Regulation of the growth of sprouting roots of black locust seedlings using root barrier panels

How can we regulate an invasive alien species of high commercial value?Black locust(Robinia pseudoacacia L.)has a unique capacity for seed dispersal and high germination.Field surveys indicate that black locust increases its growing area with sprouting roots and the elongation of horizontal roots at a soil depth of 10 cm.Therefore,a method to regulate the development of horizontal roots could be eff ective in slowing the invasiveness of black locust.In this study,root barrier panels were tested to inhibit the growth of horizontal roots.Since it is labor intensive to observe the growth of roots in the fi eld,it was investigated in a nursery setting.The decrease in secondary fl ush,an increase in yellowed leafl ets,and the height in the seedlings were measured.Installing root barrier panels to a depth of 30 cm eff ectively inhibit the growth of horizontal roots of young black locust.

Effects of Dietary Straw Content on Growth and Development of Locusta migratoria and Its Egg Hatching

[Objectives]This study was conducted to investigate the effects of dietary straw content on the growth and development of oriental migratory locusts(Locusta migratoria),as well as the effects of temperature and substrate on their egg hatching.[Methods]The eggs of oriental migratory locusts were hatched at 15,20,25,30,35,and 40℃in sawdust,soil and sawdust+soil conditions,respectively,to determine suitable environmental conditions for artificial hatching of oriental migratory locusts.Rice straw was added at 0%,20%,40%,60%,80%and 100%to the basic diet,and the obtained diets was feed to oriental migratory locusts at the 4^(th)instar,to investigate the effects on their growth and development.[Results]The eggs of oriental migratory locusts had a good hatching rate at 25-30℃,and sawdust was the best choice for their hatching substrate.Adding 40%of rice straw to the diet could ensure the normal growth and development of oriental migratory locusts while consuming as much rice straw as possible.[Conclusions]This study explored a technical solution for efficiently producing insect protein from discarded crop straw(treating waste with insects,and turning waste into treasure),providing support for breeding of oriental migratory locusts and locust disaster prevention.

Expression and Characterization of a Sigma-Class Glutathione S-transferase of the Oriental Migratory Locust, Locusta migratoria manilensis (Meyen)

A cDNA encoding a sigma-class glutathione S-transferase of the locust, Locusta migratoria manilensis （LmGSTs1）, was cloned by reverse transcriptase-polymerase chain reaction. The 830 bp-long cDNA encoded a 615 bp open reading frame （204 amino acid polypeptide）, which exhibited the structural motif and domain organization characteristic of GST sigma-class. It revealed 59, 57, 57, and 56% identities to sigma-class GSTs from Blattella germanica, Gryllotalpa orientalis, Nasonia vitripennis, and Pediculus humanus corporis, respectively. A recombinant protein （LmGSTs1） was functionally expressed in Escherichia coli cells in a soluble form and purified to homogeneity. LmGSTs1 was able to catalyze the biotranslation of glutathione with 1-chloro-2,4-dinitrobenzene, a model substrate for GSTs, as well as with p-nitro-benzyl chloride. Its optimal activity was observed at pH 8.0 and at 30℃. Incubation for 30 min at temperatures below 50℃ scarcely affected the activity. The I50 of reactive blue （RB） was 18.5 μmol L-1. In the presence of 0.05 mmol L-1 ethacrynic acid （ECA）, LmGSTs1 showed （81±3）% of the original activities.

Geospatial Opinion on Unusual Locust Swarm Invasions during Amphan Cyclone

The desert locust, Schistocerca gregaria Forsk. (Orthoptera: Acrididae) is a peculiar insect that exhibits density-dependent phase polyphenism. Gregarious phase enables desert locust to form a large groups and mass migrations during which significant crop loss and food security issues may occur. Currently, the most recent upsurge of desert locust is prevailing across Eastern Africa and Southwestern Asia. Usually desert locusts are restricted to regions like semi-arid and arid regions. A super cyclonic storm, namely Amphan originated during May 2020, in the Bay of Bengal of North Indian Ocean has influenced numerous swarms to migrate from the Thar desert region to other parts of India. In this research, satellite data were used to investigate the reasons for this sudden swarm migration. The results that revealed the wind jets passing above the Thar desert region have integrated with the cyclogenesis of Amphan and led to the formation of conduits. The favorable conditions in the conduits include the open sky conditions, air temperature and fresh vegetation availability. Moreover, the wind settings in the conduits have enabled the swarm migrate to follow the downwind facing the sunrays during early mornings for an easy and successful take-off. It is observed that during the take-off session the wind speed at 850 hPa pressure level is mostly double than that of surface wind in both the conduits.

中国飞蝗(Locusta migratoria)灾害地理分布模拟及其生物气候因子分析

飞蝗Locusta migratoria(Linnaeus)系斑翅蝗科Oedipodidae飞蝗属Locusta Linnaeus洲际性农业重大害虫,在我国主要包括东亚飞蝗L.migratoria manilensis(Meyen)、亚洲飞蝗L.migratoria(Linnaeus)和西藏飞蝗L.migratoria tibetensis Chen。掌控飞蝗灾害的地理空间分布并预测起潜在的适宜分布区,对于我国飞蝗灾害的综合防控具有重要意义。结合三种中国飞蝗灾害记录地理信息和生物环境环境因子参数,应用最大熵模型(MaxEnt)和地理信息技术(GIS),在3 km×3 km尺度上对三种飞蝗灾害在中国的地理分布空间格局梯度、灾害风险概率和风险等级进行了模拟预测与分析,并对影响分布的关键生物气候环境因子进行了分析。结果显示,蝗灾害风险区的地理分布模拟结果与历史记录完全符合,ROC检验表明MaxEnt模型预测可靠性极高。三种飞蝗东亚飞蝗、亚洲飞蝗和西藏飞蝗在中国的灾害风险区总面积依次分别为315.87×10^4km^2、395.80×10^4km^2和125.00×10^4km^2,分别占国土面积的33.43%、41.96%和13.25%。东亚飞蝗和亚洲飞蝗的灾害风险区存在75.8×10^4km^2的空间重叠,主要分布于我国农牧交错区及以南区域。三种飞蝗灾害风险区的地理梯度与分布格局与中国三大自然地理区高度吻合,其地理分布格局表现出显著的经度和纬度空间梯度异质性。刀切法检测(Jackknife test)表明,三种飞蝗灾害的主导生物-气候影响因子的不同导致了其地理分布格局的显著差异,表明蝗灾爆发概率同时受到各自不同飞蝗物种对气候环境的适应性与地理空间隔离作用的共同制约。研究结果可为我国飞蝗灾害的跨界联合全程防控、区域联网监测联控和综合治理提供参考依据。

基于ECC安注热混合试验的LOCUST 1.2分析与验证

在失水事故(LOCA)工况下安注系统投入使用时,蒸汽与安注冷却剂会发生流体热力学混合,热混合过程中冷腿段的冷却是直接影响堆芯再淹没与否的重要因素。中国广核集团有限公司自主研发了一款两相流热工水力系统分析软件LOCUST,可用于压水堆核电厂事故工况的分析计算。基于西安交通大学堆芯应急冷却系统(ECCS-XJTU)试验台架进行的堆芯应急冷却(ECC)安注热混合试验,本文使用LOCUST软件对ECC热混合试验进行了几何建模及计算分析。ECC热混合试验工况主要为不同流量下主管纯蒸汽与安注管过冷水的混合,蒸汽流量为25~125 kg/h,过冷水流量为100~500 kg/h。模拟计算结果和试验结果的对比分析表明:试验段出口质量流量计算值的最大相对误差在13.8%以内,混合后温度计算值的最大相对误差在8%以内,LOCUST在计算高温蒸汽和过冷水混合时的计算结果相对保守,总体上验证了LOCUST在LOCA下两相热混合安注计算的可靠性和准确性。

Long-term impact of municipal sewage irrigation on treated soil and black locust trees in a semi-arid suburban area of Iran

The effects of municipal sewage irrigation on the soil and black locust （Robinia pseudoacacia L.） tree were studied. For this purpose, two artificial black locust stands under irrigation of municipal sewage and well water were selected in south of Tehran, Iran. Data were collected using technique of systematic random sampling with 4 replicates in each stand. It was found that the growth of black locust tree, as indicated by diameter at breast height, total height, crown length, average crown diameter, basal area and volume, in sewage irrigation stand was much higher than that of well water irrigation stand （P 〈 0.01）. Plant analysis indicated that concentrations of leaf nutrients （N, E K, Ca, Mg, Na, Fe, Mn, Cu and Zn） were greater in sewage-irrigated trees, without toxicity to the minerals of tree leaf, than those of well waterirrigated trees, and positively correlated with their respective value in soil. Ni, Cr and Pb were not detected in leaf samples. Application of sewage resulted in a 1.5-fold increase in the concentrations of soil nutrients, Ni, Cr and Pb. Among these minerals only Pb and Ni in some soil samples exceeded the toxicity limit. The increase in pH, electrical conductivity （EC） and organic carbon of soil was also observed in sewage irrigation. Results confirm that besides the use as irrigation water, municipal sewages are also a potential source of plant nutrients. However, significant accumulation of heavy metals such as Pb and Ni in soil needs to be monitored.

Biomechanical and dynamic mechanism of locust take-off

The biomimetic locust robot hopping vehicle has promising applications in planet exploration and reconnaissance. This paper explores the bionic dynamics model of locust jumping by using high-speed video and force analysis. This paper applies hybrid rigid-flexible mechanisms to bionic locust hopping and studies its dynamics with emphasis laid on the relationship between force and jumping performance. The hybrid rigid-flexible model is introduced in the analysis of locust mechanism to address the principles of dynamics that govern locust joints and mechanisms during energy storage and take-off. The dynamic response of the biomimetic mechanism is studied by considering the flexi- bility according to the locust jumping dynamics mechanism. A multi-rigid-body dynamics model of locust jumping is established and analyzed based on Lagrange method; elastic knee and tarsus mechanisms that were proposed in previous works are analyzed alongside the original bionic joint configurations and their machinery principles. This work offers primary theories for take-off dynamics and establishes a theoretical basis for future studies and engineering applications.

Ways to Improve Low-Benefit Black Locust Forests in Loess Plateau

This paper presents a general standard for the low-benefit black locust （Robinia pseudoacacia L.） torests m Loess Plateau based on defining the concept of “tri-low forest”, and emphasizes the major factors which result in low-benefit black locust, such as, lack of soil moisture of forest and nutrient, breaching the principle of matching tree species to sites, and high density of forests. Based on different characteristics of low-benefit forests, following the principle of “adjusting measures to local conditions, giving priority to ecological benefits, assisting with economic benefits”, the authors put forward some technical ways to reform low-benefit black locust forests, for example, taking measurements of collecting runoff and storing water, lowering the forest density, introducing mixed forests and transforming species, directive breeding and so on.

Using an image segmentation and support vector machine method for identifying two locust species and instars

Locusts are agricultural pests around the world. To cognize how locust distribution density and community structure are related to the hydrothermal and vegetation growth conditions of their habitats and thereby providing rapid and accurate warning of locust invasions, it is important to develop efficient and accurate techniques for acquiring locust information. In this paper, by analyzing the differences between the morphological features of Locusta migratoria manilensis and Oedaleus decorus asiaticus, we proposed a semi-automatic locust species and instar information detection model based on locust image segmentation, locust feature variable extraction and support vector machine(SVM) classification. And we subsequently examined its applicability and accuracy based on sample image data acquired in the field. Locust image segmentation experiment showed that the proposed GrabCut-based interactive segmentation method can be used to rapidly extract images of various locust body parts and exhibits excellent operability. In a locust feature variable extraction experiment, the textural, color and morphological features of various locust body parts were calculated. Based on the results, eight feature variables were selected to identify locust species and instars using outlier detection, variable function calculation and principal component analysis. An SVM-based locust classification experiment achieved a semi-automatic detection accuracy of 96.16% when a polynomial kernel function with a penalty factor parameter c of 2 040 and a gamma parameter g of 0.5 was used. The proposed detection model exhibits advantages such as high applicability and accuracy when it is used to identify locust instars of L. migratoria manilensis and O. decorus asiaticus, and it can also be used to identify other species of locusts.

Temporal changes in nitrogen acquisition of Japanese black pine(Pinus thunbergii) associated with black locust(Robinia pseudoacacia)

The alien woody legume, black locust （Robinia pseudoaca-cia）, has invaded Japanese black pine （Pinus thunbergii） forests located in Japan’s coastal plain and hill regions where gaps are formed in pine forests after nematode infestation. Nitrogen fixation by legumes acceler-ates N cycling in forest ecosystems. We studied temporal change in the annual tree-ring resolution N stable isotope composition （δ15N, a per mil deviation of δ15N/14N ratio, relative to atmospheric N2δ15N=0‰） at two natural locations of Japanese black pine forest with black locust that differed in the time since black locust establishment （Shohnai in north-east and Kita-Kyushu in southwest Japan）. Analyzed tree-rings covered the period from 1990/1992 to 2009. N acquisition by Japanese black pine from black locust N input to the soil was evidenced by temporal shifting of N stable isotope composition on the annual pine tree rings. With pro-gressive development of the forest stand,δ15N values of earlier tree-ringsδ15N of -5‰） from black pine associated with black locust shifted to-wards values similar to those of black locustδ15N values nearly to-1‰）, which suggests acquisition of N by N2 fixation （Shohnai site）. In con-trast, in a forest where black locust had settled for two or three genera-tions, in a black pine stand （Kita-Kyushu site）, longer periods of N en-richment in the soil were reflected in the elevated tree-ringδ15N values of newly established black pine trees. Based on tree-ringδ15N data from the Shohnai site, we determined that about 10 years after black locust establishment, soil N had already been enriched by black locust N, this, in turn, contributed to N fertilization of surrounding trees in mixed stands.

Dynamic model and performance analysis of landing buffer for bionic locust mechanism

The landing buffer is an important problem in the research on bionic locust jumping robots, and the different modes of landing and buffering can affect the dynamic performance of the buffering process significantly. Based on an experimental observation, the different modes of landing and buffering are determined, which include the different numbers of landing legs and different motion modes of legs in the buffering process. Then a bionic locust mechanism is established, and the springs are used to replace the leg muscles to achieve a buffering effect. To reveal the dynamic performance in the buffering process of the bionic locust mechanism, a dynamic model is established with different modes of landing and buffering. In particular, to analyze the buffering process conveniently, an equivalent vibration dynamic model of the bionic locust mechanism is proposed.Given the support forces of the ground to the leg links, which can be obtained from the dynamic model, the spring forces of the legs and the impact resistance of each leg are the important parameters affecting buffering performance, and evaluation principles for buffering performance are proposed according to the aforementioned parameters. Based on the dynamic model and these evaluation principles, the buffering performances are analyzed and compared in different modes of landing and buffering on a horizontal plane and an inclined plane. The results show that the mechanism with the ends of the legs sliding can obtain a better dynamic performance. This study offers primary theories for buffering dynamics and an evaluation of landing buffer performance,and it establishes a theoretical basis for studies and engineering applications.

The Special Expression and Comparison of the c-kit Protein in Spermatogenesis of Three Species of Locusts of Arcypteridae

The aim of this study was to elucidate the expression and regulation of the c.kit protein in spermatogenesis of locusts. Immunohistochemistry and biological statistics were used to investigate the expression of the c-kit protein in four representative phases of spermatogenesis of three dominant species of locusts of Arcypteridae （Orthoptera： Acridoidea）, namely, Omocestus viridulus （Linnaeus）, Euchorthippus unicolor （Ikonn.）, and Euchorthippus vittatus Zheng, and so on, in Siping area of Jilin Province, China. The results revealed the following： （1） There was weak positive expression of the c-kit protein in spermatogonia and the positive granules were thinner; （2） there was a strong positive expression of the c-kit protein in primary spermatocyte and the positive granules became the largest than in all developmental stages; （3） the c-kit protein positive expression became stronger in secondary spermatocyte, while the positive granules became thinner; （4） there was strong positive expression of the c-kit protein and the positive granules were thinner in mature sperm, which were distributed on its head and tail; （5） there were strong positive protein granules massing at the end of spermary; （6） the positive intensity of the c-kit protein in spermatogenesis was significantly different among different species of locusts. The data suggested that the c-kit protein may play a crucial role in spermatogenesis as well as maintain the physiological action of sperms and fertilization, regulate the developmental speed of spermatogenesis, and/or maintain species isolation, etc.

Location and Characterization of Breeding Sites of Solitary Desert Locust Using Satellite Images Landsat 7 ETM+ and Terra MODIS

In the southern Algerian Sahara, populations of the desert locust have been monitored during the past 43 years. On a limited study area, the use of remote sensing data from Landsat 7 ETM+ and Terra MODIS, coupled with the locust population database, allowed the identification and mapping of solitary desert locust breeding areas during remission periods. These sites are mainly located in wadis and in areas of accumulation/spreading of rainwater. The use of this methodology to all the Algerian Sahara is surely possible in order to improve the preventive management of this pest.

IPM-Biological and integrated management of desert locust

Locusts have caused periodic disasters in the recorded history of humankind.Up to now,locust disaster is still the biggest threat to the world’s agricultural production.The desert locust Schistocerca gregaria is one of the most harmful locusts,which has caused massive food crises,economic losses,and ecological disasters.The desert locust is a migratory insect pest that occurs year-round in the tropic and subtropical regions.Under the wind and seasonal alternation,it moves and flies in the African continent and West Asia.Desert locust damages the stems and leaves of more than 300 plants,including Gramineae,Tribulus terrestris,and Euphorbiaceae.Locusts cause devastating disasters to local plants,especially field crops,and significantly threaten food security.To date,voluminous research has been conducted regarding the ecology and management of desert locusts.This review represents an effort to summarize the basic information on the biology and ecology,distribution,damage,and economic impact of desert locusts,examine the recent developments in integrated locust management,and make recommendations for future research.

Ecology,growth and management of black locust(Robinia pseudoacacia L.),a non-native species integrated into European forests

Black locust(Robinia pseudoacacia L.),a species native to the eastern North America,was introduced to Europe probably in 1601 and currently extends over2.3×10~6 ha.It has become naturalized in all sub-Mediterranean and temperate regions rivaling Populus spp.as the second most planted broadleaved tree species worldwide after Eucalyptus spp.This wide-spreading planting is because black locust is an important multipurpose species,producing wood,fodder,and a source of honey as well as bio-oil and biomass.It is also important for carbon sequestration,soil stabilization and re-vegetation of landfills,mining areas and wastelands,in biotherapy and landscaping.In Europe,black locust is drought tolerant so grows in areas with annual precipitation as low as 500-550 mm.It tolerates dry,nutrient poor soils but grows best on deep,nutrient-rich,well-drained soils.It is a fast-growing tree and the height,diameter and volume growth peak before the age of 20.It mostly regenerates vegetatively by root suckers under a simple coppice system,which is considered the most cost-effective management system.It also regenerates,but less frequently,by stool sprouts.Its early silviculture in production forests includes release cutting to promote root suckers rather than stool shoots,and cleaning-respacing to remove low-quality stems,reduce the number of shoots per stool,and adjust spacing between root suckers.In addition,early,moderate and frequent thinning as well as limited pruning are carried out focusing on crop trees.The species is regarded as invasive in several European countries and its range here is expected to expand under predicted climate changes.

Energy partitioning and evapotranspiration in a black locust plantation on the Yellow River Delta,China

Plantations of woody tree species play a crucial role in ecological security along coastal zones.Understanding energy partitioning and evapotranspiration can reveal land–atmosphere interaction processes.We investigated energy fluxes,evapotranspiration,and their related biophysical factors using eddy covariance techniques in a black locust(Robinia pseudoacacia L.)plantation in 2016,2018,and 2019 on the Yellow River Delta.Downward longwave radiation offsets 84–85%of upward longwave radiation;upward shortwave radiation accounted for 12–13%of downward shortwave radiation.The ratio of net radiation to downward radiation was 18–19%over the three years.During the growing season,latent heat flux was the largest component of net radiation;during the dormant season,the sensible heat flux was the dominant component of net radiation.The seasonal variation in daily evapotranspiration was mainly controlled by net radiation,air temperature,vapor pressure deficit,and leaf area index.Black locust phenology influenced daily evapotranspiration variations,and evapotranspiration was greater under sea winds than under land winds because soil water content at 10-cm depth was greater under sea winds during the day.Seasonal patterns of daily evaporative fraction,Bowen ratio,crop coefficient,Priestley–Taylor coefficient,surface conductance,and decoupling coefficient were mainly controlled by leaf area index.The threshold value of daily surface conductance was approximately 8 mm sover the plantation.

Recent Advances in the Preparation, Characterization and Applications of Locust Bean Gum-Based Films

Locust bean gum(LBG)is a typical galactomannan isolated from carob bean(Ceratonia siliqua L.)cultivated in the Mediterranean area.Due to its superior biodegradable,rheological and film-forming properties,LBG has been used alone or combined with other biopolymers(e.g.,polysaccharides,proteins and lipids)to develop films.Till now,different kinds of functional ingredients(e.g.,montmorillonite,bacteriocins,antibiotics,plant extract,essential oils and microbial cells)have been added into LBG-based films.Notably,the physical and functional properties of LBG-based films are affected by many factors,such as the structure of LBG,the type and content of other biopolymers and functional ingredients,and the physical treatment of film-forming solution.LBG-based films can be not only used as active packaging and edible coating in food industry but also used as wound dressings in pharmaceutical industry.For the first time,this review focuses on the recent advances in the preparation,characterization,physical and functional properties,and potential applications of LBG-based films.

Egg tanning improves the efficiency of CRISPR/Cas9-mediated mutant locust production by enhancing defense ability after microinjection

The mutant efficiency and hatching ratio are two key factors that significantly affect the construction of genome-modified mutant insects.In the construction of CRISPR/Cas9-mediated dsLmRNase2^(–/–)mutant locusts,we found that the tanned eggs which experienced a 20-min contact with the oocyst exhibited a higher success rate compared to fresh newly-laid eggs that were less tanned.However,the heritable efficiency of the dsLmRNase2 deletion to the next generation G_(1 )progeny was similar between adults derived from the tanned or less tanned engineered eggs.Further,the similar effective mutant ratios in the normally developed eggs and G_(0) adults of tanned and less tanned eggs also indicated that tanning did not reduce the absolute mutation efficiency induced by CRISPR/Cas9.Moreover,we found that the syncytial division period,which was longer than the time for tanning,conferred a window period for microinjection treatment with efficient mutation in both tanned and less tanned eggs.We further found that tanned eggs exhibited a higher hatching rate due to a reduced infection rate following microinjection.Both the anti-pressure and ultrastructure analyses indicated that the tanned eggs contained compressed eggshells to withstand increased external pressure.In summary,tanned eggs possess stronger defense responses and higher efficiency of genome editing,providing an improved model for developing Cas9-mediated gene editing procedures in locusts.

Predation Capability of Black Kite (Milvus migrans parasitus) on Locust as a Biological Control Option in Madagascar

In Madagascar, the South and Southwest regions have for decades had locust outbreaks that have devastated crop fields. The locust species dominant in this area are the red locust (Nomadacris septemfasciata) and the Migratory Locust (Locusta migratoria capito). This paper aimed at determining the predation values from the Black Kite (Milvus migrans parasitus), a natural enemy for locusts, as a biological measure for locust outbreak control. Two types of experiments were done that included observed predation and experimental predation. It was observed, in the observed predation, that a higher number of locusts were found in the bird’s stomach during the afternoon session (mean = 66) than during the morning session (mean = 21). The high peak observed during the afternoon session was also associated with the feeding of larvae of the migratory locust. The experimental predation results showed that almost 100 percent of the larval and 97 percent of the fledglings were fed on. The experimental predation results also showed that there was no preference for larvae or fledglings in the cage and that the bird fed on the different combinations equally. This study showed that the Black Kite birds can effectively control locust population in an outbreak when they are easy to predate on. However, there is a need to assess the population of birds in locust infested areas to determine if the bird population is enough to predate on a locust outbreak.