Rice crops are frequently threatened by pests such as rice planthoppers(Nilaparvata lugens,Sogatella furcifera,and Laodelphax striatellus)and leafhoppers(Cicadellidae),which cause significant yield losses.Accurate ide...Rice crops are frequently threatened by pests such as rice planthoppers(Nilaparvata lugens,Sogatella furcifera,and Laodelphax striatellus)and leafhoppers(Cicadellidae),which cause significant yield losses.Accurate identification of both pest developmental stages and their natural predators is crucial for effective pest control and maintaining ecological balance.However,conventional field surveys are often subjective,inefficient,and lack traceability.To overcome these limitations,this study proposed RiceInsectID,a two-stage cascaded detection method designed to identify and count tiny rice pests and their natural predators from white flat plate images captured by head-worn AR glasses.The method recognizes 25 insect classes,including 17 instars of rice planthoppers,2 instars of leafhoppers,4 spider species(Araneae),as well as Miridae and rove beetles(Staphylinidae Latreille).At the first coarse-grained detection stage,16 visually similar classes are consolidated into 6 broader categories and detected using an enhanced YOLOv6 model.To improve small object detection and address class imbalance,the fullregion overlapping sliding slices and target pasting(FOSTP)algorithm was applied,increasing the mean average precision at a 50%IoU threshold(mAP50)by 35.46%over the baseline YOLOv6.Feature extraction and fusion were further improved by incorporating an efficient channel attention path aggregation feature pyramid network(ECA-PAFPN)and adaptive structure feature fusion(ASFF)modules,while the balanced classification mosaic(BCM)enhanced detection of minority classes.With test-time augmentation(TTA),mAP50 improved by an additional 2.06%,reaching 84.71%.At the second fine-grained classification stage,each of the six broad classes from the first stage is further classified using individual ResNet50 models.Online data augmentation and transfer learning were employed to significantly enhance generalization.Compared with the baseline YOLOv6,the two-stage cascaded method improved recall by 4.06%,precision by 3.79%,and the F1-score by 3.92%.Overall,RiceInsectID achieved 82.85%recall,80.62%precision,and an F1-score of 81.72%,demonstrating an efficient and practical solution for monitoring tiny rice pests and their natural predators in paddy fields.This study provides valuable insights for ecosystem monitoring and supporting sustainable pest management in rice agriculture.展开更多
Nest predation is the leading cause of reproductive failure in birds and a major driving force in the evolution of anti-predation strategies.Current studies on the anti-predation strategies of birds driven by predatio...Nest predation is the leading cause of reproductive failure in birds and a major driving force in the evolution of anti-predation strategies.Current studies on the anti-predation strategies of birds driven by predation pressure have mainly focused on adults.However,the detection and behavioral responses of nestlings toward predation risk require further investigation.In this study,we examined nestling responses to predator sounds.Two species of nestlings,the Reed Parrotbill(Paradoxornis heudei)and Vinous-throated Parrotbill(Sinosuthora webbiana),were exposed to the Sparrowhawk(Accipiter nisus,less common)and Oriental Magpie(Pica serica,more common),which are predator species,the Oriental Turtle Dove(Streptopelia orientalis),which is a commonly found harmless species,and background noise.Our findings revealed that compared to pre-playback of natural begging and playback of background noise and Oriental Turtle Dove sounds,playback of the two predator types decreased the total begging time and total number of calls of the two nestlings species,with the calls of the Sparrowhawk leading to greater suppression of nestling begging behavior than those of the Oriental Magpie.Therefore,our results indicated that these nestlings were able to distinguish predators from harmless species based on auditory cues.展开更多
The rapid expansion of Internet of Things(IoT)networks has introduced challenges in network management,primarily in maintaining energy efficiency and robust connectivity across an increasing array of devices.This pape...The rapid expansion of Internet of Things(IoT)networks has introduced challenges in network management,primarily in maintaining energy efficiency and robust connectivity across an increasing array of devices.This paper introduces the Adaptive Blended Marine Predators Algorithm(AB-MPA),a novel optimization technique designed to enhance Quality of Service(QoS)in IoT systems by dynamically optimizing network configurations for improved energy efficiency and stability.Our results represent significant improvements in network performance metrics such as energy consumption,throughput,and operational stability,indicating that AB-MPA effectively addresses the pressing needs ofmodern IoT environments.Nodes are initiated with 100 J of stored energy,and energy is consumed at 0.01 J per square meter in each node to emphasize energy-efficient networks.The algorithm also provides sufficient network lifetime extension to a resourceful 7000 cycles for up to 200 nodes with a maximum Packet Delivery Ratio(PDR)of 99% and a robust network throughput of up to 1800 kbps in more compact node configurations.This study proposes a viable solution to a critical problem and opens avenues for further research into scalable network management for diverse applications.展开更多
Predator–prey interactions are fundamental to understanding ecosystem stability and biodiversity.In this study,we propose and analyze a stochastic predator–prey model that incorporates two critical ecological factor...Predator–prey interactions are fundamental to understanding ecosystem stability and biodiversity.In this study,we propose and analyze a stochastic predator–prey model that incorporates two critical ecological factors:prey refuge and harvesting.The model also integrates disease transmission within the predator population,adding an important layer of realism.Using rigorous mathematical techniques,we demonstrate the existence and uniqueness of a global positive solution,thereby confirming the model's biological feasibility.We further derive sufficient conditions for two key ecological scenarios:stochastic permanence,which ensures the sustained co-existence of prey and predators over time,and extinction,where one or both populations decline to zero.The interplay between prey refuge and harvesting is thoroughly examined to understand their combined impact on population dynamics.All theoretical results are validated by detailed numerical simulations,highlighting the applicability of the model to real-world ecological systems.From the simulation results,we observed that with an adequate level of prey refuge and predator harvesting,the susceptible predator and prey coexist with extensive oscillations,while the infected predator population was moving towards extinction.In addition,we have investigated the effect of disease transmission on system dynamics.Our results show that,as the transmission rate of disease increases,the susceptible predator approaches extinction,whereas,on the other hand,when it declines,the susceptible predator shows robust oscillations while the infected approaches extinction.In both cases,the prey population demonstrates robust stability due to the prey refuge.Our findings show that the management of harvesting and the prey refuge can be effective ecological tactics for disease control and species protection under stochastic environmental effects.展开更多
To address the critical challenge of risk perception and assessment for autonomous vehicles in dynamic interactive envi-ronments,this study proposes a semi-supervised spatiotemporal interaction risk cognition network ...To address the critical challenge of risk perception and assessment for autonomous vehicles in dynamic interactive envi-ronments,this study proposes a semi-supervised spatiotemporal interaction risk cognition network with attention mecha-nism(SS-SIRCN),inspired by the behavioral adaptation patterns of biological groups under external threats.First,by thoroughly analyzing the dynamic interaction characteristics exhibited by typical biological collectives when exposed to risk,the study reveals the underlying patterns of trajectory changes influenced by external danger.Then,an attention-based spatiotemporal risk cognition network is designed to establish a mapping between driving behavior features and potential driving risks.Finally,a semi-supervised learning framework is employed to enable risk assessment for autono-mous vehicles using only a small amount of labeled data.Experimental results on real-world vehicle trajectory datasets demonstrate that the proposed method achieves a risk prediction accuracy of 90.76%,outperforming other baseline models in performance.展开更多
Transgenic Bt rice has been shown to be an effective means of controlling Lepidoptera pests of rice. However, the potential roles of transgenic rice on planthoppers and their predators need to be investigated before i...Transgenic Bt rice has been shown to be an effective means of controlling Lepidoptera pests of rice. However, the potential roles of transgenic rice on planthoppers and their predators need to be investigated before its commercialization. Population density, species dominance and population dynamics are important parameters of arthropods populations in field. So the impacts of three transgenic Bt rice strains expressing crylAb/crylAc, crylC and cry2A on population density, species dominance and population dynamics of three species of planthoppers （Nilaparvata lugens, Sogatella furcifera and Laodelphax striatellus） and their three main predators （ Cyrtorhinus lividipennis, Pirata subpiraticus and Theridium octomaculatum） were evaluated at three sites in Hubei Province, China, in the current study. The results showed that among three species of planthoppers, both in transgenic and non-transgenic rice field, the predominant species ofplanthoppers within phytophagous guild was S. furcifera at any site either growing season （46-50%）. Significantly higher population density ofN. lugens was observed in T2A-1 field relative to Minghui 63 field at Wuxue in 2010. The species dominance of predator, P. subpiraticus, in TT51 field was significantly higher than that in T 1 C-19 and T2A-1 fields in 2009 at Xiaogan site. Sampling date significantly influenced six arthropods except for P. subpiraticus in 2010. The interaction between rice strain^sampling date had no significant adverse effects on the population dynamics of three species of planthoppers and their predators, except for several individual species in 2009. The interaction among rice strain^sampling date^sampling site also had no significant effect on six arthropods except for S. furcifera in 2009. The results indicated that transgenic Bt rice expressing crylAb/crylAc, cry2A and crylC had no significant adverse effects on the population dynamics of three planthoppers and their predators in most investigated data and sampling site.展开更多
Transgenic insect-resistant cotton is being increasingly planted in Xinjiang cotton-planting regions, where geographical climate conditions and species composition of pests and natural enemies are greatly unique in Ch...Transgenic insect-resistant cotton is being increasingly planted in Xinjiang cotton-planting regions, where geographical climate conditions and species composition of pests and natural enemies are greatly unique in China. Limited studies have been conducted on the ecological impacts of transgenic insect-resistant cotton, especially for transgenic double genes （Bt＋CpTI） cotton, in this region. In this study, the potential effects of transgenic Bt＋CpTI cotton on the seasonal abundance of non-target pests and predators were assessed from 2009 to 2011 in Korla, Xinjiang. The results showed that species composition and seasonal abundance of 5 groups of pests and 5 groups of predators were not significantly different between transgenic Bt＋CpTI cotton and non-transgenic cotton every year. It suggests that transgenic Bt＋CpTI cotton per se does not affect the population dynamics of non-target pests and predators on this crop in Xinjiang.展开更多
Background: The Emei Shan Liocichla(Liocichla omeiensis) is a globally vulnerable babbler, endemic to southwestern China. We investigated its nest predators, nest-site selection and nest success at the Laojunshan Nati...Background: The Emei Shan Liocichla(Liocichla omeiensis) is a globally vulnerable babbler, endemic to southwestern China. We investigated its nest predators, nest-site selection and nest success at the Laojunshan National Nature Reserve in Sichuan, China in order to identify the precise nesting-habitat requirements of the species, and to test whether the nest-site-selection cues, preferred by the Emei Shan Liocichla, are positively associated with nest success.Methods: We used infrared cameras to determine nest predators. We compared the microhabitat attributes between nest and random sites, as well as successful and failed nests. We used Binary Logistic Regression to determine the most important variables affecting nest-site selection of the Emei Shan Liocichla. We used the nest survival analysis in Program MARK to estimate daily nest survival rates(DSR). Nest success was calculated using the Mayfield method.Results: In total 56 nests were found. The DSR for all nests that contained at least one egg was 0.9564 ± 0.0091(95 % CI 0.9346–0.9711)(n = 40), while the total nest success was 27.5 %. We identified four categories of predators in 10 nest predation events, i.e. squirrels(n = 5), snakes(n = 3), raptors(n = 1) and wasps(n = 1). We found that:(1) nest predation was the primary reason for nest failure of the Emei Shan Liocichla,(2) tree cover, bamboo cover, liana abundance and distance to forest edge or gap were the most important variables affecting nest-site selection of this species, and(3) the nest-site-selection variables we measured appeared not to be positively associated with nest success.Conclusions: Our findings suggest that the Emei Shan Liocichla tended to select nest sites near forest edges or gaps with good concealment and that nest-site selection by this species was nonrandom but not necessarily adaptive. Reducing forest-edge development and protecting bamboo stands should be effective for conservation of this species.展开更多
Interactions between disruptive colouration and the match between prey and background spot size were manipulated in two experiments that used time taken by human ＇predators＇ to find artificial prey （virtual crab mo...Interactions between disruptive colouration and the match between prey and background spot size were manipulated in two experiments that used time taken by human ＇predators＇ to find artificial prey （virtual crab morphs） against heterogeneous backgrounds as a measure of the their camouflage. Experiment 1, in which the spots and their placement imitated the arrangement on the crab Carcinus maenas, tested whether high and low contrast spots touching the body outline （disruptive ＇edge＇ morphs） made the artificial prey more difficult to detect than when the spots did not touch the outline （non-disruptive ＇inner＇ morphs） against three different backgrounds： ＇small＇, ＇middle＇ and ＇large＇ spot size. In Experiment 2, the range of spot sizes and their positions （＇edge＇ and ＇inner＇） on the crab morphs were varied to determine the most effective combination against the ＇mid- dle＇ background. Altogether, 640 volunteers participated in these computer trials, representing a high degree of independent replication. All patterned morphs were significantly harder to detect than plain morphs, indicating that possessing at least some degree of background matching can provide camouflage. Both experiments demonstrated that various morphs, though not having the same spot sizes as the background, had similar or better survivorship as those with matching spot sizes--indicating that opti- mal camouflage did not come from background matching alone. In Experiment 2, edge-disrupted morphs consistently took longer to find than their non-disruptive counterparts. The relative effects of edge disruption, contrast, and background/prey spot size are clearly context-dependent, highlighting the complexity of prey concealment [Current Zoology 61 （4）： 718-728, 2015].展开更多
Predation is thought to be one of the main structuring forces in animal communities. However, se- lective predation is often measured on isolated traits in response to a single predatory species, but only rarely are s...Predation is thought to be one of the main structuring forces in animal communities. However, se- lective predation is often measured on isolated traits in response to a single predatory species, but only rarely are selective forces on several traits quantified or even compared between different predators naturally occurring in the same system. In the present study, we therefore measured be- havioral and morphological traits in young-of-the-year Eurasian perch Perca fluviatilis and com- pared their selective values in response to the 2 most common predators, adult perch and pike Esox lucius. Using mixed effects models and model averaging to analyze our data, we quantified and compared the selectivity of the 2 predators on the different morphological and behavioral traits. We found that selection on the behavioral traits was higher than on morphological traits and perch predators preyed overall more selectively than pike predators. Pike tended to positively se- lect shallow bodied and nonvigilant individuals （i.e. individuals not performing predator inspec- tion）. In contrast, perch predators selected mainly for bolder juvenile perch （i.e. individuals spend- ing more time in the open, more active）, which was most important. Our results are to the best of our knowledge the first that analyzed behavioral and morphological adaptations of juvenile perch facing 2 different predation strategies. We found that relative specific predation intensity for the di- vergent traits differed between the predators, providing some additional ideas why juvenile perch display such a high degree of phenotypic plasticity.展开更多
Some rodent-dispersed seeds have a hard seed-coat(e.g.woody endocarp).Specific scrapes or dental marks on the hard seed-coat left by rodents when they eat these seeds can be used to identify seed predators.In this stu...Some rodent-dispersed seeds have a hard seed-coat(e.g.woody endocarp).Specific scrapes or dental marks on the hard seed-coat left by rodents when they eat these seeds can be used to identify seed predators.In this study we measured the morphological traits of endocarp-remains of seeds of wild apricot Prunus armeniaca used by Chinese white-bellied rats Niviventor confucianus and Korean field mice Apodemus peninsulae.We established their Fisher's linear discriminant functions to separate endocarp-remains between the two predators.A total of 90.0% of the endocarp-remains left by Korean field mice and 88.0% of those left by Chinese white-bellied rats were correctly classified.The overall percentage of correct classification was 89.0%.One hundred and sixty endocarp-remains of unknown what species predated them were classified using the functions.The method may allow more reliable quantitative studies of the effects of Chinese white-bellied rats and Korean field mice on seed consumption and dispersal of wild apricot and this study might be used for reference in other studies of seed predators identification on hard seeds.展开更多
Wireless Sensor Networks(WSNs)play an indispensable role in the lives of human beings in the fields of environment monitoring,manufacturing,education,agriculture etc.,However,the batteries in the sensor node under dep...Wireless Sensor Networks(WSNs)play an indispensable role in the lives of human beings in the fields of environment monitoring,manufacturing,education,agriculture etc.,However,the batteries in the sensor node under deployment in an unattended or remote area cannot be replaced because of their wireless existence.In this context,several researchers have contributed diversified number of cluster-based routing schemes that concentrate on the objective of extending node survival time.However,there still exists a room for improvement in Cluster Head(CH)selection based on the integration of critical parameters.The meta-heuristic methods that concentrate on guaranteeing both CH selection and data transmission for improving optimal network performance are predominant.In this paper,a hybrid Marine Predators Optimization and Improved Particle Swarm Optimizationbased Optimal Cluster Routing(MPO-IPSO-OCR)is proposed for ensuring both efficient CH selection and data transmission.The robust characteristic of MPOA is used in optimized CH selection,while improved PSO is used for determining the optimized route to ensure sink mobility.In specific,a strategy of position update is included in the improved PSO for enhancing the global searching efficiency of MPOA.The high-speed ratio,unit speed rate and low speed rate strategy inherited by MPOA facilitate better exploitation by preventing solution from being struck into local optimality point.The simulation investigation and statistical results confirm that the proposed MPOIPSO-OCR is capable of improving the energy stability by 21.28%,prolonging network lifetime by 18.62%and offering maximum throughput by 16.79%when compared to the benchmarked cluster-based routing schemes.展开更多
基金supported by the National Key Research Program of China during the 14th Five-Year Plan Period(Grant No.2021YFD1401100)the Zhejiang Provincial Natural Science Foundation of China(Grant No.LTGN24C140007)the‘San Nong Jiu Fang’Sciences and Technologies Cooperation Project of Zhejiang Province,China(Grant No.2024SNJF010)。
文摘Rice crops are frequently threatened by pests such as rice planthoppers(Nilaparvata lugens,Sogatella furcifera,and Laodelphax striatellus)and leafhoppers(Cicadellidae),which cause significant yield losses.Accurate identification of both pest developmental stages and their natural predators is crucial for effective pest control and maintaining ecological balance.However,conventional field surveys are often subjective,inefficient,and lack traceability.To overcome these limitations,this study proposed RiceInsectID,a two-stage cascaded detection method designed to identify and count tiny rice pests and their natural predators from white flat plate images captured by head-worn AR glasses.The method recognizes 25 insect classes,including 17 instars of rice planthoppers,2 instars of leafhoppers,4 spider species(Araneae),as well as Miridae and rove beetles(Staphylinidae Latreille).At the first coarse-grained detection stage,16 visually similar classes are consolidated into 6 broader categories and detected using an enhanced YOLOv6 model.To improve small object detection and address class imbalance,the fullregion overlapping sliding slices and target pasting(FOSTP)algorithm was applied,increasing the mean average precision at a 50%IoU threshold(mAP50)by 35.46%over the baseline YOLOv6.Feature extraction and fusion were further improved by incorporating an efficient channel attention path aggregation feature pyramid network(ECA-PAFPN)and adaptive structure feature fusion(ASFF)modules,while the balanced classification mosaic(BCM)enhanced detection of minority classes.With test-time augmentation(TTA),mAP50 improved by an additional 2.06%,reaching 84.71%.At the second fine-grained classification stage,each of the six broad classes from the first stage is further classified using individual ResNet50 models.Online data augmentation and transfer learning were employed to significantly enhance generalization.Compared with the baseline YOLOv6,the two-stage cascaded method improved recall by 4.06%,precision by 3.79%,and the F1-score by 3.92%.Overall,RiceInsectID achieved 82.85%recall,80.62%precision,and an F1-score of 81.72%,demonstrating an efficient and practical solution for monitoring tiny rice pests and their natural predators in paddy fields.This study provides valuable insights for ecosystem monitoring and supporting sustainable pest management in rice agriculture.
基金funded by the National Natural Science Foundation of China (32301295 to J.W.,32101242 to L.M.and 32260253 to L.W.)High-Level Talents Research Start-Up Project of Hebei University (521100222044 to J.W.)。
文摘Nest predation is the leading cause of reproductive failure in birds and a major driving force in the evolution of anti-predation strategies.Current studies on the anti-predation strategies of birds driven by predation pressure have mainly focused on adults.However,the detection and behavioral responses of nestlings toward predation risk require further investigation.In this study,we examined nestling responses to predator sounds.Two species of nestlings,the Reed Parrotbill(Paradoxornis heudei)and Vinous-throated Parrotbill(Sinosuthora webbiana),were exposed to the Sparrowhawk(Accipiter nisus,less common)and Oriental Magpie(Pica serica,more common),which are predator species,the Oriental Turtle Dove(Streptopelia orientalis),which is a commonly found harmless species,and background noise.Our findings revealed that compared to pre-playback of natural begging and playback of background noise and Oriental Turtle Dove sounds,playback of the two predator types decreased the total begging time and total number of calls of the two nestlings species,with the calls of the Sparrowhawk leading to greater suppression of nestling begging behavior than those of the Oriental Magpie.Therefore,our results indicated that these nestlings were able to distinguish predators from harmless species based on auditory cues.
文摘The rapid expansion of Internet of Things(IoT)networks has introduced challenges in network management,primarily in maintaining energy efficiency and robust connectivity across an increasing array of devices.This paper introduces the Adaptive Blended Marine Predators Algorithm(AB-MPA),a novel optimization technique designed to enhance Quality of Service(QoS)in IoT systems by dynamically optimizing network configurations for improved energy efficiency and stability.Our results represent significant improvements in network performance metrics such as energy consumption,throughput,and operational stability,indicating that AB-MPA effectively addresses the pressing needs ofmodern IoT environments.Nodes are initiated with 100 J of stored energy,and energy is consumed at 0.01 J per square meter in each node to emphasize energy-efficient networks.The algorithm also provides sufficient network lifetime extension to a resourceful 7000 cycles for up to 200 nodes with a maximum Packet Delivery Ratio(PDR)of 99% and a robust network throughput of up to 1800 kbps in more compact node configurations.This study proposes a viable solution to a critical problem and opens avenues for further research into scalable network management for diverse applications.
基金supported by the National Natural Science Foundation of China(Grant No.32271554)the Guangdong Basic and Applied Basic Research Foundation(Grant No.2023A1515011501)。
文摘Predator–prey interactions are fundamental to understanding ecosystem stability and biodiversity.In this study,we propose and analyze a stochastic predator–prey model that incorporates two critical ecological factors:prey refuge and harvesting.The model also integrates disease transmission within the predator population,adding an important layer of realism.Using rigorous mathematical techniques,we demonstrate the existence and uniqueness of a global positive solution,thereby confirming the model's biological feasibility.We further derive sufficient conditions for two key ecological scenarios:stochastic permanence,which ensures the sustained co-existence of prey and predators over time,and extinction,where one or both populations decline to zero.The interplay between prey refuge and harvesting is thoroughly examined to understand their combined impact on population dynamics.All theoretical results are validated by detailed numerical simulations,highlighting the applicability of the model to real-world ecological systems.From the simulation results,we observed that with an adequate level of prey refuge and predator harvesting,the susceptible predator and prey coexist with extensive oscillations,while the infected predator population was moving towards extinction.In addition,we have investigated the effect of disease transmission on system dynamics.Our results show that,as the transmission rate of disease increases,the susceptible predator approaches extinction,whereas,on the other hand,when it declines,the susceptible predator shows robust oscillations while the infected approaches extinction.In both cases,the prey population demonstrates robust stability due to the prey refuge.Our findings show that the management of harvesting and the prey refuge can be effective ecological tactics for disease control and species protection under stochastic environmental effects.
基金the Jilin Provincial Department of Science and Technology Youth Science and Technology Talent Cultivation Project(20250602051RC)Fundamental Research Funds for the Central Universities(2025-JCXK-19)National Natural Science Foundation of China under Grant 52272417.
文摘To address the critical challenge of risk perception and assessment for autonomous vehicles in dynamic interactive envi-ronments,this study proposes a semi-supervised spatiotemporal interaction risk cognition network with attention mecha-nism(SS-SIRCN),inspired by the behavioral adaptation patterns of biological groups under external threats.First,by thoroughly analyzing the dynamic interaction characteristics exhibited by typical biological collectives when exposed to risk,the study reveals the underlying patterns of trajectory changes influenced by external danger.Then,an attention-based spatiotemporal risk cognition network is designed to establish a mapping between driving behavior features and potential driving risks.Finally,a semi-supervised learning framework is employed to enable risk assessment for autono-mous vehicles using only a small amount of labeled data.Experimental results on real-world vehicle trajectory datasets demonstrate that the proposed method achieves a risk prediction accuracy of 90.76%,outperforming other baseline models in performance.
基金supported by the National Genetically Modified Organisms Breeding Major Project:Technology of Environmental Risk Assessment on Transgenic Rice (2008ZX08011-001)Technology of Environment Risk Assessment of Transgenic Rice on Rice Planthopper Population (2009ZX08011-009B)
文摘Transgenic Bt rice has been shown to be an effective means of controlling Lepidoptera pests of rice. However, the potential roles of transgenic rice on planthoppers and their predators need to be investigated before its commercialization. Population density, species dominance and population dynamics are important parameters of arthropods populations in field. So the impacts of three transgenic Bt rice strains expressing crylAb/crylAc, crylC and cry2A on population density, species dominance and population dynamics of three species of planthoppers （Nilaparvata lugens, Sogatella furcifera and Laodelphax striatellus） and their three main predators （ Cyrtorhinus lividipennis, Pirata subpiraticus and Theridium octomaculatum） were evaluated at three sites in Hubei Province, China, in the current study. The results showed that among three species of planthoppers, both in transgenic and non-transgenic rice field, the predominant species ofplanthoppers within phytophagous guild was S. furcifera at any site either growing season （46-50%）. Significantly higher population density ofN. lugens was observed in T2A-1 field relative to Minghui 63 field at Wuxue in 2010. The species dominance of predator, P. subpiraticus, in TT51 field was significantly higher than that in T 1 C-19 and T2A-1 fields in 2009 at Xiaogan site. Sampling date significantly influenced six arthropods except for P. subpiraticus in 2010. The interaction between rice strain^sampling date had no significant adverse effects on the population dynamics of three species of planthoppers and their predators, except for several individual species in 2009. The interaction among rice strain^sampling date^sampling site also had no significant effect on six arthropods except for S. furcifera in 2009. The results indicated that transgenic Bt rice expressing crylAb/crylAc, cry2A and crylC had no significant adverse effects on the population dynamics of three planthoppers and their predators in most investigated data and sampling site.
基金the 973 Program (2001CB109004and 2007CB109202)the Key Projects for Breeding Genetically Modified Organisms of China (2011ZX0811-002 and 2009ZX08011-008B)
文摘Transgenic insect-resistant cotton is being increasingly planted in Xinjiang cotton-planting regions, where geographical climate conditions and species composition of pests and natural enemies are greatly unique in China. Limited studies have been conducted on the ecological impacts of transgenic insect-resistant cotton, especially for transgenic double genes （Bt＋CpTI） cotton, in this region. In this study, the potential effects of transgenic Bt＋CpTI cotton on the seasonal abundance of non-target pests and predators were assessed from 2009 to 2011 in Korla, Xinjiang. The results showed that species composition and seasonal abundance of 5 groups of pests and 5 groups of predators were not significantly different between transgenic Bt＋CpTI cotton and non-transgenic cotton every year. It suggests that transgenic Bt＋CpTI cotton per se does not affect the population dynamics of non-target pests and predators on this crop in Xinjiang.
基金supported by the National Natural Science Foundation of China(No.31272330)the Scientific Research Innovation Team Projects of Leshan Normal University
文摘Background: The Emei Shan Liocichla(Liocichla omeiensis) is a globally vulnerable babbler, endemic to southwestern China. We investigated its nest predators, nest-site selection and nest success at the Laojunshan National Nature Reserve in Sichuan, China in order to identify the precise nesting-habitat requirements of the species, and to test whether the nest-site-selection cues, preferred by the Emei Shan Liocichla, are positively associated with nest success.Methods: We used infrared cameras to determine nest predators. We compared the microhabitat attributes between nest and random sites, as well as successful and failed nests. We used Binary Logistic Regression to determine the most important variables affecting nest-site selection of the Emei Shan Liocichla. We used the nest survival analysis in Program MARK to estimate daily nest survival rates(DSR). Nest success was calculated using the Mayfield method.Results: In total 56 nests were found. The DSR for all nests that contained at least one egg was 0.9564 ± 0.0091(95 % CI 0.9346–0.9711)(n = 40), while the total nest success was 27.5 %. We identified four categories of predators in 10 nest predation events, i.e. squirrels(n = 5), snakes(n = 3), raptors(n = 1) and wasps(n = 1). We found that:(1) nest predation was the primary reason for nest failure of the Emei Shan Liocichla,(2) tree cover, bamboo cover, liana abundance and distance to forest edge or gap were the most important variables affecting nest-site selection of this species, and(3) the nest-site-selection variables we measured appeared not to be positively associated with nest success.Conclusions: Our findings suggest that the Emei Shan Liocichla tended to select nest sites near forest edges or gaps with good concealment and that nest-site selection by this species was nonrandom but not necessarily adaptive. Reducing forest-edge development and protecting bamboo stands should be effective for conservation of this species.
文摘Interactions between disruptive colouration and the match between prey and background spot size were manipulated in two experiments that used time taken by human ＇predators＇ to find artificial prey （virtual crab morphs） against heterogeneous backgrounds as a measure of the their camouflage. Experiment 1, in which the spots and their placement imitated the arrangement on the crab Carcinus maenas, tested whether high and low contrast spots touching the body outline （disruptive ＇edge＇ morphs） made the artificial prey more difficult to detect than when the spots did not touch the outline （non-disruptive ＇inner＇ morphs） against three different backgrounds： ＇small＇, ＇middle＇ and ＇large＇ spot size. In Experiment 2, the range of spot sizes and their positions （＇edge＇ and ＇inner＇） on the crab morphs were varied to determine the most effective combination against the ＇mid- dle＇ background. Altogether, 640 volunteers participated in these computer trials, representing a high degree of independent replication. All patterned morphs were significantly harder to detect than plain morphs, indicating that possessing at least some degree of background matching can provide camouflage. Both experiments demonstrated that various morphs, though not having the same spot sizes as the background, had similar or better survivorship as those with matching spot sizes--indicating that opti- mal camouflage did not come from background matching alone. In Experiment 2, edge-disrupted morphs consistently took longer to find than their non-disruptive counterparts. The relative effects of edge disruption, contrast, and background/prey spot size are clearly context-dependent, highlighting the complexity of prey concealment [Current Zoology 61 （4）： 718-728, 2015].
文摘Predation is thought to be one of the main structuring forces in animal communities. However, se- lective predation is often measured on isolated traits in response to a single predatory species, but only rarely are selective forces on several traits quantified or even compared between different predators naturally occurring in the same system. In the present study, we therefore measured be- havioral and morphological traits in young-of-the-year Eurasian perch Perca fluviatilis and com- pared their selective values in response to the 2 most common predators, adult perch and pike Esox lucius. Using mixed effects models and model averaging to analyze our data, we quantified and compared the selectivity of the 2 predators on the different morphological and behavioral traits. We found that selection on the behavioral traits was higher than on morphological traits and perch predators preyed overall more selectively than pike predators. Pike tended to positively se- lect shallow bodied and nonvigilant individuals （i.e. individuals not performing predator inspec- tion）. In contrast, perch predators selected mainly for bolder juvenile perch （i.e. individuals spend- ing more time in the open, more active）, which was most important. Our results are to the best of our knowledge the first that analyzed behavioral and morphological adaptations of juvenile perch facing 2 different predation strategies. We found that relative specific predation intensity for the di- vergent traits differed between the predators, providing some additional ideas why juvenile perch display such a high degree of phenotypic plasticity.
基金funded by the National Natural Science Foundation of China(30800120) and the Foundation for New Teachers of Huazhong Normal University
文摘Some rodent-dispersed seeds have a hard seed-coat(e.g.woody endocarp).Specific scrapes or dental marks on the hard seed-coat left by rodents when they eat these seeds can be used to identify seed predators.In this study we measured the morphological traits of endocarp-remains of seeds of wild apricot Prunus armeniaca used by Chinese white-bellied rats Niviventor confucianus and Korean field mice Apodemus peninsulae.We established their Fisher's linear discriminant functions to separate endocarp-remains between the two predators.A total of 90.0% of the endocarp-remains left by Korean field mice and 88.0% of those left by Chinese white-bellied rats were correctly classified.The overall percentage of correct classification was 89.0%.One hundred and sixty endocarp-remains of unknown what species predated them were classified using the functions.The method may allow more reliable quantitative studies of the effects of Chinese white-bellied rats and Korean field mice on seed consumption and dispersal of wild apricot and this study might be used for reference in other studies of seed predators identification on hard seeds.
文摘Wireless Sensor Networks(WSNs)play an indispensable role in the lives of human beings in the fields of environment monitoring,manufacturing,education,agriculture etc.,However,the batteries in the sensor node under deployment in an unattended or remote area cannot be replaced because of their wireless existence.In this context,several researchers have contributed diversified number of cluster-based routing schemes that concentrate on the objective of extending node survival time.However,there still exists a room for improvement in Cluster Head(CH)selection based on the integration of critical parameters.The meta-heuristic methods that concentrate on guaranteeing both CH selection and data transmission for improving optimal network performance are predominant.In this paper,a hybrid Marine Predators Optimization and Improved Particle Swarm Optimizationbased Optimal Cluster Routing(MPO-IPSO-OCR)is proposed for ensuring both efficient CH selection and data transmission.The robust characteristic of MPOA is used in optimized CH selection,while improved PSO is used for determining the optimized route to ensure sink mobility.In specific,a strategy of position update is included in the improved PSO for enhancing the global searching efficiency of MPOA.The high-speed ratio,unit speed rate and low speed rate strategy inherited by MPOA facilitate better exploitation by preventing solution from being struck into local optimality point.The simulation investigation and statistical results confirm that the proposed MPOIPSO-OCR is capable of improving the energy stability by 21.28%,prolonging network lifetime by 18.62%and offering maximum throughput by 16.79%when compared to the benchmarked cluster-based routing schemes.
