Insect Pest Of Wheat Research Articles

RpUGT344J7 is involved in the reproduction switch of Rhopalosiphum padi with holocyclic life cycle.

Many aphid species exhibit both cyclical parthenogenesis (CP) and the obligate parthenogenesis (OP) life history, which are genetically determined. In CP aphid lineages, the parthenogenetic individuals can switch from asexual to sexual reproduction quickly in response to environmental factors such as changes in photoperiod and temperature. However, the OP aphid lineages do not undergo sexual reproduction under any conditions. So far, mechanisms underlying the reproduction switch in CP aphids have not been fully elucidated. Rhopalosiphum padi, a serious worldwide insect pest of wheat, has both CP and OP lineages. Uridine diphosphate-glycosyltransferases (UGTs) are enzymes that participate in the metabolic detoxification of xenobiotics. Here, we identified 43 RpUGT genes from R. padi genome and transcriptome sequences, and found that: (1) the UGT content of the CP lineage was significantly higher than that in the OP lineage at the key time points when CP lineage mainly produce virginoparae, gynoparae, and males under inducing condition, while there were no significant difference under normal conditions; (2) RpUGT344J7 gene was highly expressed during the time points when CP lineages produce gynopara and males; (3) the critical time points for CP lineages to produce virginoparaee, gynoparae, and males were affected when the CP lineages were injected with dsRpUGT344J7; (4) the knockdown of RpUGT344J7 caused a significant reduction in the total number of virginoparae, gynoparae, and males in the offspring under inducing condition. The findings contribute to our understanding of the molecular mechanisms underlying the quick shift from asexual to sexual reproduction in aphid species.

Evaluation f the Insecticidal Activity of Nerium Oleander and Artemisia Campestris Powder and Extract on Wheat Insect Pests

Objective: The study aimed to evaluate the insecticidal potential of powders and methanolic extracts of two plants of the Lamiaceae and Apocynaceae families spontaneously growing in the region of Tiaret. Method: Insecticide tests were carried out in the laboratory using the Direct Contact Method. Results and Discussion: The obtained results showed that Nerium oleander and Artemisia campestris powders have remarkable insecticidal properties. N oleander powders induced 100% mortality in adults and up to 80% mortality in Tribolium castaneum larvae at a dose of 0.5g, after 7 days of exposure. Adults of Tribolium confusum showed some resistance to the powders of both plants, with an optimum mortality rate equal to 50% for adults. Larvae of both species were found to be sensitive to N. oleander powder with a mortality rate ranging from80to 90%. As for the powder of A. campestris, adults of T. castaneum were more sensitive than those of T.confusum, with adults’mortality rate equal to 100%. The methanolic extracts of both plants showed a very remarkable efficacy against the larvae of both species as well as the adults of T. castaneum with a mortality rate equal to 100%, after 7 days of treatment at different concentrations. Research Implications: Algeria has an abundance and diversity of flora that could provide new sources of compounds of plant origin with phytopharmaceutical properties, these results allow us to affirm that powders and methanolic extracts, of the studied plants, can be used for industrial application in the production of bio-insecticides. Originality/Value: This work could provide alternative or complementary solutions to the use of synthetic organic pesticides to protect stored beans. The development of bio-insecticides derived from plant extracts and the selection of varieties resistant to this pest are part of sustainable agriculture and development.

Relative susceptibility of advanced breeding lines to major insect pests of wheat (Triticum aestivum L.)

Relative susceptibility of advanced breeding lines to major insect pests of wheat (Triticum aestivum L.)

The hidden indirect environmental effect undercuts the contribution of crop nitrogen fertilizer application to the net ecosystem economic benefit

The current environmental and economic challenges of the application of nitrogen (N) fertilizer on crops are not only to provide an adequate food supply but also to reduce the resulting environmental pollution. A comprehensive understanding of the multiple effects of N fertilizer application on crops will help to more accurately guide the application of N fertilizer to meet current challenges, and to promote sustainable crop production. It is widely known that excessive N fertilizer applied to crops can lead to N-related direct environmental effects, including reactive N (Nr) losses, greenhouse gas emissions, and high environmental costs. However, few studies have revealed the hidden indirect environmental effect of crop N fertilizer application and its impact on the net ecosystem economic benefit (NEEB), which may be triggered by a N-crop-pest cascade pathway. In this study, we conducted three-year wheat field experiments at five N fertilizer application rates (0, 70, 140, 210, and 280 kg ha−1) in a city on the North China Plain. Excluding wheat yield and direct N-related environmental effects, the indirect effects of N fertilizer application, including the occurrence of cereal aphids (the most important wheat insect pests), the use of chemical pesticides for pest control, the impacts on the environmental and human health damage costs and NEEB were studied. Our results showed that the abundances of cereal aphids positively correlated with the N fertilizer application rates. At each N fertilizer application rate (70, 140, 210, 280 kg ha−1), 0.447 kg of active ingredients of chemical pesticides (0.222 kg insecticides and 0.225 g fungicides) per hectare per season were used to control insect pests and pathogens, while no pesticides were used at 0 kg ha−1(i.e., no N fertilizer was applied). The environmental and human health damage costs of pesticides for pest control increased $8 per hectare for wheat at four N fertilizer application rates and then reduced NEEB by the same amount. Our work extends previous studies and reveals the indirect negative environmental effect of N fertilizer application on crops triggered by a N-crop-pest cascade pathway. This effect undercuts the contribution of crop N fertilizer application on NEEB.

Efficacy of Some Essential Oil for the Management of Rice Weevil (Sitophilus oryzae) on Stored Wheat

The experiment was conducted in Completely Block Design (CRD) at the laboratory of the Department of Entomology, Naini Agriculture Institute Sam Higginbottom University of Agriculture, Science and Technology, Prayagraj, Uttar Pradesh with three replications seven treatments and untreated control against Rice Weevil Sitophilus oryzae (L.) i.e.T1 (Neem Oil), T2 (Clove Oil), T3 (Lavender Oil), T4 (Karanj Oil), T5 (Eucalyptus oil), T6 (Lemongrass Oil), and T7 (Tea tree Oil) and T0 (control). The experiment was conduct on the efficacy of different essential oil for the management of rice weevil, Sitophilus oryzae and adult mortality at 24, 48 and 72 hrs of exposure. The treatments included Neem Oil (0.5ml/lit), Clove Oil (0.5ml/lit), Lavender Oil (0.4ml/lit), Karanja Oil (0.4ml/lit), Eucalyptus Oil (0.5ml/lit), Lemon grass Oil (0.5ml/lit) and Tea tree Oil (0.5ml/lit). Among the treatments the largest number of mortality was observed in neem oil (83.33%), followed by karanj oil (77.77%), and least mortality was observed in the lavender oil (31.11%), rest of the treatments were found intermediate as followed by clove oil (67.77%), followed by eucalyptus oil (57.77%), followed by lemon grass oil (54.44%) and tea tree oil (51.10%). Percent weight loss of treated wheat grains at intervals of 30, 60 and 90 days after treatment. The results revealed that neem oil (7.32%), followed by karanj oil (11.99%). Least weight loss was recorded in lavender oil (41.06%). Whereas rest of treatments were found intermediate. And the highest germination was found in neem oil treated wheat seeds. The present study clearly revealed that these naturally occurring indigenous plant products could be used to manage the storage insect pests in wheat.

Novel insecticides for the management of shoot fly, Atherigona approximata Malloch (Diptera: Muscidae): an emerging insect pest of wheat in India

Shoot flies (Atherigona spp.) are the members of muscidae family which have got economic importance as pest of several crops of Gramineae family mainly cereals and millets. One of the most effective management strategies for controlling shoot fly is the use of novel insecticides either as seed dressers, soil applicators or as foliar treatment. Under the field condition, seed treatment with thiamethoxam 30 FS @ 5 ml/kg seed followed by a spray of cypermethrin 10 EC @ 0.5 ml/l has recorded least shoot fly oviposition (0.84 and 0.94 eggs/plant), dead heart (8.90% and 9.96%), more per cent productive tillers (79.68% and 79.50%), grain yield (32.22 and 31.27 q/ha) and BC ratio (2.05 and 1.99) as compared to the rest of the combinations during the investigation in rabi, 2019–20 and 2020–21, respectively. Under the changing climate where, the minor insect pests attaining major pest status, the present investigation would help the policy makers to reduce the losses caused by shoot fly infestation significantly by using an effective above-mentioned chemical treatment combination that can be integrated in future IPM modules.

Predicting the incidence and severity of wheat aphids and development of a web-enabled forewarning system in India

Aim: Forecasting the incidence and severity of aphids, the major insect pest of wheat, is expected to significantly help in their management. In the present study, a set of weather-based models were developed to predict the timing and severity of Rhopalosiphum maidis infestation at Ludhiana falling under the North Western Plain Zone and R. padi at Niphad in the Peninsular Zone of India. Methodology: The weather indices-based regression models for two locations, Ludhiana and Niphad, were developed using the aphid population and weather data gathered over eight years (2006–14), and the models' predictive accuracy was successfully tested over four additional years (2014-18). The developed statistical models were transformed into three-tier architecture, web-based system, i.e. Presentation, application and data tier for dissemination of information. Results: The developed models can predict the crop’s age - when aphids first colonize the plants, when the aphid population attains the peak and the information about the peak intensity of the aphid population. For predicting the crop’s age at which population peaked at Ludhiana, the weighted interaction of the relative humidity (RH) in the evening and the number of hours of sunshine (NHS) along with the weighted interaction of minimum temperature and RH (morning) were important parameters while, at Niphad, the weighted NHS and the interaction of RH (morning and evening) were important. Likewise, for predicting the maximum aphid population at Ludhiana, the weighted interaction of minimum temperature and RH (morning) were important, while at Niphad, the key parameters were the weighted interaction of RH (evening) with the NHS. Interpretation: A prototype system developed to forecast the location-specific (Ludhiana and Niphad) infestation of wheat crops by aphids is expected to facilitate aphid management through an accurate forewarning at the locations.

Silencing an aphid-specific gene SmDSR33 for aphid control through plant-mediated RNAi in wheat.

Grain aphid (Sitobion miscanthi) is one of the most dominant and devastating insect pests in wheat, which causes substantial losses to wheat production each year. Engineering transgenic plants expressing double strand RNA (dsRNA) targeting an insect-specific gene has been demonstrated to provide an alternative environmentally friendly strategy for aphid management through plant-mediated RNA interference (RNAi). Here we identified and characterized a novel potential RNAi target gene (SmDSR33) which was a gene encoding a putative salivary protein. We then generated stable transgenic wheat lines expressing dsRNA for targeted silencing of SmDSR33 in grain aphids through plant-mediated RNAi. After feeding on transgenic wheat plants expressing SmDSR33-dsRNA, the attenuated expression levels of SmDSR33 in aphids were observed when compared to aphids feeding on wild-type plants. The decreased SmDSR33 expression levels thus resulted in significantly reduced fecundity and survival, and decreased reproduction of aphids. We also observed altered aphid feeding behaviors such as longer duration of intercellular stylet pathway and shorter duration of passive ingestion in electroneurography assays. Furthermore, both the surviving aphids and their offspring exhibited decreased survival rates and fecundity, indicating that the silencing effect could be persistent and transgenerational in grain aphids. The results demonstrated that SmDSR33 can be selected as an effective RNAi target for wheat aphid control. Silencing of an essential salivary protein gene involved in ingestion through plant-mediated RNAi could be exploited as an effective strategy for aphid control in wheat.

A Mini Review on Insect Pests of Wheat and Their Management Strategies

A Mini Review on Insect Pests of Wheat and Their Management Strategies

Efficacy of Essential Oils of Two Local Weed Plants in Controlling Major Stored Wheat Insect Pests Rhyzopertha dominica (Fabricius) and Trogoderma granarium (Everts) Under Laboratory Conditions

Efficacy of Essential Oils of Two Local Weed Plants in Controlling Major Stored Wheat Insect Pests Rhyzopertha dominica (Fabricius) and Trogoderma granarium (Everts) Under Laboratory Conditions

Comparison of Droplet Distribution and Control Effect of Wheat Aphids under Different Operation Parameters of the Crop Protection UAV in the Wheat Flowering Stage

Aphid is one of the main insect pests of wheat in the flowering stage, so timely and effective control of wheat aphids plays an important role in ensuring wheat yield. The crop protection Unmanned Aerial Vehicle (UAV) is widely used in the control of wheat pests and diseases nowadays. In order to screen out the suitable operation parameters of the crop protection UAV to control the wheat aphids, this study conducted wheat aphid distribution investigation tests and droplet distribution tests. With the P20 electric four-rotor crop protection UAV (Guangzhou Jifei Technology Co., Ltd., Guangzhou, China) as the test equipment, four levels of flight speed (FS: 3, 4, 5, 6 m/s) and three levels of flight height (FH: 1.5, 2, 2.5 m) were combined as operation parameters, tests were carried out to compare the density and uniformity of droplet coverage, and the wheat aphid control tests were carried out by using the optimized operation parameters. The results of the wheat aphid distribution investigation test showed that aphids mainly distributed in the lower layer of the wheat plant canopy, accounting for more than 90.61%. The results of the droplet distribution test showed that with the increase in FS and FH, the coverage density and the droplet distribution uniformity in the upper and lower layers of wheat showed a downward trend under the condition of considering the boundary overlap of spraying width (SW) in multi-routes. Through the comparison of operation efficiency and droplet distribution quality, two combinations of parameters A1 (FS: 3 m/s, FH: 1.5 m) and B1 (FS: 4 m/s, FH: 1.5 m) were selected for the aphid control effect test. The results of the control test showed that the average control effect of A1 (92.05%) on aphids was 10.3% higher than that of B1 (81.75%) 7 days after pesticide application, which indicated that improving the droplet distribution uniformity in the lower layer of wheat could significantly improve the control effect of aphids. This study result could provide reference for the same type of crop protection UAV to control the same type of wheat diseases and insect pests in the same growing stage.

Effects of Midazolam on Antioxidant Levels, Biochemical and Metabolic Parameters in Eurygaster integriceps Puton (Hemiptera: Scutelleridae) Eggs Parasitized by Trissolcus semistriatus Nees (Hymenoptera: Scelionidae)

Eurygaster integriceps Puton (Hemiptera: Scutelleridae) is among the most important insect pests of wheat (Triticum sativum L.) and barley (Hordeum vulgare L.) grown in the Middle East. Biological and chemical methods are insufficient to control E. integriceps populations below economic thresholds. In this study, we investigated the effects of midazolam, a clinical drug, on selected metabolic enzyme activity, antioxidant levels, and biochemical parameters in E. integriceps eggs parasitized by Trissolcus semistriatus Nees (Hymenoptera: Scelionidae). Increasing concentrations of midazolam caused cell damage in the parasitized eggs due to its oxidative effects. Transferase enzymes, such as, aspartate transferase, alanine transferase, and gamma glutamyl transferase activities were altered following exposure. Metabolic enzymes, such as, creatine kinase, alkaline phosphatase, amylase, and lactate dehydrogenase also were adversely affected. Levels of the non-enzymatic antioxidants uric acid, bilirubin, and albumin also were altered.

Comparative transcriptome analysis of wheat in response to corn leaf aphid, Rhopalosiphum maidis F. infestation.

Aphids are one of the most important insect pests of wheat crop in all wheat growing regions of the world. Amongst various aphid species, the corn leaf aphid (Rhopalosiphum maidis F.) is considered one of the most destructive insect pests of wheat in the North Western Plains region of India. Transcriptome profiling of highly susceptible wheat Triticum durum genotype, A-9-30-1 and tolerant wheat Triticum aestivum genotype, HD2967 was performed to investigate aphid-host interactions. The results obtained from differential gene expression analysis of R. maidis on the highly susceptible genotype, A-9-30-1 plants, when compared with the tolerant genotype, HD2967, showed that 212 genes were significantly upregulated and 1009 genes were significantly downregulated. Our findings demonstrated that the genes associated with defense were significantly higher in response to R. maidis on HD2967 as compared to A-9-30-1. Additionally, various genes with physiological attributes were expressed during aphid attack. Based on gene ontology classification, three classifications, such as, cellular components (CC), molecular function (MF), and biological processes (BP) of sequences were identified. KEGG enrichment analysis revealed that twenty-five pathway genes were differentially expressed during the infestation of wheat with R. maidis. Notable changes were observed in A-9-30-1 and HD2967 transcriptomic profiling after infestation. The results obtained in the present study will help to elucidate the mechanism governing host-pest interaction and may lead to the development of new methods for increasing the resistance level of wheat against R. maidis, including over-expression of defense-related genes.

Rhyzopertha dominica (Coleoptera: Bostrychidae): Studies on screening techniques of wheat genotypes/varieties for resistance

Lesser grain borer, R. dominica (Coleoptera: Bostrychidae) is a notorious insect pest of wheat and it can cause both quantitative and qualitative losses and also decrease the sustenance of stored wheat. The host preference of R. dominica were studied in twenty five wheat genotypes/varieties with both free and force choice test. Free choice screening provided prefatory information which was antixenosis usually measured. In force choice’s per cent weight loss, F1 adult emergence and susceptibility index demonstrated the rapid increases in the R. dominica population in wheat variety GW 190 compared than wheat genotypes/varieties VD18-12, VD18-13, VD18-14 and LOK1. Based on per cent weight loss, the genotype/varieties were graded by arbitary categorization as resistant (9), moderately resistant (6), less susceptible (5), moderately susceptible (3), and susceptible (2). Correlation done between the weight loss and all other growth parameters revealed that the weight loss has positive and significant correlation with mean developmental period and highly significant and positive correlation with F1 adult emergence and susceptibility index. The wheat genotypes/varieties resistant to R. dominica VD18-12, VD18-13, VD18-14 and LOK1 have the potential to reducing the loss of wheat during storage condition and it can also used as donor lines for future breeding purpose.

Identification of Biomarker Volatile Organic Compounds Released by Three Stored-Grain Insect Pests in Wheat.

Monitoring and early detection of stored-grain insect infestation is essential to implement timely and effective pest management decisions to protect stored grains. We report a reliable analytical procedure based on headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC-MS) to assess stored-grain infestation through the detection of volatile compounds emitted by insects. Four different fibre coatings were assessed; 85 µm CAR/PDMS had optimal efficiency in the extraction of analytes from wheat. The headspace profiles of volatile compounds produced by Tribolium castaneum (Herbst), Rhyzopertha dominica (Fabricius), and Sitophilus granarius (Linnaeus), either alone or with wheat, were compared with those of non-infested wheat grains. Qualitative analysis of chromatograms showed the presence of different volatile compound profiles in wheat with pest infestation compared with the wheat controls. Wheat-specific and insect-specific volatile compounds were identified, including the aggregation pheromones, dominicalure-1 and dominicalure-2, from R. dominica, and benzoquinones homologs from T. castaneum. For the first time, the presence of 3-hydroxy-2-butanone was reported from S. granarius, which might function as an alarm pheromone. These identified candidate biomarker compounds can be utilized in insect surveillance and monitoring in stored grain to safeguard our grain products in future.

Precise mapping of QTL for Hessian fly resistance in the hard winter wheat cultivar 'Overland'.

A major QTL for Hessian fly resistance was precisely mapped to a 2.32 Mb region on chromosome 3B of the US hard winter wheat cultivar 'Overland'. The Hessian fly (HF, Mayetiola destructor) is a destructive insect pest of wheat in the USA and worldwide. Deploying HF-resistant cultivars is the most effective and economical approach to control this insect pest. A population of 186 recombinant inbred lines (RILs) was developed from 'Overland' × 'Overley' and phenotyped for responses to HF attack using the HF biotype 'Great Plains'. A high-density genetic linkage map was constructed using 1,576 single nucleotide polymorphism (SNP)markers generated by genotyping-by-sequencing(GBS). Two quantitative trait loci (QTLs) with a significant epistatic effect on HF resistance were mapped to chromosomes 3B (QHf.hwwg-3B) and 7A (QHf.hwwg-7A) in Overland, which are located in similar chromosome regions as found for H35 and H36 in the cultivar 'SD06165', respectively. QHf.hwwg-3B showed a much larger effect on HF resistance than QHf.hwwg-7A. Five and four GBS-SNPs, respectively, in the QHf.hwwg-3B and QHf.hwwg-7A QTL intervals were converted into Kompetitive allele specific polymerase chain reaction (KASP) markers. QHf.hwwg-3B was precisely mapped to a 2.32Mb interval (2,479,314-4,799,538bp) using near-isogenic lines (NILs) and RILs that have recombination within the QTL interval. The US winter wheat accessions carrying contrasting alleles at KASP markers KASP-3B4525164, KASP-7A47772047 and KASP-7A65090410 showed significant difference in HF resistance. The combination of the two KASP markers KASP-3B3797431 and KASP-3B4525164 is near-diagnostic for the detection ofQHf.hwwg-3B in a US winter wheat panel and can be potentially used for screening the QTL in breeding programs.

Wheat Breeding for Resistance to Major Insect Pests

Studies to-date have shown the availability of enough genetic diversity in the wheat genetic resources (land races, wild relatives, cultivars, etc.) for resistance to the most economically important insect pests such as Hessian fly, Russian wheat aphid, greenbug, and Sun pest. Many R genes - including 37 genes for Hessian fly, 11 genes for Russian wheat aphid and 15 genes for greenbug - have been identified from these genetic resources. Some of these genes have been deployed singly or in combination in the breeding programs to develop high yielding varieties with resistance to insects. Deployment of resistant varieties with other integrated management measures plays key role for the control of wheat insect pests.

Tillage Intensity Influences Insect-Pest and Predator Dynamics of Wheat Crop Grown under Different Conservation Agriculture Practices in Rice-Wheat Cropping System of Indo-Gangetic Plain

Tillage can alter the soil habitats wherein many insect pests and their natural enemies reside during at least part of their life cycle. To enhance crop productivity and reduce climate change effects, conservation agriculture (CA) with reduced-tillage or no-tillage practices have been advocated to farmers. However, information relating to the effect of CA on insect pests and their natural enemies is very scarce, at least in the Indo-Gangetic region. In this study, the effect of tillage on the abundance of, and damage by, major insect pests (foliar aphids, root aphids, termites, and pink stem borer) and their natural enemies in wheat managed under three tillage practices, i.e., zero-till (ZT), reduced tillage (RT), and conventional tillage (CT) with (protected) and without (unprotected) insecticide protection scenarios, was investigated. Foliar aphid and termite numbers were lowest in the ZT-protected system, and highest in the CT-unprotected system. Pink stem borer damage was significantly higher in the ZT-unprotected system, whereas the root aphid number was maximum in the RT-unprotected system. The natural enemies of these four major insect pests of wheat showed variable trends under the studied tillage systems. The abundance and damage of these major insect pests showed a positive correlation with the normalized difference vegetative index (NDVI) and canopy temperature. The dynamics of the insect pests and their predators were driven by soil habitat-related changes (direct) as well as crop growth-related effects (indirect). A fine-tuning of insect-pest management tactics based on these relations would enhance the success of CA systems.

First combined resistance to Hessian fly and Sunn pest identified in synthetic hexaploid wheat

AbstractHessian fly, Mayetiola destructor (Say), and Sunn pest, Eurygaster integriceps (Puton), are the two most damaging insect pests of wheat in North Africa, West and Central Asia. Host plant resistance is the most environmental friendly, cost‐effective and practical means of controlling insect pests. Twenty synthetic hexaploid wheat lines selected as resistant to Syrian Sunn pest in 2010 were screened for resistance to Moroccan Hessian fly biotype in 2016. The Hessian fly screening was carried out in standard greenhouse flats using a randomized complete block design with three replications, with susceptible and resistant checks in every test flat. The results showed that three synthetic hexaploid wheat lines exhibited resistance to both Moroccan Hessian fly biotype and Syrian Sunn pest. This is the first record of combined resistance to these two pests in wheat. Mapping populations using these sources of resistance are being developed using double haploid techniques for subsequent genetic characterization and identification of linked molecular markers for marker assisted selection.

Influence of sowing date and weather parameters on the relative abundance and damage of major insect-pests of wheat in North-Western plains of India

Influence of sowing date and weather parameters on the relative abundance and damage of major insect-pests of wheat in North-Western plains of India