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The objective of our study was to identify how actors from the main socio-economic sectors perceive their interactions and impacts on a sensitive wetland in an arid climate, specifically the salt pans of Chott Merouane in Algeria. The results revealed that there are three main economic stakes including agriculture, livestock production and salt mining, each activity providing a great benefit for local and national populations. The local population perceived that the current activities are conducted in such a way that they created conflict between socio-economic sectors and caused a threat for long term sustainability of the wetlands. The results highlighted the need to initiate an integrated management approach between the different sectors and to develop a shared vision for the territory.

<p>The population changes of <em>Tuta absoluta</em> was surveyed during three growing seasons in greenhouse tomatoes in Biskra. Introduced in 2009 for the first time, it seems to be well established on tomato crops in Biskra; while their natural enemies remained lacking, due possibly to pesticides overuse. All pest stages were present on tomato plants during the three cropping seasons. Important numbers of males were captured during the first growing season and the least during the third growing season. The first adults’ flight spread out between October and December. Adults’ flight significantly rose at the end of the plant cycle due to increased temperatures in all cultivation seasons. This can provide information on the infestation levels for the following cultivation years. The numbers of immature were low during the three cultivation seasons. March, April and May seem more favorable to the different leaf miner instars development for the three cropping seasons. This was due probably to temperature rising.</p>

Globally, thrips pest of agro-ecosystems are well studied. Nevertheless, in Algeria this insect group remains poorly known. The research was conducted to determine thrips composition and population changes of F. occidentalis on three melon cultivar. The study highlighted six thrips species on three melon cultivars (Star plus, DRM and Mimosa), including two of economic importance pests, namely Frankliniella occidentalis and Thrips tabaci. The remaining species are: Odontothrips loti, Aeolothrips intermedius, T. minutissimus and Melanthrips fuscus. The western flowers thrips (WFT) F. occidentalis was eudominant species, while T. tabaci was subrecedent. Blue sticky traps allow detecting thrips early for monitoring and from crop development starting. A positive and significant relationship was observed between thrips abundance in traps and WFT recovered from flowers and leaves on all cultivars. The highest numbers of WFT were recorded on DRM flowers and Star plus leaves while the least numbers were noticed on Mimosa flowers and leaves. F. occidentalis flight activity was observed early in the growing season. Similar trend of thrips population changes was recorded during crop season. Nevertheless, one to two peaks of F. occidentalis population were registered on flowers and leaves on all cultivars. They were mainly observed in April when temperatures were high and humidity low, their numbers were not considerable. No fruits damage was observed in situ on all cultivars. This work allowed to improve knowledge about thrips linked to some melon cultivars the most used in greenhouse in the region of Biskra. The presence of these pests can be a source of concern for farmers. Extending monitoring to other crops and localities to know their status and distribution remains a priority due to direct damage caused and virus transmission hazard.

La description des attributs botaniques et éthologiques du patrimoine floristique messicole des agroécosystèmes à l’Aurès, Nord-est d’Algérie s’appuie sur 144 relevés. Cette étude a permis d’inventorier 77 espèces adventices, appartenant essentiellement aux dicotylédones et monocotylédones, réparties en 23 familles botaniques, dont quatre fournissent à elles seules 58%, Asteraceae, Poaceae, Apiaceae et Brassicaceae. L’analyse biologique montre une prédominance des thérophytes avec 69 % suivi des géophytes et des hémicryptophytes avec 25 % et 6 % respectivement. L’analyse du degré de similitude entre les différentes stations a fait ressortir 19 espèces communes à toutes les stations échantillonnées. La prise en compte de l’indice de nuisibilité a dégagé 36 espèces nuisibles vis à vis de blé dont 7 espèces peuvent être considérablement nuisibles pour la zone de l’Aurès. Ce travail a permis de déterminer la structure de la flore adventice des céréales, les spectres taxonomiques et biologiques ainsi que les espèces envahissantes. Ce diagnostic sur la biodiversité des adventices constituent un outil principal pour la lutte intégrée et privilégier des pratiques les plus respectueuses de l’environnement pour la protection et la valorisation de la biodiversité agricole.