-Introduction. In the water-saving and income-generating agroforestry cropping systems developed and promoted by the ICRISAT in the Sudano-Sahelian zone of West Africa, particularly in Niger, fruits of domesticated Ziziphus mauritiana ("apples of the Sahel") are severely damaged by fruit flies (Carpomya incompleta), and chemical pesticide application poses economic, environmental and human health problems. In the Bio-reclamation of Degraded Lands (BDL) system, apple of the Sahel is the main high-value crop, while in the Dryland Eco-Farm (DEF), it is grown alongside watermelon. Sclerocarya birrea (marula plum) is presently being investigated as a dryland tree species for fruit and oil production, either in orchards or such systems as BDL. Materials and methods. To complete preliminary results of earlier studies published elsewhere, we collected and incubated in 2010 ripe fruits of marula plum and watermelon in Sadoré, Niger, where the above-mentioned agroforestry systems are developed, and we recorded emerging fruit flies. We also conducted a spot-spraying experiment (using GF-120) in an apple of the Sahel orchard in Niamey in 2010; we recorded undamaged and damaged fruits and incubated the latter. In the same orchard, we set up in 2011 a fruit fly trapping survey targeting the invasive species Bactrocera invadens (Chempac ® traps using methyl eugenol as the attractant). Results and discussion. The results showed that only Ceratitis cosyra emerged from marula plums, and only Dacus spp. from watermelon. The GF-120 spot-spraying experiment showed that C. incompleta was not attracted / intoxicated, contrary to Ceratitis spp. and Dacus spp.; the sprayed trees yielded significantly more marketable fruits than unsprayed ones; only C. incompleta emerged from damaged fruit. Detection trapping revealed for the first time the presence of B. invadens in the Sahelian zone of Niger, including at the time of apple of the Sahel fruit production. Conclusion. This, alongside results of earlier studies, suggests a repellent effect of GF-120 on the monophagous C. incompleta species (Trypetinae), while it is attractive to oligophagous/polyphagous Dacinae fruit flies; some of them (e.g., Dacus spp.) damage watermelon, which is part of the DEF system, and produce fruit at the same time as the jujube tree. The prospects for harnessing these two opposite regulation pathways are discussed.Niger / Ziziphus mauritiana / Citrullus lanatus / pest control / Carpomya incompleta / Bactrocera invadens / Ceratitis / Dacus / control methods / integrated control / attractants / repellents Impacts du GF-120 sur des mouches des fruits (Diptera : Tephritidae) en systèmes agroforestiers sahéliens à base de cultures horticoles.Résumé -Introduction. Dans les systèmes de culture agroforestiers économes en eau et générateurs de revenus promus par l'ICRISAT dans la zone soudano-sahélienne d'Afrique de l'Ouest, en particulier au Niger, les fruits du jujubier domestiqué Ziziphus mauritiana (« pommes du Sahel ») sont sévèrement attaqués par des mouche...

The potential of perimeter trap cropping, using short and extra-short duration pigeon pea (SD PP and ESD PP), sorghum and cotton, was evaluated in Niger as an agroecological alternative to pesticide application on okra for the management of the tomato fruit worm (TFW) Helicoverpa armigera (Hübner). In 2008, infestation by TFW and damage by fruit worms of unsprayed okra with SD PP borders was intermediate between cypermethrin-sprayed and unsprayed pure okra crops. In 2009, the cypermethrin-sprayed okra was significantly less damaged by fruit worms than in the unsprayed pure okra, as well as in the unsprayed okra crops with SD PP, sorghum and cotton borders. In 2010, the pure okra crop sprayed with cypermethrin was significantly less infested by TFW than the unsprayed pure okra crop and the unsprayed okra crop with SD PP borders. The unsprayed okra crop with ESD PP borders was intermediate between cypermethrin-sprayed and unsprayed pure okra crops. The slightly lower TFW infestation of the unsprayed okra crop with ESD PP borders was a result of increased top-down regulation by predator spiders, whose colonization was significantly higher on the unsprayed okra crop with ESD PP borders than on both (sprayed and unsprayed) pure okra crops. (Résumé d'auteur

a b s t r a c tFrom 2010 to 2011 in Niger, the effects of a wind erosion-alleviating practice, i.e. mulching pearl millet fields with crop residue, on populations of and damage induced by millet stem borer (MSB), head miner (MHM), and head scarab (MHS) were studied. Significant differences in the survival of MSB diapausing larvae in millet stems at the end of the dry season were found at both Sadore and Doukoudoukou. At Sadore, mean MSB larval survival in the treatment where stems were exported at harvest and stored on platforms (treatment 1) was 1.2/stem, i.e. significantly higher than in all other treatments. Survival was between 0.1 and 0.2 larva in treatments 2 (with millet stems left standing from harvest throughout the dry season) and 3 (with millet stems flattened toward the end of the dry season, four months after harvest). It was less than 0.1 larva in treatments 4 (with millet stems flattened in the middle of the dry season, two months after harvest) and 5 (with millet stems flattened at the beginning of the dry season, at harvest). At Doukoudoukou, mean MSB larval survival in treatment 1 was 0.14/stem, i.e. significantly higher than in treatments 4 and 5 (0.02-0.03 larva), with intermediary findings obtained in treatments 2 and 3 (0.04-0.08 larva). The population and biomass of diapausing MHM pupae and of MHS larvae in the soil were low at both locations, and not affected by crop residue management. Thus, crop residue management whereby stems were left standing until the end of the dry season did not enhance control of millet head pests via increased predator activity, while it increased MSB survival in stems.

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