1 groundnut (Arachis hypogaea L.) in Mali, West Africa 2 3 ABSTRACT 13 Groundnut is a major source of livelihood for the rural poor in Mali. However, the crop is 14 prone to pre-and post-harvest aflatoxin contamination caused by Aspergillus flavus and A. 15 parasiticus. Therefore, to minimize health related hazards from exposure to aflatoxin 16 contaminated food, information on the prevalence and distribution of aflatoxins (AFB1) in 17 the groundnut value chain in Mali is needed for timely interventions. To this end, a study was 18 undertaken in three districts (Kayes, Kita and Kolokani) to assess aflatoxin contamination in 19 the field and storage. Ninety pod samples in each district were collected from fields (30 20 villages/district and 3 samples/village) during 2009 and 2010. Pre-harvest contamination was 21 estimated at harvest, whereas samples for post-harvest contamination were collected from 22 granaries of the same farmers at a monthly interval for 3 months. The villages in each district 23 were categorized into safe, acceptable, moderate risk and high risk areas based on pre-harvest 24 AFB1 levels. Kayes recorded more pod samples (77%) within 20 µg/kg of pre-harvest 25 aflatoxins followed by Kolokani (55.6%) and Kita (45.6%) based on 2009 and 2010 mean 26 values. Toxin concentrations at harvest were comparatively less in Kayes during both years. 27 Further, Kayes had more villages under safe and acceptable limits when compared to 28 Kolokani and Kita. Overall, 46 out of 90 villages in the three districts had acceptable pre-29 harvest toxin limits. Further, 12 villages in Kolokani were in the high risk category. An 30 increase in toxin levels was noticed with period of storage during both years. Comparatively, 31 toxin levels after storage were least in Kayes during 2009. Kayes also recorded less AFB1 32 levels in 2010 after Kita. Our results indicate that Kayes is relatively safe over Kita and 33 Kolokani in pre-harvest aflatoxin contamination. The reasons for district-wide variations in 34 pre-harvest contamination; and the reasons for post-harvest flare up of the problem are 35 discussed. Further, proper storage of pods at farmers' granaries in Mali is suggested to 36 overcome the problem from reaching alarming levels. 37 38

Six Alabama Satsuma mandarin orchards (four conventionally sprayed and two unsprayed) were surveyed during 2005 and 2006 to determine the population dynamics of arthropod pests and their natural enemies. Twenty-eight arthropod pest species were encountered; the major foliage pests were citrus whitefly, Dialeurodes citri (Ashmead); purple scale, Lepidosaphes beckii (Newman); Glover scale, L. gloveri (Packard); and citrus red mite, Panonychus citri (McGregor). Two distinct population peaks were recorded for citrus whitefly at most locations. The most important direct sources of citrus whitefly mortality were parasitism by Encarsia lahorensis (Howard) and infection by the pathogenic fungus, Aschersonia aleyrodis Webber. In general, all stages of both scale insects (purple scale and Glover scale) were present in the orchards year-round, indicative of overlapping generations; however, the highest densities were recorded during the early season. Citrus whitefly, purple scale, and Glover scale were more abundant on leaves collected from the interior of the tree canopy than in the exterior canopy. Citrus red mite densities were highest in the spring, with populations declining at the start of the summer, and were more abundant in the exterior canopy than in the interior canopy. The most important natural enemies of citrus red mite were predatory mites belonging to several families, of which Typhlodromalus peregrinus Muma (Phytoseiidae) was the predominant species. Major differences were recorded in the relative abundance of different arthropod pest species in the orchards: citrus whitefly, purple scale, and Glover scale predominated in the unsprayed orchards, whereas citrus red mite infestations were more severe in the sprayed orchards. The results are discussed in relation to the possible effect of orchard management practices on abundance of the major pests.

Fruit flies of sweet oranges in Nigeria: species diversity, relative abundance and spread in major producing areas.Abstract --Introduction. Fruit fly attack on citrus causes economic yield losses in Nigeria. The high demand for sweet oranges in recent times necessitates the need to develop control strategies that can reduce fruit fly damage and ameliorate yield. This can be achieved by identifying the diversity, abundance and spread of major sweet orange fruit flies. Materials and methods. Surveys were conducted during the citrus fruit maturity periods of 2003 and 2006 in citrus-producing areas of Nigeria. Owners of the sampled orchards were interviewed on their cultural practices that could contribute to fruit fly abundance and spread. The fruit flies were sampled by using two types of trap; namely, the McPhail ® trap with yeast hydrolysate bait and the yellow sticky trap impregnated with ammonium acetate. The traps were hung on the citrus trees at a distance of 1.8 m from the ground. The distance between trees was 25 m and the traps were replicated three times per site. Results and discussion. Fruit flies identified on citrus belonged to the genera Bactrocera, Ceratitis, Dacus and Trirhithrum. While higher fruit fly diversity was observed in Edo, Ogun and Oyo states in the rainforest ecological zone, relatively higher populations of major genera (Bactrocera and Ceratitis) were recorded in Benue and Kaduna states in the Guinea savanna ecological zone. Bactrocera species occurrence increased during the second sampling period. Some farmers' cultural practices were implicated as factors likely to have contributed to fruit fly abundance and spread. Conclusion. Fruit fly species of economic importance to citrus in Nigeria belonged to the genera Ceratitis and Bactrocera species. These genera were observed in the majority of surveyed areas.Nigeria / Citrus / fruit-damaging insects / Tephritidae / Ceratitis / Bactrocera / Dacus umehi / identification / cultivation / traps Les mouches des fruits des agrumes au Nigéria : diversité des espèces, abondance relative et extension dans les principales zones productrices.Résumé --Introduction. L'attaque des agrumes par les mouches des fruits au Nigéria cause des pertes de rendement à répercussions économiques. La forte demande d'oranges douces enregistrée ces derniers temps impose de développer des stratégies de contrôle aptes à réduire les dommages imputables aux mouches des fruits et à améliorer le rendement. Cela peut être réalisé en identifiant la diversité, l'abondance et la diffusion des principales mouches des fruits des oranges douces.

No abstract

Development of citrus fruit fly control strategies for small-holders in Nigeria.Abstract --Introduction. Damage of citrus fruits by the Mediterranean fruit fly Ceratitis capitata Weid. results in economic losses in Nigeria. The majority of the citrus producers are smallholders who are yet to adopt standard citrus production practices. A trial was therefore established in a savannah zone of Nigeria with a Southern Guinea agroecology to evaluate simple fruit fly control practices. Materials and methods. The efficacy of combining cultural practices such as removal of dropped fruits, changes of harvest period, and three applications of dimethoate/cypermethrine mixture in controlling fruit fly damage was tested on sweet orange Citrus sinensis (L.) Osbeck var. Valencia Late in 2000 and 2001. Results. Fruits attacked by C. capitata increased with fruit maturity and were positively correlated with the number of dropped fruits. Insecticide applications and removal of dropped fruits significantly reduced the number of fruits attacked by the fruit flies. Similarly, early harvesting at 50% fruit ripening significantly (P < 0.05) reduced the number of fruits attacked by the fruit flies when compared with the late harvesting at 90% ripening. The interactive effects of insecticide applications and the period of harvest significantly (P < 0.05) reduced attacks on fruits. Discussions. Judicious use of insecticides, periods of harvest and removal of fallen fruits reduce fruit fly damage. Late harvest and non-removal of fallen fruits constitute fruit fly reservoirs for the re-infestation of other clean fruits. Since the tested control methods were simple, they can be adopted by small-holders for the control of fruit flies.Nigeria / Citrus / insect control / integrated control / Ceratitis capitata / insecticides / cultivation Développement des méthodes de lutte contre la mouche des agrumes pour les petits cultivateurs au Nigéria.Résumé --Introduction. Les dégâts causés aux agrumes par la mouche des fruits Ceratitis capitata Weid. causent de fortes pertes économiques au Nigeria. La plupart des producteurs d'agrumes sont de petits producteurs qui n'utilisent pas encore de techniques de production appropriées. Pour cette raison, des essais ont été établis pour évaluer des méthodes de lutte simples contre la mouche des fruits dans la savane d'une zone du Nigeria ayant une écologie sudguinéenne. Matériel et méthodes. L'efficacité de la combinaison de pratiques culturales, telles que le ramassage des fruits tombés, la modification de la période de récolte et l'application d'un mélange de diméthoate/cyperméthrine, contre les dégâts de mouches des fruits sur oranges Citrus sinensis (L.) Osbeck var. Valencia Late a été évaluée en 2000 et 2001. Résultats. Le nombre de fruits attaqués par C. capitata a augmenté avec la maturation des fruits et il a été positivement corrélé aux nombres de fruits tombés. Les traitements insecticides et l'élimination des fruits tombés ont significativement réduit le nombre de fruits attaqués par les mouches. De ...

Among the major arthropods in soil and plant samples taken from groundnut farms during the 1996 cropping season in Mali, Burkina-Faso, Niger, and Nigeria, termites in the genus Microtermes (Isoptera: Termitidae) were the most abundant and widely distributed species of economic importance. None of the termite species identified on trees in the surveyed farms attacked groundnuts. At plant maturity, termites were less frequently observed in soils taken from bare ground but were predominantly found on plants. Residues of previous cereal crops in the fields contributed to termite spread. Most of the whitegrub (Coleoptera: Scarabaeidae) and millipede (Myriapoda: Odontopygidae) species identified belonged to the genera of Schyzonycha and Peridontopyge respectively. There was a general decrease in both their population densities and the percentages of farms they infested at plant maturity compared to the early stages of the crop. Mean percentages of plants attacked by termites, whitegrubs and millipedes in the surveyed groundnut fields were 39.4, 10.9, and 9.3% respectively. Yield loss due to termites, which predominantly damaged harvested kernels, was estimated at 9.6-30.4%, and was significantly correlated with percentage of plants damaged by termites (r 2 = 0.73).

Six Alabama Satsuma mandarin orchards (four conventionally sprayed and two unsprayed) were surveyed during 2005 and 2006 to determine the population dynamics of arthropod pests and their natural enemies. Twenty-eight arthropod pest species were encountered; the major foliage pests were citrus whitefly, Dialeurodes citri (Ashmead); purple scale, Lepidosaphes beckii (Newman); Glover scale, L. gloveri (Packard); and citrus red mite, Panonychus citri (McGregor). Two distinct population peaks were recorded for citrus whitefly at most locations. The most important direct sources of citrus whitefly mortality were parasitism by Encarsia lahorensis (Howard) and infection by the pathogenic fungus, Aschersonia aleyrodis Webber. In general, all stages of both scale insects (purple scale and Glover scale) were present in the orchards year-round, indicative of overlapping generations; however, the highest densities were recorded during the early season. Citrus whitefly, purple scale, and Glover scale were more abundant on leaves collected from the interior of the tree canopy than in the exterior canopy. Citrus red mite densities were highest in the spring, with populations declining at the start of the summer, and were more abundant in the exterior canopy than in the interior canopy. The most important natural enemies of citrus red mite were predatory mites belonging to several families, of which Typhlodromalus peregrinus Muma (Phytoseiidae) was the predominant species. Major differences were recorded in the relative abundance of different arthropod pest species in the orchards: citrus whitefly, purple scale, and Glover scale predominated in the unsprayed orchards, whereas citrus red mite infestations were more severe in the sprayed orchards. The results are discussed in relation to the possible effect of orchard management practices on abundance of the major pests.

During surveys conducted in 40 maize-cassava intercrops in the humid forest zone of southwestern Nigeria, the following termite species were identified from soil samples: Microtermes spp., Macrotermes nigeriensis (Sjostedt), Macrotermes subhyalinus (Rambur), Amitermes evuncifer (Silvestri) and Anoplotermes quietus (Fr. Muller). High incidence of Microtermes and Macrotermes spp. was observed. The population density of predominant species was generally higher in the rainy seasons than in the dry seasons, indicating the role of moisture in their spread. The soil texture of surveyed farms did not influence the presence of the subterranean species Microtermes. The level of weeds in the surveyed farms also did not affect the population density of termites. However, Microtermes population increased significantly (P < 0.05) with increase in crop residues and its presence in farms partly depended on the presence of maize in such farms. Microtermes and Macrotermes species inflicted most of the damage observed on maize crops, while that caused by Amitermes evuncifer was low. No termite attack was observed on growing cassava during the surveys. The presence of live cassava in the intercrop did not influence damage by termites. Nasutitermes and Microcerotermes species which attack economic trees such as cocoa, citrus, oil palm, and forest trees did not attack cassava or maize.Resume-Les echantillonnages effectues sur 40 champs de mais associes au manioc dans la zone agroecologique de la f oret humide dans le sud-oeust du Nigeria indiquaient la presence des especes de termites suivantes sur les prelevements du sol: Microtermes spp., Macrotermes nigeriensis (Sjostedt), Macrotermes subhyalinus (Rambur), Amitermes evuncifer (Silvestri) et Anoplotermes quietus (F. Muller). Une haute presence des especes de Microtermes et Macrotermes a ete constatee. La presence ainsi que la population des especes predominantes etaient generalement plus hautes pendant la saison pluvieuse que pendant la saison seche, indiquant le role de l'humidite sur leur propagation. Les textures du sol des champs echantillonnes n'avaient pas d'effets significatifs aux presences des especes souterraines, Microtermes. Les niveaux de mauvaises herbes dans les champs echantillones n'avaient pas aussi d'effet sur la densite des termites. Neanmoins, la population de Microtermes augmentait significativement (P < 0,05) selon la quantite de residue des plantes restant aux champs, et leur presence dans les champs depandait de la presence du mais. Les especes de Microtermes et Macrotermes infligaient les pluparts des degats observes sur les cultures de mais. Les degats causes par Amitermes evuncifer au mai's etaient f aibles. Aucune attaque par les termites n'a ete constatee sur les cultures du manioc pendant les echantillonnages. Les especes de Nasutitermes et Microcerotermes qui ont attaque's les arbres economiques comme les cacaos, les agrumes, les palmiers a huile et les arbres forestiers n'ont pas attaques le manioc ni le mai's.