Roux, O., Martin, J. M., Ghomsi, N. T., & Dejean, A. (2009). A Non-lethal Water-based Removal-reapplication Technique for Behavioral Analysis of Cuticular Compounds of Ants. J. Chem. Ecol., 35(8), 904–912.
Abstract: Interspecific relationships among insects are often mediated by chemical cues, including non-volatile cuticular compounds. Most of these compounds are hydrocarbons that necessitate the use of solvents for their extraction, identification, and manipulation during behavioral assays. The toxicity of these solvents often precludes the removal and reapplication of hydrocarbons from and to live insects. As a consequence, dummies often are used in behavioral assays, but their passivity can bias the behavior of the responding insects. To overcome these limitations, we propose a method where cuticular compounds are extracted from live ants by placing them into glass vials half-filled with tepid water (ca. 34A degrees C) and vigorously shaking the vials to form an emulsion whose supernatant can be analyzed and/or reapplied to other ants. We demonstrate that cuticular compounds can be extracted from workers of the red fire ant, Solenopsis saevissima, and reapplied to the cuticle of workers from a sympatric species, Camponotus blandus (both Hymenoptera: Formicidae), while keeping the ants alive. Gas chromatographic-mass spectrometric analysis and behavioral assays were used to confirm the successful transfer of the behaviorally active compounds.
Keywords: Ants; Behavioral assay; Behavioral ecology; Camponotus blandus; Chemical composition; Chemical ecology; Cuticular hydrocarbons; Gas chromatography-mass spectrometry; Live dummies; Solenopsis saevissima; Methods
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Houadria, M., Salas-Lopez, A., Orivel, J., Blüthgen, N., & Menzel, F. (2015). Dietary and Temporal Niche Differentiation in Tropical Ants-Can They Explain Local Ant Coexistence? Biotropica, 47(2), 208–217.
Abstract: How species with similar ecological requirements avoid competitive exclusion remains contentious, especially in the species-rich tropics. Niche differentiation has been proposed as a major mechanism for species coexistence. However, different niche dimensions must be studied simultaneously to assess their combined effects on diversity and composition of a community. In most terrestrial ecosystems, ants are among the most abundant and ubiquitous animals. Since they display direct, aggressive competition and often competitively displace subordinate species from resources, niche differentiation may be especially relevant among ants. We studied temporal and trophic niche differentiation in a ground ant community in a forest fragment in French Guiana. Different baits were presented during day and night to assess the temporal and dietary niches of the local species. They represented natural food resources such as sugars, carrion, excrements, seeds, and live prey. In addition, pitfalls provided a background measure of ant diversity. The communities attracted to the different baits significantly differed from each other, and even less attractive baits yielded additional species. We detected species specialized on living grasshoppers, sucrose, seeds, or dead insects. Community-level differences between day and night were larger than those between baits, and many species were temporally specialized. In contrast to commonness, foraging efficiency of species was correlated to food specialization. We conclude that many ant species occupy different temporal or dietary niches. However, for many generalized species, the dietary, and temporal niche differentiation brought forward through our sampling effort, cannot alone explain their coexistence.
Keywords: Ants; Baiting; Dietary specialization; Functional traits; Niche breadth; Partitioning; Temporal distribution
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Groc, S., Orivel, J., Dejean, A., Martin, J. M., Etienne, M. P., Corbara, B., et al. (2009). Baseline study of the leaf-litter ant fauna in a French Guianese forest. Insect. Conserv. Divers., 2(3), 183–193.
Abstract: 1. Leaf-litter ants represent a major component of biodiversity and are excellent bioindicators reflecting the health of terrestrial ecosystems. This study, conducted in an unspoiled forest near the Nouragues Research Station, represents the first inventory of leaf-litter ant diversity conducted in French Guiana, and so can be considered as the baseline dataset for ants in this country. 2. Ants were extracted from the leaf-litter using the Ants of the Leaf Litter Protocol, along an altitudinal gradient at four forest sites, including an inselberg. 3. A total of 196 ant species representing 46 genera distributed over eight subfamilies were collected. Four distinct communities spread over a gradient of diversity were thus identified: the liana forest was the most species-rich (140 species) followed by the forested plateau (102 species), the transition forest (87 species) and the forest at the top of the inselberg (71 species). 4. The discovery of species new to science plus several species recorded for the first time in French Guiana, coupled with the particular context of this area, suggests that the Nouragues Research Station might represent a centre of endemism. Once completed, this leaf-litter ant dataset will contribute greatly to the knowledge of ant biodiversity in French Guiana, and has the potential to progressively become an indispensable tool for country-wide conservation planning programmes.
Keywords: Ants of the Leaf Litter Protocol; baseline study; leaf-litter ants; Nouragues; Winkler method
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Dejean, A., Corbara, B., Roux, O., & Orivel, J. (2014). The antipredatory behaviours of neotropical ants towards army ant raids (Hymenoptera: Formicidae). Myrmecological News, 19, 17–24.
Abstract: Group hunting, nomadism, wingless queens and colony fission characterize army ants, allowing them to have become the main tropical arthropod predators, mostly of other social insects. We studied the reactions of different ant species to the New World army ants Eciton burchellii (WESTWOOD, 1842) and E. hamatum (FABRICIUS, 1782) (Ecitoninae). We compiled our results with those already known in a synthetic appendix. A wide range of ant species react to the ap-proach of army ant raids by evacuating their nests with several workers transporting brood. The Eciton plunder a large part of the brood but rarely kill workers or queens, so that the latter return to their nest and resume colony activity. One exception is Paratrechina longicornis (LATREILLE, 1802) colonies that quickly evacuate their nest, so that the entire col-ony can generally escape a raid. Another is Leptogenys mexicana (MAYR, 1870) that leave their nests in columns while some nestmates resist the attack; they therefore lose only a few larvae. We noted that colonies can avoid being raided if the army ants ignore them (Atta cephalotes (LINNAEUS, 1758)), or if the workers produce a repellent substance (Azteca associated with myrmecophytic Cecropia) or are repellent themselves (Pachycondyla villosa (FABRICIUS, 1804), Ec-tatomma spp.). In the other cases, a part of the brood is lost. When an Eciton raid approached the base of their host-tree trunk, Azteca andreae GUERRERO, DELABIE and DEJEAN, 2010 workers dropped a part of their brood on the ground. While numerous Eciton workers were gathering up this brood, the front of the column advanced, so that the Azteca andreae nests were not plundered. Pheidole megacephala (FABRICIUS, 1793) nests were partly plundered as the workers reacted aggressively, blocking the Eciton inside their nests during a long time. When the latter returned toward their bivouac, they were attacked and killed by their nestmates whether or not they had retrieved Pheidole brood. Consequently, the front of the column turned away from the Pheidole nest.
Keywords: Antipredatory behaviour; Army ants; Ecitoninae; Prey-ant species
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Dejean, A., Azémar, F., & Roux, O. (2014). An invasive ant species able to counterattack marabunta raids. C. R. Biol., 337(7-8), 475–479.
Abstract: In the Neotropics where it was introduced, the invasive ant Pheidole megacephala counterattacked raids by the army ants Eciton burchellii or E. hamatum. The Eciton workers that returned to their bivouac were attacked and spread-eagled and most of them killed by their outgoing colony mates. Little by little the zone where returning and outgoing Eciton workers encountered one another moved away from the Pheidole nest which was no longer attacked, so that most of the colony was spared. Using a water-based technique rounded out by bioassays, we show that Pheidole compounds were transferred onto the Eciton cuticle during the counterattacks, so that outgoing workers do not recognize returning colony mates, likely perceived as potential prey. Because P. megacephala is an introduced African species, this kind of protection, which cannot be the result of coevolutive processes, corresponds to a kind of by-product due to its aggressiveness during colony defence. © 2014 Académie des sciences.
Keywords: Antipredation; Army ants; Colony mate recognition; Eciton; Pheidole; aggression; ant; article; bioassay; Eciton burchellii; Eciton hamatum; emulsion; insect society; mass fragmentography; Neotropics; nonhuman; Pheidole megacephala
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Casella, T. M., Eparvier, V., Mandavid, H., Bendelac, A., Odonne, G., Dayan, L., et al. (2013). Antimicrobial and cytotoxic secondary metabolites from tropical leaf endophytes: Isolation of antibacterial agent pyrrocidine C from Lewia infectoria SNB-GTC2402. Phytochemistry, 96, 370–377.
Abstract: Because of the symbiotic nature of endophytes, this survey aims to investigate the probability of discovering antibacterial, antifungal and cytotoxic activities in leaf endophytic microbes. We isolated 138 cultivable microbes (121 fungi, 3 bacteria and 14 unidentified or unknown microbes) from 24 plant species, a significant relative proportion of which exhibited antifungal and cytotoxic potential against Candida albicans ATCC 10213 and the human cell lines KB (uterine cervical carcinoma), MDA-MB-435 (melanoma), and MRC5 (normal human lung fibroblasts). Three active fungal extracts were fractionated, resulting in the isolation of eight compounds. Seven had been described in the literature including the following: acremonisol A, semicochliodinol A, cochliodinol, griseofulvin, pyrenocin A, novae zelandin A and alterperylenol. A previously unreported compound named pyrrocidine C was isolated from Lewia infectoria SNB-GTC2402 and identified by spectroscopic analysis. As in pyrrocidines A and B, this compound is a cis-substituted decahydrofluorene with a quaternary carbon at C-5 and opposite stereochemistry at C-8 corresponding to C-6 of pyrrocidines A and B.© 2013 Elsevier Ltd. All rights reserved.
Keywords: Antimicrobials; Cytotoxic metabolites; Functional chemodiversity; Leaf endophytes; Lewia; Pyrrocidine C
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Boulogne, I., Constantino, R., Amusant, N., Falkowski, M., Rodrigues, A. M. S., & Houel, E. (2017). Ecology of termites from the genus Nasutitermes (Termitidae: Nasutitermitinae) and potential for science-based development of sustainable pest management programs. Journal of Pest Science, 90(1), 19–37.
Abstract: 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. © 2016, Springer-Verlag Berlin Heidelberg.
Keywords: Antimicrobial and insecticidal botanical extracts; Ipm; Nasutitermes corniger; Sustainable management; Taxonomic history; Termitidae
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Bertani, S., Houel, E., Bourdy, G., Stien, D., Jullian, V., Landau, I., et al. (2007). Quassia amara L. (Simaroubaceae) leaf tea: Effect of the growing stage and desiccation status on the antimalarial activity of a traditional preparation. J. Ethnopharmacol., 111(1), 40–42.
Abstract: In French Guiana, Quassia amara L. (Simaroubaceae) leaf tea is a well-known widely used traditional antimalarial remedy. Impact of the vegetal sampling condition on in vivo and in vitro antimalarial activity was assessed. Traditional infusions were prepared with juvenile or mature leaves, both either fresh or dried. Results showed that growing stage and freshness of vegetal material exert a striking effect on antimalarial activity, both in vitro and in vivo. By far, leaf tea made from fresh juvenile (FJ) Quassia amara leaves was the most active. In vitro, active component (simalikalactone D) concentration correlates biological activities, although unexplained subtle variations were observed. In vivo, tea made with dried juvenile (DJ) leaves displays a peculiar behavior, meaning that some components may help simalikalactone D delivery or may be active in vivo only, therefore enhancing the expected curative effect of the traditional preparation. (c) 2006 Elsevier Ireland Ltd. All rights reserved.
Keywords: antimalarial; Quassia amara; quassinoids; simalikalactone D; traditional medicine
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Bertani, S., Houel, E., Stien, D., Chevolot, L., Jullian, V., Garavito, G., et al. (2006). Simalikalactone D is responsible for the antimalarial properties of an amazonian traditional remedy made with Quassia amara L. (Simaroubaceae). J. Ethnopharmacol., 108(1), 155–157.
Abstract: French Guiana (North-East Amazonia) records high malaria incidence rates. The traditional antimalarial remedy most widespread there is a simple tea made out from Quassia amara L. leaves (Simaroubaceae). This herbal tea displays an excellent antimalarial activity both in vitro and in vivo. A known quassinoid, simalikalactone D (SkD), was identified as the active compound, with an IC50 value of 10 nM against FeB1 Plasmodium falciparum chloroquine resistant strain in vitro. Lastly, it inhibits 50% of Plasmodium yoelii yoelii rodent malaria parasite at 3.7 mg/kg/day in vivo by oral route. These findings confirm the traditional use of this herbal tea. (c) 2006 Elsevier Ireland Ltd. All rights reserved.
Keywords: antimalarial; Quassia amara; quassinoids; simalikalactone D; traditional medicine
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Bertani, S., Houel, E., Jullian, V., Bourdy, G., Valentin, A., Stien, D., et al. (2012). New findings on Simalikalactone D, an antimalarial compound from Quassia amara L. (Simaroubaceae). Exp. Parasitol., 130(4), 341–347.
Abstract: Quassia amara L. (Simaroubaceae) is a species widely used as tonic and is claimed to be an efficient antimalarial all over the Northern part of the Amazon basin. Quassinoid compound Simalikalactone D (SkD) has been shown to be one of the molecules responsible for the antiplasmodial activity of a watery preparation made out of juvenile fresh leaves of this plant. Because of its strong antimalarial activity, we decided to have a further insight of SkD pharmacological properties, alone or in association with classical antimalarials. At concentrations of up to 200 μM, we showed herein that SkD did not exert any apoptotic or necrotic activities in vitro on lymphoblastic cells. However, an antiproliferative effect was evident at concentrations higher than 45. nM. SkD was inefficient at inhibiting heme biomineralization and the new permeability pathways induced by the parasite in the host erythrocyte membrane. With respect to Plasmodium falciparum erythrocytic stages, SkD was almost inactive on earlier and later parasite stages, but potently active at the 30th h of parasite cycle when DNA replicates in mature trophozoites. In vitro combination studies with conventional antimalarial drugs showed that SkD synergizes with atovaquone (ATO). The activity of ATO on the Plasmodium mitochondrial membrane potential was enhanced by SkD, which on its own had a poor effect on this cellular parameter. © 2012 Elsevier Inc.
Keywords: Antimalarial; Plasmodium; Quassia amara; Quassinoid; Simalikalactone d
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