Evaluation of the Efficacy of an Aloe barbadensis Based Biological Insecticide against Pests of Abelmochus esculentus for Promoting Ecological Agriculture (Far-North, Cameroon)

Chemical insecticides have been considered as a means to combat crop pests. Although their effectiveness is evident, their impact on the environment is increasingly being discussed. The aim of this study is to determine the agro-ecological potential of a biological insecticide (C25H32O12) based on Aloe barbadensis in a Sahelian context. For this purpose, a completely randomized block experimental design with 3 replications and 4 treatments was set up to experiment with Aloe barbadensis as a bioinsecticide against pests of Abelmoschus esculentus. However, data were collected using an observation and parameter monitoring grid. This includes the cultivation of Abelmoschus esculentus, soil preparation, seeding and watering, plot labeling, preparation of the bioinsecticide (selection and preparation of raw materials, grinding of Aloe barbadensis miller and extraction of the crude bioinsecticide, quantification of treatment doses and dilution, and obtaining the formulated bioinsecticide), plant watering, plant treatment, and finally parameter monitoring. The results obtained reveal that the level of damage is significantly high in the control treatment T0 (63%) compared to the other treatments, with 29% for treatment T1, 7% for T2, and 1% for T3, implying a strong action capability of this insecticide against pests of Abelmoschus esculentus. Therefore, it can be concluded that for a normal growing season of Abelmoschus esculentus, this biological insecticide should be sprayed 12 times. Furthermore, this biological insecticide is unique in that it does not inflict any gastric toxicity on the pests, which gives it the characteristic of being a repellent. It is a biological insecticide whose efficacy period has been tested, with a minimum duration of 21 days. In conclusion, this formulated bioinsecticide based on Aloe barbadensis demonstrates significant efficacy against pests of Abelmoschus esculentus. In the future, we will consider experimenting with its effectiveness against pests of other plants.

Social Cost Analysis of Biological Control Technology for Crop Diseases and Insect Pests

With the rapid development of modern agriculture,the prevention and control of crop diseases and insect pests has become an important part to ensure the safety of agricultural production,the quality of agricultural products and the safety of agricultural ecological environment.Although the effect of traditional chemical prevention and control technology is remarkable,the health risks and environmental problems brought by it should not be ignored.As a green and environmentally friendly means of prevention and control,biological prevention and control technology has gradually become a hot research topic and a trend of agricultural production.This paper is intended to comprehensively evaluate the social costs of biological control technologies for crop diseases and pests,including the health risks reduced,environmental improvements,economic benefits,and barriers to promotion,and put forward corresponding policy recommendations.

Application of Biological Pesticides in Medicinal Plants

At present, the excessive application of traditional chemical pesticides, serious pesticide residue pollution and destruction of the ecological balance in China have become important factors affecting the quality and safety of medicinal material. Biological pesticides are rapidly developed due to their characteristics of high efficiency, low toxicity and residue. This study aimed to introduce the specific property of biological pesticides, review the classification of biological pesticides and their application in medicinal plants, analyze the problems in the production and utilization process of biological pesticides, and forecast the developmental prospect.

Biological Control of Insect Pests of Agricultural Crops through Habitat Management Was Discussed

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.

In vitro biological activities of aqueous extracts of Tetrapleura tetraptera(Schumach. & Thonn.) taub. and Aframomum citratum(C. Pereira) K.Schum from three Agroecologic Zones in Cameroon

Objective:To investigate some phytochemical constituents and biological activities of twelve samples of Tetrapleura tetraptera(Schumach&Thonn.)taub.and nine samples of Aframomum citratum(C.Pereira)K.Schum fruits collected in the bimodal forest zone(ZONEⅤ),the unimodal forest zone(ZONEⅣ)and the highlands zone(ZONEⅢ)in Cameroon.Methods:Fresh fruits extracts were obtained by aqueous infusion(100℃during 15 min)and evaluated by spectrophotometric methods for total polyphenol(TPP),total flavonoids(TFLV)contents and antioxidant(DPPH,total antioxidant capacity by the phosphomolybdenum method,iron reducing power or ferric reducing antioxidant power and inhibition of beta carotene discoloration assays)and anti-inflammatory(inhibitions of protein denaturation and 5-LOX represented by INH.PROT and INH.5-LOX respectively)properties.Principal component analysis was performed.Results:For both species,fruits from ZONEⅤhave the highest TPP,TFLV levels and biological activities.TPP and TFLV content of Aframomum citratum and Tetrapleura tetraptera fruits are positively and significantly(P<0.05)correlated.The biological activities of all extracts(0.25,2.5,25,250 mg/mL)were dosedependent and the extracts have shown strong antioxidant and antiinflammatory activities,but less than references(ascorbic acid,diclofenac,quercetin,and butylated hydroxytoluene).There was a positive correlation between TPP,TFLV and total antioxidant capacity,ferric reducing antioxidant power,and inhibition of beta carotene discoloration assays,and inverse correlations were observed with the IC50(g/mL)of DPPH,INH.5-LOX and INH.PROT assays for both species.Conclusions:The fruits exhibit variabilities and those from ZONEⅤfor both species are economically and healthcare challenging for herbalists,pharmaceutical firms,scientists and consumers.Indeed,most important extraction yield of bioactive compounds correlated with significant biological activities and the use of less material compared with an implementation in other Agro-ecologic Zones with the same results are noted.

Study on Biological Habits and Control of Scirothrips dorsalis Hood on Mangoes

[Objective] This study aimed to explore the biological habits of Scirothrips dorsalis Hood and methods for controlling this pest. [Method] From 2009 to 2011, the biological habits of Scirothrips dorsalis Hood and the regularity of its occurrence on mangoes were investigated at the experimental base of the Institute of Tropical and Subtropical Cash Crops, Yunnan Academy of Agricultural Sciences and Shuanghongqiao Mango Orchard in Baoshan, Yunnan Province. In addition, a field trial on the effects of four medicaments on controlling this pest was also conducted. [Result] The result showed that Scirothrips dorsalis Hood completed 10-12 genera- tions per year in Baoshan area, and the peak period of its incidence was from February to April. The results of the pest control testing showed that at 0.05 level, there were significant differences of effect on pest controlling among the treatments I, II and IV, and the treatment III showed significant differences of controlling effect with the treatment IV, while no significant differences with either the treatment I or the treatment II; at 0.01 level, there was no significant difference among the treat- ments I, II and III, while all the three treatments showed significant differences with treatment IV. [Conclusion] This study revealed that the occurrence and the severity of Scirothrips dorsalis Hood on mangoes in Baoshan, Yunnan Province. In addition, pesticides with certain efficacy on controlling Scirothrips dorsalis Hood were screened, which provides more options for fruit growers to control this pest on mangoes.

Potential of Steinernema carpocapsae(Weiser) as a biological control agent against potato tuber moth, Phthorimaea operculella(Zeller)(Lepidoptera: Gelechiidae)

The entomopathogenic nematode,Steinernema carpocapsae,was evaluated for control of the potato tuber moth,Phthorimaea operculella,under laboratory conditions.We evaluated different concentrations of S.carpocapsae for control of 2 nd,3 rd,and 4 th instar P.operculella.The median lethal concentration(LC50)of S.carpocapsae infective juveniles(IJs)to 2 nd,3 rd and 4 th instar larvae of P.operculella was 200,363,181 IJs mL–1,respectively.With the extension of treatment time,the cumulative mortality increased for 2 nd,3 rd,and 4 th instar larvae and pupae of P.operculella.Fourth instars were the most susceptible for all observation periods.Therefore,our results suggest that S.carpocapsae could be an effective biological control agent for P.operculella.

Biological Characteristics and Control Measures of Cydia pomonella(Linnaeus)

Cydia pomonella （Linnaeus） is a fruit decay pests attacking apples, pears and other fruits, and it is an important quarantine pests in China. In recent years, the momentum of the eastward aggression of the insect in our country was more and more serious, and the harm degree was deepening. If Cydia pomonella （Linnaeus） is introduced, fruit production will be significantly affected in Hebei Province. The damage characteristics, morphological characteristics and life habit of Cydia pomonella （Linnaeus） were reviewed, and the control measures were proposed, in order to provide technical support for promoting the sound development of fruit industries in Hebei province.

Biological Diversity, Land Degradation and Sustainable Rural Livelihoods

The 1998 Conference of Parties to the Convention on Biological Diversity asked national governments to demonstrate the importance of biological diversity in supporting rural communities. This paper introduces‘agrodiversity’as the primary way in which farmers use biological diversity and, more generally, the natural diversity of the environment for production, including their choice of crops, and management of land, water and biota as a whole. Promoting agrodiversity and understanding how it functions in tropical smallholder farming systems is the best way that importance may be shown. A win-win scenario is presented which links agrodiversity to land degradation control and sustainable rural livelihoods as evidenced by food security. It is argued that policies that encourage biological diversity in areas of land use will not only meet countries’ responsibilities under the Convention but will also address land degradation problems and support to rural livelihoods. The human significance of various types of biological diversity is shown. Sustainable rural livelihoods are presented in the new capital assets framework to demonstrate how rural households may use various components to control land degradation. To enable agrodiversity to be implemented practically, it has been codified into core elements of: biophysical diversity, the diversity of the natural environment that controls the resource base for food production; management diversity that embraces the practices (many of them indigenous) of farmers such as live hedges, soil amendments and ridge tillage techniques; agro-biodiversity which is the diversity of crop, plant and animal combinations; and organisational diversity, the way that farms are owned and operated, and the way that capital assets are allocated. Each element is then systematically related to show how agrodiversity controls land degradation and how it promotes food security. The example of the maize-Mucuna system in South America is cited as an evident demonstration of the value of agrodiversity to both soil conservation and to smallholder farmers’ livelihoods.

Combined Effect of Nutrient and Pest Managements on Substrate Utilization Pattern of Soil Microbial Population in Hybrid Rice Cropping System

A field experiment was conducted to study the combined effect of nutrient andpest managements on soil biomass phospholipid contents, functional biodiversity and substrateutilization patterns of soil microbial populations in hybrid rice cropping system. The mineral N, Pand K fertilizers (as urea, calcium superphosphate and KCl respectively) were incorporated at 100,25, and 100 kg ha^(-1), respectively, and the various pesticides were applied at the recommendedrates. The results of the experiment demonstrated a decline in the microbial abundance and soilmicrobial biomass phospholipid contents with the advancement of crop growth, and significant changesin substrate utilization pattern of soil microbial population studied were observed with differentmanagement practices and at different growth stages. The principal component analysis (PCA) usingall 95-carbon sources (BIOLOG plates) gave good differentiation among the treatments, indicatingthat they have different patterns of carbon utilization under different habitats. The data showedthat diversity in microbial community continuously changed with the progression in crop stage,particularly at physiological maturity (PM) stage that was evident from the utilization of differentcarbon sources at various crop stages.

Invasion genetics of alien insect pests in China: Research progress and future prospects

An unwelcome side effect of the globalization of the world's economy and dramatic increase in human mobility and trade has been a marked increase in species invasions that have posed severe threats to the ecological, economic, and/or social stability of the introduced regions. In this review, we analyzed the application of molecular markers in invasion genetics of invasive alien insect pests(IAIPs) in China based on a bibliometric survey. Our report discusses the considerable progress that has been made during the past two decades in understanding the invasion genetics of IAIPs in China. We reviewed the major findings in the main topics including the effects of origin and routes of invasion on genetic structure, spatial and temporal genetic changes, factors contributing to the genetic changes of IAIPs, and genetic mechanisms involved in IAIPs' invasions. On the other hand, some of these research areas remain relatively unexplored in China, especially those pertaining to spatial and temporal genetic changes of IAIPs and genetic mechanisms of IAIPs' invasions. Finally, the future research prospects of IAIPs in China are discussed. We hope this review will stimulate an interest in and provide an increased understanding of the field of invasion genetics of IAIPs in China, and provide a basis for future research in this area.

Current research on soybean pest management in China

Pest is one of the important factors affecting soybean yield and quality. Until now, 404 species on soybean have been known based on literature review and a large scale survey. More than 20 key pests occur every year and are causing serious damage. In 3 different ecoregions(Northern ecoregion, Huang-Huai-Hai ecoregion and Central south ecoregion), pests occurrence and damage styles show a variety of regional characteristics. Soybean pests occurrence from north to south were shown as follow: from large pests to small pests, from chewing pests to sucking pests, from low reproductive rate and less generation pests to high reproductive rate and more generation pests. Soybean pest management is mainly based on resistant breeding, combining with monitoring, plant quarantine, cultural, biological, physical, mechanical and chemical controls in China. Although pesticides play an important role in practice, the absence of reasonable use has threatened sustainability of China's soybean production. Soybean integrated pest management is not the only strategy, and it still needs improvement and development, but it's the best alternative for pest control. It can be expected that integrated pest management will remain as the main strategy for soybean pest control in future. Further innovation of green prevention and control technology will also become a focus of future research in view of new pest problems brought about by crop restructuring, agricultural system change and global climate change. Integration of above technologies will reduce the harm of pests and production costs as well as improving soybean production capacity. In this review, research progress of Chinese soybean pest and its management was summarized and some suggestions were provided to adapt for soybean pest management under current situation.

Test Bench for the Mechanical Distribution of Predators to Control Insect Pests

In agriculture, chemical insecticides are widely used to protect crops from insect pests. Over a period of years, some insects such as Colorado potato beetle （CPB） succeed in developing resistance to most of the registered chemical insecticides. Consequently, heavy applications of chemical insecticides to control this pest become ineffective on a long-term basis and can lead to serious health and environmental problems. The use of natural enemies to control CPB is an interesting alternative to chemical means However, hand release of predators is not feasible on a large scale in the field. The main objective of this research study was to design and build a test bench to investigate the technical feasibility of mechanically releasing predators. The test bench consisted of a vertical chain conveyor mounted on two vertical shafts driven by an electric motor. Since the predators are small and fragile, they were placed in a specially designed container to preserve their physical integrity. Trials using this test bench showed that a carrier material was required, because most of the predators remained inside the container. The success of this mass predator release system will be highly valuable for the biological control of insect pests in many crops.

A Review of the History and Development of Integrated Pest Management(IPM)

The evolvement of IPM has experienced several significant stages. IPM is an ecosystem as a governance unit. It allows the presence of low numbers of pests because a direct or indirect relationship between biological species and their associated environmental living conditions could keep a long-term ecological balance. IPM also emphasizes overall benefits; it is necessary to integrate all kinds of safe, effective, economic, and simple managements as far as possible. When synthesizing and coordinating various managements, effective control object, effective time limit, effective scope, and effective degree of the individual method should be analysed first. The ultimate goal of IPM is for the sustainable development of agriculture. In the future IPM system engineering, crop resistance, the role of natural enemies, agricultural control, and the application of biological control technologies will be greatly strengthened, and the role of chemical pesticides will be significantly reduced. Safe, effective, and long-lasting control of pest populations will be below the level of harm caused, which could protect the ecological environment and the health of people and livestock, and promote the development of production.

Influence of Agro Ecology on Rice Varietal Resistance to <i>Sitophilus oryzae</i>(Coleoptera: Curculionidae) and <i>Sitotroga cerealella</i>(Lepidoptera: Gelechiidae) in Benin

The rice weevil, Sitophilus oryzae (L.) and the Angoumois grain moth, Sitotroga cerealella (Oliv.), are serious pests of stored rice in Africa. This study aims to evaluate the influence of growing environments to rice resistance to these pests. Thus, eleven rice varieties including 6 upland NERICA, 2 Oryza glaberrima and 3 O. sativa were grown at four agro ecological zones of Benin. After harvest, samples of 1500 grains of each genotype were infested with 20 adults of S. oryzae (10 males and 10 females) and 1500 additional ones were infested with 50 eggs of S. cerealella. Results showed significant effect of agro ecological zones on pest incidence and on varietal resistance as well. O. glaberrima varieties (TOG 5681 and CG 14) were the most resistant in each location whereas the resistance of NERICA and Sativa varieties varied from tolerant to susceptible according to the growing ecology. This result highlights the impact of growing environment on rice resistance status and will provide the best advice to farmers on how to choose best genetic material according to cropping ecology.

Natural Enemies and Pest Control in Field-Grown Crop in Southern Senegal

Crop pests are a permanent threat to horticultural production. Several control methods are recommended for their control, including biological control. This method based on the use of natural enemies is not well established. The objective of this study was to assess the diversity and abundance of natural enemies of crop pests. A survey of crops associated with pests was carried out on 144 fields in southern Senegal to measure the diversity and abundance of natural enemies of various crop pests, determine the native parasitoid complex and assess parasitism rates. Ecological indices were calculated to assess the diversity of natural enemies. A total of 25 natural enemy species were identified, including 15 parasitoids and 10 predators. Predatory Hemiptera and Parasitoid Hymenoptera were high biodiversity. The parasitism rates vary between 0 and 50% depending on the abundance of pests and parasitoid species. Knowledge of the diversity of natural enemies and the understanding of trophic interactions with pests are important in the development of biological crop protection in order to preserve resilience in agroecosystems.

露地油豆角化肥农药减施增效技术

从农药、化肥减施增效方面介绍了露地油豆角的栽培技术,该技术相较以往传统的露地油豆角种植方式,化肥施用量平均减少32.91%,农药平均喷施次数减少2.2次,油豆角667 m^(2)平均纯利润增加575元,该技术为露地油豆角绿色生产提供参考依据。

曲虫主要类群、危害风险性及其防控研究现状

曲虫是指以酒曲为食的昆虫,其栖息在酒曲中,进行取食、排泄和繁殖等活动,对酒曲理化性质、酒品产量和质量带来不利影响,严重时会引发食品安全问题,造成白酒企业的巨大损失。因其种类多、繁殖快、个体小和善于隐蔽等适应性特点,在酒曲仓储中不易被发现,一旦猖獗繁殖,会引起酒曲仓库周围环境的仓储害虫滋生和惊扰民生等问题。为了明确曲虫发生情况和防治策略,本文从曲虫的主要种类、生物学习性、为害特点和管理现状等方面进行综述,以期为曲虫的有效防控提供参考。

山核桃丰产栽培管理技术

研究了山核桃树的生长习性、栽培条件、播种育苗、定植密度、修剪整形、施肥灌溉和病虫害防治等,总结了一套适合我国不同地区的山核桃丰产栽培管理技术体系。采用合理的栽培措施,可以显著提高山核桃树的成活率、生长势、开花坐果率、单果质量和产量,同时也可以改善山核桃的品质,增加经济效益和社会效益,为山核桃的推广和发展提供科学依据和技术指导。

基于捕食性天敌及害虫种群动态筛选功能植物的研究

新兴的生态调控技术是利用非作物植物进行天敌生境管理的重要措施。为筛选出适宜增效捕食性天敌的功能植物,进而提高天敌对农林生态系统害虫的控制能力,本文通过追踪调查15种功能植物与对照杂草区域内节肢动物群落时序动态,比较了捕食性天敌及植食性害虫的累积量、益害比以及优势天敌类群与主要害虫关联性、时序动态变化。结果显示,绿豆Vigna radiata、紫花苜蓿Medicago sativa、蓖麻Ricinus communis、芥蓝Brassica alboglabra、罗勒Ocimum basilicum、芝麻Sesamum indicum上捕食性天敌累积量、益害比高于其他植物,且与主要害虫的关联性和时序变化关系明确,有益于优势天敌中华通草蛉Chrysoperla sinica、异色瓢虫Harmonia axyridis等种群,可以作为捕食性天敌的生境管理功能植物。本研究为今后进一步更好的筛选出应用于田间保护性生物防治的植物提供基础以及新思路。