Éditeur(s) : TRAMIL

Droits : Ce document est protégé par le droit d'auteur. Il ne peut en aucun cas être utilisé sans l'autorisation de l'auteur et des ayant droits
Permalien : http://www.manioc.org/recherch/T15023
T15023

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
In the Caribbean, Pterocarpus officinalis swamp forest, a coastal freshwater wetland, has been locally transformed by human activities into Colocasia esculenta monoculture (under the swamp forest) or pasture (where deforestation has occurred). The aim of this study was to evaluate the impact of three land uses of this tropical wetland (swamp forest, C. esculenta monoculture and pasture) on soil abiotic and biological features. We hypothesized that increasing the level of ecosystem alteration by agricultural intensification would negatively impact soil chemical characteristics, soil fauna diversity and carbon mineralization. As expected, land use significantly affected soil characteristics and changes followed the increasing intensity of land use. The ‘undisturbed system’, that is swamp forest, was characterized by a large soil organic matter content, a high level of soil moisture, a small phosphorus content and a slightly lower pH. These characteristics were correlated with a small faunal abundance and diversity and slow carbon (C) mineralization. The ‘low disturbance system’, that is C. esculenta monoculture, was the closest to swamp forest characteristics and changes between the both systems principally concerned a very slight decrease in organic matter content and very small increase in C mineralization and Coleoptera diversity. By contrast, all parameters (soil chemical characteristics, C mineralization and faunal abundance and diversity) were impacted in the most intensive land-use, pasture. Our study confirmed that agricultural practices have an influence on soil fauna and C mineralization processes in wetlands. Moreover, our study suggested that a C. esculenta traditional agroecosystem under swamp forest cover could be considered as an ‘eco-friendly’ agricultural practice.
ISSN: 0266-0032

hal-01562423
https://hal.archives-ouvertes.fr/hal-01562423
DOI : 10.1111/sum.12273

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
The genus Nasutitermes is among the most abundant wood-feeding Termitidae and an extremely diverse and heterogeneous group in terms of its biogeography and morphology. Despite the major role of several Nasutitermes species as structural pests, the phylogenetic status of this genus is still unclear, along with a confused taxonomy and species identification remaining difficult. The first aim of this review was thus to gather and discuss studies concerning the taxonomic status of the genus Nasutitermes in order to clarify this crucial point. Then, our goal was to gain new insights into the management of N. corniger, considered to be the most economically detrimental pest of this genus in South America and a Nasutitermes model species, while filtering available information concerning its biology through the prism of termite control, as well as critically examine the existing methods. We indeed strongly believe that increasing our knowledge of this species’ biological strategies is the key to progress in the challenging question of their sustainable management.
ISSN: 1612-4758

hal-01467356
http://hal.upmc.fr/hal-01467356
http://hal.upmc.fr/hal-01467356/document
http://hal.upmc.fr/hal-01467356/file/Boulogne_2017_Ecologysur termites.pdf
DOI : 10.1007/s10340-016-0796-x

Éditeur(s) : HAL CCSD American Chemical Society
Résumé : Four new sesquiterpene alkaloids (1-4) with a β-dihydroagrofuran skeleton and a new triterpenoid (5) were isolated from an ethyl acetate extract of Maytenus oblongata stems. Their structures were elucidated using 1D and 2D NMR spectroscopy as well as MS and ECD experiments. The M. oblongata stem EtOAc extract and the pure compounds isolated were tested for larvicidal activity against Aedes aegypti under laboratory conditions, and compounds 2 and 3 were found to be active.
ISSN: 0163-3864

hal-01603411
https://hal.archives-ouvertes.fr/hal-01603411
DOI : 10.1021/acs.jnatprod.6b00850
PUBMED : 28186749
PRODINRA : 406747

Résumé : Les attines sont des fourmis champignonnistes dans la zone allant des Etats-Unis à l'Argentine en passant par la Caraïbe. Les dégâts causés par ces ravageurs sont considérables et estimés à plusieurs millions de dollars par an. Elles sont de ce fait considérées comme l'un des premiers fléaux de l'agriculture de la zone (Cameron & Riggs, 1985 ; Fowler et al., 1986). En Guadeloupe, la "fourmi manioc" (Acromyrmexoctospinosus Reich) cause de nombreux dommages, aussi bien pour l'agriculture que dans les milieux naturels. Les dégâts occasionnés par ces fourmis ont nécessité l'utilisation de pesticides de synthèse. pour tenter de les combattre. La dangerosité de ces substances pour les milieux naturels et anthropisés ainsi que pour la santé publique est un contexte favorable à l'exploration de nouvelles pistes telles que l'utilisation de plantes à usages phytosanitaires. L'objet principal de cette thèse consiste à savoir si on peut déceler à partir de l'ethnopharmacologieTRAMIL des usages permettant de combattre cette fourmi et son symbiote fongique, Leucocoprinuss 'gongylophorus (Heim) MoeIler. Les protocoles retenus et présentés dans ce travail permettent d'observer les effets des usages de plantes choisis sur la survie et le comportement des insects et sur la croissance du symbiote. Ils ont été sélectionnés pour leur potentialité à mettre en évidence les différents types d'effets des extraits végétaux (insecticide par contact, insectifuge, toxique par ingestion, fongistatique ou fongicide). Six usages traditionnels issus de cinq plantes sont testés sur la fourmi: Mammea americana L., Nerium oleander L., Nicotiana tabacum L., Rollinia mucosa (Jacq.) Baill. et Trichilia pallida Sw. Cinq autres usages traditionnels sont testés sur le champignon : Allium cepa L., Allium sativum L., Lycopersicom esculentum Mill., Manihot esculenta Crantz et Senna alata (L.) Roxb. Les resultants obtenus permettent de dégager quelques pistes de lutte intéressantes contre ce ravageur.
Leaf-cutting ants are fungus-growing ants.Their geographie distribution ranges from southern United States to northern Argentina, incIuding the West Indies, Economic losses due to these ants were estimated at several million dollars per year. The latter statement makes they are considered as one of the most important pest species of the agricultural productions (Cameron & Riggs, 1985 ; Fowler et al., 1986). In (Guadeloupe, the most important invasive pest species which caused important losses in forests, gardens and field crops is 'cassava ant' (Acromyrmex octospinosus Reich). These huge losses required to use, synthetic chemical pesticides to control these leaf-cutting ants, the consequence of which is, irreversible' injuries on environment and on human health. As a matter of fact, this situation has prompted an increasing interest in alternative methods for pest control like plants with pesticide used. The main objective of this thesis is to know if traditional ethnopharmacological TRAMIL uses could help to fight against this ant and against the symbiotic fungus, Leucocoprinus gongylophorus (Heim) . Moeller. Methods used and presented in this work aIIowed to observe effects of selected plant uses on mortality and insect's behavior. The protocols performed were selected for their potentiality to detect the different types of insecticidal effects (contact toxicity, repellent effect, toxicity by ingestion, fungicidal or fungistatic). Six traditional plant uses of five plants were tested on the ant : Mammea americana L., Nerium oleander L., Nicotiana tabacum L.,Rollinia mucosa (Jacq) Baill. and Trichilia pallida Sw.Five other plants uses were tested on the fungus:Allium cepa L.,Lycopersicon esculentum Mill.,Manihot esculenta Crantz and Senna alata (L.) Roxb.The obtained résults provide us with some interesting trails to fight against this pest.

http://www.theses.fr/2011AGUY0469/document