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The study was undertaken to contribute to the sustainable management of Spodoptera frugiperda Smith on maize. It aims to evaluate the insecticidal efficacy of Jatropha curcas L. oil on S. frugiperda larvae. Two concentrations of J. curcas oil (10 and 20ml.l-1) were tested by ingestion on the six larval stages of S. frugiperda grouped into (L1-2 (3-5 days of age); L3-4 (6-8 days of age); L5-6 (>10 days of age)). The insecticidal efficacy of the oil was determined in the laboratory and the phytosanitary protection tests on maize were carried out in the field. In the laboratory, the concentration of 10 ml.l-1 with/without emulsifier caused a mortality rate of (87-92%) at stage L1-2, (51-58%) at stage L3-4, and (57- 68%) at L5-6 stage after 72 hours of ingestion. Concentration of 20 ml.l-1 caused over 70% mortality whether applied with or without an emulsifier at all stages. Adult emergence was nil for L1-2 stages at 20 ml.l-1 and

The infestation of the fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) in Africa since 2016 has been a major threat to maize production. Previous studies in Togo and Ghana from 2016 to 2018 did not correlate FAW infestation to yield losses. Thus, the aim of this study which assesses the impact of FAW infestation by inspecting 150 maize farms throughout the five Agro-Ecological Zones (AEZs) of Togo for FAW plant damage, and third instar larvae were used to infest 10-day-old maize plants in netted plots under controlled conditions at an experiment station (Station d'Expérimentations Agronomiques de Lomé) in 2019 and 2020. As control plots at the experiment station, plots were both netted and treated with emamectin benzoate, simply netted, or open to natural infestation. The number of larvae, egg masses, percent damaged plants, and damage proportions of leaves and ears were scored until harvest. Infestations and damages on maize plant throughout Togo were similar between the two years but were higher in the southern part of the county (AEZ5). At the experiment station, the yield losses were significantly considerable and increased from 25% infestation. The losses were 0.37 t ha−1 for 25% infestation, 0.34 t ha−1 for 30%, 0.59 t ha−1 for the open plots, 0.70 t ha−1 for simple netted and 50% infestation, 1.03 t ha−1 for 75%, and 1.27 t ha−1 for 100% infestation. This current study suggested thorough inspection on maize farms to set off management practices from 25% of infestation.

Although there has been intensive use of insecticides for fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae) management, their effects on population reduction and performance of natural enemies have not been adequately investigated. Therefore, this study assessed the diversity and performance of natural biocontrol agents under insecticide and insecticide-free applications. Bio-agents were annually collected from 2016 to 2022 in 348 maize farms throughout the West African nation of Togo. The collections included the entomopathogenic nematode Ovomermis sinensis (Nematoda: Mermithidae), unidentified bacteria from Enterobacteriaceae and Enterococcus, unidentified viruses from Ascoviruses and Baculoviruses, and fungi Isaria spp. (Hypocreales: Clavicipitaceae) and Metarhizium rileyi (Hypocreales: Cordycipitaceae). Eggs were parasitized by Telenomus remus (Hymenoptera: Platygastridae), and the egg-larval parasitoid Chelonus bifoveolatus (Hymenoptera: Braconidae). Larval parasitoids included Anatrichus erinaceus (Diptera: Chloropidae), Archytas spp. and Lespesiaspp. (Diptera: Tachinidae), Bracon sp., Coccygidium luteum, Cotesia icipe and Meteoridea testacea (Hymenoptera: Braconidae), and Campoletis grioti and Ophion spp. (Hymenoptera: Ichneumonidae). The collected predators included Orius insidiosus (Heteropterans: Anthocoridae), Haematochares obscuripennis, Peprius nodulipes, Rhynocoris sp. and Zelus renardii (Heteroptera: Reduviidae), Calleida sp. (Coleoptera: Carabidae), Cheilomenes sulphurea, Coccinella septempunctata and Cycloneda sanguinea (Coleoptera: Coccinellidae), Euborellia annulipes, Forficula auricularia and F. senegalensis (Dermaptera: Forficulidae), Pheidole megacephala and Polyrhachis lamellidens (Hymenoptera: Formicidae), Chrysoperla carnea (Neuroptera: Chrysopidae), and Mantis religiosa(Mantodea: Mantidae). The parasitism rates were from 14.72% in 2018 to 45.38% in 2022 for egg masses, and from 1.32% in 2016 to 41.85% in 2021 for larvae. The parasitism rates were three to four times higher in unsprayed farms than sprayed farms.

Spodoptera frugiperda, est un ravageur exotique du maïs qui menace la sécurité alimentaire en Afrique subsaharienne en général et du Togo en particulier. Dans le but de contribuer à une gestion durable du ravageur, la présente étude vise à évaluer l’effet des associations maïs– soja et maïs-manioc sur la dynamique de la population et les dégâts du ravageur. Les traitements (culture pure de maïs, de soja, de manioc, association maïs-soja, et maïs-manioc) ont été installés suivant un dispositif en blocs aléatoires complets avec quatre répétitions. Les boutures de manioc ont été mises en terre un mois avant le maïs. Le maïs et le soja ont été semés simultanément. Les associations maïs-manioc et maïs-soja ont réduit respectivement l’infestation (56 et 40%), le nombre d’amas d’oeufs (50 et 25%) et de larves (57 et 43%), le taux d’attaque (45 et 34%) et les dégâts (40 et 27%) comparé à la monoculture du maïs. L’association maïs-manioc est plus efficace dans le contrôle du ravageur. En termes d’utilisation du sol, les associations maïs-soja et maïs-manioc (LER> 1) sont plus efficientes que la monoculture mais n’entrainent pas l’amélioration des rendements du maïs. Ces associations peuvent être envisageables pour une gestion durable de S. frugiperda. Spodoptera frugiperda is an exotic maize pest that threatens food security in sub-Saharan Africa in general and Togo in particular. In the present study, the effect of intercropping maize with soybean and cassava on the infestation of the pest were studied. Field experiments were conducted using a device in complete random blocks with four repetitions. Cassava were planted one month before the maize and soybeans were planted simultaneously maize. Maize-cassava and maize-soybean intercropping respectively reduced infestation (56 and 40%), the number of egg (50 and 25%), larvae (57 and 43%) and damage (40 and 27%) of S. frugiperda compared with the monocrop. In terms of land use, maize-soya and maize-cassava associations (LER> 1) are more efficient than monoculture but do not lead to improved maize yields. The maize-cassava association is more effective in controlling the pest. These associations may be possible for the sustainable management of S. frugiperda.

Although the egg is one of the foods offering nutrients of high biological value, the diet of layer chickens can change these characteristics. The aim of this study was to evaluate the effect of a long-term dietary replacement of fish meal with maggot meal of black soldier fly larvae on egg quality of hens. A total of 480 one-day-old Isa brown chicks were randomly assigned to 4 dietary treatment groups. The groups were named T0 (8% fish meal), T1 (4% maggot meal and 4% fish meal), T2 (6% maggot meal and 2% fish meal), and T3 (8% maggot meal). Each treatment group had 6 replicates of 20 chicks each. Data were collected on the eggshell quality parameters between 22 and 56 weeks of age. The results indicated that egg weight, shell weight, shape index, shell index, egg surface area, egg volume, density, yolk pH, albumen pH, yolk and albumen moisture content, yolk color, and yolk height were not influenced by the use of larval meals. Although the proportion of the yolk increased with age, there was no interaction between the use of fly larvae and the duration of its use for the collected parameters. However, the proportion of albumen, Haugh’s unit in T1 and T3 treatments were higher than those of T0 and T2. The proportion of egg yolk, the yolk to albumen ratio, and the count of cracked eggs of T0 and T2 varied significantly compared to T1 and T3. Total egg fat decreased significantly as a result of the use of maggot meal. Total cholesterol, High-density lipoprotein (HDL) cholesterol, Low-density lipoprotein (LDL) cholesterol, and LDL/HDL ratio were lower in groups fed larvae meal, compared to the control group. It was concluded that the use of black soldier fly larvae meal during the entire rearing cycle and period of layers did not adversely affect the eggshell quality and nutritional content of the eggs.

The fall armyworm Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) is an important maize pests that threaten food security in sub-Saharan Africa. In order to evaluate the diversity of natural enemies and especially their effectiveness for a sustainable management of this pest in Africa, a literature review was carried out. It consisted in exploiting 35 scientific publications from the most highly rated journals, over the period 2015-2020 relating to the inventory of the natural enemies of S. frugiperda and their effectiveness in the world in general and more particularly in Africa. It emerges from this study that there is a large diversity of natural enemies of S. frugiperda in the world. In total, 66 species of natural enemies belonging to 21 families in 10 orders have been recorded. Parasitoids have been the most studied 43 (64.18%) and the most used in the control of S. frugiperda, followed by predators 13 (19.40%) and entomopathogens (13.42%). In Africa, 24 of the 67 species have been recorded in 9 countries. Parasitoids were also created with a rate of 26.86% or 75.00% at the African level. The main most effective parasitoids were Telenomus remus (Hymenoptera: Scelionidae), Chelonus insularis Cresson (Hymenoptera: Braconidae) and Cotesia marginiventris Cresson (Hymenoptera: Braconidae) with parasitism rates varying between 0.85 and 9.90% depending on the environments. In view of the results, since these species have been listed in Africa, they seem to be real candidates for future programs for the sustainable management of this caterpillar. Research is underway in Togo and probably in the rest of the countries of the continent for a better knowledge and development of these natural enemies.

The South American tomato pinworm, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) first invaded Africa in 2008. Since then, the pest has been causing considerable losses to tomatoes across the continent, thereby affecting food security and livelihood of millions of growers and consumers. In this paper, the agroecological-based occurrence of the alien invasive species was reported for the first time in Togo. Fifteen sites were surveyed countywide in the five regions of the country from November 2018 to February 2019. Male moths were trapped using pheromone-based delta traps, and the larvae were collected through sampling of infested tomato leaves and fruits. The field-collected and laboratory-emerged specimens were used for the morphological features and molecular analysis and sequence deposit into GenBank under the accession number MN759250. The pest was present in all regions and sites surveyed across different agro-ecological zones, with significant disparities between agroecologies in relation to population densities. The daily as well as the cumulative catches of T. absoluta male moths was higher in the Coastal Savannah zone than in other agro-ecological zones surveyed, with a daily mean value of 10.78 ± 0.99 individuals per trap. This study is the first report confirming the geo-occurrence of T. absoluta in Togo and represents a baseline for further studies.

The fall armyworm, Spodoptera frugiperda (J.E. Smith) is native to the Americas and a major pest of corn and several other crops of economic importance. The species has characteristics that make it of particular concern as an invasive pest, including broad host range, long-distance migration behavior, and a propensity for field-evolved pesticide resistance. The discovery of fall armyworm in western Africa in 2016 was followed by what was apparently a remarkably rapid spread throughout sub-Saharan Africa by 2018, causing economic damage estimated in the tens of billions USD and threatening the food security of the continent. Understanding the history of the fall armyworm invasion of Africa and the genetic composition of the African populations is critical to assessing the risk posed to different crop types, the development of effective mitigation strategies, and to make Africa less vulnerable to future invasions of migratory moth pests. This paper tested and expanded on previous studies by combining data from 22 sub-Saharan nations during the period from 2016-2019. The results support initial descriptions of the fall armyworm invasion, including the near absence of the strain that prefers rice, millet, and pasture grasses, while providing additional evidence that the magnitude and extent of FAW natural migration on the continent is more limited than expected. The results also show that a second entry of fall armyworm likely occurred in western Africa from a source different than that of the original introduction. These findings indicate that western Africa continues to be at high risk of future introductions of FAW, which could complicate mitigation efforts.

The intergovernmental Panel on Climate Change has predicted sub-tropical region to be more vulnerable to the effects of Climate Change(CC). Additionally, to CC, land use and land cover (LULC) changes and dam contruction often neglected, plays and important role on the spatial and temporal distribution of water balance components(WBC) for agriculture production and socio-ecological equilibrium. The aim of this study wa sto analyze and compare the changes in LULC and WBC for the periode before Nangbeto dam construction (1964-1986) and the period after its construction (1988-2010) in the Mono River Basin(MRB). To this end, the study used mainly WBC extracted from the validated Soil and Water Assessment Tool and LULC data of the years 1975 and 2000 in the MRB to explore their temporal distributions and the link in their changes. The results showed that the mean monthly actual evapotranspiration, percolation, water yield, surface runoff, groundwater and lateral flow represent 51.05%, 17.53%, 15.93%, 9.43%, 5.67% and 0.42%, respectively of total water balance between 1964 and 1986. The same components represented 51.02%, 9.17%, 20.43%, 6.30%, 10.56% and 2.59%, respectively between 1988 and 2010. The contribution of these WBC in mean-annual (1964-1986) period were for actual evapotranspiration (31.33%), water yield (25.95%), percolation(17.67%), groundwater(14.71%), surface runoff (9.94%) and lateral flow (0.40%). Meanwhile, between 1988 and 2010, the contribution of actual evapotranspiration, water yield, percolation, groundwater, surface runoff and lateral flow are 49.85%, 19.97%, 11.17%, 10.34%, 6.15% and 2.52%, resepctively. The results showed that the peaks of the evapotranspiration, surface runoff, percolation and water yield appeared in September corresponding to a month after the maximum of rainfall in August. However, our more detailed analysis showed that a significant decrease of forest and savanna and increase of cropland let to a decrease in actual evapotranspiration and lateral flow over the second period of simulation compared to the first period of simulation over the MRB scale. These findings showed that sustainable management and conservation of natural vegetation is crucial for integrated water resource management and conservation in MRB.

A joint project between West African Science Service Center on Climate Change and Adapted Land Use (WASCAL), the University of Lomé and the German Biomass Research Center (Deutsches Biomasseforschungszentrum; DBFZ) was initiated in 2020. The project aims at evaluating alternative and regenerative energy sources for rural areas and creating the basis for successful implementation. In three different work packages, therefore, biomass potentials should be quantified, technologies should be examined with regard to their suitability and - in the case of biogas application - a research structure, pilot biogas laboratory, should be created that is necessary to enable the sustainable implementation of technologies.

The moth pest fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is now present throughout much of the Eastern Hemisphere where it poses a significant economic threat to a number of crops. Native to the Western Hemisphere, fall armyworm is one of the primary pests of corn in the Americas and periodically causes significant economic damage to sorghum, millet, cotton, rice, and forage grasses. This broad host range is in part the result of two populations historically designated as host strains (C-strain and R-strain) that differ in their host plant preferences. Reports of infestations in Africa have to date mostly been limited to the C-strain preferred crops of corn and sorghum, with little evidence of an R-strain presence. However, this could reflect a bias in monitoring intensity, with the R-strain perhaps being more prevalent in other crop systems that have not been as routinely examined for the pest. Because knowledge of whether and to what extent both strains are present is critical to assessments of crops at immediate risk, we analyzed specimens obtained from a systematic survey of pasture grass and rice fields, habitats typically preferred by the R-strain, done contemporaneously with collections from corn fields in Ghana and Togo. Substantial larval infestations were only observed in corn, while pheromone trap capture numbers were high only in corn and rice habitats. Little to no fall armyworm were found in the pasture setting. Comparisons with a meta-analysis of studies from South America identified differences in the pattern of strain-specific markers typically found in fall armyworm collected from rice habitats between the two hemispheres. Genetic tests of specimens from rice and corn area traps failed to show evidence of differential mating between strains. These results are consistent with the R-strain being rare or even absent in Africa and, at least for the Ghana-Togo area, this R-strain lack does not appear to be due to limitations in pest monitoring. The implications of these results to the crops at risk in Africa and the accuracy of existing molecular markers of strain identity are discussed.

The economic impact of the invasion of Spodoptera frugiperda (J.E. Smith, Lepidoptera: Noctuidae) into Africa has so far been limited to maize agriculture but could potentially impact many other crops. Trapping based on pheromone lures provides a cost-effective method for detecting this important pest (commonly known as fall armyworm) and will be essential for large-scale monitoring of populations to determine its geographical distribution and migration behavior as the species equilibrates to its new environment. However, the effective use of pheromone trapping requires optimization for a given location. An earlier report demonstrated that two commercial lures (one 3-component and the other 4-component) that were effective for trapping S. frugiperda in maize fields in Togo, Africa. The current study extends these findings to agricultural areas that differ in plant host composition (maize, pasture grasses, rice, and sorghum) in multiple locations in Ghana and Togo. In two seasons, significantly higher numbers of moths were found in maize, and in one season, higher numbers were found in rice than in sorghum and pasture grass systems. The results confirm the effectiveness of pheromone trapping and identify pheromone lures and trapping methods best suited for the different agroecosystems common to West Africa and that are at risk of infestation by S. frugiperda.

The fall armyworm Spodoptera frugiperda (J. E. Smith) invaded several West African countries in 2016 causing severe injury to maize plants and economic damage. This study assesses variations in the occurrence of this species in different Agro-Ecological Zones (AEZs) in Togo and Ghana during the 3 yr following its discovery. The surveys were conducted on 120 farms in Togo and 94 farms in Ghana by collecting larvae from 200 maize plants per hectare. Infestation levels were 68.46% in 2016, 55.82% in 2017, and 17.76% in 2018. The number of larvae recorded per hectare and infestation levels were higher in Togo than in Ghana. The lowest number of collected larvae and infestation levels of S. frugiperda were in 2018, compared to the other 2 yr. Larvae per hectare and the infestation level varied regionally inside the two countries. The southern part of Togo (AEZ five) contained higher numbers of larvae and higher infestation levels during the 2 yr following the invasion of the pest. We concluded that infestation levels of S. frugiperda are much lower in 2018 than the two previous years and it is therefore necessary to determine the factors that affect the population dynamics of S. frugiperda in the field, which is a perquisite for developing management interventions.

Fall armyworm (Spodoptera frugiperda J.E. Smith) is a noctuid moth pest endemic throughout the Western Hemisphere that has recently become widespread in sub-Saharan Africa. There is a strong expectation of significant damage to African maize crop yield and a high likelihood of further dispersal, putting the rest of the Eastern Hemisphere at risk. Specimens from multiple locations in six countries spanning the northern portion of the infested region were analyzed for genetic markers. The similarity of haplotypes between the African collections was consistent with a common origin, but significant differences in the relative frequency of the haplotypes indicated limitations in migration. The mitochondrial marker frequently used to identify two host strains appears to be compromised, making uncertain previous reports that both strains are present in Africa. This more extensive study confirmed initial indications based on Togo populations that Florida and the Greater Antilles are the likely source of at least a subset of the African infestation and further suggest an entry point in western Africa. The origin of a second subgroup is less clear as it was rarely found in the collections and has a haplotype that has not yet been observed in the Western Hemisphere.

The fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is an invasive insect pest attacking maize in Ghana and sub-Saharan Africa countries. Biological control will need to be an important management strategy, and a first step was to identify potential natural enemies. Sampling was conducted in different localities of the 10 regions of Ghana from May to Nov 2017. A total of 1,062 larvae were collected from 106 maize farms, and the presence of natural enemies was recorded in 18 (17.0%) farms. Among natural enemies recorded, 7 species were parasitoids: Chelonus bifoveolatus Szpligeti, Coccygidium luteum (Brull), Cotesia icipe Fernandez, Meteoridea testacea (Granger), and Bracon sp. (all Hymenoptera: Braconidae), Anatrichus erinaceus Loew (Diptera: Chloropidae), and an undetermined tachinid fly (Diptera: Tachinidae). The parasitism rate was 3.58%. Three predator species were collected: Pheidole megacephala (F.) (Hymenoptera: Formicidae), Haematochares obscuripennis Stal, and Peprius nodulipes (Signoret) (both Heteroptera: Reduviidae). The 2 most abundant parasitoids were C. bifoveolatus and C. luteum with a relative abundance of 29.0% and 23.7%, respectively, and a parasitism rate of 1.04% and 0.85%, respectively. However, C. bifoveolatus was the most dispersed parasitoid, found in 6.6% of the inspected sites within all the agroecological zones of Ghana. This species is a good candidate as a biological control agent for fall armyworm in Africa. The predator that was most abundant (46.0%) and dispersed (3.8% of the farms) was P. megacephala.

Parmi les ravageurs du gombo, Abelmoschus Spp L., les altises, Podagrica Spp (Coleoptera: Chrysomelidae), causent d’importants dommages a la culture. Les fortes infestations de l’insecte reduisent les activites photosynthetiques de la plante, entrainant des pertes elevees de rendement. La presente etude vise a comparer l’effet de deux bioinsecticides, Suneem 1% EC, 10 g/l d’azadirachine (20%), Beauveria bassiana (1 x1011 spores/ha) et le cypermethrine 50 EC (1 l / ha), un insecticide de synthese, pour le controle de Podagrica Spp, en conditions de champ. Deux applications des differentes formulations ont ete faites a intervalle de 6 jours sur la partie aerienne des plantes. Les resultats ont montre que la cypermethrine a cause la plus forte reduction de la densite de population des altises (89,56 ± 0,76), suivi de Suneem (81,24 ± 2,40) et du B. bassiana (64,90 ± 3,07). De meme le pourcentage des feuilles attaquees et le pourcentage de surface foliaire endommagee par l’insecte ont ete significativement affectes par les traitements. Il ressort de cette etude que B. Bassiana et le Suneem, peuvent etre utilises pour lutter efficacement contre les populations d’altises de gombo, Podagrica Spp en condition de champ. Mots cles : Bioinsecticide, champignon entomopathogene, altise du gombo, reduction de la densite.

The population located along Mono River in the Yoto district faces great challenges in terms of repeated flood disasters in recent years. This paper aims at assessing the conditions which influence flood damage in the study area by using indicators to compute a Flood Vulnerability Index (FVI). The study relies on Turner et al.’s vulnerability framework and distinguishes three main components (exposure, susceptibility and resilience) that allow a more in-depth analysis and interpretation of local indicators. As a result flood disaster in the study area is not only due to the extreme variability in terms of flood magnitude and frequency in the Mono River, but also to the interaction between human and the environment. The lack of vegetation along the river bank, the closeness of households’ farmlands to the river body, the type of construction and the position of settlements, the household size, the low level education of household head, the lack of diversification of livelihood strategies, the lack of adequate flood warning system, the lack of willingness and ability to take responsive actions coupled with inadequate emergency services, are identified as main determinants increasing communities’ vulnerability to flood disaster. Furthermore, the computation of Flood Vulnerability Index (FVI) offers easy comparison of communities’ vulnerability to flood disaster and pinpoints the most vulnerable communities. At the end of the study, flood exposure, susceptibility, resilience and vulnerability maps were generated.

The fall armyworm (Spodoptera frugiperda, J.E. Smith) is a noctuid moth that is a major and ubiquitous agricultural pest in the Western Hemisphere. Infestations have recently been identified in several locations in Africa, indicating its establishment in the Eastern Hemisphere where it poses an immediate and significant economic threat. Genetic methods were used to characterize noctuid specimens infesting multiple cornfields in the African nation of Togo that were tentatively identified as fall armyworm by morphological criteria. Species identification was confirmed by DNA barcoding and the specimens were found to be primarily of the subgroup that preferentially infests corn and sorghum in the Western Hemisphere. The mitochondrial haplotype configuration was most similar to that found in the Caribbean region and the eastern coast of the United States, identifying these populations as the likely originating source of the Togo infestations. A genetic marker linked with resistance to the Cry1Fa toxin from Bacillus thuringiensis (Bt) expressed in transgenic corn and common in Puerto Rico fall armyworm populations was not found in the Togo collections. These observations demonstrate the usefulness of genetic surveys to characterize fall armyworm populations from Africa.

Objectif : L’objectif de cette etude est d’evaluer l’effet de quatre souches de champignon mycorhizien arbusculaire d’origine locale sur la production du soja et le controle des nematodes parasitaires, Meloidogyne sp. au champ. Methodologie et resultats : L’essai a ete conduit a la Station d’Experimentation Agronomique de Lome au Togo, de Juillet a Octobre 2016 suivant un dispositif de Fisher a quatre repetitions. Glomus mosseae, Glomus hoi, Acaulospora spinoza et BEN 10 ont ete testees en comparaison au temoin. L’inoculation a ete faite lors du semis du soja. Il ressort de cette etude que les plants de soja inocules sont fortement mycorhizes. Sur les quatre souches dans cette etude, Glomus mosseae a induit la meilleure reduction de la densite des nematodes dans les racines, entrainant une amelioration du rendement en graines du soja. Conclusion et applications des resultats : Cette etude a montre que l’inoculation directe des CMA pendant le semis entraine une reduction de la densite des nematodes parasites et ameliore le rendement du soja. Elle peut donc etre un des moyens ecologiquement durable de production du soja au Togo. Mots cles : Inoculation mycorhizienne, nematodes, rendement, soja.

In southern Benin, the use of cover crops to improve and maintain soil fertility is on the increase. The present study investigated the effect of two leguminous cover crops, Canavalia ensiformis (L.) DC and Sesbania rostrata Brem. & Oberm., planted at different dates before maize (Zea mays (L.)), and cowpea (Vigna unguiculata L.) planted as border rows on infestations of maize by the pyralid Mussidia nigrivenella Ragonot and of other cob-boring lepidopteran pests. In both trials, M. nigrivenella densities at harvest tended to be higher in the maize alone than the legume treatments, but the effect depended on the timing of planting of the cover crop in relation to that of maize. There were no discernible trends for other borers such as the noctuid Sesamia calamistis Hampson, the pyralid Eldana saccharina Walker, and the tortricid Thaumatotibia leucotreta Meyrick. Furthermore, M. nigrivenella pest loads were considerably higher on C. ensiformis than maize, indicating that the presence of alternative host plant species in the vicinity of maize fields did not increase M. nigrivenella attack on maize. Though in some of the legume treatments, grain damage and grain losses were higher than in the maize alone plots, per area yields did not vary significantly.

Rice is the second most important cereal in Togo. Among constraints that affect rice production, plant parasitic nematodes are of great importance. The objective of this study was to determine the distribution, abundance and frequency of plant nematodes in different agroecological zones of Togo. A total of 50 composite soil and root samples (25 each) were taken from 25 fields (5 per zone) randomly selected from the five agroecological zones. Nematodes were extracted from 100 ml soil and 1g fresh root samples using the Hermann techniques. Nematodes were then fixed and mounted on slide and identified to genus level using identification keys. The survey documented twelve plant-parasitic nematode genera among which ten, ( Hirschmanniella spp., Meloidogyne spp., Xiphinema spp., Scutellonema spp., Helicotylenchus spp., Heterodera spp., Criconema spp., Pratylenchus spp., Trichodorus spp. and Tylenchid spp .), were recorded from lowland, two ( Helicotylenchus and Scutellonema ) from upland and five ( Dolichodorus spp., Helicotylenchus spp., Tylenchorhynchus spp., Scutellonema spp. and Xiphinema spp .), from flooded ecosystem. Hirschmanniella spp., Meloidogyne spp and Helicotylenchus spp. were the most frequent and abundant plant-parasitic nematode genera recorded from more than 71% of the samples. Helicotylenchus spp., Hirschmanniella spp., Meloidogyne spp. and Scutellonema spp ., were recorded in both soil and root samples while Pratylenchus spp., Heterodera spp. and Tylenchorhynchus spp ., were found to be associated to root and Trichodorus spp., Tylenchid spp., Xiphinema spp., Criconema spp. and Dolichodorus spp. , were recorded from soil samples only. The high diversity of nematode genera recorded in the survey is attributed to the rice ecosystem, which is mostly characterized by lowland ecosystem with intensive cropping. This study established the evidence that nematodes could be important constraints for rice production, suggesting further research focusing on their damage potential and development of effective rice nematode management strategy for sustainable rice production in Togo. Keywords : plant parasitic nematode, abundance, occurrence, rice ecosystem, distribution.

In West Africa, the most damaging lepidopteran pest of maize ears is the pyralid Mussidia nigrivenella . Although it is mostly described as a field pest, it can be found feeding on maize stored for up to 4 months. A survey was conducted in Benin in 2006 to assess M. nigrivenella infestations in different maize storage systems in the Southern (SGS) and Northern Guinea Savanna (NGS). In SGS and NGS the percentage of infested stores decreased from 86.7% to 26.7% and from 51.4% to 14.3%, respectively, during the first 28 weeks of storage. During the same time, mean numbers of M. nigrivenella per cob decreased from 0.36 to 0.04 across both zones. All larval stages, but mostly 3rd–5th instars, were frequently found even after more than 12 weeks, indicating that M. nigrivenella may have reproduced in storage, although reinfestation or delayed development could also explain this observation. The highest M. nigrivenella incidences of 16.8% and 14.4% were found in the “Ava” and crib stores, respectively. Infestations were highest in “Ava” and lowest in maize grain stored in polyethylene bags or in mud silos. In a laboratory experiment, the presence of post-harvest beetles negatively affected the bionomics of M. nigrivenella , indicating strong interspecific competition.

The effects of intercropping maize with cowpea, lima bean, soybean, three leguminous cover crops (Tephrosia vogelii Hook F., Canavalia ensiformis L., Sesbania rostrata Bremek. & Oberm.) and cassava on the infestation of Mussidia nigrivenella Ragonot (Lepidoptera: Pyralidae) and other lepidopteran ear borers were studied. Field experiments were conducted in four locations in Benin using a 4x2 pattern of maize-legumes or maize-cassava planting. Intercropping reduced the number of eggs (by >25%) and larvae (by 17.9–53%) of M. nigrivenella compared with the monocrop. Maize-C. ensiformis and maize-T. vogelii proved to be the most effective combinations for reducing M. nigrivenella populations in the different locations. Grain loss and ear damage, which were significantly correlated with the number of insects in the ear, were significantly affected by the intercrops, with losses abated by 47–84% in the four sites. No parasitized larvae were found in any of the locations.

The objective of our study was to assess thepotential of the egg parasitoid Anagrusatomus L. (Hymenoptera: Mymaridae) for controlof the greenhouse leafhopper Empoascadecipiens Paoli (Homoptera: Cicadellidae). Theegg-adult development time, survivorship andreproduction of A. atomus were evaluatedat four constant temperatures (16, 20, 24 and28°C). Developmental time ranged from33.6 days at 16°C to 13.3 days at 28°C. Based on a linear regression ofdevelopment rate on temperature the lowerthreshold was estimated at 8.39°C. Anagrus atomus required 263.2 degree-days tocomplete its development from egg to adult. Theegg-adult survival rate and the sex ratio weresignificantly lower at 28°C than at theother three temperatures tested. The intrinsicrate of increase (rm) variedsignificantly between all four temperatures.The potential of A. atomus to attackdifferent host ages was additionallyinvestigated. Host eggs were parasitizedthroughout their development but rate ofparasitism was reduced in host eggs older thansix days. The number of eggs parasitized waspositively density dependent but the rate ofparasitism decreased with increasing hostdensity. A maximum rate of parasitism of 62.5%was recorded. The potential impact of the eggparasitoid on the population dynamics of E. decipiens is discussed.

Anagrus atomus L. is an important egg parasitoid of the green leafhopper Empoasca decipiens Paoli. In this study the ability of the parasitoid to locate and parasitize its host was investigated on four host plants, i.e., broad beans (Vicia faba L.), sweet pepper (Capsicum annuum L.), cucumber (Cucumis sativus L.), and French beans (Phaseolus vulgaris L.). For each plant species, the behavior of the parasitoid was observed on E. decipiens infested and noninfested plants. Searching and oviposition behavior were characterized by drumming, probing, and resting. Parasitoids spent significantly less time on non-infested than infested plants, 274.5 and 875.7 s, respectively, and no probing behavior was observed on non-infested plants. Frequency of resting behavior was significantly greater on non-infested than on infested plants. Total foraging time was significantly longer on infested than on non-infested plants, indicating that A. atomus females can efficiently discriminate between leaves with and without infestation. Parasitism of A. atomus was influenced by parasitoid density, with the highest parasitism rate (64.0%) obtained at a density of 10 A. atomus females/0.1356 m2 but the number of parasitized eggs per female and the searching efficiency decreased with increasing parasitoid density.

Aqueous extracts of Tephrosia vogelii and Hyptis suaveolens, and of oils of Azadirachta indica and Jatropha curcas, as well as the pesticide Furadan 5G were evaluated for their insecticidal activity against the maize cob borer Mussidia nigrivenella Ragonot in laboratory and field experiments. In general, treated plants had a strong deterrent effect on ovipositing M. nigrivenella. The oviposition deterrence index was highest with neem oil at both concentrations, J. curcas at 5% and H. suaveolens at 20%. In addition, neem and Jatropha oils adversely affected egg hatch; it decreased with an increase in concentrations of oil emulsions and varied between 3 and 25.5% for neem and 6 and 16% for J. curcas. The lethal concentration 50 values calculated were 1.3 and 0.8%, respectively, for neem and J. curcas. By contrast, larval survival was not affected by the oil treatments. In the field, Furadan, neem and J. curcas oils significantly reduced the number of M. nigrivenella larvae by 16–49.2%, while aqueous extracts of T. vogelii and H. suaveolens were similar to the emulsified water control. The treatments did not significantly influence cob weight, and only neem oil at both concentrations and Furadan significantly reduced cob damage and consequently grain losses. These results showed that oil emulsions of A. indica and J. curcas oils act not only as an oviposition deterrent but also as ovicides. The prospects for possible inclusion of botanicals into integrated M. nigrivenella control in maize cropping systems are discussed.