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Rastrococus invadens was the only reported mealybug species on the mango tree in Western Burkina Faso. This study aimed at carrying out the inventory and showing the importance and distribution of other mealybug species associated with the mango tree. It was also important to determine the periods of abundance of these species vis-a-vis R. invadens. For this purpose, the density of mealybugs was assessed in three study sites (Toussiana, Bérégadougou and Orodara) in Western Burkina Faso. The observations were made from June 2014 to June 2015 at a frequency of 15 ± 1 days. They focused on 20 leaves (5 leaves/cardinal point) levied on each mango tree. The species identified as Ferrisia virgata Cockerell and Icerya aegyptiaca Douglas were collected from mangos infested by R. invadens representing 98% -99% of the density of the observed mealybug species. The periods of abundance of F. virgata and I. aegyptiaca were respectively the dry season and the rainy season. The effect of temperature, relative humidity and rainfall on the populations of F. virgata and I. aegyptiaca was also discussed. These results highlight the distribution range of F. virgata and I. aegyptiaca worldwide including Burkina Faso. R. invadens was the main mealybug species on mango in Burkina Faso in general and in the Western region of the country in particular.

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This study was carried out to evaluate the effects of the bio pesticide Metarhizium anisopliae ICIPE 69 and the chemical pesticide Chlorpyriphos-ethyl on Rastrococcus invadens and its parasitoids Anagyrus mangicola and Gyranusoidea tebygi in orchards. A Randomized Complete Block design consisting of 5 treatments was set up in Mahon and Niampédougou. There were the untreated control, the reference chemical Chlorpyriphos-ethyl (480 g/l) and 3 doses of the bio pesticide (10 8 conidia/ml, 10 9 conidia/ml and 2.10 9 conidia/ml). Live or dead mealybugs were counted on 20 leaves/mango trees before the first application of the chemicals and then successively each week for 3 to 4 weeks. Highest mortality rates of mealybugs were observed with Chlorpyriphos-ethyl (50-90%) followed by the higher dose of the bio pesticide (28-40%). The level of parasitoids expressed in log (N + 1) was low (0-0.86) on trees treated with Chlorpyriphos-ethyl compared to bio pesticide (0.15-1.86) and untreated control (0.33-1.53). Significant differences (0.047≤P<0.001) were observed between treatments after the first application of the chemicals. Although the rate of mortality of mealybugs was twice as high with Chlorpyriphos-ethyl, M. anisopliae ICIPE 69 could be an alternative to synthetic insecticides for compatibility with parasitoids.

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L'espèce Bactrocera dorsalis (Hendel) constitue une contrainte majeure à l'épanouissement de la filière des fruits et légumes au Burkina Faso. Son parasitoïde, Fopius arisanus (Sonan) a été introduit afin de mener une lutte biologique. L'étude a été conduite pour déterminer l'influence des supports alimentaires sur l'élevage du ravageur et de son parasitoïde. La fécondité des imagos et le développement du stade pré-imaginal du ravageur ont été évalués avec des aliments protéiques. Deux substrats ont permis d'évaluer le taux d'émergence et le sex-ratio du parasitoïde. Le nombre moyen d'oeufs pondus par femelle a varié de 0 oeuf à 48,30 oeufs respectivement pour la farine de blé et l'hydrolysat enzymatique. Il est ressorti une masse larvaire de 0,005 g à 0,031 g pendant que la masse des pupes se situait entre 0,009 g et 0,026 g. Le taux de survie larvaire et de pupaison n'était pas significativement différent. Par contre, les taux d'émergence de F. arisanus ont évolué de 1,15% à 9,86%. Ces résultats donnent des orientations par rapport au type et à la quantité de substrat à utiliser pour réduire les coûts de production de masse du ravageur et de son parasitoïde. © 2019 International Formulae Group. All rights reserved Mots clés: Source alimentaire protéique, élevage de masse, lutte biologique, mouche des fruits, parasitoïde, Burkina Faso. Influence of feed sources on some biological parameters of Bactrocera dorsalis (Hendel) and its parasitoid Fopius arisanus (Sonan) under laboratory conditions ABSTRACTBactrocera dorsalis (Hendel) species is major constraint to the development of the fruit and vegetable sector in Burkina Faso. Its parasitoid, Fopius arisanus (Sonan) was introduced for a biological control. For this purpose, the performance of feeds sources was evaluated in order to achieve a mass rearing (pest and parasitoid). The fertility of adults and the development of the preimaginal stage of the pest were evaluated by protein sources. Two feed formulations were used to evaluate the emergence rate and sex ratio of A . B. G. SANOU et al. / Int. J. Biol. Chem. Sci. 13(2): 870-881, 2019 871 the parasitoid. The average number of eggs laid per female ranged from 0 eggs to 48.30 eggs for wheat flour and enzymatic hydrolysate, respectively. A larval weight of 0.005 g to 0.031 g was observed while the weight of the pupae was between 0.009 g and 0.026 g. The rate of larval survival and pupation was not significantly different whatever the treatments. The emergence of F. arisanus was ranged from 1.15% to 9.86% for the formulations used. These results provide directions on the type and quantities of substrate to be used to reduce the mass rearing costs of the pest and its parasitoid.

L’oignon est le premier légume produit au Burkina Faso. Thrips tabaci constitue son principal insecte ravageur. Ce travail avait pour objectif  d’évaluer la distribution, l’incidence et la sévérité des attaques de T. tabaci sur l’oignon. L’étude a été réalisée dans trois bassins de production  représentatifs de deux zones agroécologiques du Burkina Faso : la zone sahélienne caractérisée par une pluviosité moyenne annuelle inférieure à 600 mm et une température moyenne annuelle de 35 °C ; contre une pluviosité moyenne annuelle comprise entre 600 et 900 mm et une  température moyenne annuelle de 33 °C pour la zone nord soudanienne Nous avons réalisé des prospections dans 45 parcelles paysannes dans les zones de production ciblées. Des plantes d’oignon ont été prélevées dans trois quadrats posés sur une des diagonales de chaque parcelle, et les thrips trouvés sur chaque plante de chaque quadrat comptés. Tous les plants à l’intérieur du quadrat ont été donc observés. La densité moyenne la plus élevée (216 ±385 thrips au m2) a été observée dans la région du Nord tandis que l’incidence moyenne la plus élevée (95,91±8,92%) a été observée dans la Boucle du Mouhoun. La plus faible sévérité (19,29±13,27%) a été enregistrée dans le Plateau central. Cette étude est un premier pas vers le développement de stratégies alternatives de lutte contre les parasites dans le cadre de systèmes de production végétale durables à l’aide de bonnes pratiques agricoles et de l’utilisation des pesticides biologiques.Mots clés : Oignon, Thrips tabaci, incidence, sévérité, répartition, Burkina Faso.   English Title: Distribution and damage associated with the onion thrips, Thrips tabaci L. (Thysanoptera: Thripidae) according to the agro-climatic zone in Burkina FasoOnion is the first vegetable produced in Burkina Faso. Thrips tabaci is its main insect pest. We assessed the distribution, incidence and severity of T. tabaci attacks on onion in three-production areas representative of two agroecological zones of Burkina Faso: the the Sahelian zone characterized by an average annual rainfall of less than 600 mm and an average annual temperature of 35 °C; compared to an average annual rainfall of between 600 and 900 mm and an average annual temperature of 33 °C for the northern Sudanian zone. We carried out surveys in 45 farmer plots in the targeted production zones. Thus, onion plants were taken from three quadrats placed on one of the diagonals of each plot, and the thrips found on each plant were counted. All plants within the quadrat were therefore observed. The highest average density (216±385 thrips per m²) was observed in the North while the highest average incidence (95.91±8.92%) was observed in the Boucle du Mouhoun. The lowest severity (19.29±13.27%) was recorded in the Plateau central region. This study is a first step towards the development of alternative pest control strategies within sustainable crop production systems using good agricultural practices and the use of biopesticides.Keywords: Onion, Thrips tabaci, incidence, severity, distribution, Burkina Faso.