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 60°N to 75°N. 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.
Cydia pomonella granulovirus (CpGV) is successfully used worldwide as a biocontrol agent of the codling moth (CM) (
). The occurrence of CM populations with different modes of resistance against ...commercial CpGV preparations in Europe, as well as the invasiveness of CM in China, threatening major apple production areas there, requires the development of new control options. Utilizing the naturally occurring genetic diversity of CpGV can improve such control strategies. Here, we report the identification of seven new CpGV isolates that were collected from infected CM larvae in northwest China. Resistance testing using a discriminating CpGV concentration and the determination of the median lethal concentration (LC
) were performed to characterize their levels of virulence against susceptible and resistant CM larvae. The isolates were further screened for the presence of the 2 × 12-bp-repeat insertion in CpGV gene
(open reading frame 24 ORF24), which was shown to be the target of type I resistance. It was found that three isolates, CpGV-JQ, -KS1, and -ZY2, could break type I resistance, although delayed mortality was observed in the infection process. All isolates followed the
model of breaking type I resistance, except for CpGV-WW, which harbored the genetic factor but failed to overcome type I resistance. However, CpGV-WW was able to overcome type II and type III resistance. The bioassay results and sequencing data of
support previous findings that
is the major target for type I resistance. The new isolates show some distinct virulence characteristics when infection of different CM strains is considered.
CpGV is a highly virulent pathogen of the codling moth (CM). It is registered and widely applied as a biocontrol agent in nearly all apple-growing countries worldwide. The emergence of CpGV resistance and the increasing lack of chemical control options require improvements to current control strategies. Natural CpGV isolates, as well as resistance-breaking isolates selected in resistant CM strains, have provided resources for improved resistance-breaking CpGV products. Here, we report novel CpGV isolates collected in China, which have new resistance-breaking capacities and may be an important asset for future application in the biological control of codling moths.
•A red photoselective netting system covering full canopy was used to improve apple production in a semi-arid meditteranean orchard.•The nets modified light intensity and improved photosynthesis ...efficiency.•The nets significantly improved external fruit quality and grading.•The nets significantly reduced major pests’ damages without the use of insecticides.
An assessment of a red photoselective netting system on apple production was conducted in a Mediterranean semi-arid climate. For two seasons, blocks of trees from an early bearing (cv Jonagold) and late bearing (cv Fuji) cultivars were covered to full canopy with red photoselective nets with 20% shading factor and an exclusion mesh size of 5.2 × 2.1 mm in an experimental orchard and compared to uncovered blocks of trees in the same orchard. The influence of nets on microclimate was assessed by measuring light intensity, Photosynthetic active radiation (PAR), Air temperature and relative humidity. An average decrease of 22.8% in light intensity along with a reduction in the average PAR radiation incidence by 23% improved the leaves photosynthesis efficiency with no influence on air temperature and relative humidity. The nets, installed after petal fall, had no significant influence on annual shoot growth and fruit set.
At harvest, apples taken from netted trees were better graded than in the control in terms of both quality and quantity. Fruit weight, size and color blush were significantly higher in apples grown under nets compared to uncovered ones in both cultivars. While apple firmness was slightly lower under nets, no significant differences were reported in terms of sugar content and malic acid between both treatments.
Nets significantly reduced the population of codling moth and the fruit damages caused by this pest without use of insecticides. Nets also decreased the amount of fruit fly caught in traps. No differences were recorded in terms of powdery mildew occurrence, aphids, mites and leafminer populations between both treatments. At last, nets also protected apples from sunburn and bird damages.
To our knowledge, this is the first overall assessment of apple production in a pest-exclusion setting using red photoselective nets.
Ants are widespread across terrestrial ecosystems, including agroecosystems, where they take part in several important processes. They often can act as predators of a wide range of insect pests in ...agricultural fields, which should be considered by management programs, and can sometimes be actively exploited to promote sustainable biological control strategies. In a recent experiment conducted in Europe, pear trees visited by larger numbers of ants suffered fewer attacks to their fruits by the codling moth, a small lepidopteran, which is a significant economic pest worldwide, especially in apple, pear, and walnut orchards. However, the exact form of the interaction between the ants and codling moths remained unclear. While ants were already known to prey upon mature larvae or pupae in the soil, this new evidence suggested they could also control the eggs or newly hatched larvae that had not yet attacked the fruits, which are the two stages whose removal would directly prevent fruit damage. We conducted laboratory experiments to determine whether two common European ants could prey upon these stages. Our results suggest that these ants are effectively able to kill newly hatched larvae, while the eggs do not appear directly vulnerable to predation. Further investigation under field conditions would be needed to assess whether ants may also interfere with the oviposition by adult moths. The predatory ability of ants (Hymenoptera, Formicidae) against insect pests can offer an important service to agricultural activities and may sometimes be directly exploited in biological control strategies. The codling moth Cydia pomonella (Lepidoptera, Tortricidae) is a major agricultural pest of fruit orchards, whose biological control is complicated by the fact that the larvae spend most of their life protected within the fruits they damage. In a recent experiment in Europe, pear trees in which ant activity was artificially increased by the addition of sugary liquid dispensers (artificial nectaries) suffered less damage caused by the larvae to their fruits. While some ants were already known to prey upon the mature larvae or pupae of C. pomonella in the soil, prevention of fruit damage would require predation upon eggs or newly hatched larvae, which have not yet excavated into the fruits. We verified whether two different Mediterranean ants frequently observed in fruit orchards, Crematogaster scutellaris and Tapinoma magnum, were able to prey upon C. pomonella eggs and larvae in laboratory conditions. Our experiments demonstrated that both species similarly attacked and killed young C. pomonella larvae. On the other hand, the eggs mostly attracted the attention of T. magnum but were never damaged. Further field assessments are required to understand whether ants may also interfere with oviposition by adults or whether larger ant species, although generally rarer in orchards, may also prey upon eggs.
•Potential of using VIS/NIR hyperspectral imaging for detecting codling moth in apple was investigated.•Several multivariate analysis and classification techniques were applied.•Wavelengths selection ...was conducted using sequential methods.•Feasible application of monitoring codling moth in GoldRush apples was shown.
Effective detection of insect infestation is important for preserving quality of fresh fruits like apples. The objective of this research was to study the effectiveness of visible (VIS)/near-infrared (NIR) hyperspectral imaging (HSI) (400–900nm) in the diffuse reflectance mode for detecting and classifying codling moth (CM) infestation in apples. A pushbroom HSI was implemented to acquire hyperspectral images for GoldRush apples of fresh-picked and stored at 4, 10, 17, and 27°C, s for 4 months. Mean reflectance spectra (MRS) were calculated for the images and several classification techniques were applied including linear discriminant analysis (LDA), decision trees, K-nearest neighbor (Knn), partial least squares discriminant analysis (PLSDA), feed forward artificial neural networks (FFNN) in addition to majority voting. The most influential wavelengths were determined using the sequential forwards selection (SFS) approach. The highest classification performance was obtained using decision trees at 5 selected wavelengths (434.0nm, 437.5nm, 538.3nm, 582.8nm and 914.5nm) with overall classification rate of 82% for the test set, and 81% and 86% for healthy and CM-infested apples. This study shows the potential of using VIS/NIR hyperspectral imaging as a non-destructive method for detecting CM infestation in apples.
Management of direct apple pests, such as codling moth, continues to be problematic despite the widespread implementation of behavioral and chemical controls. Apple growers have increased their use ...of netting to protect fruit from environmental injury, with some structures enclosing the entire orchard.These enclosures represent a new pest management tactic through physical exclusion. We conducted a two-year trial to examine the effects of full exclusion netting on pests and natural enemies of apples. Insect densities and damage in trees under fully enclosed (net) cages were compared with conventionally (insecticide only) treated and untreated plots. Caged plots had 18.1- and 11.4-fold less codling moth damage than the check, and 4.9- and 4.2-fold less damage than the insecticide-only plots in 2016 and 2017, respectively. However, densities of woolly apple aphid and its parasitoid Aphelinus mali (Haldeman) (Hymenoptera: Aphelinidae) were significantly greater in the caged plots. Densities of earwigs, a typically flightless generalist predator, were not different among treatments, while adults of more mobile flying generalist predators, lacewings and syrphids, were significantly lower in cages compared with uncaged plots.These results demonstrate that although biological control may be partially disrupted, net enclosures have significant potential as a holistic apple management technique.
A systems approach was previously developed for mitigating phytosanitary risk of Thaumatotibia leucotreta (Meyrick) in citrus fruit exported from South Africa, as an alternative to a standalone cold ...disinfestation treatment. The present study first tested the original systems approach by applying it on a semicommercial scale in 10 Nova mandarin orchards. Fruit were inspected at points in the production, packing, and simulated shipping process, to assess performance of the systems approach. Additional data were obtained from 17 Valencia orange orchards and six packinghouses. In the second part of this study, the systems approach was accordingly revised and improved, consisting of three measures: 1) preharvest controls and measurements and postpicking sampling, inspection, and packinghouse procedures; 2) postpacking sampling and inspection; and 3) shipping conditions. The model quantifying the effectiveness of the systems approach was improved by correcting errors in the original version, updating parameter values and adding a component that provides for comparison with the risk mitigation provided by a standalone disinfestation treatment. Consequently, the maximum potential proportion of fruit that may be infested with live T. leucotreta after application of the improved systems approach is no greater than the proportion of fruit that may be infested after application of a Probit 9 efficacy postharvest disinfestation treatment to fruit with a 2% pretreatment infestation. The probability of a mating pair surviving is also determined. The model enables a priori determination of the required threshold levels for any of the three measures, based on quantification of the other two measures.
A systems approach was developed as an alternative to a standalone quarantine disinfestation treatment for Thaumatotibia leucotreta in citrus fruit exported from South Africa. The systems approach ...consists of three measures: pre and postharvest controls and measurements, postpacking inspection, and postharvest exposure to low temperatures. Different cold treatment conditions with a range of efficacy levels can be used for this last measure. A series of trials reported here evaluated the efficacy of seven temperatures ranging from 0 to 5°C for durations from 14 d to 26 d. Mortality of the most cold-tolerant larval stages of T. leucotreta was determined. Temperatures of 0, 1, 2, and 3°C for 16, 19, 20, and 24 d respectively, induced 100% mortality of the tested populations. Probit 9 level treatment efficacy was achieved at 0 and 1°C for 16 and 19 d respectively. Mortalities higher than 90% were obtained with temperatures of 4, 4.5, and 5°C, after exposure for the longer durations. We demonstrated a significant difference in cold-induced insecticidal efficacy between 1, 2, 3, and 4°C. There was no significant difference in insecticidal efficacy between 4 and 4.5°C, but both of these temperatures were more efficacious than 5°C. The results of this study are valuable to support the use of cold treatment conditions with lower risk of fruit chilling injury in an effective systems approach, where the cold treatment efficacy can be augmented with other components of the systems approach.
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