Ovicidal effects of entomopathogenic fungal isolates on the invasive Fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae)

Maize is a major staple food for over 300 million people in sub‐Saharan Africa. Sustainable productivity of this primary crop has been recently threatened by Fall armyworm (FAW), Spodoptera frugiperda invasion. Due to lack of environmentally safe management strategies, immediate responses by growers and governments to tackle FAW are based on rampant use of pesticides. Looking for efficient biopesticides, twenty entomopathogenic fungal isolates (14 Metarhizium anisopliae and 6 Beauveria bassiana) were screened for their efficacy against eggs and second instar larvae of FAW. A single discriminating concentration of 1 × 10⁸ conidia ml^?1 and four replicates per treatment were used in all experiments. Isolates were assessed for their ability to cause mortality of FAW second instar larvae, eggs and the neonate larvae that emerged from treated eggs. Among the isolates tested, only B. bassiana ICIPE 676 caused moderate mortality of 30% to second instar larvae. Metarhizium anisopliae ICIPE 78, ICIPE 40 and ICIPE 20 caused egg mortalities of 87.0%, 83.0% and 79.5%, respectively, and M. anisopliae ICIPE 41 and ICIPE 7 outperformed all the others by causing 96.5% and 93.7% mortality to the neonate larvae, respectively. The cumulated mortality of eggs and neonates was highest with M. anisopliae ICIPE 41 (97.5%), followed by M. anisopliae ICIPE 7, 655, 40, 20 and 78 with total mortality of 96.0%, 95.0%, 93.5%, 93.0% and 92.0%, respectively. These isolates with high cumulated mortality (≥92%), especially ICIPE 78 and 7, which are already commercialized for spider mites and ticks control respectively, would be good candidates for development as biopesticides for management of FAW in Africa if further evidence of their efficacy is obtained in the field.     

试论拓宽生物防治范围，发展虫害可持续治理

该文针对我国生物防治资源极其丰富和农民经济实力薄弱的特点,结合我国微孢子虫治蝗和苹果园植被多样化持续治理虫害的成果,论述了应如何发展和拓宽具有我国特色的害虫生物防治,进一步提高综合防治水平,促进农业可持续发展。     

生物技术学和害虫综合防治对热带亚洲小农户的重要意义(英文)

作者是澳大利亚著名昆虫学家,长期在东南亚农村工作,积累了宝贵经验。他在文中提出,害虫综合防治（ＩＰＭ）的含义是综合害虫治理的方法以达到农业上的最大收益和持续发展,同时注意对环境有良好的影响。对小农户应提供确实可行的整套害虫治理方法,并开创他们能自行选择的机会;他们经过田间学校培训后可成为农作物管理专家,并对怎样防治害虫能作出有根据的抉择。与ＩＰＭ有关的生物防治最近的发展包括：对害虫的准确鉴定、经生物工程处理和未处理过的生物杀虫药的应用、对转基因动植物的利用、及情报资料的收集。文章讨论了这些生物技术在东南亚地区水稻和蔬菜综合治理中的应用,以8及巴西大豆害虫和越南稻瘟病的治理,阐明通过农户、技术员和研究人员通力合作所获得的成绩对农业持续的发展起了主要的推动作用。     

Application of GM crops in Sub-Saharan Africa: lessons learned from Green Revolution

While the Green Revolution has been successful in some regions like South and East Asia, it could hardly address any achievement in Sub-Saharan Africa (SSA). This paper tries to draw a picture on lessons learned from the failures of this revolution that should be taken into account before implementing the so-called Gene Revolution in the SSA region. After scrutinizing the failures and the pros and cons of GM crops in the region, the paper introduces some potentials for improving the malnutrition situation in SSA through launching a successful GM technology. However, it remains doubtful whether this technology can improve the situation of small-scale farmers as long as they receive no financial support from their national governments. Therefore, before any intervention, the socio-economic and environmental impacts of GM technology need to be carefully addressed in the framework of a series of risk assessment studies. Besides, some sort of multi-stakeholder dialog (from small-scale farmers to consumers) involving public–private sector and non-governmental organizations should be heated up at both national and regional levels with regard to the myths and truths of this technology.     

BIOTECHNOLOGY AND IPM: THE RELEVANCE TO SMALL SCALE FARMERS IN TROPICAL ASIA*

Abstract This paper deals with the relevance of biotechnology and IPM to small scale farmers in South and Southeast Asia. IPM may be defined as the combination and integration of approaches to pest management. which maximizes real profitability and genuine sustainability for the users and farming system and gives due regard to the environment. Alternative and practical pest management options should be developed for small scale farmers who could become experts in crop management and capable of making informed decisions through training in field schools. The latest development of biotechnology includes diagnostics, biological pesticides (either genetically manipulated or not genetically manipulated), transgenic plants and animals (vertebrates and invertebrates) and informatics. The place of biotechnology in rice IPM and vegetable IPM in South and Southeast Asia is discussed. Examples of soybean caterpillar in Brazil and rice blast in Vietnam illustrate the benefits of a strong working partnership between farmers, trainers and researchers in creating new knowledge which promotes sustainable agriculture.     

Spatio-temporal partitioning and sharing of parasitoids by fall armyworm and maize stemborers in Cameroon

Biological invasion is a global concern with species deployed out of native range, the most recent in Africa being the invasion by fall armyworm (FAW) Spodoptera frugiperda J.E. Smith (Lepidoptera: Noctuidae). One of the most mentioned ecological consequences is the capacity of invaders to change native communities' structure. Busseola fusca Fuller (Lepidoptera: Noctuidae) has long been the most destructive pests of maize in Africa. Few or no studies have attempted to look at the interaction between FAW and native maize pests over a cropping cycle for sustainable management. Maize trials were established over two cropping cycles in Cameroon to investigate the nature of such interactions and eventual sharing of parasitoids. FAW incidence decreased with maize growth, while the reverse was observed for stemborers. Few cases of co-occurrence were recorded at the later maize growth stage. There was a clear indication that FAW infestation was associated with vegetative stages, while stemborers were associated with reproductive stages. Only FAW eggs were found on abaxial and adaxial leaf surfaces, while only stemborer eggs were inside leaf sheaths. Similarly, while larvae of both groups were found in maize whorl and on ears, only FAW larvae were found in closed tassels, while only stemborers were found inside stems. These results are in favour of segregation in time and space in plant colonization by native and invasive pests, which may limit competition and exacerbates damage if no control is provided. The same egg, larval and pupal parasitoids respectively Telenomus remus, Cotesia icipe and Procerochasmias nigromaculatus emerged from isolated FAW and B. fusca eggs, larvae, and pupae. The sharing of parasitoids by both species provides a unique opportunity for augmentative biocontrol.     

草地贪夜蛾的性信息素通讯研究进展

草地贪夜蛾Spodoptera frugiperda原产于美洲,具有长距离迁飞特性。该虫于1988年入侵欧洲,2016年入侵非洲,并引起巨大的粮食损失,2018年入侵亚洲,2019年从缅甸传入中国,并在短时间扩散至全国10多个省。草地贪夜蛾依赖性信息素通讯,实现雌雄间识别、交配和繁衍,为了深入研究草地贪夜蛾的性信息素通讯及其机制并开发更高效的预测预报和防治技术,本文综述了草地贪夜蛾性信息素通讯的研究现状。1967年首次报道草地贪夜蛾性信息素为顺9-十四乙酸酯,随后发现有不同的鉴定结果,1986年确认其性信息素由顺9-十四乙酸酯和顺7-十二乙酸酯两个组分组成,其比例为96.6∶3.4时表现出最强的引诱活性。除此而外,对不同地理种群的研究发现,草地贪夜蛾雌蛾的信息素腺体提取物还存在顺9-十二乙酸酯、顺11-十六乙酸酯和反7-十二乙酸酯,田间实验表明这些物质在性信息素通讯中也可发挥作用。根据分子标记和喜食寄主,草地贪夜蛾可分为玉米品系和水稻品系。两个品系在外部形态上无法区分,性信息素组分也相同,但在组分比例上存在一定的差异。两个品系间存在一定程度的生殖隔离,但室内可以正交和反交并产生可育的F1代,F1代的性信息素比例与母本的比较相似。关于草地贪夜蛾雄性对性信息素的感受机制方面研究较少,仅见有感器形态的鉴定和对性信息素组分的触角电位反应研究的报道。根据目前草地贪夜蛾在我国的发生情况及其性信息素通讯机制的研究现状,我们建议尽快开展以下研究：(1)鉴定草地贪夜蛾我国入侵种群的雌性性信息素,尽快用于其种群动态监测及防治;(2)研究草地贪夜蛾雄性对性信息素的嗅觉编码机制;(3)研究草地贪夜蛾两个品系的行为隔离程度及其演化结局。     

Increasing ecological heterogeneity can constrain biopesticide resistance evolution

Microbial biopesticides containing living parasites are valuable emerging crop protection technologies against insect pests, but they are vulnerable to resistance evolution. Fortunately, the fitness of alleles that provide resistance, including to parasites used in biopesticides, frequently depends on parasite identity and environmental conditions. This context-specificity suggests a sustainable approach to biopesticide resistance management through landscape diversification. To mitigate resistance risks, we advocate increasing the range of biopesticides available to farmers, whilst simultaneously encouraging other aspects of landscape-wide crop heterogeneity that can generate variable selection on resistance alleles. This approach requires agricultural stakeholders to prioritize diversity as well as efficiency, both within agricultural landscapes and the biocontrol marketplace.     

The development, regulation and use of biopesticides for integrated pest management

Over the past 50 years, crop protection has relied heavily on synthetic chemical pesticides, but their availability is now declining as a result of new legislation and the evolution of resistance in pest populations. Therefore, alternative pest management tactics are needed. Biopesticides are pest management agents based on living micro-organisms or natural products. They have proven potential for pest management and they are being used across the world. However, they are regulated by systems designed originally for chemical pesticides that have created market entry barriers by imposing burdensome costs on the biopesticide industry. There are also significant technical barriers to making biopesticides more effective. In the European Union, a greater emphasis on Integrated Pest Management (IPM) as part of agricultural policy may lead to innovations in the way that biopesticides are regulated. There are also new opportunities for developing biopesticides in IPM by combining ecological science with post-genomics technologies. The new biopesticide products that will result from this research will bring with them new regulatory and economic challenges that must be addressed through joint working between social and natural scientists, policy makers and industry.     

The national determinants of deforestation in sub-Saharan Africa

For decades, the dynamics of tropical deforestation in sub-Saharan Africa (SSA) have defied easy explanation. The rates of deforestation have been lower than elsewhere in the tropics, and the driving forces evident in other places, government new land settlement schemes and industrialized agriculture, have largely been absent in SSA. The context and causes for African deforestation become clearer through an analysis of new, national-level data on forest cover change for SSA countries for the 2000–2005 period. The recent dynamic in SSA varies from dry to wet biomes. Deforestation occurred at faster rates in nations with predominantly dry forests. The wetter Congo basin countries had lower rates of deforestation, in part because tax receipts from oil and mineral industries in this region spurred rural to urban migration, declines in agriculture and increased imports of cereals from abroad. In this respect, the Congo basin countries may be experiencing an oil and mineral fuelled forest transition. Small farmers play a more important role in African deforestation than they do in southeast Asia and Latin America, in part because small-scale agriculture remains one of the few livelihoods open to rural peoples.     

Farmer knowledge,attitude and practice on cotton (Gossypium hirsutum L.) pest resistance management strategies in Zimbabwe

Cotton is an important cash crop and a means of survival for Zimbabwe’s smallholder farmers who are located in the semi-arid areas. However, it is plagued by a wide variety of pests. The cotton industry in Zimbabwe came up with sustainable pest management strategies which include within the season rotation of bollworm pesticides, a closed season and acaricide rotation scheme. The land reform programme brought new players in the cotton industry and it was critical to determine their knowledge on the pest management strategies. A survey was conducted to determine farmer knowledge, practice and perception on the resistance management strategy. Responses indicated that both communal and new farmers based their spray on egg counts. Communal farmers knew when to use pyrethroids compared to new farmers. Farmers observed the acaricide rotation scheme although they use some non acaricide pesticides. More than half of the new farmers could not say which acaricides were in the acaricide scheme. The majority of the farmers reported that they adhered to the closed season although field observation revealed otherwise. A significantly higher number of new farmers knew when to slash cotton compared to communal farmers. Knowledge of acaricides was not common among farmers. Use of pyrethroids was not limited to 1 February onwards as stipulated in the cotton pest resistance management strategy. The results suggest the need for training among the cotton farmers especially the new farmers or refresher courses among the communal farmers.     

Farmers' management of cabbage and cauliflower pests in India and their approaches to crop protection

Cabbage (Brassica olearaceae var. capitata) and cauliflower (Brassica oleracea var. botrytis) are two major vegetables produced and consumed in India. Over the years, they have been cultivated more intensively. This has resulted in higher rates of pest infestation, especially by the diamondback moth (Plutella xylostella) and higher pesticide use. This, in turn, has contributed to insecticide resistance, environmental degradation, and human health impacts, which have triggered a growing interest in alternative management techniques. There is a dearth of knowledge on current pest management practices in cabbage and crucifer. Knowledge about pest management practices is necessary to develop appropriate strategies such as Integrated Pest Management. The main purpose of this study was to obtain comprehensive information on pest management practices among farmers growing cabbage and cauliflower in India.A survey was conducted in the states of Gujarat, West Bengal, and Karnataka from October 2006 through January 2007. Three hundred farmers were interviewed to obtain information on pesticide use in cabbage and cauliflower production, the cost of pesticide use, and socioeconomic characters that influence cabbage and cauliflower production.Farmers relied on pesticides as the major and often exclusive crop protection strategy. Ten of the active ingredients (16.4% of all pesticides reported by all farmers in this survey) were listed as extremely or highly hazardous (classes Ia and Ib) by the World Health Organization. The results confirmed that pesticide use differs between states of India, but that location alone does not determine pesticide spraying pattern. A regression model was used to identify determinants of pesticide application frequency and pesticide cost per hectare. After controlling for location, individual level variables, such as age, education and experience, had significant effects on how often farmers sprayed. Farmers also spent more for pesticides, and sprayed more frequently on cauliflower than on cabbage and on open-pollinated varieties than on hybrid varieties.Our findings highlight the excessive use of pesticides in cabbage and cauliflower, and the reliance on pesticides as the only pest management strategy. The results confirm the need for alternative management strategies. Bt vegetables may be one of these alternative strategies. However, it is questionable whether cultivation of Bt vegetables will reduce the strong reliance on pesticides. Small-scale farmers will need training in the identification of pests, natural enemies, basic ecology, and integrated pest management strategies to ensure sustainable and safe vegetable production.     

Soil‐dwelling insect pests of tree crops in Sub‐Saharan Africa,problems and management strategies—A review

This review aims to draw the attention of researchers, ecologists and farmers to the threats of soil‐dwelling insect pests on important tree crops in sub‐Saharan Africa, with a special focus on termites. It synthesizes the information on the effects of various factors affecting soil pest occurrence and damage, suggesting that the resultant undesirable effects of soil pests in this region are largely as a result of indiscriminate tree cutting, slash‐and‐burn agriculture and indiscriminate use of pesticides. Major insect orders, their host ranges and the nature of damage on selected tree crops are described. This study further critiques existing soil pest management practices, showing that majority of soil pest management practices are ineffective. Thus, management strategies like “attract and kill” approach based on entomopathogenic fungi need to be studied, developed and emphasized for the management of soil insect pests in sub‐Saharan Africa. A conclusion section attempts to offer suggestions for ways in which future work on soil pests in sub‐Saharan Africa could proceed.     

Potential failsafe mechanisms against the spread and introgression of transgenic hypervirulent biocontrol fungi

Microbial biocontrol agents are typically inefficient owing to the evolutionary necessity to be in balance with their hosts to survive. If transgenetically rendered hypervirulent, however, they could be competitive alternatives to pesticides. Potential means are delineated to prevent, contain or mitigate uncontrollable spread of hypervirulent biocontrol organisms, mutations that increase their host range, and the sexual or asexual introgression of hypervirulence genes into pathogens of other organisms. The use of asporogenic deletion mutants as a platform for generating transgenic hypervirulent biopesticides would prevent such spread. Hypervirulence genes flanked with available 'transgenetic mitigator' (TM) genes (genes that are neutral or positive to the biocontrol agent but deleterious to recombinants) would decrease virulence to non-target species.     

Combining Pest Repellent Plants and Biopesticides for Sustainable Pest Management in Chinese Kale

The objective of this investigation was to study the use of pest repellent plant (PRP) species and biopesticides for sustainable pest management in Chinesekale(Brassica oleracea L. var. alboglabra Bailey). Ten selected treatments composed of three PRP species namely citronella grass - (CG) [Cymbopogon nardus L. (Rendle)], sweet basil - (SwB) (Ocimum basilicum L.) and sacred basil - (SaB) (Ocimum sanctum L.)] were intercropped with Chinese kale, integrated with two commonly used biopesticides, viz. Bacillus thuringiensis (Bt) and neem extract (Azadirachta indica) and a control were tested in a randomized complete block design (RCBD) with 3 replicates. The insect pest species infested in Chinese kale and their populations, % pest damage, fresh weight and quality of yield were investigated. The results showed that diamondback moth - (DBM) [Plutella xylostella (Linnaeus)] density was lowest in CG alone, CG+SaB, SwB+biopesticides and SaB+biopesticides, relatively low in SwB alone, CG+SaB+SwB, and CG+biopesticides, and moderate in biopesticides and sacred basil alone, and highest in the control. The densities of common cutworm - (CCW) [Spodoptera litura (Fabricius)], cabbage webworm - (CWW) [Hellula undalis (Fabricius)] and flea beetle - (FBT) (Phyllotreta sinuata Steph.) were not significantly different among treatments. The overall pest damage was lowest in CG+biopesticides treated plots followed by SwB+ biopesticides, SaB+biopesticides and biopesticides alone, and CG+biopesticides gave the best quality of yield of Chinese kale, and hence such combinations could be integrated for managing crucial insect pests, i.e. DBM and to minimize/avoid the use of highly toxic synthetic pesticides in Chinese kale.     

Impact of integrated pest management on food and horticultural crops in Africa

In sustainable agricultural development, integrated pest management (IPM) can play a key role in the reduction of crop losses, thereby increasing productivity while minimizing environmental contamination and health hazards. In recent years, agricultural research and development partners have pioneered outstanding contributions in IPM, notably in varietal resistance against pests, biological control of alien invasive species, substitution of inorganic pesticides with biopesticides, new export market opportunities, and new tools in biotechnology. Success stories are not limited to these areas, but are also found in the areas of human capital development, information management, and participatory approaches. The potential of IPM to contribute to poverty alleviation and food security is, however, poorly realized in Africa due to a myriad of factors, including inadequate deployment of high-yielding crop varieties, harmful pesticide regimes, political instability, conflicts in social values and civil wars, inappropriate agricultural policies, biased global trade policies, lack of market information, and poor rural infrastructures. Few African countries have adopted IPM as the official national crop protection policy and there is no framework for resource allocation to support widespread promotion of research and training in IPM. This calls for reshaping and revisiting a number of policies related to food production and agricultural development, in order to encourage partnership and participation in the identification, analysis, advocacy, and follow-up of agricultural policy issues as well as public awareness of the effect of pests and diseases on food security and the environment.     

Using Risk Assessment as Part of a Systems Approach to the Control and Prevention of HPAIV H5N1

Since its emergence in China in 1996, highly pathogenic avian influenza virus subtype H5N1 has spread across Asia, Africa, and Europe. Countries had to promptly implement control and prevention measures. Numerous research and capacity building initiatives were conducted in the affected regions to improve the capacity of national animal health services to support the development of risk-based mitigation strategies. This paper reviews and discusses risk assessments initiated in several South-East Asian and African countries under one of these projects. Despite important data gaps, the risk assessment results improved the ability of policy makers to design appropriate risk management policies. Disease risk was strongly influenced by various human behavioral factors. The ongoing circulation of HPAIV H5N1 in several Asian countries and in Egypt, despite major disease control efforts, supports the need for an interdisciplinary approach to development of tailored risk management policies, in accordance with the EcoHealth paradigm and the broad concept of risk governance. In particular, active stakeholders engagement and integration of economic and social studies into the policy making process are needed to optimize compliance and sustainable behavioral changes, thereby increasing the effectiveness of mitigation strategies.     

Epizootic ulcerative syndrome (EUS) in fish: history and current status of understanding

Epizootic ulcerative syndrome (EUS) is one of the most important diseases affecting more than 100 species of wild and cultured finfish. EUS was first reported in farmed ayu (Plecoglossus altivelis) from Japan in 1971 and has since then spread across different countries of four continents including Asia, Australia, North America and Africa. The spread of the disease, especially in Asia–Pacific region and Africa has led to substantial damage to the fish resources and livelihood of the fish farmers. No reports are available confirming the outbreak of the disease from Europe and South America. The latest outbreak of EUS has been reported from Canada in a new susceptible species brown bullhead, Ameiurus nebulosus. It seems that the disease has potential to spread further, owing to the epizootic nature of the disease and broad susceptible host range. Considering the global importance of this disease, this review provides the current status of understanding about the etiology, process of diseases development, species affected, diagnostic methods as well as control and preventive measures, in light of the historical developments in those areas.     

Plant protection and growth stimulation by microorganisms: biotechnological applications of Bacilli in agriculture

The increasing demand for a steady, healthy food supply requires an efficient control of the major pests and plant diseases. Current management practices are based largely on the application of synthetic pesticides. The excessive use of agrochemicals has caused serious environmental and health problems. Therefore, there is a growing demand for new and safer methods to replace or at least supplement the existing control strategies. Biological control, that is, the use of natural antagonists to combat pests or plant diseases has emerged as a promising alternative to chemical pesticides. The Bacilli offer a number of advantages for their application in agricultural biotechnology. Several Bacillus-based products have been marketed as microbial pesticides, fungicides or fertilisers. Bacillus-based biopesticides are widely used in conventional agriculture, by contrast, implementation of Bacillus-based biofungicides and biofertilizers is still a pending issue.