Search results for "arthropod"
showing 10 items of 308 documents
Modulation of voltage-gated Na+ and K+ channels by pumiliotoxin 251D: A “joint venture” alkaloid from arthropods and amphibians
2008
Abstract Certain amphibians provide themselves with a chemical defense by accumulating lipophilic alkaloids into skin glands from dietary arthropods. Examples of such alkaloids are pumiliotoxins (PTXs). In general, PTXs are known as positive modulators of voltage-gated sodium channels (VGSCs). Unlike other PTXs, PTX 251D does not share this characteristic. However, mice and insect studies showed that PTX 251D is highly toxic and to date the basis of its toxicity remains unknown. In this work, we searched for the possible target of PTX 251D . The toxin was therefore made synthetically and tested on four VGSCs (mammalian rNa v 1.2/β 1 , rNa v 1.4/β 1 , hNa v 1.5/β 1 and insect Para/tipE ) and…
Behaviour-modifying compounds for management of the red palm weevil (Rhynchophorus ferrugineus Oliver).
2014
BACKGROUND: Populations of red palm weevil (RPW), a severe pest of palms in Mediterranean countries, might be limited by semiochemical-based behaviour-disrupting methods. We evaluated the effects of electroantennogram (EAG)-active plant volatiles on the behaviour of RPWs from Italy and Israel. In field experiments, α-pinene, citronellol, geraniol, citral and 1-octen-3-ol were tested for their ability to disrupt attraction to pheromone-kairomone and molasses baited traps. Those that were found to be disruptive in the field were evaluated in a laboratory choice bioassay in individual cages for their effect on RPW female feeding and oviposition. RESULTS: Field experiments showed reduced captur…
The diversity and evolution of chelicerate hemocyanins
2012
Abstract Background Oxygen transport in the hemolymph of many arthropod species is facilitated by large copper-proteins referred to as hemocyanins. Arthropod hemocyanins are hexamers or oligomers of hexamers, which are characterized by a high O2 transport capacity and a high cooperativity, thereby enhancing O2 supply. Hemocyanin subunit sequences had been available from horseshoe crabs (Xiphosura) and various spiders (Araneae), but not from any other chelicerate taxon. To trace the evolution of hemocyanins and the emergence of the large hemocyanin oligomers, hemocyanin cDNA sequences were obtained from representatives of selected chelicerate classes. Results Hemocyanin subunits from a sea s…
Notes on Afrotropical Cydnidae (Heteroptera) with emphasis on vehicle-mounted net samples and description of a new species from Liberia, West Africa
2019
Notes on the Cydnidae fauna in Liberia, sampled with a vehicle-mounted net, the species taxonomy and general distribution are reported, including the description of Chilocoris elongatus sp. nov. In addition, new country records are provided for Angola, Ethiopia, Gabon, Guine a-Bissau, Namibia, Niger, Republic of South Africa, Sierra Leone, Tanzania, Togo, Uganda, and Zimbabwe.
Exploit biodiversity in viticultural systems to reduce pest damage and pesticide use, and increase ecosystem services provision: the Biovine project
2019
International audience; Organic vineyards still rely on large external inputs to control harmful organisms (i.e., pests). The BIOVINE project aims to develop natural solutions based on plant diversity to control pests and reduce pesticide dependence. The capability of plants of increasing the ecosystem resistance to pests and invasive species is a well-known ecosystem service. However, monocultures (including vineyards) do not exploit the potential of plant diversity. BIOVINE aims to develop new viticultural systems based on increased plant diversity within (e.g., cover crops) and/or around (e.g., hedges, vegetation spots) vineyards by planting selected plant species for the control of arth…
Les épandages de déchets modifient-ils la qualité biologique des sols agricoles à long terme ? Résultats du programme VADEBIO
2012
EA EcolDur CT3; National audience
Réseau Bayésien Dynamique étiqueté pour l’apprentissage de réseau écologique d’arthropodes dans les cultures
2018
National audience; Un réseau écologique représente l’ensemble des interactions entre les différentes espèces d’un écosystème. Parmi les réseaux d’intérêt, on peut citer les réseaux écologiques renseignant sur les interactions entre les espèces vivantes de parcelles cultivées. La connaissance de tels réseaux peut être très utile dans la connaissance de la biodiversité et la gestion des parcelles cultivées. Cependant, la connaissance de la structure de ces réseaux est rarement complète. Dans cet article, nous décrivons l’apprentissage de réseau écologique d’arthropodes dans des parcelles expérimentales au Royaume-Uni à partir de l’information de la présence/absence des espèces au cours du tem…
All-day activity of Dolichovespula saxonica (Hymenoptera, Vespidae) colonies in Central Finland
2022
In social vespid wasps, colony activity varies at many temporal scales. We studied the peak season activity (number of individuals entering the nest per min) of colonies of the social vespine wasp Dolichovespula saxonica in its native range in boreal Finland. Six colonies were monitored non-stop for a full day, starting before sunrise and ending after sunset. Shorter monitoring was carried out before and/or after the full-day monitoring. All colonies were active before sunrise and after sunset, and the overall activity was positively linked with colony size. Activity showed irregular minute-to-minute cycles in all colonies. The broader within-day dynamics were idiosyncratic among the coloni…
Lipocalins in Arthropod Chemical Communication.
2021
Abstract Lipocalins represent one of the most successful superfamilies of proteins. Most of them are extracellular carriers for hydrophobic ligands across aqueous media, but other functions have been reported. They are present in most living organisms including bacteria. In animals they have been identified in mammals, molluscs, and arthropods; sequences have also been reported for plants. A subgroup of lipocalins, referred to as odorant-binding proteins (OBPs), mediate chemical communication in mammals by ferrying specific pheromones to the vomeronasal organ. So far, these proteins have not been reported as carriers of semiochemicals in other living organisms; instead chemical communicatio…
Tempo and mode of early gene loss in endosymbiotic bacteria from insects
2006
Abstract Background Understanding evolutionary processes that drive genome reduction requires determining the tempo (rate) and the mode (size and types of deletions) of gene losses. In this study, we analysed five endosymbiotic genome sequences of the gamma-proteobacteria (three different Buchnera aphidicola strains, Wigglesworthia glossinidia, Blochmannia floridanus) to test if gene loss could be driven by the selective importance of genes. We used a parsimony method to reconstruct a minimal ancestral genome of insect endosymbionts and quantified gene loss along the branches of the phylogenetic tree. To evaluate the selective or functional importance of genes, we used a parameter that meas…