RNA interference(RNAi)has been used for agricultural insect pest control based on silencing of targeted insect genes.However,the effectiveness of RNAi and its applications in insect pest control remain challenging.Her...RNA interference(RNAi)has been used for agricultural insect pest control based on silencing of targeted insect genes.However,the effectiveness of RNAi and its applications in insect pest control remain challenging.Here we review factors that may affect the effectiveness of RNAi application,including the variability in RNAi efficacy among different insect species,a limited understanding of double-stranded RNA(dsRNA)uptake and systemic RNAi mechanisms,and the effective delivery of dsRNA in field conditions.Furthermore,we summarize recent progress in RNAi strategies for crop protection,discuss the advantages and disadvantages of RNAi-based insect control,and propose potential strategies to increase the effectiveness of RNAi in insect control.展开更多
Comparisons were performed between self-propelled boom sprayer and traditional mechanis, such as knapsack sprayer and sprayer-duster, stretcher-type powered sprayer, as well as single rotor unmanned sprayer and multi-...Comparisons were performed between self-propelled boom sprayer and traditional mechanis, such as knapsack sprayer and sprayer-duster, stretcher-type powered sprayer, as well as single rotor unmanned sprayer and multi-rotor un- manned sprayer. The effects on rice injury, lodging, and rehabilitation were conclud- ed and drug uniform distribution, sedimentation and prevention effects were ana- lyzed. The results showed that the self-propelled boom sprayer is characterized by high degree of automation, convenient operation, high adaptability, and high work efficiency. What＇s more, the sprayed fog quality is better, and fog distribution is more uniform. During the work process, fog loss would be diminished substantially, improving work efficiency and cutting down drug and water. It is notable that the underpart of the sprayer can be widely applied to plant protection in large-scale ar- eas in Jiangsu Province, significantly advancing whole-process mechanization of rice production.展开更多
The longitudinal steady-state control for going from hovering to small speed flight of a model insect is studied, using the method of computational fluid dynamics to compute the aerodynamic derivatives and the techniq...The longitudinal steady-state control for going from hovering to small speed flight of a model insect is studied, using the method of computational fluid dynamics to compute the aerodynamic derivatives and the techniques based on the linear theories of stability and control for determining the non-zero equilibrium points. Morphological and certain kinematical data of droneflies are used for the model insect. A change in the mean stroke angle （δФ） results in a horizontal forward or backward flight; a change in the stroke amplitude （δФ） or a equal change in the down- and upstroke angles of attack （δα1） results in a vertical climb or decent; a proper combination of δФ and δФ controls （or δФ and δα1 controls） can give a flight of any （small） speed in any desired direction.展开更多
The efficacies of biological and conventional chemical insecticides against two major insect pests of alfalfa(aphids and thrips)were compared in three sites across China’s alfalfa belt.In addition,the persistence of ...The efficacies of biological and conventional chemical insecticides against two major insect pests of alfalfa(aphids and thrips)were compared in three sites across China’s alfalfa belt.In addition,the persistence of the residues of chemical insecticides in alfalfa and their influence on the quality of alfalfa hay were examined.Efficacy varied among the different biological and chemical insecticides.The chemical insecticides were significantly more effective than biopesticides in a short time-frame.The efficacy period of biopesticides was significantly longer than that of chemical insecticides,and the corrected mortality rate of aphids in all regions was above 50%at 14 days after application.The analysis of pesticide residues showed that the residual doses of all the pesticides were within the allowed ranges after the safe period.The acid detergent fiber and neutral detergent fiber contents in alfalfa hay were higher and the protein content was lower in chemical insecticide treatments than in biopesticide treatments in Hebei.The relative feeding value of alfalfa hay treated with Metarhizium anisopliae IPP330189 was the highest among the treatments.Compared with chemical insecticides,the yield of alfalfa hay was higher in the biopesticides treatments.Biopesticides show a stronger control effect on insect populations and also a better improvement in the quality of alfalfa hay than chemical insecticides.This study provides a basis for exploring and developing a comprehensive control regime for alfalfa insect pests in the different alfalfa-growing regions in China,and for reducing chemical insecticide usage and improving forage quality.展开更多
Biological control through habitat management leads to sustainable insect pest control. Different types of land composition such as multiple landscapes, patchiness of landscapes enhance the natural enemies which ultim...Biological control through habitat management leads to sustainable insect pest control. Different types of land composition such as multiple landscapes, patchiness of landscapes enhance the natural enemies which ultimately lead to control of insect pest. Plant characteristics such as flower shape, flower color and blooming period ensures excess food for natural enemies like nectar and pollen. Moreover, some agricultural practices such as tillage, crop rotation, and intercropping influence the natural enemies especially parasitoid and preda-tors. Consequently, they increase longevity and fecundity of parasitoid and predator that help to control insect pest. One of the most important recently used methods is push-pull which consists of semiochemicals called Herbi-vore-Induced Plant Volatiles (HIPVs). This compound has been used to pre-vent pest and attract natural enemies.展开更多
Cotton bollworm(Helicoverpa armigera) is an important agricultural pest that causes severe yield loss to crops,particularly to cotton.Transgenic Bt crops have been successful in
[ Objective] The paper was to study control effects of 12 kinds of insecticides on sugarcane pests at different periods. [ Method] By field experiment, the control effects of different insecticides against sugarcane p...[ Objective] The paper was to study control effects of 12 kinds of insecticides on sugarcane pests at different periods. [ Method] By field experiment, the control effects of different insecticides against sugarcane pests at planting stage, seedling stage and tillering stage of sugarcane were studied. [ Result] After seedcane was treated by Chlorantraniliprole, Durivo and Seed soaking, the dead heart seedlings were significantly reduced in fields, and the control effects were 87.13% ± 12.87%, 85.22% ± 14.78%, 82.71% ± 17.29%, respectively ; Durivo （ seedling emergence rate is 63.00% ± 10.30% ） and Seed soaking （ seedling emergence rate is 57.75 % ± 4.50% ） could also significantly enhance seedling emergence rate. After ＂removal-irrigation＂ treatment during seedling stage, the con- tml effects of Flubendiamide （76.26% ±4.31% ） and Chlorantraniliprele （61.66% ±6.65% ） against sugarcane stem borer were significantly higher than Virtako （60.17% ±7.06%）, Deltamethrin（38.75% ±9.88%）, lambda-cyhalothrin （54.06% ±6.83%）, 18% Dimehypo AS （37.98% ±10.31%） and Dipterex （38.64% ±9.34% ）. During tillering stage, with the increased application of 3.6% Dimehypo GR in cultivation and earthing up, the control effect on stem borer was significantly increased, and the control effect reached （72.03%± 17.06% ） as the dosage was 120 kg/hm2 ; when the dosage of phoxim exceeded 30 kg/hm2, the control effect on underground pests reached 44.00% ± 14.80%, and the control effect did not have significant difference as the dosage was ranged from 30 kg/hm2 to 60 kg/hm2. [ Conclusion] The paper provided scientific basis for selection of different control methods, different chemicals and dosages against pests during different periods.展开更多
<span style="font-family:Verdana;">The new coronavirus called SARS-CoV-2 is a new type of virus named as COVID-19. Although, </span><span style="font-family:Verdana;">it has </...<span style="font-family:Verdana;">The new coronavirus called SARS-CoV-2 is a new type of virus named as COVID-19. Although, </span><span style="font-family:Verdana;">it has </span><span style="font-family:Verdana;">few similarities with pandemic flu viruses</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> the respiratory system and immune system are damaged through the viruses infected the population wh</span><span style="font-family:Verdana;">o</span><span style="font-family:Verdana;"> has weakened immunity. SARS-CoV-2 spread</span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> when people don’t have the sign and symptoms. This virus COVID-19 appears to spread more easily than the flu, and asymptomatic transmission may account for a greater proportion of COVID-19’s spreader over the World. In inundation of the current understanding</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> the roles of insect vectors are helping in the transmission of viral pathogens as well and the possible roles of some newly joined insects in the mechanical transmission of COVID-19.</span><span style="font-family:Verdana;"> We also specifically provide the prevention and control methods related to contamination, disease burden, risk pattern in the family, near and dear to maintain the precision of social distancing and development of the immune system to fight against SARS-CoV-2.展开更多
Soybean rust,soybean downy mildew,and soybean thrips,soybean pod borers,and soybean nocturnal moths are the world wide diseases and insect pests in soybean production,which pose a potential threat to soybean productio...Soybean rust,soybean downy mildew,and soybean thrips,soybean pod borers,and soybean nocturnal moths are the world wide diseases and insect pests in soybean production,which pose a potential threat to soybean production in Great Mekong Sub-region（ GMS）,comprising Cambodia,Lao People＇s Democratic Republic,Myanmar,Thailand,Vietnam,and Yunnan province,the People＇s Republic of China. This paper summarized the host range,epidemiology,damage and control methods of these diseases and insect pests in GMS,with the aim to provide information basis for understanding and effective control of soybean diseases and insect pests in GMS.展开更多
Enriched by the-medium containingchitin and cell wall of Phizoctoniasolani AG-1,a bacterium X2-23 withhigher chitinase activity was isolatedfrom 166 chitinase-producing bacteria.It could distinctly inhibit the fungi
[ Objective] In order to construct the specific equine disease-free zone of of the Guangzhou Asian Games, to ensure that the equestrian events of Guangzhou Asian Games be smoothly held. [Methods] The species, quantiti...[ Objective] In order to construct the specific equine disease-free zone of of the Guangzhou Asian Games, to ensure that the equestrian events of Guangzhou Asian Games be smoothly held. [Methods] The species, quantities, distribution and seasonal variations of insects and wild animals in related zones were investigated from 2008 to 2010, and the collected samples of the insects and wild animals were tested in laboratory for related equine diseases. [Results] The investigations indicated that there were some mosquitoes, flies, horseflies, punkies, ticks, bats, wild birds and wild bears in equastrianism venue and peripheral regions of disease-free zone of the Guangzhou Asian Games, the laboratory results of Japa- nese encephalitis, vesicular stomatitis, Nipah virus disease, West Nile fever, and Trypanosomiasis evansi, were all negative. According to the in- vestigations and test results, the risk assessments of insect and wild animal vectors in the prevalence of related equine diseases were made to con- firm that the risk was relatively low or very low, and comprehensive prevention and control measures with prevention as major measures and insecti- cides application and environment managements as supplementary means were made on the basis of the risk assessment conclusions. [ Conclu- sions] This research has laid a solid foundation for the successful building of the first specific equine disease-free zone in our country, ensured the smooth holding of the 16th equastdan competition in Guangzhou Asian Games.展开更多
Reduction of mosquito populations will, at least, reduce substantially the transmission of malaria disease. One potential method of achieving this reduction is the environmentally-friendly population control method kn...Reduction of mosquito populations will, at least, reduce substantially the transmission of malaria disease. One potential method of achieving this reduction is the environmentally-friendly population control method known as the Sterile Insect Control (SIT) method. The SIT method has so far not been widely used against insect disease vectors, such as mosquitoes, because of various practical difficulties in rearing, sterilization and distribution of the parasite population. For mosquitoes, male-only release is considered essential since sterile females will bite and so may transmit disease, whereas male mosquitoes do not bite. This work concerns the mathematical modelling of the effectiveness of Sterile Insect Technique for Aedes aegypti mosquitoes, when the female sexual preference is incorporated. We found that for a released value of the sterile male mosquito below 40,000, the wild mosquito population decreases over time while the sterile male mosquito population increases. Therefore, the transmission of malaria and dengue infection declines because the sterile male mosquitoes dominated the environment. We also found that for a released value of the sterile male mosquito above 40,000, the wild mosquito population decreases and the sterile male mosquito population decreases as well. Therefore, if the injection of sterile male mosquitoes is large enough, the environment will be rid of mosquitoes over time. The result also shows that if sexual selection is incorporated into a reaction diffusion system, modelling the spread of Aedes aegypti mosquitoes, the Sterile Insect Technique (SIT) will still be a successful control measure.展开更多
Cotton leaf worm, Spodoptera littoralis, is considered one of the most common arthropod pests that contribute to crop devastation of cotton. Previously, agricultural pests were controlled through the application of ch...Cotton leaf worm, Spodoptera littoralis, is considered one of the most common arthropod pests that contribute to crop devastation of cotton. Previously, agricultural pests were controlled through the application of chemical insecticides. However, insecticide-resistant insect populations emergence, as well as increasing concerns about the environmental and human health risks. Venomous animals introduce valuable sources of bioactive compounds which are employed for defence. Some of these toxins have high phyletic specificity, making them appropriate for use in IPM programs. This study aims to test the insecticidal effects of Polistes dominulus and Apis mellifera venoms. Crude venoms were examined for their insecticidal effect against cotton leaf worms by four different application methods including: leaf dipping, integument dropping, spraying, and injection. The data demonstrated a strong response to purified (Polistes dominulus) venom at an initial time than that of honey bee (Apis mellifera) which increases response with increasing the dose and the time interval. A dosage of 0.015 - 0.16 ml of both venoms had notably varied in LD<sub>50</sub> values on Spodoptera littoralis that showed higher wasp venom toxicity. Cotton leaf worms showed more susceptibility and mortality to the Polistes sp. venom than that of honey bees.展开更多
基金funded by the National Natural Science Foundation of China(32188102 to Lanqin Xia)Natural Science Foundation for Distinguished Young Scholars of Jiangxi province(20212ACB215001 to Xiudao Yu)+1 种基金supported by the China Scholarship Council(202303250062)the GSCAAS-ULg Joint PhD Program。
文摘RNA interference(RNAi)has been used for agricultural insect pest control based on silencing of targeted insect genes.However,the effectiveness of RNAi and its applications in insect pest control remain challenging.Here we review factors that may affect the effectiveness of RNAi application,including the variability in RNAi efficacy among different insect species,a limited understanding of double-stranded RNA(dsRNA)uptake and systemic RNAi mechanisms,and the effective delivery of dsRNA in field conditions.Furthermore,we summarize recent progress in RNAi strategies for crop protection,discuss the advantages and disadvantages of RNAi-based insect control,and propose potential strategies to increase the effectiveness of RNAi in insect control.
基金Supported by National Natural Science Foundation of China(31401296)Independent Innovation Foundation of Science and Technology in Jiangsu Province(CX(14)2101)
文摘Comparisons were performed between self-propelled boom sprayer and traditional mechanis, such as knapsack sprayer and sprayer-duster, stretcher-type powered sprayer, as well as single rotor unmanned sprayer and multi-rotor un- manned sprayer. The effects on rice injury, lodging, and rehabilitation were conclud- ed and drug uniform distribution, sedimentation and prevention effects were ana- lyzed. The results showed that the self-propelled boom sprayer is characterized by high degree of automation, convenient operation, high adaptability, and high work efficiency. What＇s more, the sprayed fog quality is better, and fog distribution is more uniform. During the work process, fog loss would be diminished substantially, improving work efficiency and cutting down drug and water. It is notable that the underpart of the sprayer can be widely applied to plant protection in large-scale ar- eas in Jiangsu Province, significantly advancing whole-process mechanization of rice production.
基金the National Natural Science Foundation of China (10732030)the 111 Project (B07009)Specialized Research Fund for the Doctoral Program of Higher Education(SRFDP, 200800061013)
文摘The longitudinal steady-state control for going from hovering to small speed flight of a model insect is studied, using the method of computational fluid dynamics to compute the aerodynamic derivatives and the techniques based on the linear theories of stability and control for determining the non-zero equilibrium points. Morphological and certain kinematical data of droneflies are used for the model insect. A change in the mean stroke angle （δФ） results in a horizontal forward or backward flight; a change in the stroke amplitude （δФ） or a equal change in the down- and upstroke angles of attack （δα1） results in a vertical climb or decent; a proper combination of δФ and δФ controls （or δФ and δα1 controls） can give a flight of any （small） speed in any desired direction.
基金supported by China Agriculture Research System of MOF and MARA(CARS-34).
文摘The efficacies of biological and conventional chemical insecticides against two major insect pests of alfalfa(aphids and thrips)were compared in three sites across China’s alfalfa belt.In addition,the persistence of the residues of chemical insecticides in alfalfa and their influence on the quality of alfalfa hay were examined.Efficacy varied among the different biological and chemical insecticides.The chemical insecticides were significantly more effective than biopesticides in a short time-frame.The efficacy period of biopesticides was significantly longer than that of chemical insecticides,and the corrected mortality rate of aphids in all regions was above 50%at 14 days after application.The analysis of pesticide residues showed that the residual doses of all the pesticides were within the allowed ranges after the safe period.The acid detergent fiber and neutral detergent fiber contents in alfalfa hay were higher and the protein content was lower in chemical insecticide treatments than in biopesticide treatments in Hebei.The relative feeding value of alfalfa hay treated with Metarhizium anisopliae IPP330189 was the highest among the treatments.Compared with chemical insecticides,the yield of alfalfa hay was higher in the biopesticides treatments.Biopesticides show a stronger control effect on insect populations and also a better improvement in the quality of alfalfa hay than chemical insecticides.This study provides a basis for exploring and developing a comprehensive control regime for alfalfa insect pests in the different alfalfa-growing regions in China,and for reducing chemical insecticide usage and improving forage quality.
文摘Biological control through habitat management leads to sustainable insect pest control. Different types of land composition such as multiple landscapes, patchiness of landscapes enhance the natural enemies which ultimately lead to control of insect pest. Plant characteristics such as flower shape, flower color and blooming period ensures excess food for natural enemies like nectar and pollen. Moreover, some agricultural practices such as tillage, crop rotation, and intercropping influence the natural enemies especially parasitoid and preda-tors. Consequently, they increase longevity and fecundity of parasitoid and predator that help to control insect pest. One of the most important recently used methods is push-pull which consists of semiochemicals called Herbi-vore-Induced Plant Volatiles (HIPVs). This compound has been used to pre-vent pest and attract natural enemies.
文摘Cotton bollworm(Helicoverpa armigera) is an important agricultural pest that causes severe yield loss to crops,particularly to cotton.Transgenic Bt crops have been successful in
基金Supported by Basal Research Fund of Central Public-interest Scientific Institution(ITBB110503)Special Fund for Construction of Modern AgriculturalTechnology System(CARS-20-2-5)Sub-topics of Hainan Major Scientificand Technological Project:Germplasm and Genetic Resources of Tropical Organism(ZDZX2013023-1)
文摘[ Objective] The paper was to study control effects of 12 kinds of insecticides on sugarcane pests at different periods. [ Method] By field experiment, the control effects of different insecticides against sugarcane pests at planting stage, seedling stage and tillering stage of sugarcane were studied. [ Result] After seedcane was treated by Chlorantraniliprole, Durivo and Seed soaking, the dead heart seedlings were significantly reduced in fields, and the control effects were 87.13% ± 12.87%, 85.22% ± 14.78%, 82.71% ± 17.29%, respectively ; Durivo （ seedling emergence rate is 63.00% ± 10.30% ） and Seed soaking （ seedling emergence rate is 57.75 % ± 4.50% ） could also significantly enhance seedling emergence rate. After ＂removal-irrigation＂ treatment during seedling stage, the con- tml effects of Flubendiamide （76.26% ±4.31% ） and Chlorantraniliprele （61.66% ±6.65% ） against sugarcane stem borer were significantly higher than Virtako （60.17% ±7.06%）, Deltamethrin（38.75% ±9.88%）, lambda-cyhalothrin （54.06% ±6.83%）, 18% Dimehypo AS （37.98% ±10.31%） and Dipterex （38.64% ±9.34% ）. During tillering stage, with the increased application of 3.6% Dimehypo GR in cultivation and earthing up, the control effect on stem borer was significantly increased, and the control effect reached （72.03%± 17.06% ） as the dosage was 120 kg/hm2 ; when the dosage of phoxim exceeded 30 kg/hm2, the control effect on underground pests reached 44.00% ± 14.80%, and the control effect did not have significant difference as the dosage was ranged from 30 kg/hm2 to 60 kg/hm2. [ Conclusion] The paper provided scientific basis for selection of different control methods, different chemicals and dosages against pests during different periods.
文摘<span style="font-family:Verdana;">The new coronavirus called SARS-CoV-2 is a new type of virus named as COVID-19. Although, </span><span style="font-family:Verdana;">it has </span><span style="font-family:Verdana;">few similarities with pandemic flu viruses</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> the respiratory system and immune system are damaged through the viruses infected the population wh</span><span style="font-family:Verdana;">o</span><span style="font-family:Verdana;"> has weakened immunity. SARS-CoV-2 spread</span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> when people don’t have the sign and symptoms. This virus COVID-19 appears to spread more easily than the flu, and asymptomatic transmission may account for a greater proportion of COVID-19’s spreader over the World. In inundation of the current understanding</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> the roles of insect vectors are helping in the transmission of viral pathogens as well and the possible roles of some newly joined insects in the mechanical transmission of COVID-19.</span><span style="font-family:Verdana;"> We also specifically provide the prevention and control methods related to contamination, disease burden, risk pattern in the family, near and dear to maintain the precision of social distancing and development of the immune system to fight against SARS-CoV-2.
基金Supported by the Natural Science Fund for the Youth of Yunnan Agricultural University(2016ZR18)the Project of Key Laboratory of Integrated Pest Management on Crops in South China,Ministry of Agriculture,P.R.China(SCIPM2018-08)the Key Project of Agricultural Entomology and Pest Control in Yunnan Agricultural University(A2001206)
文摘Soybean rust,soybean downy mildew,and soybean thrips,soybean pod borers,and soybean nocturnal moths are the world wide diseases and insect pests in soybean production,which pose a potential threat to soybean production in Great Mekong Sub-region（ GMS）,comprising Cambodia,Lao People＇s Democratic Republic,Myanmar,Thailand,Vietnam,and Yunnan province,the People＇s Republic of China. This paper summarized the host range,epidemiology,damage and control methods of these diseases and insect pests in GMS,with the aim to provide information basis for understanding and effective control of soybean diseases and insect pests in GMS.
文摘Enriched by the-medium containingchitin and cell wall of Phizoctoniasolani AG-1,a bacterium X2-23 withhigher chitinase activity was isolatedfrom 166 chitinase-producing bacteria.It could distinctly inhibit the fungi
基金the help and strong support of Departments the Chinese Animal Health and Epidemic Center,Guangdong Rsearch Institute of Entomology,Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences,the Agriculture,Fisheries and Conservation Department of Hong Kong and the Hong Kong Jockey Club etc.,during the entomophily and wild animals prevention and control in the disease-free zone of Guangzhou Asian Games
文摘[ Objective] In order to construct the specific equine disease-free zone of of the Guangzhou Asian Games, to ensure that the equestrian events of Guangzhou Asian Games be smoothly held. [Methods] The species, quantities, distribution and seasonal variations of insects and wild animals in related zones were investigated from 2008 to 2010, and the collected samples of the insects and wild animals were tested in laboratory for related equine diseases. [Results] The investigations indicated that there were some mosquitoes, flies, horseflies, punkies, ticks, bats, wild birds and wild bears in equastrianism venue and peripheral regions of disease-free zone of the Guangzhou Asian Games, the laboratory results of Japa- nese encephalitis, vesicular stomatitis, Nipah virus disease, West Nile fever, and Trypanosomiasis evansi, were all negative. According to the in- vestigations and test results, the risk assessments of insect and wild animal vectors in the prevalence of related equine diseases were made to con- firm that the risk was relatively low or very low, and comprehensive prevention and control measures with prevention as major measures and insecti- cides application and environment managements as supplementary means were made on the basis of the risk assessment conclusions. [ Conclu- sions] This research has laid a solid foundation for the successful building of the first specific equine disease-free zone in our country, ensured the smooth holding of the 16th equastdan competition in Guangzhou Asian Games.
文摘Reduction of mosquito populations will, at least, reduce substantially the transmission of malaria disease. One potential method of achieving this reduction is the environmentally-friendly population control method known as the Sterile Insect Control (SIT) method. The SIT method has so far not been widely used against insect disease vectors, such as mosquitoes, because of various practical difficulties in rearing, sterilization and distribution of the parasite population. For mosquitoes, male-only release is considered essential since sterile females will bite and so may transmit disease, whereas male mosquitoes do not bite. This work concerns the mathematical modelling of the effectiveness of Sterile Insect Technique for Aedes aegypti mosquitoes, when the female sexual preference is incorporated. We found that for a released value of the sterile male mosquito below 40,000, the wild mosquito population decreases over time while the sterile male mosquito population increases. Therefore, the transmission of malaria and dengue infection declines because the sterile male mosquitoes dominated the environment. We also found that for a released value of the sterile male mosquito above 40,000, the wild mosquito population decreases and the sterile male mosquito population decreases as well. Therefore, if the injection of sterile male mosquitoes is large enough, the environment will be rid of mosquitoes over time. The result also shows that if sexual selection is incorporated into a reaction diffusion system, modelling the spread of Aedes aegypti mosquitoes, the Sterile Insect Technique (SIT) will still be a successful control measure.
文摘Cotton leaf worm, Spodoptera littoralis, is considered one of the most common arthropod pests that contribute to crop devastation of cotton. Previously, agricultural pests were controlled through the application of chemical insecticides. However, insecticide-resistant insect populations emergence, as well as increasing concerns about the environmental and human health risks. Venomous animals introduce valuable sources of bioactive compounds which are employed for defence. Some of these toxins have high phyletic specificity, making them appropriate for use in IPM programs. This study aims to test the insecticidal effects of Polistes dominulus and Apis mellifera venoms. Crude venoms were examined for their insecticidal effect against cotton leaf worms by four different application methods including: leaf dipping, integument dropping, spraying, and injection. The data demonstrated a strong response to purified (Polistes dominulus) venom at an initial time than that of honey bee (Apis mellifera) which increases response with increasing the dose and the time interval. A dosage of 0.015 - 0.16 ml of both venoms had notably varied in LD<sub>50</sub> values on Spodoptera littoralis that showed higher wasp venom toxicity. Cotton leaf worms showed more susceptibility and mortality to the Polistes sp. venom than that of honey bees.
