Applying the difference-in-difference (DID) estimation procedure, this study quantifies the wheat blast (Magnaporthe oryzae pathotype Triticum) induced losses in wheat yield, quantity of wheat sold, consumed, or stored, as well as wheat grain value in Bangladesh in 2016 following a disease outbreak that affected over 15,000 ha. Estimates show that the blast-induced yield loss was 540 kg ha−1 on average for households in blast-affected districts. Estimated total wheat production loss was approximately 8,205 tons worth USD 2.1 million in during the 2016 outbreak. Based on these insights, we discuss the need for long-term assured investment and concerted research efforts in controlling transboundary diseases such as wheat blast, including the importance of weather forecast driven early warning systems and the dissemination of blast-resistant varieties.

Predation by Engytatus varians (Distant) adults on different development stages of the prey species Bactericera cockerelli (Sulcer) (egg, second, and third nymphal instars), Spodoptera exigua (Hübner) and Spodoptera frugiperda (J. E. Smith) (egg, first, and second larval instars) was evaluated using tomato (Solanum lycopersicum L.) leaflets or plants. These insects are the primary pest of several agriculturally important crops. The influence of E. varians age on the predation capacity was also analysed. Engytatus varians females consumed significantly more B. cockerelli eggs and nymphs than males. Additionally, female predators consumed significantly more second than third instar prey at two predator ages, while males consumed significantly more the second instar than third instar prey at all predator ages. In most of the cases, females also consumed significantly more S. exigua and S. frugiperda eggs than males; however, in terms of larvae consumption, this difference was observed only in some predator ages. Females consumed more the first than second instar S. exigua than males, whereas this behaviour was only observed in males when the predators were 15 and 17 days old. No significant differences were observed in the consumption of first and second instar of S. frugiperda for both sexes of the predators. Predator age did not cause any systematic effects on the predation rates of any prey species. Based on these results, we confirmed that E. varians has potential as a biological control agent for B. cockerelli and also for the Spodoptera species bioassayed.

Corn and soybean farmers across Indiana were surveyed in 2003 to determine the perceived importance of weeds at the state and district levels. Weeds were considered the primary crop pest by 69 to 84% of farmers, depending on district. Diseases or insects were ranked first by no more than 14% of farmers and nematodes were ranked first by no more than 11%. Giant ragweed, Canada thistle, common lambsquarters, common cocklebur, and velvetleaf were considered the most problematic summer annual and perennial weeds statewide. Chickweed, horseweed, dandelion, and henbit were considered the most problematic winter annual weeds statewide. However, no weed species was listed by more than 41% of farmers statewide suggesting that relatively unique weed management problems may exist on many farms. Also, the perceived importance of most weed species varied substantially among Indiana's nine districts. For example, velvetleaf was not listed as a problematic weed by any farmers in three districts. Burcucumber was not considered a statewide problem but was listed among the top three weeds by 14 and 16% of farmers in two southern districts. This survey supports the idea that educational programs focused on weed management should be tailored to geographic regions within Indiana.

Corn and soybean growers across Indiana were surveyed in 2003 to determine their perceptions of the importance of weed problems in various crop rotations. Growers were asked to list the three most problematic weeds in the following rotation systems: soybean and corn planted in alternate years (SC) and corn (CC) or soybean (SS) planted to the same field for 2 or more years. Although some summer annuals and perennials (common lambsquarters, Canada thistle, and common cocklebur) and winter annuals (chickweed and henbit) were considered problematic by at least 10% of growers in all three systems, there were differences among systems in the relative importance of weed species. Giant ragweed was considered problematic by at least 30% of SC and CC growers but by less than 10% of SS growers. Horseweed was listed as a problematic summer annual by 13% of SS growers but by only 3% of CC growers. Purple deadnettle was listed by 15% of CC growers but by less than 6% of SC and SS growers. Perennial dicots were more problematic in SS than in CC. Annual and perennial grasses were more problematic in CC than in SC or SS. Despite these differences, the results of this survey suggest that the cumulative effect of weed management practices in corn and soybean rotation systems in Indiana has been the promotion of larger seeded, broadleaf, summer annual species.

Effective, statistically robust sampling and surveillance strategies form an integral component of large agricultural industries such as the grains industry. Intensive in-storage sampling is essential for pest detection, integrated pest management (IPM), to determine grain quality and to satisfy importing nation's biosecurity concerns, while surveillance over broad geographic regions ensures that biosecurity risks can be excluded, monitored, eradicated or contained within an area. In the grains industry, a number of qualitative and quantitative methodologies for surveillance and in-storage sampling have been considered. Primarily, research has focussed on developing statistical methodologies for in-storage sampling strategies concentrating on detection of pest insects within a grain bulk; however, the need for effective and statistically defensible surveillance strategies has also been recognised. Interestingly, although surveillance and in-storage sampling have typically been considered independently, many techniques and concepts are common between the two fields of research. This review aims to consider the development of statistically based in-storage sampling and surveillance strategies and to identify methods that may be useful for both surveillance and in-storage sampling. We discuss the utility of new quantitative and qualitative approaches, such as Bayesian statistics, fault trees and more traditional probabilistic methods and show how these methods may be used in both surveillance and in-storage sampling systems.

Cowpea (Vigna unguiculata (L.) Walp) is an important food staple in sub-Saharan Africa. The legume pod borer Maruca vitrata Fabricius is one of the key pests of cowpea as the larvae feed on the tender parts of the stem, peduncles, flower buds, flowers and on pods of the plant, causing significant yield losses. Understanding the seasonal and geographical patterns of M. vitrata is essential for the establishment of effective pest management strategies. Sites in three ecological zones in Burkina Faso were sampled for the presence of M. vitrata adults and larvae both during and outside of the cowpea-growing season. Our data suggest that M. vitrata do not maintain a permanent population in the Sahelian or Sudano-Sahelian zones, but emigrate from the Sudanian zone where M. vitrata populations evidently may occur throughout the year.

The insect fauna of rain-fed rice, Oryza sativa, was assessed using the sweep net and direct count methods. The objective of the study was to provide basic information on the insect pest complex of rice in the area and their natural enemies. One hundred and five insect species belonging to nine orders and 57 families were found. The insect orders in order of abundance were Diptera (45.67%), Coleoptera (12.77%), Lepidoptera (12.23%), Orthoptera (8.44%), Heteroptera (8.23%), Homoptera (7.03%), Hymenoptera (3.25%), Dermaptera (1.95%) and Dictyoptera (0.43%). Diopsis thoracica Westwood (Diopsidae) (69.43%) was the most abundant dipteran followed by the sarcophagids (14.93%) and calliphorids (7.11%). Members of the family Chrysomelidae represented 50% of the coleopterans followed by the coccinellids (17.46%). While 31% of the lepidopterans were noctuids, 60% were pyralids. The pentatomids (50.57%) were the most abundant heteropterans while the acridids (43%) were the most prevalent orthopterans. The homopterans were mainly Cofanaunimaculata Signoret (which represented 79%). The insects were clustered into three groups with D. thoracica alone in group 1, C. unimaculata and Sarcophaga species in group 2 and the rest in group 3. We therefore conclude that D. thoracica is the most important pest of rice in Ekpoma while C. unimaculata may also be very important, but Sarcophaga species appears to be the most important natural enemy in the system.

Historique. L’anacardier (Anacardium occidentale), originaire du nord-est du Brésil, a été introduit au Mozambique à la fin du xvie siècle. Ce pays a longtemps été le premier producteur mondial avec 216 000 t de noix commercialisées en 1971–1972. Par la suite, certaines mesures politiques et la concurrence d’autres pays producteurs lui ont fait perdre sa place. Face à cette situation, des actions d’appui à la filière anacarde ont été entreprises à partir des années quatre-vingt. Relance de l’anacarde au Mozambique. Au Mozambique, l’anacardier se rencontre tout le long de la côte, mais il est surtout localisé dans les provinces du Nord. Le contexte de la libéralisation et de la privatisation de la filière engagées ces dernières années est décrit, ainsi que les conséquences engendrées par ces actions. Les différents projets d’appui à la filière ont surtout concerné la production et la diffusion de plants. Le plus récent, le « Projet de relance du cajou » (PRC) a été élaboré en 1999. Il a visé l’amélioration de la productivité de l'anacarde et la production de noix de qualité au travers de systèmes d'exploitation aptes à conserver la fertilité des sols. Dans ce contexte, les recherches d’accompagnement se sont focalisées sur la lutte contre les maladies et parasites de l’anacarde et la sélection de matériel végétal performant. Lutte contre les maladies de l’anacardier. Les résultats obtenus pour le contrôle de l’oïdium avec des fongicides organiques et la possibilité d’une alternance de produits (soufre / triazole) sont présentés. De même, l’utilisation de fongicides organiques pour le contrôle de l’anthracnose est abordée. Contrôle des ravageurs. Ce point nécessite la formation en cours d’un entomologiste et la mise en place d’un système d’avertissement qui devrait permettre à terme de disposer d’un outil multirégional d’alerte et d’aide à la décision. Sélection et amélioration. L’obtention de nouvelles variétés a été abordée par un essai de comportement clonal, la sélection de types communs locaux et la création d’hybrides. Conclusions. Les premiers résultats du PRC sont encourageants et sa réalisation a permis la constitution d’une unité de recherche régionale qui est venue conforter et redynamiser la recherche anacarde à l’échelle nationale.

Southern Sudan has tremendous agricultural potential, particularly in the high rainfall green belt of western Equatoria that borders the Democratic Republic of the Congo. A wide range of tropical and semi-tropical crops is grown there in a variety of complex cropping systems. Although a long civil war severely disrupted agriculture in the region, there is now hope that the recent peace accord will return stability and agriculture will remain a mainstay of a revived economy in western Equatoria. The environment supports crop production, but pests and diseases also thrive, although very little has been recorded about them. This article represents the sole record of an agricultural insect pest collection and disease notes assembled at Yei over several years in the early 1980s, but which were destroyed during the civil war. It is hoped that these notes will be useful in addressing biotic constraints to rehabilitation of agriculture in western Equatoria. Traditional methods of pest and disease management will be particularly important given the poor state of the economy, the need to produce crops for subsistence farming and the relative geographical isolation and poor communications that characterize southern Sudan. Le sud du Soudan offre d'énormes potentialités de développement agricole, en particulier dans la ceinture verte humide de la région Ouest de l'Equateur qui borde la République Démocratique du Congo. Une large gamme de cultures tropicales et subtropicales y est cultivée selon une grande variété de systèmes culturaux complexes. Bien qu'une longue guerre civile ait sévèrement perturbé l'agriculture de la région, il y a maintenant un espoir que les accords de paix récemment signés rétablissent la stabilité et que l'agriculture puisse constituer la base d'un renouveau économique dans l'Ouest de l'Equateur. L'environnement est favorable á la production agricole, mais également au développement des ravageurs et des maladies, bien que nous ayons très peu d'informations. Cet article constitue une source unique d'informations sur les insectes ravageurs et les maladies des cultures répertoriées pendant plusieurs années au début des années 80 dans la région de Yei, mais dont les notes ont été détruites pendant la guerre civile. On espère que ces notes seront utiles pour identifier les contraintes biotiques et permettre la réhabilitation de l'agriculture dans l'Ouest de l'Equateur. Les méthodes traditionnelles de gestion des ravageurs et des maladies seront particulièrement importantes compte tenu du mauvais état de l'économie, du besoin de produire des cultures de subsistance, du relatif isolement géographique et des mauvaises communications qui caractérisent le sud du Soudan.

Introduction. L’espèce Ricinodendron heudelotii, plante aux amandes oléagineuses en voie de domestication au Cameroun, est attaquée par un cortège d’insectes phytophages. Parmi ceux-ci, Diclidophlebia xuani Messi et al. (Hemiptera, Psyllidae) constitue son principal ravageur. Un inventaire de la faune d’arthropodes associée à cette plante a été effectué afin d’identifier les ennemis naturels de ce psylle. Matériel et méthodes. Des échantillons ont été collectés de 2001 à 2002 dans les environs de Yaoundé. Les organes végétatifs attaqués de R. heudelotii ont été récoltés chaque semaine et observés sous stéréomicroscope pour récupérer les arthropodes. Résultats et dicussion. Outre D. xuani, de nombreux autres phytophages ont été identifiés, les plus importants étant des lépidoptères. Des prédateurs et parasitoïdes du psylle et des autres arthropodes phytophages ont également été identifiés. Parmi les prédateurs du psylle, les plus importants sont les Anthocoridae, Coccinellidae, Miridae et Syrphidae ; les araignées jouent également un rôle indéniable dans la régulation des populations de D. xuani ; celles-ci n’ont toutefois pas pu être identifiées. Très peu de parasitoïdes ont été trouvés, essentiellement des Encyrtidae. Conclusion. Malgré la diversité de la faune auxiliaire recensée sur R. heudelotii au Cameroun, son impact sur les populations du psylle est apparu limité.

Introduction. Pentaclethra macrophylla, Mimosaceae, is the only species of the genus present in West Africa. The plant's diseases are not well known. The numerous uses of the plant's seeds and pods aroused our interest in investigating its pests and mycoflora, which would constitute a drawback to the plant's production, value and use. Materials and method. Mature pods of P. macrophylla were collected from different locations in Nigeria and tree-top observations were also made for studying the pests present. Isolation, characterization and identification of the mycoflora were done by plating washings from pods, skin and seeds on different media and incubating for 2 to 3 days at 28 °C. Control plating was done with sterile peptone water. Streptomycin was incorporated in the test and control media to avoid bacteria. Some pods and seeds were also stored before being treated as above. A pathogenicity test was also carried out. Results and discussion. Many insect species and pathogens were found to attack the pods and seeds of the plant. The major insect pests identified were Cossus cadaribae, Sitophilus spp., Spodoptera exempta and silkworms. The major fungal pathogens included Aspergillus niger, Rhizopus stolonifer, Cladosporium herbarum, Penicillium sp., Botryodiplodia theobromae and Fusarium sp. Some of the insect pests skeletonize the green pods, depriving them of photosynthetic surfaces; some bore into the pods, eating up and damaging the seeds' fleshy cotyledons; others lacerate the pods, causing lesions of varying sizes and shapes, thereby creating portals for the penetration of fungal and bacterial pathogens which invade and rot the predisposed seeds. Conclusion. Our study established many pests and mycoflora which attack P. macrophylla pods and seeds. They might have been the cause of the observed symptoms and damage, and the cause of the reduction in the crops planted, reported by previous authors.

In the Eduardo Mondlane irrigation scheme in Chokwe, southern Mozambique, land had been allocated in 1983 to approximately 12000 farmers for growing rice (85%) and maize (15%). From the onset, maize production in the warm season was severely constrained by a number of pathogens and pests. During 1984–1988 a study on downy mildew, maize streak virus, stemborers and rodents, was carried out. This resulted in the formulation of a package of recommendations along lines of integrated pest and disease management, which was subsequently disseminated to farmers by the extension service. In order to evaluate the effectiveness of technology transfer, farmers were interviewed just before the new recommendations were disseminated (1988) and again two years after the start of the training and extension programme. Severe constraints in technology transfer to farmers were encountered due to the poor functioning of the extension service. It is concluded that improvements in communication and feedback mechanisms between farmers, extensionists and researchers and substitution of the prevailing ‘top-down’ training and extension methods by a ‘bottom-up’ approach are needed. In addition, rehabilitation and proper maintenance of the irrigation system and better land allocation to smallholders is required before research recommendations can be expected to work.

Survey questionnaires were administered to 50 farmers in three chiefdoms in the Moyamba District of southern Sierra Leone. The study was undertaken to gain insight into the indigenous farming practices for cowpea with emphasis on pest management. This is to serve as a guide in drawing up a research agenda and identifying appropriate measures for the control of cowpea pests. Farm sizes were generally small, usually less than 2 ha of intercropped cowpea. This suggests that the farmers were mostly subsistent and would require low cost inputs to boost production. Vertebrate and insect pests were identified by the farmers as limiting cowpea grain production. Insect pests were considered more serious than vertebrates. Pest control was mostly traditional and involved cultural measures such as weeding of plots, fencing, trapping and scaring of birds. These may be inefficient and labour intensive. Varieties planted by the farmers were mostly land races that have low yield potential and lack some other desirable agronomic character like semi-erectness and bold seeds. Selection criteria in breeding programmes should incorporate farmers' preferences which include high yields, sweet taste, resistance to pests and diseases, compatibility with the farming systems and acceptable seed appearance that would enhance marketing. The study further revealed that at present cowpea is grown mostly as a secondary crop. Therefore, introduced pest control efforts would have to be cheap, easy to adopt and integrative. These would include:

(a) education on control options hitherto unknown to the farmers;

(b) identifying and developing effective strategies that are low cost, labour insensitive, environmentally friendly and compatible with the socioculturel background of the farming community; and

(c) creating awareness on the necessity for the inputs to be readily available and affordable at the local government level.

Food production in Africa is declining, while her population is increasing rapidly. Some factors responsible for low food productivity are mentioned; special attention is given to the problem of agricultural pests. The hazards of overuse of pesticides in developed countries are cited to caution farmers in developing countries from getting drawn into a similar situation when attempting to solve pest problems. Integrated pest management (IPM), which aims to increase food productivity and profitability without endangering the environment, is recommended as a sustainable solution to the pesticide problem. The role of biological control agents, i.e., introduction, augmentation and preservation of natural enemies is emphasized. In developing sustainable agriculture through IPM, the importance of incorporating farmers' traditional methods of farming into an IPM package and of identifying farmers' overriding concerns, is recommended as a prerequisite to the acceptability and success of such packages.

An experiment to examine the effects of different plant spacings on cowpea insect numbers and yields was undertaken at two sites in Nigeria. Two varieties, viz. Tvx 3236 and IT84E-1-108 were planted under field conditions at three different plant spacings. Plant spacing did not affect the number of Ootheca beetles, pod-borers, flower thrips and pod sucking bugs. Yield differences were not significant for the spacing regimes and there were no interactions between spacings and insect numbers for yields. Thus, plant spacing may not be an important control tactic in the management of the key cowpea insect pests in Nigeria.

The first report on the entomopathogenic fungi in the tropics dates back to 1853. Despite their variety, little attention has been focused on their incidence on agricultural pests. Studies over the last 20 years in the tropics have revealed that entomogenous fungi (Deuteromycetes and Entomophthorales) may play an important role in natural control of arthropod populations. Therefore, the use of insect pathogenic fungi as pest control agents is promising.

An important consideration in developing an entomopathogenic fungus as a mycoinsecticide is the selection of the correct and well-adapted strain. New techniques in biotechnology will help in developing methodology for mass production and formulations. Other factors which can be considered, and which may be determinants on the potential of insect pathogenic fungi include the environmental conditions and cultural techniques (e.g. intercropping, planting density, irrigation). The cultural techniques can result in change of the environment favourable to the disease.

Economics can make an important contribution to the evaluation of pest management projects. It provides a conceptual basis and tools for assessing the economic losses caused by pests and, therefore, the potential benefits of control. Economics is also concerned with the degree of adoption and the extent to which the potential benefits of a project are likely to be realized in practice. Since agricultural pest problems and control options are continuously changing, with changes in cropping practices, policies and economics, and technological developments, research evaluation must also take these aspects into account. Examples concerning rice pest control in Malaysia and cattle pest management in Brazil are used to illustrate these points.

Recent developments in the assessment and collection of yield loss data due to pests are discussed. The information is needed for decision-making on resource allocation, on pest management, crop production planning and crop improvement. The difficulties in accurate loss assessment include lack of information on the distribution of pests in space and time, the difference between research and farmers yields, how much control has been used, and changes in crop resistance and in pest status. Sources of data are described and examples of losses in a number of tropical crops. The difficulties met in using losses to justify research and crop improvement projects, with particular reference to banana pests in Tanzania and cassava pests in Ghana, include the absence of reliable data, the selection of a base-line yield and the effects of other causes of loss.

This paper considers the status of pests and pesticides in Mauritius, including pesticide legislation and flow.

Climatic factors, namely altitude, temperature and rainfall, influence the spatial and seasonal distribution and population dynamics of economically important pests as well as their hosts (crops and livestock). The case histories of a few selected pests (leaf miner, fruit flies, stable flies), their control measures as well as research efforts in this connection are reviewed.

An appraisal is also made on some aspects of pesticide legislation along with the distribution pattern of pesticides, in relation to pesticide management. The setting up of a recent Pesticides Management Advisory Committee is regarded as a move in the right direction to safeguard pesticide misuse and abuse. Food crop production is at the expense of huge pesticides input. A series of recommendations are made with a view to improving pesticide practices in the country.