better-suited solution, as they are portable, do not require expensive equipment, and may be used with simple methodologies. In this study, a whole-cell bacterial biosensor was developed to identify the presence of Thaumatotibia leucotreta larvae in citrus fruits. The volatile organic compounds (VOCs) released by the larvae were identified (n = 11), which were not previously tested. The change in the VOCs composition in infected and uninfected mandarin (Citrus reticulata) was examined using gas chromatography-mass spectrometry (GC-MS) and the bioluminescent bacterial panel. During this work, two fixation methods (alginate beads and tablets) were tested for the bioluminescent bacteria cells, and tablets were preferred due to their higher uniformity and consistency of the light signal from the cells. Furthermore, the response of the bacteria to the changes in the concentration of VOCs as a result of a change in the amount of the larvae was examined (larvae n = 3, 6, or 9). In addition, in order to demonstrate the ability of the whole-cell biosensor to detect the presence of larva within the fruit, infected and uninfected mandarins were tested on the 14th day of larval hatching. The results showed that the bioluminescent bacteria could differentiate between mandarins with and without larva. The differences in the light signals (Induction Factor (IF)) between the mandarin fruits can be seen in the results with the larva (cytotoxicity IF = 3.046, genotoxicity IF = 2.643, and quorum sensing IF = 1.954) and without (cytotoxicity IF = 1.589, genotoxicity IF = 1.149 and quorum sensing IF = 1.205). The findings of this study make it possible to further develop a prototype using bioluminescent bacteria in order to detect pests of citrus fruits. The early detection of infected fruits will allow their filtering from the crop and therefore reduce the damage to additional fruits. Even one larva can invalidate the whole stock and the plot for future export.
•The false codling moth (FCM), Thaumatotibia leucotreta, is a major pest.•Volatile organic compounds (VOCs) profile between infected and non-infected.•Whole-cell bacterial biosensor to identify Thaumatotibia leucotreta in citrus fruits.•Gas chromatography-mass spectrometry (GC-MS) for volatiles from the larvae.•The bioluminescent bacteria can identify mandarins with larvae.
Codling moth (CM) (Cydia pomonella L.) is the most destructive pest for apples, causing large economic losses when not properly mitigated. Efficient detection methods can limit the spread of this ...pest in the apple supply chain. Non-destructive methods have several advantages over the current methods in that they can be applied to every apple (or a much larger sample) thereby reducing the possibility of missed detection. This paper examines the feasibility of acoustic impulse response methods for detecting CM larvae-infested apples. Experiments were performed on control and artificially infested apples from three different cultivars. Signals were recorded with a contact sensor, and 21 signal features were proposed and extracted to characterise relevant properties of the response. The 21 features were evaluated with 11 machine leaning algorithms to determine if the features or their subsets contained information that could reliability determine if an apple was/is infested. Classification test results using a 10-fold cross-validation indicated accuracy rates between 80% and 92% for Fuji apples, between 92% and 99% for Gala apples, and 63% and 97% for Granny Smith apples. The impulse response required between 60 and 80 ms for each apple (not counting setup/transition time). These results from this study suggest that active impulse response classification can potentially improve the detection of post-harvest apple CM infestation detection along the supply chain.
•Acoustic impulse response signals were investigated for detection of codling moth in apples.•Ultrasonic sound from solenoid tapping were attenuated differently based on apple quality.•Ensemble methods were the better classifiers for differentiating signals from apples.•Classification rates for Gala were the best ranging between 0.92 and 0.99.
Goniozus legneri Gordh (Hymenoptera: Bethylidae) es un ectoparasitoide larval de lepidópteros con antecedentes como biocontrolador de varias plagas agrícolas alrededor del mundo. Mediante un ...extensivo monitoreo, se encontró a esta avispa en cuatro distritos distantes de la provincia de Mendoza parasitando a tres lepidópteros plaga: Lobesia botrana (Den. et Shiff.) en vid, a Ectomyelois ceratoniae (Zeller) en nogal y "espinillo" (Vachellia caven (Molina) Seigler et Ebinger) y a Cydia pomonella (L.) en nogal. Para corroborar la identificación de la especie del parasitoide y evaluar la viabilidad de la población silvestre, se realizaron estudios de la genitalia de machos y entrecruzamientos de avispas silvestres con otras seleccionadas de una cría de laboratorio. Asimismo, es la primera vez que se reporta su presencia como parasitoide de L. botrana en viñedos de Argentina en condiciones naturales de cultivo. PALABRAS CLAVE. Betílido. Carpocapsa. Parasitoide. Polilla del algarrobo. Polilla de la vid. Goniozus legneri Gordh (Hymenoptera: Bethylidae) is a larval ectoparasitoid of lepidopterans, with a worldwide history as a biocontrol agent of various agricultural pests. By means of extensive monitoring, this wasp was found in four distant districts of Mendoza province parasitizing three lepidopteran pests: Lobesia botrana (Den. et Shiff.) in grapevine, Ectomyelois ceratoniae (Zeller) in walnut and "espinillo" (Vachellia caven (Molina) Seigler et Ebinger) and Cydia pomonella (L.) in walnut. To corroborate the parasitoid species identification and to analyze its population viability in this region, studies of male genitalia and sexual crossings between wild and laboratory-reared wasps were conducted. Further, we report for the first time the natural host-parasitoid interaction of L. botrana with this parasitoid in vineyards from Argentina. KEYWORDS. Bethylid. Carob moth. Codling moth. European grapevine moth. Parasitoid.
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