Oriental Fruit Moth Research Articles

Symbiotic bacteria on the cuticle protect the oriental fruit moth Grapholita molesta from fungal infection

The oriental fruit moth, Grapholita molesta (Lepidoptera: Tortricidae), is a destructive orchard pest native to the Asian subcontinent that has spread throughout many fruit-growing regions of the world. The entomopathogenic fungus Beauveria bassiana (Balsamo-Crivelli) Vuillemin (Hypocreales: Cordycipitaceae) is widely employed for control of insect pests, including G. molesta. Various studies have shown that microorganisms present on the insect cuticle can inhibit fungal spore germination and growth, thus inhibiting their pathogenicity and biological control efficacy. We conducted bioassays on larvae pre-treated with antibiotics to test whether cuticular microbiota could reduce the pathogenicity of B. bassiana to G. molesta. Control larvae (untreated with antibiotics) had higher survival than antibiotic-treated larvae following inoculation with B. bassiana, indicating that cuticular microbiota inhibited infection of G. molesta by B. bassiana. The bacterial diversity present on the cuticle of G. molesta larvae was characterized by 16S rDNA amplicon sequencing. The dominant bacterium isolated was Pantoea sp. and its antagonism toward B. bassiana was assayed in vitro using the inhibition zone method. Inhibitory effects on the pathogenicity of Pantoea sp. against B. bassiana were demonstrated by reintroducing the bacterium to G. molesta larvae that had been pre-treated with antibiotic, which increased their survival in comparison to antibiotic-treated larvae following inoculation with B. bassiana. This study provides potentially valuable insights for maximizing the efficacy of B. bassiana applications for biological control of G. molesta.

Polylactic acid nanoparticles for co-delivery of dinotefuran and avermectin against pear tree pests with improved effective period and enhanced bioactivity

Pesticide compounding technology for disease and pest control emerges as an effective way to increase the effectiveness of pesticides while reducing pesticides resistance. Nanomaterials and encapsulation technology have offered a new insight into preparing efficient pesticide formulations, especially constructing a co-delivery nanoparticle for synergistic pesticides. In this study, a dinotefuran/avermectin co-delivery nanoparticles (DACNPs) against pear tree pests with polylactic acid (PLA) as the wall material were constructed by double-emulsion method combined with high-pressure homogenization technique. The drug content of the DACNPs was 39.1% with an average size of 245.7 ± 4.2 nm and the mean polymer dispersity index (PDI) value was 0.123. The DACNPs showed high foliar retention and good spread performance on target leaves due to the nanoscale effect. The obtained DACNPs showed a better control effect on Grapholitha molesta Busck and Psylla chinensis Yang et Li compared with the commercial formulations, which could significantly prolong the effective duration and enhance the bioactivity with lower amounts and application frequency of pesticides. This study may provide new insights into developing novel pesticide formulations to improve the utilization rate of pesticides, reduce environmental pollution and minimize the cost of farming.

Enhancement of attraction to sex pheromone of Grapholita molesta (Busck) (Lepidoptera: Tortricidae) by structurally unrelated sex pheromone compounds of Conogethes punctiferalis (Guenée) (Lepidoptera: Crambidae)

• OFM and C. punctiferalis are sympatric moth species in orchards. • The two moths belong to different families and use completely different pheromone compounds. • Pheromone compounds of C. punctiferalis elicited antennal responses in OFM males. • The interspecific pheromone compounds also enhanced pheromone attraction of OFM. • Field responses suggested additional semiochemicals for pheromone-based control for OFM. Grapholita molesta (Busck) (the oriental fruit moth; OFM) and Conogethes punctiferalis (Guenée) are both fruit and stem borers with overlapping habitats, occurrences, and outbreak cycles. These two species are in different families and they have completely different sex pheromone components. Here, the effects of the sex pheromone components of C. punctiferalis , ( E )-10-hexadecenal ( E 10-16:Ald) and ( Z )-10-hexadecenal ( Z 10-16:Ald) and their mixture, were evaluated on the sexual communication of OFM by examining electrophysiological (EAG) and behavioral responses. We found that a considerably large amount of E 10-16:Ald or Z 10-16:Ald and a tiny amount of OFM pheromone elicited comparable EAG responses in OFM males, indicating the low antennal olfactory sensitivity of OFM males to the heterospecific pheromone compounds. In two different peach orchard parcels, captures of OFM by their pheromone lures baited in delta traps were increased by at least 1.5 times when OFM pheromone lures were combined with lures that contained 1000 μg of either E 10-16:Ald, Z 10-16:Ald or their mixture. In two other pear orchard parcels, both E 10-16:Ald and Z 10-16:Ald increased captures of OFM in Unitraps in a dose-dependent manner with more than a four-fold increase. Therefore, the enhanced attractiveness of OFM lures by the two interspecific pheromones suggests their potential application to improve mass trapping, population monitoring and mating disruption of OFM.

Oviposition site selection in the crepuscular moth, Grapholita molesta: does light matter?

AbstractSome insects that particularly prefer sunny or shaded sites use light intensity to locate suitable oviposition sites during the day. However, it is not known whether crepuscular species can be guided by light for oviposition under dim or variable light conditions. We used the crepuscular moth Grapholita molesta (Busck) (Lepidoptera: Tortricidae), a major pest of stone and pome fruits worldwide, to investigate oviposition response to light at various intensities (1000, 100, 10, and 1 mW m−2). Light intensity in sunny sites in a peach tree canopy is about 10× higher than in shaded sites. In both light vs. dark and brighter light vs. darker light choices, G. molesta females can discriminate differences in light intensity, exhibiting a strong preference for brighter light, independent of light intensity. Moreover, the light‐dependent oviposition responses did not change when exposed to odor stimuli. Our findings show that this crepuscular moth G. molesta can use light intensity to direct oviposition toward relatively sunny sites under dim light conditions. This study highlights the importance of vision for crepuscular species in oviposition site selection.

Population genomic signatures of the oriental fruit moth related to the Pleistocene climates

The Quaternary climatic oscillations are expected to have had strong impacts on the evolution of species. Although legacies of the Quaternary climates on population processes have been widely identified in diverse groups of species, adaptive genetic changes shaped during the Quaternary have been harder to decipher. Here, we assembled a chromosome-level genome of the oriental fruit moth and compared genomic variation among refugial and colonized populations of this species that diverged in the Pleistocene. High genomic diversity was maintained in refugial populations. Demographic analysis showed that the effective population size of refugial populations declined during the penultimate glacial maximum (PGM) but remained stable during the last glacial maximum (LGM), indicating a strong impact of the PGM rather than the LGM on this pest species. Genome scans identified one chromosomal inversion and a mutation of the circadian gene Clk on the neo-Z chromosome potentially related to the endemicity of a refugial population. In the colonized populations, genes in pathways of energy metabolism and wing development showed signatures of selection. These different genomic signatures of refugial and colonized populations point to multiple impacts of Quaternary climates on adaptation in an extant species.

Structural insights into the discrepant synergistic activity of Codlemone and (Z)-8-dodecenol towards Grapholita molesta pheromones.

Insect pheromone synergists have been widely used to produce potent pheromone products for environment-friendly pest control. Codlemone (Cod) and (Z)-8-dodecenol (Dod) are two major Grapholita molesta pheromone synergists, with Cod having greater synergism and affinity for G. molesta pheromone binding protein 2 (GmolPBP2). Uncovering structural information key to the different binding affinity of Cod and Dod to GmolPBP2 would gain insights into what causes their synergy activity discrepancy. Binding modes of the two synergists in the binding pocket of GmolPBP2 were analyzed and compared by molecular dynamics-based approaches. Although Cod and Dod were stabilized in a similar hydrophobic pocket, their interaction details with GmolPBP2 were divergent due to the extra double bond (C10═C11) in Cod. The C10═C11 improved the hydrophobic interactions of Cod with around residues. Such hydrophobic interaction improvement was also reflected in the raised importance of Phe11 in the GmolPBP2-Cod interaction. Not only that, the increased hydrophobic forces introduced by the C10═C11 changed the CH2-OH orientation in the GmolPBP2-Cod complex, which improved the H-bond interaction. Electrostatic complementarity analysis further indicated the positive role of C10═C11 in optimizing GmolPBP2-Cod interaction. The C10═C11 is thought to contribute greatly to Cod's stronger synergy as a group key to the higher GmolPBP2-affinity, based on which the improvement directions for Cod and Dod were addressed as well. Our findings will aid in the development and optimization of more effective pheromone synergists, resulting in more effective pheromone-based pest management.

Cover Image

The cover image is based on the Original Article Female and male Grapholita molesta (Busck) adults responding to various acetic acid and ethanol lure ratios by Weina Kong et al., https://doi.org/10.1111/jen.12948.

Effect of a short-cycle apple tree cultivar on oriental fruit moth (Lepidoptera: Tortricidae) development and larval behavior.

The oriental fruit moth, Grapholita molesta (Busch, 1916) has historically been a major problem in traditional apple-growing regions in Rio Grande do Sul and Santa Catarina; however, a lower occurrence of G. molesta has been observed in early variety ('Eva') than long cycles cultivar 'Gala' in Paraná State. The objective of this study was to evaluate the performance of immature and adult G. molesta in apple cultivars with short and long cycles, in addition to elucidating whether there is adaptive potential for development and fertility from the first generation to the fourth. The experimental treatments consisted of larvae fed 'Eva' and 'Gala' fruit and a commercial diet. Immature development time, head capsule width, longevity and reproductive parameters were compared across the treatments. The larvae of the fourth generation exhibited better performance than those of the first on 'Eva' and 'Gala'. Immature oriental fruit moth development occurred via four or five instars. A greater number of larvae with four instars occurred on 'Eva' than on 'Gala'. The head capsule width was narrower on 'Gala' than on 'Eva' for larvae with four instars. Females reared on 'Eva' also laid more eggs than those reared on 'Gala'. The larvae that were more adapted to the feeding conditions showed reduced cycles/instars, and the females exhibited better performance when new generations originated from the same substrate. The high fluctuation of G. molesta in 'Gala' orchards is not due to the nutritional condition of the fruits.

Molecular Identification of Carboxylesterase Genes And Their Potential Roles in the Detoxification Metabolism of Three Insecticides in Grapholita Molesta

Molecular Identification of Carboxylesterase Genes And Their Potential Roles in the Detoxification Metabolism of Three Insecticides in Grapholita Molesta

Mating Disruption in Insect Pests by Sex Pheromones: A Profound Integrated Pest Management Technique

Mating disruption or ‘attract and kill’ approach provides an excellent source for suppression of major lepidopterans’ pest in agriculture field. Important success to date in pest management through mating disruption recorded to oriental fruit moth in peaches, pink boll worm, codling moth in pome fruit and pyralid moth in stored grain pest. Pheromonal formulations are efficient, non–toxic and species–specific that makes this technique different with conventional and synthetic insecticides which have adverse effects on environment and non–specific organisms as well. Large scale implementation of this technique resulted in significant reduction in pesticides use while maintaining acceptably low–crop damage level. Because of some problem like instant and mass control to pests with rich populations, these approaches should not be seen as stand–alone strategies but rather as one new and alternative plan within a suite of integrated pest management options.

The influence of weather conditions on the features of seasonal dynamics of oriental fruit moth (Grapholitha molesta Busck.) in the conditions of the Southern Steppe of Ukraine

The influence of weather conditions on the features of seasonal dynamics of oriental fruit moth (Grapholitha molesta Busck.) in the conditions of the Southern Steppe of Ukraine

Farklı Meyve Türlerinde ve Lokasyonlarda Grapholita molesta (Busck 1916) (Lepidoptera: Tortricidae) ‘nın Ergin Popülasyon Gelişmesi

Oriental fruit moth, Grapholita molesta Busck (Lepidoptera: Tortricidae) is an important fruit pest with a wide range of host in many fruit producing countries. This study was conducted with the purpose of determining the adult population development of G. molesta on different fruit species in different locations in Çanakkale province of Turkey. With this purpose pheromone traps were placed in peach, cherry and apricot orchards in Central, Biga, Lapseki and Bayramiç districts of Çanakkale province. The traps were checked weekly and the number of adult G. molesta in traps were recorded. At the end of the study, the pest is confirmed to exist in all fruit producing areas of Çanakkale province. First adult emergence was at early May with the adult population continuing until October. The pest has 2-3 generations throughout production season, which may change with relation to fruit species and location. According to the statistical analysis of the data, both location and fruit species have significant effects on adult population development of the pest with the highest population occuring in peach as the fruit species and Lapseki disrict as the location. It is thought that, the differences in adult population density and development between orchards with the same fruit species is caused by different fruit cultivars used in orchards, different treatments by farmers and climate differences.

MATING DISRUPTION OF GRAPHOLITA MOLESTA BUSCK. TO IMPROVE QUALITY AND HEALTHY OF PEACH FRUITS

In Bulgarian fruit growing agriculture mainly chemical plant protection is applied. Applications with organophosphates and pyrethroids are carried out to control the economically most important peach pest - the oriental fruit moth (Grapholita molesta Busck.). Annually during the vegetation season 7-8 insecticide treatments are applied. This leads to contamination of fruit products and the environment, which is a prerequisite for seeking other approaches. Regarding to fruit moth, sex pheromones are one of the most widely used environmental control methods, but they are most commonly used in apples. Their introduction in the monitoring of the main peach pest can lead to a reduction of chemical treatments and production with less pesticide residues. A promising direction is the use of pheromones to control the pests through sexual disorientation of males. The trial of mating disruption in the present study were carried out with ISOMATE® OFM TT dispensers in 0.9 ha peach orchard in 2020 and 2021. Pheromone traps type "Delta" of the Hungarian company CSALOMON® were used. The ISOMATE OFM TT dispensers, installed before the first flight of OFM at the rate of 250 units per ha, efficiently reduced fruit damages - down to 0.1-0.2% at harvest. In the reference orchard with 6 insecticide treatment against OFM, the damages reached 3.0-3.6%. The results indicate that mating disruption for control of Grapholita molesta Busck. can be used in production of quality and healthy peach fruits.

Technical effectiveness of insecticides against oriental fruit mothand paech twigborerin peachorchards of the South of Ukraine

Goal. To determine the effectiveness of insecticides for peach orchards protection from the main Lepidoptera pests on the basis of clarifying their biological characteristics in the conditions of the South of Ukraine.
 Methods. Field methods. Technical effectiveness of insecticides was determined in peach orchards of Redhaven and Zolota Moskva cultivars. The scheme of the experiment included 6 variants using 5 chemical insecticides. Biological features of Lepidoptera pests development were specified using pheromone traps, in accordance with the generally accepted methodology.
 Results. It was determined that in the conditions of the South of Ukraine during the vegetation periods of the studied years, the development of the oriental fruit moth (Grapholitha molesta Busck.) took place in four generations (one overwintering and three summer generations). The seasonal dynamics of the flight of peach twig borer (Anarsia lineatella Zell.) took place with three peaks, which indicates the development of three generations of the pest. Insecticide trials in the control of oriental fruit moth and peach twig borer in peach orchards allowed to determine that the level of damage to shoots and fruits of the studied peach cultivars by caterpillars of Lepidoptera pests decreased by 4.3—11.3 times compared to the control variant. High technical efficiency was observed when using Lufox 105 EC (1.0 l/ ha) and Match 050 EC (1.0 l/ha) insecticides — 88.0—91.2% and 84.5—88.2%. Use of Radiant 120 SC (0.5 l/ ha) and Proclaim 5 SG, (0.5 kg/ha) provided a reduction in the harmfulness of oriental fruit moth and peach twig borer by 76.5—83.3% and 80.0—86.1% compared to the control.
 Conclusions. Evaluation of the effectiveness of insecticide application in peach orchards showed that all preparations can effectively control the number and harmfulness of oriental fruit moth and peach twig borer in peach orchards in Southern Ukraine. Under the conditions of registration of insecticides Lufox 105 EC, Match 050 EC and Radiant 120, SC can be recommended to protect plantations of this crop.

English

In this study, the impact of insecticides on the chlorophyll and carotenoid contents in peach leaves was assessed. Applied insecticides are registered in Republic of Serbia and some EU countries for the control of the oriental fruit moth (Grapholita molesta Busck) in peach orchards. The experiments were set up in peach orchards (variety “Royal gem”) at the localities of Čelarevo and Šišatovac (northern region of the Republic of Serbia). The applied spray liquids from different chemical groups based on cyantraniliprole (a.i. 100 g/l), chlorantraniliprole (a.i. 200 g/l), spinetoram (a.i. 250 g/l), indoxacarb (a.i. 150 g/l), acetamiprid (a.i. 200 g/kg), deltamethrin (a.i. 25 g/l), pyriproxyfen (a.i. 100 g/l) and chlorpyrifos (a.i. 250 g/l), were foliar applied at a concentrations of 0.06, 0.02, 0.02, 0.05, 0.025, 0.05, 0.1 and 0.25%, respectively. Leaves were sampled 3 and 7 days after treatment and analysed for the contents of photosynthetic pigments. Results showed the most adverse impact on the total chlorophyll; their content decreased after application of chlorantraniliprole (32.6-52.7%), indoxacarb (31.1-47.5%), chlorpyrifos (32.4-36.9%), pyriproxyfen (19.5-37.7%) and cyantraniliprole (22.8-33.4%). However, the carotenoid content was increased (16.3 to 117.1%) in the analyzed samples three and seven days after the treatment at both localities, except spinetoram which reduced carotenoids content by 2%. In general, the tested pigments in peach leaves showed a different biochemical reaction depending on the applied insecticides.

Female and male Grapholita molesta (Busck) adults responding to various acetic acid and ethanol lure ratios

AbstractGrapholita molesta (Busck) is a menacing pest of fruit trees worldwide. A mixture of glucose, acetic acid, ethanol, and water (GAEWM) has been widely used for monitoring or trapping G. molesta adults. Previous research has shown that acetic acid captures more moths compared to ethanol; however, the respective roles of acetic acid and ethanol in bisexual attraction remain unknown. This study investigated the olfactory behaviours of virgin females, virgin males, and gravid females to variations in nine concentration levels of acetic acid (A) and ethanol (E) for GAEWM using electroantennography, a wind tunnel experiment, and a field test. There was a significant dose‐dependent response by moths to the GAEWM lure variations that affected the range of lure detection and the probability of a moth being trapped. In contrast, adult sex and mating status had the strongest effect on the behaviours associated with flying close to the trap. For medium level dosages of A and E, one combination with acetic acid exceeding ethanol content (A > E; #3, A:E = 3:1) elicited antennal detection by the test adults, and upwind flight of the females. In another combination with ethanol predominating (E > A; #7, A:E = 1:3), the lured traps caught more males than control groups. For low dosages, with the acetic acid level equal to ethanol (A = E; #1, A:E = 1:1), females flew upwind, and virgin females flew around the lure. For high level dosages, with A > E (#6, A:E = 3:2), the antennae of gravid females and virgin males reacted to the lure. These results concluded that the acetic acid to ethanol ratios of either 3:1 or 1:3 in GAEWM has the potential to improve the attraction of both G. molesta sexes to traps.

Genetic knockout and general odorant-binding/chemosensory protein interactions: Revealing the function and importance of GOBP2 in the yellow peach moth's olfactory system

The GOBP2 protein has a unique function in the yellow peach moth (Conogethes punctiferalis (Guenée)). Several general odorant-binding proteins (GOBPs) have been identified in various lepidopteran species, but the functional difference between GOBP1 and GOBP2 in recognition of host plant odorants is still unknown. The functions of GOBP1 and GOBP2 in the yellow peach moth were evaluated in this study by using the CRISPR-Cas9 system. The results revealed the importance of GOBP2 in the olfaction mechanism in the yellow peach moth. The perception of the GOBP1-knockout larvae toward feeding decreased but did not reach a significant level while knocking out the GOBP2 and GOBP1/2 genes resulted in huge differences. On the other hand, electroantennograms (EAGs) and wind tunnel tests showed that the sensitivity of GOBP2 knockout adults to odorants decreased more than that of GOBP1 knockout individuals. The results of STRING database text mining grabbed our attention in protein-protein interaction studies. In this research, we first proved the existence of physical interactions between GOBPs and chemosensory proteins (CSPs) through the surface plasmon resonance (SPR) and isothermal titration calorimetry (ITC) methods. Interestingly, GOBP1 and GOBP2 could not interact with each other, but they could interact with CSPs. The interaction results indicated that GOBP2 could physically interact with CSP15, CSP5, and OBP17, whereas GOBP1 could bind only with CSP5 and CSP10, and its association constant (ka) was also more substantial than that of GOBP1. These results strongly suggest the importance of the function of GOBP2 in the perception of host plant odorants by the yellow peach moth.

Reverse chemical ecology guides the screening for Grapholita molesta pheromone synergists.

Pheromone-based management is a leading nonpesticidal strategy among integrated pest management options. Improving the potency of pheromone products by adding synergists would be a practical way to popularize pheromone-based management as well as to reduce pesticide use. Using reverse chemical ecology, synergists for Grapholita molesta sex pheromone were screened. Combined molecular docking and in vitro binding assay led to the determination of four potentially active odorants showing high affinity to G. molesta pheromone binding protein 2 (GmolPBP2). Thereafter, the high affinity between Codlemone and GmolPBP2 was further verified by exploration of GmolPBP2-Codlemone interactions. As the only sex pheromone synergist validated by both laboratory behavioral tests and field trapping, Codlemone was used to optimize commercial sex attractants currently used in G. molesta control. The recommended formulation [(Z)-8-dodecenyl acetate:(E)-8-dodecenyl acetate:Codlemone=95:4:10] was found to trap about five to six times more G. molesta adults than the commercial sex attractant [(Z)-8-dodecenyl acetate:(E)-8-dodecenyl acetate: (Z)-8-dodecenol=95:4:1]. Codlemone is an excellent pheromone synergist that can be potentially sensed by GmolPBP2, which can remarkably improve the potency of G. molesta sex attractants. It is believed that the introduction of reverse chemical ecology would increase the chance of discovering pheromone synergists, promoting the development of more efficacious pheromone products that can be used in controlling G. molesta and beyond. © 2021 Society of Chemical Industry.

Sublethal Effects of Abamectin on the Development, Reproduction, Detoxification Enzyme Activity, and Related Gene Expression of the Oriental Fruit Moth (Lepidoptera: Tortricidae).

Grapholita molesta is one of the most important fruit pests worldwide. Abamectin is a biological pesticide frequently used to control fruit borers like G. molesta in part owing to its translaminar properties. In this study, we characterized the toxicity of abamectin to G. molesta larvae using the diet incorporation method. The sublethal effects of abamectin on the development, reproduction, detoxification enzyme activity, and related gene expression of G. molesta were assessed. The results showed that the LC20 and LC50 values of the insecticide against G. molesta 72 h post-treatment were 1.17 mg L-1 and 5.85 mg L-1, whereas the LC20 and LC50 values 96 h post-treatment were 0.34 mg L-1 and 3.63 mg L-1. When compared to the control, sublethal concentrations of abamectin 1) significantly increased the mortality of the larvae, prepupae, and pupae of G. molesta, 2) prolonged the duration of 3rd to 5th instar larva, prepupal and pupal periods, 3) shortened the longevity of adults, and 4) reduced female fecundity. The enzymatic activity of glutathione S-transferase (GST) varied significantly after exposure to sublethal concentrations of abamectin, but the cytochrome P450 monooxygenases and carboxylesterase activity were not significantly affected. Thirteen of the 25 GST genes were significantly upregulated under different sublethal concentrations of abamectin. The combined findings increase our understanding of the effects of abamectin on G. molesta and the potential role of GSTs in the metabolic interactions of abamectin in this pest, and have applications for more rational and effective use of abamectin to control G. molesta.

A cheap electronic sensor automated trap for monitoring the flight activity period of moths

Automated pheromone dispensers disrupt the mating behaviour of pest moths by releasing pheromone during their daily activity period, which is not the same for all target species. These periods usually occur in or close to night time and last just a few hours, so automated sampling devices are needed to characterize them. However, the commercially available automated models do not provide enough temporal resolution for characterizing the short diel periods of sexual activity of moths. Thus, we built and tested a relatively cheap and simple high-temporal-resolution image-sensor insect trap. It consisted of a Raspberry Pi computer with an infrared camera operated by open-source software and housed in a plastic box. The Raspberry Pi was powered by a solar panel and rechargeable battery that were mounted on a solid and weather-proof structure made of cheap materials. Pictures were downloaded by WiFi from the Raspberry's SD card to a computer. Six traps baited either with synthetic sex pheromone or with females of Grapholita molesta (Busk) were tested in the field. The traps were sturdy, reliable and easy to use, taking pictures at 10 min intervals, 24 h a day for over two months. These pictures confirmed previous results regarding the period of sexual activity of the oriental fruit moth, which will aid in determining the optimal time for operating automated pheromone dispensers.