GF-120 effects on fruit fly species (Diptera: Tephritidae) in Sahelian agroforestry-based horticultural cropping systems

Abstract

-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...

Rain-Fed Plantations Of The Domesticated Ziziphus Mauritiana In The Sahel: Effects Of Varieties And Rootstocks On Yields And Fruit Quality

“…The climate is characterized by a rainy season that occurs between June and September, and a dry season that prevails during the rest of the year. The mean annual rainfall at Sadoré is 560 mm and the average temperature is 29 °C (West et al 1984).…”

“…Fruits were sprayed each year with Decis (deltamethrin) against fruit flies (Carpomya incompleta), which are the dominant pests of Ziziphus fruit at Sadoré (Zakari-Moussa et al 2012). A total of three sprays were done.…”

Ecological Intensification for Crop Protection

“…7 ), and as an "attractant & killer" to protect watermelon, which is part of the Dryland Eco-Farm system (Fatondji et al 2011 ), along with jujube tree, from oliphagous Dacus fruit fl ies, thus "killing two fl ies with one spray", and even a third one, namely Bactrocera invadens , which is gaining importance as a highly polyphagous fruit pest in Niger (Zakari-Moussa et al 2012 ). In this latter case (shown in Fig.…”