Des plantes tropicales qui forment des mares : les broméliacées-citerne : un écosystème aquatique miniature capital pour la biodiversité

Les plantes qui présentent des structures anatomiques permettant de retenir de l'eau en permanence sont assez répandues en milieu tropical. Si beaucoup sont maintenant cultivées pour être vendues en jardineries, faisant le bonheur des amateurs, elles forment en milieu naturel des écosystèmes aquatiques encore très peu étudiés et renferment une biodiversité que l'on est loin d'avoir recensée. En Amérique centrale et du Sud, les broméliacées-citerne, qui représentent les plus nombreuses et les plus diversifiées de ces "plantes-mares", permettent à des organismes très variés d'accomplir leur cycle de vie

Are Algae Relevant to the Detritus-Based Food Web in Tank-Bromeliads?

We assessed the occurrence of algae in five species of tank-bromeliads found in contrasting environmental sites in a Neotropical, primary rainforest around the Nouragues Research Station, French Guiana. The distributions of both algal abundance and biomass were examined based on physical parameters, the morphological characteristics of bromeliad species and with regard to the structure of other aquatic microbial communities held in the tanks. Algae were retrieved in all of the bromeliad species with mean densities ranging from ∼102 to 104 cells/mL. Their biomass was positively correlated to light exposure and bacterial biomass. Algae represented a tiny component of the detrital food web in shaded bromeliads but accounted for up to 30 percent of the living microbial carbon in the tanks of Catopsis berteroniana, located in a highly exposed area. Thus, while nutrient supplies are believed to originate from wind-borne particles and trapped insects (i.e., allochtonous organic matter), our results indicate that primary producers (i.e., autochtonous organic matter) are present in this insectivorous bromeliad. Using a 24-h incubation of size-fractionated and manipulated samples from this plant, we evaluated the impact of mosquito foraging on algae, other microorganisms and rotifers. The prey assemblages were greatly altered by the predation of mosquito larvae. Grazing losses indicated that the dominant algal taxon, Bumilleriopsis sp., like protozoa and rotifers, is a significant part of the diet of mosquito larvae. We conclude that algae are a relevant functional community of the aquatic food web in C. berteroniana and might form the basis of a complementary non-detrital food web

First observations of the Atlantic beach cricket, Pseudomogoplistes vicentae (Grylloidea: Mogoplistidae), in the Basque autonomous community, Spain

The Atlantic beach cricket Pseudomogoplistes vicentae Gorochov, 1996 (Orthoptera: Grylloidea: Mogoplistidae) is among the rare Orthoptera species that live exclusively in coastal habitats. It inhabits cobble beaches from North Africa to Great Britain, with populations known in Morocco, Portugal, Spain, France, Channel Islands, Wales and England. P. vicentae was found on the Spanish continental coast for the first time in 2018, in Asturias. The discovery of three populations in the Basque autonomous community (Northern Spain) is reported here, and useful information for increasing its detection and monitoring its populations is provided

Part de la communication phéromonale dans l'isolement reproducteur des races d'hôtes chez la Pyrale du maïs, Ostrinia nubilalis HB. (Lépidoptère, Crambidae) et approche comportementale de son piégeage sexuel

PARIS13-BU Sciences (930792102) / SudocSudocFranceF

How Many Edible Insect Species Are There? A Not So Simple Question

Insects used as food and medicine are receiving increased attention. There is a need to scrutinise recent estimates of which and how many insect species are used as we have noticed inappropriate assessments and overestimations. We review the contemporary list of edible insects of the world published online by Wageningen University and compiled by Ijde Jongema since it is widely used in the literature. Each of the 2403 entries were scrutinised, including checking name validity, verifying insect usage in cited references, and categorising each entry. Our revision indicates inappropriate assessments and inclusions such as spiders (not insects) and insect products (e.g., honeydew) when the insect itself is not used. With relevant and accepted definitions, we provide a critical assessment and estimate of the number of food insects (1611) and medicinal insects (81), which is lower than Wageningen University and Jongema’s estimate of 2111 “edible insects”. We acknowledge that our critical assessment may also be an overestimate or an underestimate and deserves further scrutiny, and we encourage a more practical use of a database of food and medicinal insects with our suggestion for a querying online curated database. We conclude that making accurate estimates is a difficult feat but that inappropriate assessments can and need to be avoided

Breaking the silence: how shedding light on the bone-skipper fly Thyreophora cynophila (Diptera: Piophilidae) demonstrated it still has a large distribution area in the Pyrenees mountains, France

Thyreophora cynophila (Panzer, 1798) is an iconic species of the European entomofauna. This winter-flying necrophagous fly was considered long extinct in Europe, before being discovered in Spain in 2010 and re-discovered in France in 2020, with a unique locality in Saint-Paul-de-Jarrat (Ariège, southern France).After bringing this species to the attention of people that are active in nature during the winter, including hunters, skilled naturalists, nature lovers and professional naturalists, we gathered seven new occurrence data for this species at six locations on the French flanks of the Pyrenees mountains. Those data considerably extend the known distribution of the species in Europe and allows mapping the first approximate extent of occurrence for this species in France

Detection and Monitoring of Riverine Dragonfly of Community Interest (Insecta: Odonata): Proposal for a Standardised Protocol Based on Exuviae Collection

Collecting quantitative data on insect species occurrence and abundance is a major concern to document population trends. This is especially the case to assess the conservation status of species listed in the European Habitats Directive and to assess the efficiency of mitigation measures with a view to achieve the “no net loss of biodiversity” goal for protected species. However, at present, populations of riverine dragonflies listed in the Habitats Directive and protected under French national law are poorly quantified and monitored. Exuviae collection could be used for such monitoring but a standardised protocol is lacking. We here proposed and tested such a protocol to monitor riverine dragonfly populations through exhaustive exuviae collection along river bank transects. To define the optimal transect size and number of visits, ninety-eight 100 m-long transects divided into 10 m-long plots were monitored on three rivers in southern France. Each transect was visited three times over the emergence period. In the course of each visit, all the exuviae along transects were collected and identified. From our results, we recommend collecting exuviae along 100 m of river bank in the course of two visits in order to both maximise the species detection and minimise the monitoring cost

Aquatic life in Neotropical rainforest canopies: Techniques using artificial phytotelmata to study the invertebrate communities inhabiting therein

International audienceIn Neotropical rainforest canopies, phytotelmata ("plant-held waters'') shelter diverse aquatic macroinvertebrate communities, including vectors of animal diseases. Studying these communities is difficult because phytotelmata are widely dispersed, hard to find from the ground and often inaccessible. We propose here a method for placing in tree crowns "artificial phytotelmata'' whose size and shape can be tailored to different research targets. The efficacy of this method was shown while comparing the patterns of community diversity of three forest formations. We noted a difference between a riparian forest and a rainforest, whereas trees alongside a dirt road cutting through that rainforest corresponded to a subset of the latter. Because rarefied species richness was significantly lower when the phytotelmata were left for three weeks rather than for six or nine weeks, we recommend leaving the phytotelmata for twelve weeks to permit predators and phoretic species to fully establish themselves. (C) 2017 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved

Ants impact the composition of the aquatic macroinvertebrate communities of a myrmecophytic tank bromeliad

International audienceIn an inundated Mexican forest, 89 out of 92 myrmecophytic tank bromeliads (Aechmea bracteata) housed an associated ant colony: 13 sheltered Azteca serica, 43 Dolichoderus bispinosus, and 33 Neoponera villosa. Ant presence has a positive impact on the diversity of the aquatic macroinvertebrate communities (n = 30 bromeliads studied). A Principal Component Analysis (PCA) showed that the presence and the species of ant are not correlated to bromeliad size, quantity of water, number of wells, filtered organic matter or incident radiation. The PCA and a generalized linear model showed that the presence of Azteca serica differed from the presence of the other two ant species or no ants in its effects on the aquatic invertebrate community (more predators). Therefore, both ant presence and species of ant affect the composition of the aquatic macroinvertebrate communities in the tanks of A. bracteata, likely due to ant deposition of feces and other waste in these tanks. (C) 2018 Published by Elsevier Masson SAS on behalf of Academie des sciences