Bacterial plant pathogens affect the locomotor behavior of the insect vector: a case study of Citrus volkameriana-Triozae erytreae-Candidatus Liberibacter asiaticus system.

Plant pathogens can alter the behavior of their insect vectors as well as their survival and reproduction. The African psyllid, Trioza erytreae, is one of the vectors of Huanglongbing, a citrus disease caused mainly by "Candidatus Liberibacter asiaticus" (CLas). The purpose of this study was to characterize the effects of CLas on the psyllid, T.

Triple electroantennography captures the range and spatial arrangement of olfactory sensory neuron response on an insect antenna.

Background: Electroantennography (EAG) is a basic neuroscientific tool that is widely used to measure olfactory responses in insects. It is particularly adapted to probing the olfactory systems of non-model insect species in chemical ecology and evolutionary biology. As currently practiced, EAG measures have varying degrees of correlation with olfactory responses, especially for insects whose olfactory sensory neurons (OSNs) are arranged in zones on the antennae.

The African citrus psyllid : An efficient vector of Liberibacter asiaticus.

Introduction: Huanglonbing (HLB) is the most serious disease of citrus in the world, associated with three non-cultivable phloem-restricted bacteria Liberibacter asiaticus (Las), L. africanus (Laf) and L. americanus (Lam).

Life history parameters and predation capacities of : a new biological control agent for tomato crop.

Whiteflies are one of the major pests of tomato under greenhouses, and their control partly relies on biocontrol strategies. Among those biocontrol agents, parasitoids or predators are widely used. However, the introduction of a biocontrol agent in a new area is not trivial.

When European meets African honeybees (Apis mellifera L.) in the tropics: Morphological changes related to genetics in Mauritius Island (South-West Indian Ocean).

The previous genetic characterization of the honeybee population of Mauritius Island (Indian Ocean) revealed an ongoing process of hybridization between the first established African subspecies Apis mellifera unicolor and recently imported European subspecies (A. m. ligustica, A.

Genome Sequence Resource of ' Liberibacter asiaticus' from Kuwayama (Hemiptera: Liviidae) from La Réunion.

' Liberibacter asiaticus' is an insect-transmitted, phloem-restricted α-proteobacterium associated with huanglongbing. Here, we provide the whole genome sequence of ' L. asiaticus' strain ReuSP1 from its insect vector (Hemiptera: Liviidae) collected in La Réunion.

Great Genetic Diversity but High Selfing Rates and Short-Distance Gene Flow Characterize Populations of a Tree (Foetidia; Lecythidaceae) in the Fragmented Tropical Dry Forest of the Mascarene Islands.

Following the global trend of deforestation and degradation, tropical dry forests in the Mascarenes archipelago on Reunion has undergone harsh reduction and fragmentation within 3 centuries of human occupation. We investigated the genetic diversity, mating system, and gene flow in fragmented populations of the native tree Foetidia mauritiana (Lecythidaceae) on Reunion, using microsatellite genotyping of adults (in- and ex situ) and seed progenies (in situ only). To test genetic isolation between the Mascarene islands, we also genotyped conspecific adults on Mauritius, and trees of Foetidia rodriguesiana on Rodrigues.

Genetic diversity and differentiation among insular honey bee populations in the southwest Indian Ocean likely reflect old geographical isolation and modern introductions.

With globalization the Western honey bee has become a nearly cosmopolitan species, but it was originally restricted to the Old World. This renowned model of biodiversity has diverged into five evolutionary lineages and several geographic "subspecies." If Apis mellifera unicolor is indubitably an African subspecies endemic to Madagascar, its relationship with honey bees from three archipelagos in the southwest Indian Ocean (SWIO) hotspot of biodiversity is misunderstood.

Genetic diversity of Bemisia tabaci species colonizing cassava in Central African Republic characterized by analysis of cytochrome c oxidase subunit I.

After 2007, upsurges of whiteflies on cassava plants and high incidences of cassava diseases were observed in Central African Republic. This recent upsurge in the abundance of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) was directly linked to serious damage to cassava crops resulting from spread of whitefly-borne cassava mosaic geminiviruses (CMGs). There is currently very little information describing whitefly populations on cassava and associated crops in Central African Republic.

Eggplant Resistance to the Species Complex Involves Both Broad-Spectrum and Strain-Specific Quantitative Trait Loci.

Bacterial wilt (BW) is a major disease of solanaceous crops caused by the species complex (RSSC). Strains are grouped into five phylotypes (I, IIA, IIB, III, and IV). Varietal resistance is the most sustainable strategy for managing BW.

Large-scale mitochondrial DNA analysis of native honey bee Apis mellifera populations reveals a new African subgroup private to the South West Indian Ocean islands.

Background: The South West Indian Ocean (SWIO) archipelagos and Madagascar constitute a hotspot of biodiversity with a high rate of endemism. In this area, the endemic subspecies A. m.

Divergent evolutionary and epidemiological dynamics of cassava mosaic geminiviruses in Madagascar.

Background: Cassava mosaic disease (CMD) in Madagascar is caused by a complex of at least six African cassava mosaic geminivirus (CMG) species. This provides a rare opportunity for a comparative study of the evolutionary and epidemiological dynamics of distinct pathogenic crop-infecting viral species that coexist within the same environment. The genetic and spatial structure of CMG populations in Madagascar was studied and Bayesian phylogeographic modelling was applied to infer the origins of Madagascan CMG populations within the epidemiological context of related populations situated on mainland Africa and other south western Indian Ocean (SWIO) islands.

Rapid accumulation and low degradation: key parameters of Tomato yellow leaf curl virus persistence in its insect vector Bemisia tabaci.

Of worldwide economic importance, Tomato yellow leaf curl virus (TYLCV, Begomovirus) is responsible for one of the most devastating plant diseases in warm and temperate regions. The DNA begomoviruses (Geminiviridae) are transmitted by the whitefly species complex Bemisia tabaci. Although geminiviruses have long been described as circulative non-propagative viruses, observations such as long persistence of TYLCV in B.

Host Plant Specialization in the Sugarcane Aphid Melanaphis sacchari.

Most aphids are highly specialized on one or two related plant species and generalist species often include sympatric populations adapted to different host plants. Our aim was to test the hypothesis of the existence of host specialized lineages of the aphid Melanaphis sacchari in Reunion Island. To this end, we investigated the genetic diversity of the aphid and its association with host plants by analyzing the effect of wild sorghum Sorghum bicolor subsp.

Description and phylogenetic placement of Beauveria hoplocheli sp. nov. used in the biological control of the sugarcane white grub, Hoplochelus marginalis, on Reunion Island.

On Reunion Island successful biological control of the sugarcane white grub Hoplochelus marginalis Fairmaire (Coleoptera: Melolonthidae) has been conducted for decades with strains from the entomopathogenic fungal genus Beauveria (Ascomycota: Hypocreales). A study based on morphological characters combined with a multisequence phylogenetic analysis of genes that encode the translation elongation factor 1-alpha (TEF1), RNA polymerase II largest subunit (RPB1), RNA polymerase II second largest subunit (RPB2) and the Bloc nuc intergenic region was carried out on Beauveria strains isolated on Reunion and Madagascar from H. marginalis.

Assessing hygienic behavior of Apis mellifera unicolor (Hymenoptera: Apidae), the endemic honey bee from Madagascar.

Hygienic behavior (HB) is one of the natural mechanisms of honey bee for limiting the spread of brood diseases and Varroa destructor parasitic mite. Objective of our study was to measure HB of Apis mellifera unicolor colonies (N = 403) from three geographic regions (one infested and two free of V. destructor) in Madagascar.

Asystasia mosaic Madagascar virus: a novel bipartite begomovirus infecting the weed Asystasia gangetica in Madagascar.

Here, we describe for the first time the complete genome sequence of a new bipartite begomovirus in Madagascar isolated from the weed Asystasia gangetica (Acanthaceae), for which we propose the tentative name asystasia mosaic Madagascar virus (AMMGV). DNA-A and -B nucleotide sequences of AMMGV were only distantly related to known begomovirus sequence and shared highest nucleotide sequence identity of 72.9 % (DNA-A) and 66.

Low genetic diversity in Melanaphis sacchari aphid populations at the worldwide scale.

Numerous studies have examined the genetic diversity and genetic structure of invading species, with contrasting results concerning the relative roles of genetic diversity and phenotypic plasticity in the success of introduced populations. Increasing evidence shows that asexual lineages of aphids are able to occupy a wide geographical and ecological range of habitats despite low genetic diversity. The anholocyclic aphid Melanaphis sacchari is a pest of sugarcane and sorghum which originated in the old world, was introduced into the Americas, and is now distributed worldwide.

Frequency-dependent assistance as a way out of competitive exclusion between two strains of an emerging virus.

Biological invasions are the main causes of emerging viral diseases and they favour the co-occurrence of multiple species or strains in the same environment. Depending on the nature of the interaction, co-occurrence can lead to competitive exclusion or coexistence. The successive fortuitous introductions of two strains of Tomato yellow leaf curl virus (TYLCV-Mld and TYLCV-IL) in Réunion Island provided an ideal opportunity to study the invasion of, and competition between, these worldwide emerging pathogens.

Honeybee biomarkers as promising tools to monitor environmental quality.

The aim of this study was to distinguish the impacts of two different anthropogenic conditions using the honeybee Apis mellifera as a bioindicator associated with a battery of biomarkers previously validated in the laboratory. Both the urban (RAV, Ravine des Cabris) and semi-natural (CIL, Cilaos) sites in La Reunion Island were compared in order to assess the impacts of two types of local pollution using the discriminating potential of biomarkers. Hives were placed at the CIL and RAV sites and honeybees were collected from each hive every three months over one year.

Haemorrhagic shock, therapeutic management.

The management of a patient in post-traumatic haemorrhagic shock will meet different logics that will apply from the prehospital setting. This implies that the patient has beneficiated from a "Play and Run" prehospital strategy and was sent to a centre adapted to his clinical condition capable of treating all haemorrhagic lesions. The therapeutic goals will be to control the bleeding by early use of tourniquet, pelvic girdle, haemostatic dressing, and after admission to the hospital, the implementation of surgical and/or radiological techniques, but also to address all the factors that will exacerbate bleeding.

Molecular characterization of a new alphasatellite associated with a cassava mosaic geminivirus in Madagascar.

Two complete nucleotide sequences of an alphasatellite isolated from a cassava plant with mosaic disease symptoms in Madagascar are described and analyzed. While the helper begomovirus was identified as an isolate of East African cassava mosaic Kenya virus (EACMKV), its associated alphasatellite was most closely related (80 % nucleotide sequence identity) to cotton leaf curl Gezira alphasatellite. These satellite molecules have typical features of alphasatellites, with a single gene in the virion sense, an A-rich region and a stem-loop structure.