Introduction. Timing of management practices requires an understanding of pest population dynamics in given cropping systems. Our study was designed to establish the population trends of B. invadens in mango orchards and to determine if population fluctuations were reflected in fruit infestation levels during changes in mango phenology. Materials and methods. Bactrocera invadens flies were trapped weekly from February 2011 to November 2012, using methyl eugenol and DDVP (dichlorvos) insecticidal strips. Trapping was done in three mango orchards in the Luweero district of Uganda’s Lake Victoria Crescent. Mango fruit samples were incubated for the retrieval of puparia to calculate positivity (proportion of fruits infested) and fruit infestation indices (number of puparia per kg of fruit) for each stage of fruit maturity. Results. Mean trap catches of adult B. invadens varied significantly over the months (range : ~11 flies per trap per day (FTD) to over 590 FTD; P £ 0.0001). During each year, infestations peaked during June-July and January-February. Trap catches were higher in the major fruiting season compared with the minor fruiting season and were the highest when mango was at the physiological maturity and ripe stages. Fruit infestation and positivity were highest for fruit at the physiological maturity and ripe stages and lowest at the fruit set stage. Discussion. Our findings show that B. invadens is present year-round and all stages of mango fruit development are susceptible to attack. Thus, control measures should be implemented throughout the year and preferably started at fruit set to lessen fruit fly population build-up and damage to fruits.

Introduction. The invasive gall midge, Procontarinia mangiferae (= Erosomyia mangiferae Felt), is one of the most important flowering pests of mango orchards worldwide. To achieve chemical input reduction, developing integrated pest management (IPM) strategies using bio-control agents is pertinent. Materials and methods. We tested the pathogenicity of two commercial strains of the entomopathogenic fungi Beauveria on non-diapausing 3rd-instar larvae of P. mangiferae. Results and discussion. Neither the Beauveria sp. commercial strain Betel nor the B. bassiana strain Bb 147 were effective, even though they proved their pathogenicity on the control, Galleria mellonella. Hypotheses to explain the inefficiency of the two strains on P. mangiferae are discussed. Conclusion. Other strains of Beauveria or other entomopathogenic fungi or nematodes should be tested on diapausing and non-diapausing larvae of P. mangiferae.

Introduction. Plants develop mechanisms that allow them to compartmentalize injuries that they suffer during their life. In trees, pruning and injection treatments must be used in accordance with precise rules to reduce risks resulting from the injuries created. Sealing in palms. Palms, contrary to widespread belief, are quite capable of “healing” injuries (sealing); because of an anatomy quite different from trees, the sealing process in palms is much simpler. Compartmentalization of injection wounds. The controversy on the use of injection in trees is due essentially to initial mistakes that have then been rectified. Injection in palms against the red palm weevil. For palms, for decades, this technique has been employed without problems and with great efficiency against various pests, including Rhynchophorus ferrugineus, the red palm weevil (RPW). Its use has been reserved for exceptional situations either to face abnormal pest proliferation, uncontrollable by other techniques, or to implement eradication programs. Integrated eradication program. In such a program, the main aim of injection treatments is preventive. With long-persistence insecticides, the number of treatments could be greatly reduced. The resulting savings in time and money would enable the organization of the treatments of all the palms located in an infested area, and consequently the rapid eradication of the pest. New perspectives. We established that insecticides applied by injection were capable of protecting palms with only two or even one treatment per year. These results suggest a radical improvement in programs to eradicate RPW, while considerably reducing the risks to health and the environment compared with spray treatments.

Introduction. In the southern Sudanian zone of Benin, fruit flies are major pests and responsible for considerable yield losses in mango production. The two main species of economic importance affecting mango trees in Benin are Ceratitis cosyra and Bactrocera invadens. During the 2006 crop year and across seven main cultivars, losses stood at 17% in early April and exceeded 70% in mid-June. By the middle of the crop year, over 50% of losses occurred in mango orchards. Materials and methods. The Stone and Pedigo method was used to compute the economic injury level, using variables such as pest control costs, level of losses and mango prices. Results and discussion. The Economic Injury Level (EIL) was highly variable. For the cultivar Kent, for example, it varies from (30 to 75) fruit flies captured per ha and per week, whereas for Keitt the level ranges from (24 to 57) fruit flies·ha–1·week–1. EIL variability depends among other things on market price fluctuation. This method is based on the early introduction of detection traps in mango orchards. A weekly monitoring of trapped fruit flies is used to compute the EIL and make a decision about pest control. Pest control (GF-120 in this case) is recommended if the gross returns exceed production costs. If the number of trapped fruit flies is below the EIL, a treatment is not recommended because pest control will not be profitable. Conclusion. The EIL is an accurate tool to set the optimal (economic) timing of pest control treatment in mango orchards. These preliminary results should lead to the introduction of integrated pest management (IPM) activities to deal with the fruit fly species that are threatening the profitability of mango production in central and northern Benin.

Introduction. Dans plusieurs pays, le psylle Cacopsylla pyri (Hemiptera, Psyllidae) est considéré comme le ravageur majeur du poirier. Afin de préserver les ennemis naturels de ce ravageur, la lutte contre C. pyri passe actuellement par l’utilisation de matières actives aptes à préserver les auxiliaires de l’insecte, voire de substances préventives, dont la kaolinite. Pour la première fois en Tunisie, nous avons testé l’efficacité de ce produit en traitement d’hiver, en comparaison avec l’huile minérale traditionnellement utilisée. Matériel et méthodes. Pour déterminer le moment opportun d’un traitement contre C. pyri, les adultes présents en hiver dans un verger de poiriers ‘Williams’ ont été échantillonnés par frappage des branches. Les femelles récoltées ont été disséquées pour déterminer le stade de développement de leurs ovaires. Ces observations ont permis de déclencher, au moment opportun, une application hivernale à base de kaolinite, dont les résultats ont été comparés à ceux obtenus par un traitement à l’huile minérale. L’impact de ces deux traitements sur la ponte des femelles d’hiver et les larves qui en ont été issues a été étudié ; conjointement, la phénologie du poirier a été évaluée par plusieurs contrôles. Résultats. Les applications hivernales de kaolinite ont évité la ponte des femelles de psylle sur poirier. En conséquence, ce produit a réduit significativement les populations larvaires de C. pyri jusqu’au stade de chute des pétales. En outre, la kaolinite n’a pas eu d’impact sur le déroulement de la floraison. Conclusion. En Tunisie, la kaolinite s’est révélée très performante dans la prévention des pontes des femelles hivernantes de C. pyri ; elle pourrait donc être insérée dans un programme de lutte intégrée contre ce ravageur.

Chilo species constitute one of the three major lepidopterous rice stem borers in Africa and their occurrence stretches across the different rice ecosystems; two major species, C. zacconius Bles. and C. diffusilineus (J. de Joannis) are found in West Africa, while C. partellus (Swinh.) and C. agamemnon Bles. appear to be the predominant species on rice in East and North Africa, respectively. A brief note is given on some aspects of the biology, especially the life history and behaviour of C. zacconius. Control measures are discussed as well as an integrated approach towards management based essentially on growing resistant varieties, conservation of natural enemies and adjusting planting dates.