Pests detecting is an important research subject in grain storage field.In the past decades,many edge detection methods have been applied to the edge detection of stored grain pests.Although some of them can realize t...Pests detecting is an important research subject in grain storage field.In the past decades,many edge detection methods have been applied to the edge detection of stored grain pests.Although some of them can realize the stored grain pests detecting,precision and robustness are not good enough.Spectral residual(SR)saliency edge detection defines the logarithmic spectrumof image as novelty part of the image information.The remaining spectrumis converted to the airspace to obtain edge detection results.SR algorithm is completely based on frequency domain processing.It not only can effectively simplify the target detection algorithm,but also can improve the effectiveness of target recognition.The experimental results show that the edge results of stored grain pests detected by SR method are effective and stable.展开更多
In order to achieve the acoustic signal distributed acquisition of stored grain pests, a novel acoustic signal acquisition system was presented based on the wireless sensor networks. And the system architecture, hardw...In order to achieve the acoustic signal distributed acquisition of stored grain pests, a novel acoustic signal acquisition system was presented based on the wireless sensor networks. And the system architecture, hardware configuration, and software were introduced in detail. Considering bandwidth limitation of wireless sensor networks, random sampling algorithm based on the compressed sensing theory was proposed. The developed acoustic signal acquisition system was applied in sampling the crawl acoustic signal of Tribolinm castaneum Herbst adults in granary. Preliminary experimentation indicated the rationality and practicability of the developed system and the proposed algorithm. They can implement the remote, real-time, and reliable wireless transmission for the acoustic signal sampled data of multiple points stored grain pests effectively.展开更多
Insects are major pests of stored grains. In sub Sahara Africa, stored grain insect pests are mainly Coleoptera or Lepidoptera. In the Logone Valley, area covering the Far North Region of Cameroon and South-West of Ch...Insects are major pests of stored grains. In sub Sahara Africa, stored grain insect pests are mainly Coleoptera or Lepidoptera. In the Logone Valley, area covering the Far North Region of Cameroon and South-West of Chad, to our knowledge, the diversity of insect pests noxious to stored products is not established. These beetles and weevils (Insecta:Coleoptera) during their development depreciate food in storage, were able to destroy a whole stock in a very short period of time if no protection of stored food is made. To achieve the diversity of insect pests, inspections of granaries were done in 209 villages of Logone Valley where insect pests were collected and identified. Secondly, the stored grains were sampled in peasant's granaries of Logone Valley and reared in incubators in the Unit of Entomological Research of the University of Ngaound6r6. After their emergence, insects were removed, collected and identified. Their noxious efficiency on stored grains is done by the calculation of the density of each insect pests per gram of grains. This study indicates that 12 species of harmful insects attack cereals and leguminous grains in the Logone Valley during storage. The Bruchids were the main insect pests of legumes. Callosobruchus maculatus was the main pest of legume and attacking mainly cowpeas (34.92 bruchids/g of seed) and peanuts (20.75 bruchids/g of seed). Seven harmful species destroy the cereals. Sitophilus zeamais is the main pest of maize (15.86 weevils/g of maize) and S. oryzae, for sorghum (36.59 weevils/g of maize). Tribolium castaneum were the main secondary pest. T. castaneum infests both cereals and leguminous. This work summarizes the importance and the diversification of stored grain pests in Logone Valley. Knowing the pest diversity is an important step in the strategy to develop a friendly and ecological control method of these harmful insects.展开更多
Xinjiang Uygur Autonomous Region is a scarcely populated area in China and technicians for plant protection are extremely deficient.The occurrence areas of insect pests in grain and cotton crops have been increasing y...Xinjiang Uygur Autonomous Region is a scarcely populated area in China and technicians for plant protection are extremely deficient.The occurrence areas of insect pests in grain and cotton crops have been increasing year by year, causing serious economic losses. Aiming for several main grain and economic crops of Xinjiang(cotton, corn and wheat), an intelligence decision support system for diagnosis and management of grain and cotton crop pests in Xinjiang was designed and developed, which was based on android platform and windows system architecture. APP application program of smart phones was used as an implementation form. The intelligence decision support system will help plant protection personnel and farmers to solve local pest recognition and prevention control problem at the grassroots level in Xinjiang remote regions.展开更多
A mesoscale modeling methodology is proposed to predict the strain induced abnormal grain growth in the annealing process of deformed aluminum alloys. Firstly, crystal plasticity finite element(CPFE) analysis is perfo...A mesoscale modeling methodology is proposed to predict the strain induced abnormal grain growth in the annealing process of deformed aluminum alloys. Firstly, crystal plasticity finite element(CPFE) analysis is performed to calculate dislocation density and stored deformation energy distribution during the plastic deformation. A modified phase field(PF) model is then established by extending the continuum field method to consider both stored energy and local interface curvature as driving forces of grain boundary migration. An interpolation mapping approach is adopted to transfer the stored energy distribution from CPFE to PF efficiently. This modified PF model is implemented to a hypothetical bicrystal firstly for verification and then the coupled CPFE-PF framework is further applied to simulating the 2D synthetic polycrystalline microstructure evolution in annealing process of deformed AA3102 aluminum alloy.Results show that the nuclei with low stored energy embedded within deformed matrix tend to grow up, and abnormal large grains occur when the deformation is close to the critical plastic strain, attributing to the limited number of recrystallized nuclei and inhomogeneity of the stored energy.展开更多
The use of botanical pesticides in pest management during storage against insects is often encouraged because synthetic insecticides produce multiple side-effects on human health and environment. Insecticidal activity...The use of botanical pesticides in pest management during storage against insects is often encouraged because synthetic insecticides produce multiple side-effects on human health and environment. Insecticidal activity of the hexane, dichloromethane, ethyl acetate and methanol extracts of bark ofAfrostyrax lepidophyllus was tested on Sitophilus zeama~:~, Tribolium castaneum and Rhy-opertha dominica. The mortality rate was measured variable. The results of analysis showed that the mortality rate has a very highly significant variation following extracts, doses, insects and time considered (P 〈 0.001). Extracts with ethyl acetate and hexane of A. lepidophyllus are effective against S. zeamais at the highest doses (1 g/10 mL and 0.5 g/10 mL of solvent). These effective extracts werc characterized by gas chromatography coupled with mass spectrometry. Molecules such as thiocyanic acid, ethyl ester: dimetbylditbiophosphinic acid and other were characterizated. These results may consolidate traditional use ofA. lepidophylh^s in pest management.展开更多
The potential for using imidacloprid (a neonicotinoid) and indoxacarb (an oxadiazine) as grain protectants was investigated in bioassays against resistant strains of five stored grain beetles. The species investig...The potential for using imidacloprid (a neonicotinoid) and indoxacarb (an oxadiazine) as grain protectants was investigated in bioassays against resistant strains of five stored grain beetles. The species investigated were Rhyzopertha dominica (E) (the lesser grain borer), Sitophilus oryzae (L.) (the rice weevil), Tribolium castaneum (Herbst) (the rust-red flour beetle), Oryzaephilus surinamensis (L.) (the saw tooth flour beetle), and Cryptolestesferrugineus (Stephens) (the fiat grain beetle). Each of these species has developed resistance to one or more protectants, including organophosphorus insecticides, synthetic pyrethroids and the juvenile hormone analogue methoprene. Mortality and re- production after a 2-week exposure of adults to treated wheat depended on species, dose and insecticide. Imidacloprid had no effect on S. oryzae at any dose, but none of the other species produced any live progeny at 10 mg/kg. Indoxacarb had no effect on T. castaneum at any dose, but none of the other species produced any live progeny at 5 mg/kg. The results show that although both imidacloprid and indoxacarb can control at least four of the five key pests tested at doses comparable to those used for organophosphorus protectants, more potent neonicotinoid or oxadiazine insecticides would be needed than either of these to provide broad spectrum protection of stored grain .展开更多
Diatomaceous earth (DE) is a natural inert dust used to control insect pests in stored grain as an alternative to synthetic residual insecticides. Various DE formulations are now registered as a grain protectant or ...Diatomaceous earth (DE) is a natural inert dust used to control insect pests in stored grain as an alternative to synthetic residual insecticides. Various DE formulations are now registered as a grain protectant or for structural treatment in many different countries throughout the world. The mode of action of DE is through the absorption of cuticular waxes in the insect cuticle, and insect death occurs from desiccation. The main advantages of using DE are its low mammalian toxicity and its stability. The main limitations to widespread commercial use of DE are reduction of the bulk density and flowability of grain, irritant hazards during application and reduction in efficacy at high moisture contents. This paper is an updated review of published results of researches related to the use of DEs and discusses their potential use in large-scale, commercial storage and in small scale applications.展开更多
To deeply understand and even describe the evolutions of the low-energy twin boundary density(BLDΣ3n)in a thermal-plastic deformation process,an improved twin density model as a function of average grain size and sto...To deeply understand and even describe the evolutions of the low-energy twin boundary density(BLDΣ3n)in a thermal-plastic deformation process,an improved twin density model as a function of average grain size and stored energy is developed.For Nimonic 80A superalloy,the model is solved based on the EBSD statistical results of grain size and BLDΣ3n in the specimens compressed at temperatures of 1273−1423 K and strain rates of 0.001−10 s−1.The corresponding relationships of BLDΣ3n with stored energy and grain size varying with temperature and strain rate are clarified by the superimposed contour plot maps.It is summarized that BLDΣ3n increases with increasing stored energy and decreasing grain size,and higher BLDΣ3n with finer grains corresponds with lower temperatures and higher strain rates.Such relationships are described by the improved twin density model,and the prediction tolerance of the solved model is limited in 2.8%.展开更多
In January 2005, the United States Environmental Protection Agency registered spinosad as a stored grain protectant. No referenced data on the efficacy of spinosad on corn in suppressing major stored-grain insects hav...In January 2005, the United States Environmental Protection Agency registered spinosad as a stored grain protectant. No referenced data on the efficacy of spinosad on corn in suppressing major stored-grain insects have been published. In this paper, we evaluated the efficacy of spinosad against seven major stored-grain insects on shelled corn in the laboratory. Insect species tested were the red flour beetle, Tribolium castaneum (Jacquelin duVal); rusty grain beetle, Cryptolestesferrugineus (Stephens); lesser grain borer, Rhyzopertha dominica (F.); sawtoothed grain beetle, Oryzaephilus surinamensis (L.); rice weevil, Sitophilus oryzae (L.); maize weevil, Sitophilus zeamais (Motschulsky); and Indian meal moth, Plodia interpunctella (Htibner). Corn kernels were treated with spinosad at 0, 0. 1, 0.5, 1, and 2 active ingredient (a.i.) mg/kg for controlling the seven species. Beetle adults or P. interpunctella eggs were introduced into each container holding 100 g of untreated or insecticide-treated corn. The seven insect species survived well on the control treatment, produced 28 to 336 progeny, and caused significant kernel damage after 49 days. On spinosad-treated corn, adult mortality of C. ferrugineus, R. dominica, 0. surinamensis, S. oryzae, and S. zeamais was 〉 98% at 1 and 2 mg/kg after 12 days. Spinosad at≥ 0.5 mg/kg completely suppressed egg-to-larval survival after 21 days and egg-to-adult emergence of P. interpunctella after 49 days, whereas 16% T. castaneum adults survived at 1 mg/kg after 12 days. Spinosad at 1 or 2 mg/kg provided complete or near complete suppression of progeny production and kernel damage of all species after 49 days. Our results indicate that spinosad at the current labeled rate of 1 mg/kg is effective against the seven stored-grain insect pests on corn.展开更多
The simplification of 3D laser scanning point cloud is an important step of surface reconstruction and volume estimation of bulk grain in granary.This study presented an adaptive simplification algorithm based on part...The simplification of 3D laser scanning point cloud is an important step of surface reconstruction and volume estimation of bulk grain in granary.This study presented an adaptive simplification algorithm based on particle swarm optimization(PSO).It introduced PSO into the average distance method,a conventional simplification method.The basic idea of this algorithm was to adaptively determine the optimal point reducing intervals of scanning lines according to original point cloud density by PSO.By using the 3D point cloud scanned from bulk grain surface in granary,the proposed algorithm was validated.Compared with the average distance method,the proposed algorithm obtained more evenly distributed point set,smaller reduction ratio(6.96%)and higher volume estimation accuracy(relative error was less than 3‰).The 3D laser scanner(GSLS003,Jilin University and SkyViTech Co.,Ltd.,Hangzhou,China)used in this study could scan the complete picture of the grain surface in a granary in one time,so the acquired point cloud data do not have to be jointed.For the good simplification performance and capability of updating the reducing interval at any moment,the proposed algorithm and the 3D laser scanner could be used to realize online real-time measurement of stored bulk grain volume in granary.展开更多
Surfaces of stored grain bulk are often reconstructed from organized point sets with noise by 3-D laser scanner in an online measuring system.As a result,denoising is an essential procedure in processing point cloud d...Surfaces of stored grain bulk are often reconstructed from organized point sets with noise by 3-D laser scanner in an online measuring system.As a result,denoising is an essential procedure in processing point cloud data for more accurate surface reconstruction and grain volume calculation.A classified denoising method was presented in this research for noise removal from point cloud data of the grain bulk surface.Based on the distribution characteristics of cloud point data,the noisy points were divided into three types:The first and second types of the noisy points were either sparse points or small point cloud data deviating and suspending from the main point cloud data,which could be deleted directly by a grid method;the third type of the noisy points was mixed with the main body of point cloud data,which were most difficult to distinguish.The point cloud data with those noisy points were projected into a horizontal plane.An image denoising method,discrete wavelet threshold(DWT)method,was applied to delete the third type of the noisy points.Three kinds of denoising methods including average filtering method,median filtering method and DWT method were applied respectively and compared for denoising the point cloud data.Experimental results show that the proposed method remains the most of the details and obtains the lowest average value of RMSE(Root Mean Square Error,0.219)as well as the lowest relative error of grain volume(0.086%)compared with the other two methods.Furthermore,the proposed denoising method could not only achieve the aim of removing noisy points,but also improve self-adaptive ability according to the characteristics of point cloud data of grain bulk surface.The results from this research also indicate that the proposed method is effective for denoising noisy points and provides more accurate data for calculating grain volume.展开更多
For the long-term fortification of warehoused crops, the insecticidal impact of cold plasma treated wheat seeds against red flour beetles are studied.In this study, the gain weight loss,mortality and repellency tests ...For the long-term fortification of warehoused crops, the insecticidal impact of cold plasma treated wheat seeds against red flour beetles are studied.In this study, the gain weight loss,mortality and repellency tests of cold plasma treated seeds are investigated and statistical analysis is carried out by SPSS software.Cold plasma treatment is carried out at 800 V for 1 and 4 min.The results show that the minimum grain weight loss is observed in plasma treated seeds as compared to controlled seeds.It is also observed that the mortality rate is minimum in the controlled seed while maximum at 4 min plasma treatment.Similarly, the repellent effect has a very small variation as compared to the controlled seed for Tribolium Castaneum.Therefore, plasma treatment can be considered as a practical and effective method for seed protection against red floor beetles particularly during long-term storage by controlling the insecticidal effects.展开更多
A study was carried out to determine the relative susceptibility of six maize(Zea mays L.) varieties to maize weevil,Sitophilus zeamais Motschulsky(Coleoptera: Curculionidae). It was conducted at Department of Crop Pr...A study was carried out to determine the relative susceptibility of six maize(Zea mays L.) varieties to maize weevil,Sitophilus zeamais Motschulsky(Coleoptera: Curculionidae). It was conducted at Department of Crop Protection Laboratory,University of Ilorin, Nigeria at ambient temperature of 28±2℃ and 68%±3% relative humidity. Samples of the varieties were infestedwith five pairs of S. zeamais adults in their respective containers arranged in completely randomized design with three replications.Data were collected on moisture content, adult mortality, adult emergence, grain loss and grain damage. The index of susceptibilityand means of damage parameters were used to determine susceptibility of the maize varieties. The results showed that 2008 SYNEE W DT STR was highly resistant and 2004 TZE-W POP STR C4 was moderately resistant, while 2004 TZE-Y-POP STR C4,99 TZEE-Y-STR, EV99 QPM and TZE-Y-POP DT STR QPM C_0S1 were susceptible. Under artificial infestation, the weevils hadsignificantly longer survival period in the susceptible varieties than those in the resistant genotype. It could be concluded that thesusceptible varieties already released to farmers should be protected from maize weevil damage.展开更多
The use of botanical pesticides in pest management during storage against insects is often encouraged because synthetic insecticides produce undesired effects. Bark powder ofDrypetes gossweileri is used by farmers in ...The use of botanical pesticides in pest management during storage against insects is often encouraged because synthetic insecticides produce undesired effects. Bark powder ofDrypetes gossweileri is used by farmers in pest management in Central Africa Republic. Hexane, dichloromethane, ethyl acetate and methanol were used for extraction bark powder by maceration. Insecticidal activity of the extracts was tested on Sitophilus zeamais, Tribolium castaneum and Rhy_-opertha dominica. The mortality rate, the number of surviving insects and the number of emerged insects were measured variables. Calculated mortality was obtained by applying Aboth's formula. The variables are submitted to variance analysis, model with four factors (plants, insects, doses and time) in Minitab 14. The results of analysis showed that the mortality rate has a very highly significant variation following extracts, doses, insects and time considered (P 〈 0.001). Extracts with ethyl acetate and dichloromethane of D. gossweileri are effective against S. zeamais and R. dominica at high doses (1, 0.5, 0.250 g/10 mL of solvent). These effective extracts were characterized by gas chromatography coupled with mass spectrometry. Molecules such as l-isothiocyanatomethyl, thiocyanic acid, phenylmethyl ester and other were characterizated. These results may consolidate traditional use olD. gossweileri in pest management.展开更多
基金financially supported by National Natural Science Foundation of China(No.61871176)Key Scientific and Technological Project of Science and Technology Department of Henan Province(No.172102210030,182102110099)+2 种基金Key Scientific Research Project Program of Universities of Henan Province(No.18B520025)Open Fund of Key Laboratory of Grain Information Processing and Control(No.KFJJ-2018-102)supported by Collaborative Innovation Center of Grain Storage and Security of Henan Province
文摘Pests detecting is an important research subject in grain storage field.In the past decades,many edge detection methods have been applied to the edge detection of stored grain pests.Although some of them can realize the stored grain pests detecting,precision and robustness are not good enough.Spectral residual(SR)saliency edge detection defines the logarithmic spectrumof image as novelty part of the image information.The remaining spectrumis converted to the airspace to obtain edge detection results.SR algorithm is completely based on frequency domain processing.It not only can effectively simplify the target detection algorithm,but also can improve the effectiveness of target recognition.The experimental results show that the edge results of stored grain pests detected by SR method are effective and stable.
文摘In order to achieve the acoustic signal distributed acquisition of stored grain pests, a novel acoustic signal acquisition system was presented based on the wireless sensor networks. And the system architecture, hardware configuration, and software were introduced in detail. Considering bandwidth limitation of wireless sensor networks, random sampling algorithm based on the compressed sensing theory was proposed. The developed acoustic signal acquisition system was applied in sampling the crawl acoustic signal of Tribolinm castaneum Herbst adults in granary. Preliminary experimentation indicated the rationality and practicability of the developed system and the proposed algorithm. They can implement the remote, real-time, and reliable wireless transmission for the acoustic signal sampled data of multiple points stored grain pests effectively.
文摘Insects are major pests of stored grains. In sub Sahara Africa, stored grain insect pests are mainly Coleoptera or Lepidoptera. In the Logone Valley, area covering the Far North Region of Cameroon and South-West of Chad, to our knowledge, the diversity of insect pests noxious to stored products is not established. These beetles and weevils (Insecta:Coleoptera) during their development depreciate food in storage, were able to destroy a whole stock in a very short period of time if no protection of stored food is made. To achieve the diversity of insect pests, inspections of granaries were done in 209 villages of Logone Valley where insect pests were collected and identified. Secondly, the stored grains were sampled in peasant's granaries of Logone Valley and reared in incubators in the Unit of Entomological Research of the University of Ngaound6r6. After their emergence, insects were removed, collected and identified. Their noxious efficiency on stored grains is done by the calculation of the density of each insect pests per gram of grains. This study indicates that 12 species of harmful insects attack cereals and leguminous grains in the Logone Valley during storage. The Bruchids were the main insect pests of legumes. Callosobruchus maculatus was the main pest of legume and attacking mainly cowpeas (34.92 bruchids/g of seed) and peanuts (20.75 bruchids/g of seed). Seven harmful species destroy the cereals. Sitophilus zeamais is the main pest of maize (15.86 weevils/g of maize) and S. oryzae, for sorghum (36.59 weevils/g of maize). Tribolium castaneum were the main secondary pest. T. castaneum infests both cereals and leguminous. This work summarizes the importance and the diversification of stored grain pests in Logone Valley. Knowing the pest diversity is an important step in the strategy to develop a friendly and ecological control method of these harmful insects.
基金Supported by National Natural Science Foundation of China "Characterization and RNAi Silencing of Detoxification Gene Families in Cotton Mite"(31560532)
文摘Xinjiang Uygur Autonomous Region is a scarcely populated area in China and technicians for plant protection are extremely deficient.The occurrence areas of insect pests in grain and cotton crops have been increasing year by year, causing serious economic losses. Aiming for several main grain and economic crops of Xinjiang(cotton, corn and wheat), an intelligence decision support system for diagnosis and management of grain and cotton crop pests in Xinjiang was designed and developed, which was based on android platform and windows system architecture. APP application program of smart phones was used as an implementation form. The intelligence decision support system will help plant protection personnel and farmers to solve local pest recognition and prevention control problem at the grassroots level in Xinjiang remote regions.
基金the financial support from the National Natural Science Foundation of China (Nos. U2141215, 52105384 and 52075325)the support of Materials Genome Initiative Center, Shanghai Jiao Tong University, China。
文摘A mesoscale modeling methodology is proposed to predict the strain induced abnormal grain growth in the annealing process of deformed aluminum alloys. Firstly, crystal plasticity finite element(CPFE) analysis is performed to calculate dislocation density and stored deformation energy distribution during the plastic deformation. A modified phase field(PF) model is then established by extending the continuum field method to consider both stored energy and local interface curvature as driving forces of grain boundary migration. An interpolation mapping approach is adopted to transfer the stored energy distribution from CPFE to PF efficiently. This modified PF model is implemented to a hypothetical bicrystal firstly for verification and then the coupled CPFE-PF framework is further applied to simulating the 2D synthetic polycrystalline microstructure evolution in annealing process of deformed AA3102 aluminum alloy.Results show that the nuclei with low stored energy embedded within deformed matrix tend to grow up, and abnormal large grains occur when the deformation is close to the critical plastic strain, attributing to the limited number of recrystallized nuclei and inhomogeneity of the stored energy.
文摘The use of botanical pesticides in pest management during storage against insects is often encouraged because synthetic insecticides produce multiple side-effects on human health and environment. Insecticidal activity of the hexane, dichloromethane, ethyl acetate and methanol extracts of bark ofAfrostyrax lepidophyllus was tested on Sitophilus zeama~:~, Tribolium castaneum and Rhy-opertha dominica. The mortality rate was measured variable. The results of analysis showed that the mortality rate has a very highly significant variation following extracts, doses, insects and time considered (P 〈 0.001). Extracts with ethyl acetate and hexane of A. lepidophyllus are effective against S. zeamais at the highest doses (1 g/10 mL and 0.5 g/10 mL of solvent). These effective extracts werc characterized by gas chromatography coupled with mass spectrometry. Molecules such as thiocyanic acid, ethyl ester: dimetbylditbiophosphinic acid and other were characterizated. These results may consolidate traditional use ofA. lepidophylh^s in pest management.
文摘The potential for using imidacloprid (a neonicotinoid) and indoxacarb (an oxadiazine) as grain protectants was investigated in bioassays against resistant strains of five stored grain beetles. The species investigated were Rhyzopertha dominica (E) (the lesser grain borer), Sitophilus oryzae (L.) (the rice weevil), Tribolium castaneum (Herbst) (the rust-red flour beetle), Oryzaephilus surinamensis (L.) (the saw tooth flour beetle), and Cryptolestesferrugineus (Stephens) (the fiat grain beetle). Each of these species has developed resistance to one or more protectants, including organophosphorus insecticides, synthetic pyrethroids and the juvenile hormone analogue methoprene. Mortality and re- production after a 2-week exposure of adults to treated wheat depended on species, dose and insecticide. Imidacloprid had no effect on S. oryzae at any dose, but none of the other species produced any live progeny at 10 mg/kg. Indoxacarb had no effect on T. castaneum at any dose, but none of the other species produced any live progeny at 5 mg/kg. The results show that although both imidacloprid and indoxacarb can control at least four of the five key pests tested at doses comparable to those used for organophosphorus protectants, more potent neonicotinoid or oxadiazine insecticides would be needed than either of these to provide broad spectrum protection of stored grain .
文摘Diatomaceous earth (DE) is a natural inert dust used to control insect pests in stored grain as an alternative to synthetic residual insecticides. Various DE formulations are now registered as a grain protectant or for structural treatment in many different countries throughout the world. The mode of action of DE is through the absorption of cuticular waxes in the insect cuticle, and insect death occurs from desiccation. The main advantages of using DE are its low mammalian toxicity and its stability. The main limitations to widespread commercial use of DE are reduction of the bulk density and flowability of grain, irritant hazards during application and reduction in efficacy at high moisture contents. This paper is an updated review of published results of researches related to the use of DEs and discusses their potential use in large-scale, commercial storage and in small scale applications.
基金the financial supports from Chongqing Basic Research and Frontier Exploration Program, China (cstc2018jcyj AX0459)the Fundamental Research Funds for the Central Universities, China (2019CDQYTM027, 2019CDJGFCL003, 2018CDPTCG0001-6)Open Fund of State Key Laboratory of Materials Processing and Die & Mould Technology, China (P2020-001)
文摘To deeply understand and even describe the evolutions of the low-energy twin boundary density(BLDΣ3n)in a thermal-plastic deformation process,an improved twin density model as a function of average grain size and stored energy is developed.For Nimonic 80A superalloy,the model is solved based on the EBSD statistical results of grain size and BLDΣ3n in the specimens compressed at temperatures of 1273−1423 K and strain rates of 0.001−10 s−1.The corresponding relationships of BLDΣ3n with stored energy and grain size varying with temperature and strain rate are clarified by the superimposed contour plot maps.It is summarized that BLDΣ3n increases with increasing stored energy and decreasing grain size,and higher BLDΣ3n with finer grains corresponds with lower temperatures and higher strain rates.Such relationships are described by the improved twin density model,and the prediction tolerance of the solved model is limited in 2.8%.
文摘In January 2005, the United States Environmental Protection Agency registered spinosad as a stored grain protectant. No referenced data on the efficacy of spinosad on corn in suppressing major stored-grain insects have been published. In this paper, we evaluated the efficacy of spinosad against seven major stored-grain insects on shelled corn in the laboratory. Insect species tested were the red flour beetle, Tribolium castaneum (Jacquelin duVal); rusty grain beetle, Cryptolestesferrugineus (Stephens); lesser grain borer, Rhyzopertha dominica (F.); sawtoothed grain beetle, Oryzaephilus surinamensis (L.); rice weevil, Sitophilus oryzae (L.); maize weevil, Sitophilus zeamais (Motschulsky); and Indian meal moth, Plodia interpunctella (Htibner). Corn kernels were treated with spinosad at 0, 0. 1, 0.5, 1, and 2 active ingredient (a.i.) mg/kg for controlling the seven species. Beetle adults or P. interpunctella eggs were introduced into each container holding 100 g of untreated or insecticide-treated corn. The seven insect species survived well on the control treatment, produced 28 to 336 progeny, and caused significant kernel damage after 49 days. On spinosad-treated corn, adult mortality of C. ferrugineus, R. dominica, 0. surinamensis, S. oryzae, and S. zeamais was 〉 98% at 1 and 2 mg/kg after 12 days. Spinosad at≥ 0.5 mg/kg completely suppressed egg-to-larval survival after 21 days and egg-to-adult emergence of P. interpunctella after 49 days, whereas 16% T. castaneum adults survived at 1 mg/kg after 12 days. Spinosad at 1 or 2 mg/kg provided complete or near complete suppression of progeny production and kernel damage of all species after 49 days. Our results indicate that spinosad at the current labeled rate of 1 mg/kg is effective against the seven stored-grain insect pests on corn.
基金This work was financially supported by National Natural Science Foundation of China(No.50975121)Jilin Province Science and Technology Development Plan Item(No.20130522150JH)2013 Jilin Province Science Foundation for Post Doctorate Research(No.RB201361).
文摘The simplification of 3D laser scanning point cloud is an important step of surface reconstruction and volume estimation of bulk grain in granary.This study presented an adaptive simplification algorithm based on particle swarm optimization(PSO).It introduced PSO into the average distance method,a conventional simplification method.The basic idea of this algorithm was to adaptively determine the optimal point reducing intervals of scanning lines according to original point cloud density by PSO.By using the 3D point cloud scanned from bulk grain surface in granary,the proposed algorithm was validated.Compared with the average distance method,the proposed algorithm obtained more evenly distributed point set,smaller reduction ratio(6.96%)and higher volume estimation accuracy(relative error was less than 3‰).The 3D laser scanner(GSLS003,Jilin University and SkyViTech Co.,Ltd.,Hangzhou,China)used in this study could scan the complete picture of the grain surface in a granary in one time,so the acquired point cloud data do not have to be jointed.For the good simplification performance and capability of updating the reducing interval at any moment,the proposed algorithm and the 3D laser scanner could be used to realize online real-time measurement of stored bulk grain volume in granary.
基金National Natural Science Foundation of China(No.50975121)Jilin Province Science and Technology Development Plan Item(No.20130522150JH)2013 Jilin Province Science Foundation for Post Doctorate Research(No.RB201361).
文摘Surfaces of stored grain bulk are often reconstructed from organized point sets with noise by 3-D laser scanner in an online measuring system.As a result,denoising is an essential procedure in processing point cloud data for more accurate surface reconstruction and grain volume calculation.A classified denoising method was presented in this research for noise removal from point cloud data of the grain bulk surface.Based on the distribution characteristics of cloud point data,the noisy points were divided into three types:The first and second types of the noisy points were either sparse points or small point cloud data deviating and suspending from the main point cloud data,which could be deleted directly by a grid method;the third type of the noisy points was mixed with the main body of point cloud data,which were most difficult to distinguish.The point cloud data with those noisy points were projected into a horizontal plane.An image denoising method,discrete wavelet threshold(DWT)method,was applied to delete the third type of the noisy points.Three kinds of denoising methods including average filtering method,median filtering method and DWT method were applied respectively and compared for denoising the point cloud data.Experimental results show that the proposed method remains the most of the details and obtains the lowest average value of RMSE(Root Mean Square Error,0.219)as well as the lowest relative error of grain volume(0.086%)compared with the other two methods.Furthermore,the proposed denoising method could not only achieve the aim of removing noisy points,but also improve self-adaptive ability according to the characteristics of point cloud data of grain bulk surface.The results from this research also indicate that the proposed method is effective for denoising noisy points and provides more accurate data for calculating grain volume.
文摘For the long-term fortification of warehoused crops, the insecticidal impact of cold plasma treated wheat seeds against red flour beetles are studied.In this study, the gain weight loss,mortality and repellency tests of cold plasma treated seeds are investigated and statistical analysis is carried out by SPSS software.Cold plasma treatment is carried out at 800 V for 1 and 4 min.The results show that the minimum grain weight loss is observed in plasma treated seeds as compared to controlled seeds.It is also observed that the mortality rate is minimum in the controlled seed while maximum at 4 min plasma treatment.Similarly, the repellent effect has a very small variation as compared to the controlled seed for Tribolium Castaneum.Therefore, plasma treatment can be considered as a practical and effective method for seed protection against red floor beetles particularly during long-term storage by controlling the insecticidal effects.
文摘A study was carried out to determine the relative susceptibility of six maize(Zea mays L.) varieties to maize weevil,Sitophilus zeamais Motschulsky(Coleoptera: Curculionidae). It was conducted at Department of Crop Protection Laboratory,University of Ilorin, Nigeria at ambient temperature of 28±2℃ and 68%±3% relative humidity. Samples of the varieties were infestedwith five pairs of S. zeamais adults in their respective containers arranged in completely randomized design with three replications.Data were collected on moisture content, adult mortality, adult emergence, grain loss and grain damage. The index of susceptibilityand means of damage parameters were used to determine susceptibility of the maize varieties. The results showed that 2008 SYNEE W DT STR was highly resistant and 2004 TZE-W POP STR C4 was moderately resistant, while 2004 TZE-Y-POP STR C4,99 TZEE-Y-STR, EV99 QPM and TZE-Y-POP DT STR QPM C_0S1 were susceptible. Under artificial infestation, the weevils hadsignificantly longer survival period in the susceptible varieties than those in the resistant genotype. It could be concluded that thesusceptible varieties already released to farmers should be protected from maize weevil damage.
文摘The use of botanical pesticides in pest management during storage against insects is often encouraged because synthetic insecticides produce undesired effects. Bark powder ofDrypetes gossweileri is used by farmers in pest management in Central Africa Republic. Hexane, dichloromethane, ethyl acetate and methanol were used for extraction bark powder by maceration. Insecticidal activity of the extracts was tested on Sitophilus zeamais, Tribolium castaneum and Rhy_-opertha dominica. The mortality rate, the number of surviving insects and the number of emerged insects were measured variables. Calculated mortality was obtained by applying Aboth's formula. The variables are submitted to variance analysis, model with four factors (plants, insects, doses and time) in Minitab 14. The results of analysis showed that the mortality rate has a very highly significant variation following extracts, doses, insects and time considered (P 〈 0.001). Extracts with ethyl acetate and dichloromethane of D. gossweileri are effective against S. zeamais and R. dominica at high doses (1, 0.5, 0.250 g/10 mL of solvent). These effective extracts were characterized by gas chromatography coupled with mass spectrometry. Molecules such as l-isothiocyanatomethyl, thiocyanic acid, phenylmethyl ester and other were characterizated. These results may consolidate traditional use olD. gossweileri in pest management.