The production of quince (Cydonia oblonga Miller) is affected worldwide by codling moth (Cydia pomonella L.), an oligophagous pest. In this study, volatile compounds in healthy and infested fruits ...were collected from four cultivars of quince: Champion, Portugal, Smyrna and INTA 147. Volatiles were extracted by SPME and analyzed by GC-MS. Up to 30 compounds were identified in the volatile profiles of uninfested quinces, ranging from 90.9% to 98.4% of the total relative abundance. The volatile profile of all four cultivars of quince was similar, with (E,E)-α-farnesene and octanoic acid- ethyl ester as the main components. Infested fruits presented increased levels of (E,E)-α-farnesene, while minor compounds decreased significantly. Champion and Smyrna varieties might be more susceptible cultivars to infestation as their healthy fruits presented the highest contents of (E,E)-α-farnesene and Pear Ester, both codling moth kairomones. The role of these highly recognized kairomones in the chemical ecology of codling moth in quince is discussed.
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•The main component in all quince cultivars was (E,E)-α-Farnesene.•Quantitative variations were detected in the volatile profile of damaged fruits.•The levels of (E,E)-α-Farnesene were higher in infested fruits.•Smyrna and Champion quinces were the cultivars with highest contents of Pear ester.
The codling moth Cydia pomonella L. (Lepidoptera: Tortricidae) is a destructive pest of apples and pears worldwide. Due to the phytotoxic effect of chemical fumigant on postharvest apple, botanical ...insecticides are an interesting alternative to synthetic chemical insecticides regarding their low environmental impact. Hence, in the present study, we investigated the chemical composition and fumigant toxicity of Artemisia herba-alba essential oil against the fifth-instar codling moth, under laboratory conditions. In total, 49 compounds were identified by gas chromatography/mass spectrometry. The major constituents determined were dextro-camphor (30.60%), 2,6-dimethyl-1,3,6-heptatriene (26.71%), safranal (7.04%), borneol (3.94%) and eucalyptol (3.47%). A. herba-alba essential oil showed strong larvicidal activity, with minimum lethal concentration LC50 values of 13.49 and 04.45 μl L-1 air at 24 h and 48 h, respectively. The LT50 values at the lowest (1.81 μl L-1 air) and highest oil concentrations (18.18 μl L-1 air) were, in turn, 59.35 to 19.52 h. The obtained results indicated that essential oil of A. herba-alba may have a potential to be developed as a botanical fumigant against the fifth-instar codling moth.
•The essential oil of Artemisia herba-alba from Algeria was analyzed by GC-MS.•Hydrocarbon and oxygenated monoterpenes were the predominant class of the total A. herba-alba EO.•A. herba-alba essential oil may be a source of new botanical fumigants against the fifth-instar codling moth.
Long noncoding RNAs (lncRNAs) have emerged as an important class of transcriptional regulators in cellular processes. The past decades have witnessed great progress in lncRNA studies in a variety of ...organisms. The codling moth (Cydia pomonella L.) is an important invasive insect in China. However, the functional impact of lncRNAs in this insect remains unclear. In this study, an atlas of codling moth lncRNAs was constructed based on publicly available RNA-seq datasets.
In total, 9875 lncRNA transcripts encoded by 9161 loci were identified in the codling moth. As expected, the lncRNAs exhibited shorter transcript lengths, lower GC contents, and lower expression levels than protein-coding genes (PCGs). Additionally, the lncRNAs were more likely to show tissue-specific expression patterns than PCGs. Interestingly, a substantial fraction of the lncRNAs showed a testis-biased expression pattern. Additionally, conservation analysis indicated that lncRNA sequences were weakly conserved across insect species, though additional lncRNAs with homologous relationships could be identified based on synteny, suggesting that synteny could be a more reliable approach for the cross-species comparison of lncRNAs. Furthermore, the correlation analysis of lncRNAs with neighbouring PCGs indicated a stronger correlation between them, suggesting potential cis-acting roles of these lncRNAs in the regulation of gene expression.
Taken together, our work provides a valuable resource for the comparative and functional study of lncRNAs, which will facilitate the understanding of their mechanistic roles in transcriptional regulation.
Different isolates of Cydia pomonella granulovirus (CpGV) are used worldwide to control codling moth larvae (
) in pome fruit production. Two types of dominantly inherited field resistance of
to CpGV ...have been recently identified: Z-chromosomal type I resistance and autosomal type II resistance. In the present study, a CpGV-resistant
field population (termed SA-GO) from northeastern Germany was investigated. SA-GO individuals showed cross-resistance to CpGV isolates of genome group A (CpGV-M) and genome group E (CpGV-S), whereas genome group B (CpGV-E2) was still infective. Crossing experiments between individuals of SA-GO and the susceptible
strain CpS indicated the presence of a dominant autosomal inheritance factor. By single-pair inbreeding of SA-GO individuals for two generations, the genetically more homogenous strain CpRGO was generated. Resistance testing of CpRGO neonates with different CpGV isolates revealed that isolate CpGV-E2 and isolates CpGV-I07 and -I12 were resistance breaking. When progeny of hybrid crosses and backcrosses between individuals of resistant strain CpRGO and susceptible strain CpS were infected with CpGV-M and CpGV-S, resistance to CpGV-S appeared to be autosomal and dominant for larval survivorship but recessive when success of pupation of the hybrids was considered. Inheritance of resistance to CpGV-M, however, is proposed to be both autosomal and Z linked, since Z linkage of resistance was needed for pupation. Hence, we propose a further type III resistance to CpGV in
, which differs from type I and type II resistance in its mode of inheritance and response to CpGV isolates from different genome groups.
The baculovirus Cydia pomonella granulovirus (CpGV) is registered and applied as a biocontrol agent in nearly all pome fruit-growing countries worldwide to control codling moth caterpillars in an environmentally friendly manner. It is therefore the most widely used commercial baculovirus biocontrol agent. Since 2005, field resistance of codling moth to CpGV products has been observed in more than 40 field plantations in Europe, threatening organic and integrated apple production. Knowledge of the inheritance and mechanism(s) of resistance is indispensable for the understanding of host response to baculovirus infection on the population level and the coevolutionary arms race between virus and host, as well as for the development of appropriate resistance management strategies. Here, we report a codling moth field population with a new type of resistance, which appears to follow a highly complex inheritance in regard to different CpGV isolates.
Significance Registered in 34 countries worldwide, Cydia pomonella granulovirus (CpGV) is a highly important biological agent to control the codling moth in pome fruit production. Since 2005, 38 ...codling moth field populations resistant to CpGV products containing the Mexican isolate (CpGV-M) were discovered in Europe, and this was the first demonstrated field resistance against commercial baculovirus products. By identifying and sequencing different resistance-breaking CpGV isolates, it was found that resistance of codling moth is directed toward CpGV-M only. As shown by mutation experiments, CpGV-M is prone to resistance because of a 24-nucleotide repeat within the viral gene pe38 . Thus, pe38 can be used as a genetic marker to identify resistance-breaking CpGV isolates for resistance management programs.
The baculovirus Cydia pomonella granulovirus (CpGV) is widely applied as a biocontrol agent of codling moth. After field resistance of codling moth populations had been observed against the commercially used Mexican (M) isolate of CpGV, infection experiments of larvae of the resistant codling moth strain CpRR1 showed that several other naturally occurring CpGV isolates (I12, S, E2, and I07) from different geographic origins are still infectious to resistant CpRR1. Whole-genome sequencing and phylogenetic analyses of these geographic CpGV variants revealed that their genomes share only a single common difference from that of CpGV-M, which is a mutation coding for a repeat of 24 nucleotides within the gene pe38 ; this mutation results in an additional repeat of eight amino acids that appears to be inserted to PE38 of CpGV-M only. Deletion of pe38 from CpGV-M totally abolished virus infection in codling moth cells and larvae, demonstrating that it is an essential gene. When the CpGV-M deletion mutant was repaired with pe38 from isolate CpGV-S, which originated from the commercial product Virosoft and is infectious for the resistant codling moth strain CpRR1, the repaired CpGV-M mutant was found to be fully infectious for CpRR1. Repair using pe38 from CpGV-M restored infectivity for the virus in sensitive codling moth strains, but not in CpRR1. Therefore, we conclude that CpGV resistance of codling moth is directed to CpGV-M but not to other virus isolates. The viral gene pe38 is not only essential for the infectivity of CpGV but it is also the key factor in overcoming CpGV resistance in codling moth.
The sterile insect technique (SIT) is as an important component to the area-wide integrated management of the false codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), which ...was successfully implemented in the Western Cape region of South Africa and subsequently expanded to citrus areas in the Eastern Cape region of South Africa. This integrated control program, which transports sterile moths from a rearing facility in Citrusdal, South Africa to orchards in both the Western and Eastern Cape, must continuously examine production, handling, processing, transport, and release protocols to ensure the delivery of high-quality sterile moths. While the use of cold temperature to immobilize moths is standard protocol for SIT programs to increase the density of moths for purposes of collecting, handling, irradiation, transport and release, some concern has been raised that rapid chilling and long cold temperature storage of moths may negatively impact field performance of some insectary-reared insects. We conducted trials to examine the effect of irradiation with 150 Gy of gamma rays and cold temperature storage on the performance of T. leucotreta moths released in citrus orchards. The radiation treatment did not significantly affect the performance of T. leucotreta moths released in citrus orchards. However, compared with moths held at room temperature, moths that were rapidly chilled were less likely to be captured in pheromone traps and less likely to disperse as great distances following release in citrus orchards. Additional research is needed to identify an alternative to rapid chilling and cold temperature storage that does not impair mating competitiveness and dispersal of irradiated T. Leucotreta adults. Procedural changes that will maintain or enhance sterile T. leucotreta moth quality and performance in the field, while allowing for the cost-effective handling and processing of the sterile moths, need to be considered.
, known as the false codling moth, is a pest of citrus and other crops in sub-Saharan Africa. As it is endemic to this region and as South Africa exports most of its citrus around the world,
has ...phytosanitary status for most markets. This means that there is zero tolerance for any infestation with live larvae in the market. Consequently, control measures prior to exporting must be exemplary. Certain markets require a standalone postharvest disinfestation treatment for
. However, the European Union accepts a systems approach, consisting of three measures and numerous components within these measures. Although effective preharvest control measures are important under all circumstances, they are most critical where a standalone postharvest disinfestation treatment is not applied, such as within a systems approach. Conventional wisdom may lead a belief that effective chemical control tools are imperative to achieve this end. However, we demonstrate that it is possible to effectively control
to a level acceptable for a phytosanitary market, using only biological control tools. This includes parasitoids, predators, microbial control, semiochemicals, and sterile insects. Simultaneously, on-farm and environmental safety is improved and compliance with the increasing stringency of chemical residue requirements imposed by markets is achieved.
False codling moth (FCM), Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), is a priority pest on citrus, stone fruit, and table grapes. Current control focuses on the adult stage; ...however, each stage of the life cycle of the insect should be targeted. The potential of local biocontrol agents against FCM immature stages was investigated. Several entomopathogenic nematode (EPN) and entomopathogenic fungus (EPF) species were identified from soil samples collected from orchards and vineyards throughout the Western Cape province in South Africa. The eggs were proven to be susceptible (30–65%) to several EPN species, at 200 infective juveniles (IJs) per 50 µl. Xenorhabdus indica, the symbiotic bacterium of Steinernema yirgalemense Nguyen et al., caused significantly more mortality than the control. The EPNs were highly virulent against the FCM larvae, with S. yirgalemense causing 100% mortality in all trials. Metarhizium robertsii (78%), M. anisopliae (50%), and Beauveria bassiana (75%) caused high mortality in FCM larvae. The fully formed pupae were the most resistant of the immature stages, with the EPNs causing low mortality at 100 IJs per insect. As the FCM larvae were highly susceptible to S. yirgalemense and M. robertsii under laboratory conditions, they should be further tested, separately and in combination, in field conditions to illustrate the benefits of including them in a FCM‐IPM programme.
False codling moth (FCM), Thaumatotibia leucotreta (Lepidoptera: Tortricidae), is a priority lepidopteran pest in South Africa. Eggs of FCM proved to be susceptible (30–65%) to the entomopathogenic nematode Steinernema yirgalemense (100% mortality). FCM larvae were susceptible to S. yirgalemense (100% mortality), Metarhizium robertsii (78%), M. anisopliae (50%), and Beauveria bassiana (75%). As the immature FCM stages were susceptible to entomopathogens in the laboratory, field tests are needed to illustrate the benefits of including them in an IPM programme.
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