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International audience; An updated checklist of 235 mosquito species from Madagascar is presented. The number of species has increased considerably compared to previous checklists, particularly the last published in 2003 (178 species). This annotated checklist provides concise information on endemism, taxonomic position, developmental stages, larval habitats, distribution, behavior, and vector-borne diseases potentially transmitted. The 235 species belong to 14 genera: Aedeomyia (3 species), Aedes (35 species), Anopheles (26 species), Coquillettidia (3 species), Culex (at least 50 species), Eretmapodites (4 species), Ficalbia (2 species), Hodgesia (at least one species), Lutzia (one species), Mansonia (2 species), Mimomyia (22 species), Orthopodomyia (8 species), Toxorhynchites (6 species), and Uranotaenia (73 species). Due to non-deciphered species complexes, several species remain undescribed. The main remarkable characteristic of Malagasy mosquito fauna is the high biodiversity with 138 endemic species (59%). Presence and abundance of species, and their association, in a given location could be a bio-indicator of environmental particularities such as urban, rural, forested, deforested, and mountainous habitats. Finally, taking into account that Malagasy culicidian fauna includes 64 species (27%) with a known medical or veterinary interest in the world, knowledge of their biology and host preference summarized in this paper improves understanding of their involvement in pathogen transmission in Madagascar.; Une liste mise à jour des 235 espèces de moustiques de Madagascar est présentée. Le nombre d’espèces a considérablement augmenté par rapport à celui donné dans les listes précédentes, en particulier la dernière, publiée en 2003 (178 espèces). Cette liste fournit des informations concises sur l’endémisme, la position taxonomique, les stades de développement, les gîtes larvaires, la distribution, le comportement des moustiques, et aussi sur les maladies potentiellement transmises par les moustiques vecteurs. Ces 235 espèces sont réparties dans 14 genres : Aedeomyia (3 espèces), Aedes (35 espèces), Anopheles (26 espèces), Coquillettidia (3 espèces), Culex (au moins 50 espèces), Eretmapodites (4 espèces), Ficalbia (2 espèces), Hodgesia (au moins une espèce), Lutzia (une espèce), Mansonia (2 espèces), Mimomyia (22 espèces), Orthopodomyia (8 espèces), Toxorhynchites (6 espèces), Uranotaenia (73 espèces). En raison de complexes d’espèces non résolus, plusieurs espèces sont toujours non décrites. La principale caractéristique remarquable de la faune malgache de moustiques est la grande biodiversité avec 138 espèces endémiques (59 %). La présence et l’abondance des espèces, et leur association dans un endroit donné, pourrait être un bio-indicateur des particularités environnementales telles que les habitats urbains, ruraux, forestiers, déboisés et montagneux. Enfin, compte tenu que la faune malgache de moustiques comprend 64 espèces (27 %) ayant un intérêt médical ou vétérinaire connu dans le monde, la connaissance de leur biologie et de leur préférence d’hôtes résumée dans le présent document permet de comprendre leur implication dans la transmission d’agents pathogènes à Madagascar.

Background Anopheles arabiensis (Diptera: Culicidae) is a potential malaria vector commonly present at low altitudes in remote areas in Reunion Island. Little attention has been paid to the environmental conditions driving larval development and abundance patterns in potential habitats. Two field surveys were designed to determine whether factors that discriminate between aquatic habitats with and without An. arabiensis larvae also drive larval abundance, comparatively in man-made and naturally occurring habitats. Methods In an initial preliminary survey, a representative sample of aquatic habitats that would be amenable to an intensive long-term study were selected and divided into positive and negative sites based on the presence or absence of Anopheles arabiensis larvae. Subsequently, a second survey was prompted to gain a better understanding of biotic and abiotic drivers of larval abundance, comparatively in man-made and naturally occurring habitats in the two studied locations. In both surveys, weekly sampling was performed to record mosquito species composition and larval density within individual habitats, as well as in situ biological characteristics and physico-chemical properties. Results Whilst virtually any stagnant water body could be a potential breeding ground for An. arabiensis, habitats occupied by their immatures had different structural and biological characteristics when compared to those where larvae were absent. Larval occurrence seemed to be influenced by flow velocity, macrofauna diversity and predation pressure. Interestingly, the relative abundance of larvae in man-made habitats (average: 0.55 larvae per dip, 95%CI [0.3–0.7]) was significantly lower than that recorded in naturally occurring ones (0.74, 95%CI [0.5–0.8]). Such differences may be accounted for in part by varying pressures that could be linked to a specific habitat. Conclusions If the larval ecology of An. arabiensis is in general very complex and factors affecting breeding site productivity sometimes not easy to highlight, our results, however, highlight lower populations of An. arabiensis immatures compared to those reported in comparable studies conducted in the African continent. Overall, this low larval abundance, resulting from both abiotic and biotic factors, suggests that vector control measures targeting larval habitats are likely to be successful in Reunion, but these could be better implemented by taking environmental variability into account.

Reunion Island suffers from high densities of the chikungunya and dengue vector Aedes Reunion Island suffers from high densities of the chikungunya and dengue vector Aedes albopictus. The sterile insect technique (SIT) offers a promising strategy for mosquito-borne diseases prevention and control. For such a strategy to be effective, sterile males need to be competitive enough to fulfil their intended function by reducing wild mosquito populations in natura. We studied the effect of irradiation on sexual maturation and mating success of males, and compared the sexual competitiveness of sterile versus wild males in the presence of wild females in semi-field conditions. For all untreated or sterile males, sexual maturation was completed within 13 to 20 h post-emergence and some males were able to inseminate females when 15 h old. In the absence of competition, untreated and sterile males were able to inseminate the same number of virgin females during 48 h, in small laboratory cages: an average of 93% of females was inseminated no matter the treatment, the age of males, and the sex ratio. Daily mating success of single sterile males followed the same pattern as for untreated ones, although they inseminated significantly fewer females after the ninth day. The competitiveness index of sterile males in semi-field conditions was only 0.14 when they were released at 1-day old, but improved to 0.53 when the release occurred after a 5-day period in laboratory conditions. In SIT simulation experiments, a 5:1 sterile to wild male ratio allowed a two-fold reduction of the wild population's fertility. This suggests that sterile males could be sufficiently competitive to mate with wild females within the framework of an SIT component as part of an AW-IPM programme for suppressing a wild population of Ae. albopictus in Reunion Island. It will be of interest to minimise the prerelease period in controlled conditions to ensure a good competitiveness without increasing mass rearing costs.

This review describes the major stored-product insect species and their resistance to insecticides. The economic importance of the control of those pests is highlighted with a loss of more than one billion US dollars per year worldwide. A detailed common description of species resistance throughout the world has been developed, and we observed 28 recurrent studied species involved in resistance cases disseminated on the five continents. The different mechanisms, including behavioral resistance, were studied particularly onOryzaephilus surinamensis. The role of detoxifying enzymes and studies on the genetic resistance, involving thekdrmutation mechanisms and the transmission of the genes of resistance, are also described. A chapter clarifying definitions on cross and multiple resistance is enclosed.

International audience; Studies on the biology and mating behaviour of male mosquitoes are of major importance in a frame of a Sterile Insect Technique which could be used against mosquito vector species. Most particularly, the assumption of possible multiple inseminations in mosquito species must be investigated in order to optimize alternative mosquito control methods (Sterile Insect Techniques with genetically modified mosquitoes, cytoplasmic incompatibility, radiation…). The occurrence of multiple insemination events was investigated after 2 field samplings of Aedes albopictus (Diptera: Culicidae) in La Reunion Island using microsatellite markers. Respectively, 14 and 13 females after the first and the second sampling laid eggs. Seven wild females out of the 27 laying females were found with a progeny involving more than one father. This result is important for the new alternative mosquito control methods and raises the importance of pre- and post-copulatory competition.

International audience; The bacterio-insecticide Bacillus thuringiensis subsp. israelensis (Bti) represents currently a safe alternative to chemical insecticides in mosquito-borne diseases control and is intensively used worldwide. In the French Rhône-alpine mosquito Aedes rusticus Rossi, several genomic signatures of selection were detected in populations treated for more than 15 years with Bti. In this study we investigated whether detoxifying enzyme activities such as cytochromes P450, esterases and glutathione S-transferases can play a role in Bti resistance mechanisms in these populations. To examine the effect of Bti treatment on larval resistance and detoxifying enzyme activities, Bti mortality and enzymatic activities were measured in treated and untreated sites coming from four different locations in the Rhône-Alpes region. The results revealed a significant global decrease in Bti mortality in treated populations, but showed low resistance ratio up to 7.9-fold between treated and untreated sites. A positive correlation has been observed between larval resistance to Bti and glutathione S-transferase activities, raising the question of its potential role in Bti resistance. A better understanding of all the mechanisms potentially involved in Bti resistance is necessary to insure the long-term efficiency of this bacterio-insecticide.

Background An often confounding facet of the dynamics of malaria vectors is the aquatic larval habitat availability and suitable conditions under which they can thrive. Here, we investigated the impact of environmental factors on the temporal and spatial distribution of larval habitats of Anopheles arabiensis in different locations on La Reunion Island. Methods A retrospective examination was made from archival data which provided the complete enumeration of An. arabiensis breeding habitats in three distinct geographic zones - extending North-east, West and South of the island over 14 years, from January 1996 to December 2009. Data on the occurrence and the number of active larval habitats at each of a total of 4376 adjacent ellipsoid grid cells (216,506 square meters each) were used (1) to provide the geographic extent of breeding site availability from year to year and (2) to analyze associations with prevailing environmental factors, habitat types, and locations. Results Anopheles arabiensis utilized a spectrum of man-made and natural aquatic habitats, most of which were concentrated primarily in the rock pools located in ravines and river fringes, and also in the large littoral marshes and within the irrigated agricultural zones. The numbers of breeding site per sampling grid differed significantly in different parts of the island. In contrast to an originally more widespread distribution across the island in the 1950s, detailed geographic analyses of the data obtained in the period extending from 1996-2009 showed an intriguing clustered distribution of active breeding sites in three discontinuous geographic zones, in which aquatic habitats availability fluctuates with the season and year. Seasonality in the prevalence of anopheles breeding sites suggests significant responsiveness to climatic factors. Conclusions The observed retreat of An. arabiensis distribution range to lower altitudinal zones (< 400 m) and the upward shift in the most remote littoral areas in the northeast and southwest regions suggest the possible influence of biogeographic factors, changes in land use and control operations. The results of this study would allow for a more rational implementation of control strategies across the island.

To the Editor: Yersinia pestis (family Enterobacteriaceae) is a bacterium that can cause high rates of death in susceptible mammals and can provoke septicemic, pneumonic, and bubonic plague in humans (1). This zoonotic pathogen can be transmitted directly by infectious droplets or by contact with contaminated fluid or tissue or indirectly through flea bites (1). Plague was introduced into Madagascar in 1898 from rat-infested steamships that had sailed from affected areas (2). Now, Madagascar is 1 of 2 countries in Africa that have reported cases of human plague every year since 1991 (3). During January 2008–January 2013, the number of human plague cases reported in Madagascar ranged from 312 to 648 per year. Of these, 61.8%–75.5% were laboratory confirmed (National Plague Laboratory of the Ministry of Health, pers. comm.). Most (>83%) confirmed cases were bubonic plague, which most commonly results from flea bites, suggesting that these bites were the most common mode of Y. pestis transmission. In Madagascar, Xenopsylla cheopis fleas have been known as the primary plague vector in urban areas, whereas Synopsyllus fonquerniei fleas have been usually involved in plague transmission in rural areas (2). In January 2013, a total of 9 suspected bubonic plague cases, 3 confirmed, were reported in Soavina, a rural area in the district of Ambatofinandrana, Madagascar. Domestic fleas were collected with candle traps inside 5 houses during 3 nights (Table). Fleas were also caught on small mammals trapped inside houses and outside in the sisal fences and rice fields (Table). A total of 319 fleas belonging to 5 species in 5 genera were collected inside and outside the houses, an average of 44 per house (maximum 71): Pulex irritans, Echidnophaga gallinacea, and Ctenocephalides canis fleas were collected inside the houses (244, 76.5%), and S. fonquerniei and X. cheopis fleas were collected outside (75, 23.5%). The human flea, P. irritans, was the most collected flea species (233, 73.3%), followed by S. fonquerniei (62, 19.4%), X. cheopis (13, 4.1%), E. gallinacea (10, 3.1%), and C. canis (1, 0.3%). Table Fleas collected inside and outside houses in Soavina, Madagascar, January 2013 Bacterial DNA was extracted from 277 fleas of 5 species: 233 P. irritans, 24 S. fonquerniei, 9 X. cheopis, 10 E. gallinacea, and 1 C. canis. PCR to detect Y. pestis was performed by using primers YP1 (5′-ATC TTA CTT TCC GTG AGA AG-3′) and YP2 (5′-CTT GGA TGT TGA GCT TCC TA-3′) to amplify a 478-bp fragment (4). Y. pestis DNA was then amplified and genotyped by Beckman Coulter Genomics Inc. (Takeley, United Kingdom). The positive control was Y. pestis reference strain (strain 6/69, 3 × 108 bacteria/mL; Institut Pasteur de Madagascar). Detection of Y. pestis was carried out on 274 fleas belonging to 5 flea species: 230 P. irritans (181 unfed and 49 engorged), 24 S. fonquerniei (15 unfed and 9 engorged), 9 X. cheopis (8 unfed and 1 engorged), 10 E. gallinacea (blood-feeding status not identified), and 1 unfed C. canis. Y. pestis was detected in 9 P. irritans fleas (7 male [6 unfed and 1 engorged] and 2 [engorged] female) from 3 houses, including the house where a confirmed human case of plague had occurred (Technical Appendix). Eight sequences (GenBank accession nos. {"type":"entrez-nucleotide-range","attrs":{"text":"KJ361938-KJ361945","start_term":"KJ361938","end_term":"KJ361945","start_term_id":"608789158","end_term_id":"608789172"}}KJ361938-KJ361945) were obtained and share 99% nucleotide homology with plasminogen activator genes of Y. pestis published in GenBank (accession nos. {"type":"entrez-nucleotide","attrs":{"text":"AF528537","term_id":"22212811","term_text":"AF528537"}}AF528537, {"type":"entrez-nucleotide","attrs":{"text":"AY305870","term_id":"32250732","term_text":"AY305870"}}AY305870). No Y. pestis was detected in the 24 S. fonquerniei, 9 X. cheopis, 10 E. gallinacea, or 1 C. canis fleas collected. Although only X. cheopis and S. fonqueniei fleas had previously been described as plague vectors in Madagascar, P. irritans fleas were most commonly collected during this field study; engorged and unfed male and female P. irritans fleas carried Y. pestis. Other studies have found P. irritans fleas in the plague risk area in other countries in Africa (5,6); one study found that P. irritans fleas may play a role in plague epidemiology in Tanzania (5). Data on P. irritans fleas in rats make it unlikely that these fleas are involved in rat-to-human transmission of Y. pestis in Madagascar. During 1922–1995, a total of 118,608 rats were caught and examined in Madagascar, but only 148 P. irritans fleas were identified, and none have been found on rats since 1996 (http://www.pasteur.mg/spip.php?rubrique124). The high density of P. irritans fleas we observed in villages where plague outbreaks occurred in late 2012 and early 2013 (http://www.pasteur.mg/spip.php?rubrique124) supports the possibility that P. irritans fleas played a role in domestic human-to-human transmission of Y. pestis during these outbreaks. Technical Appendix: Agarose gel electrophoresis showing positive PCR results for Yersinia pestis in DNA of 9 Pulex irritans fleas collected from 3 houses in an area of Madagascar where plague outbreaks occurred in late 2012 and early 2013. Click here to view.(47K, pdf)

Identification of genes involved in local adaptation is particularly challenging for species functioning as a network of interconnected populations undergoing frequent extinctions-recolonizations, because populations are submitted to contrasted evolutionary pressures. Using amplified fragment length polymorphism markers, population genetic structure of the mosquito Aedes rusticus was analysed in five geographical areas of the French Rhône-Alpes region. We included a number of sites that were treated with the bio-insecticide Bacillus thuringiensis israelensis (Bti) for more than 15 years. Analysis of molecular variance revealed that most of the genetic variability was found within populations (96%), with no significant variation among geographical areas, although variation among populations within areas (4%) was significant. The global genetic differentiation index F(ST) was low (0.0366 +/- 0.167). However, pairwise F(ST) values were significant and no isolation-by-distance at the regional level was observed, suggesting a metapopulation structure in this species. Bti-treatment had no effect on genetic structure and on within-population genetic diversity. Potential signatures of positive selection associated with Bti-treatment were detected for five loci, even though toxicological bioassays performed on field-collected larvae showed no significant difference in mortality between Bti-treated and nontreated sites. The difficulty of detecting moderate resistance in field-collected larvae together with possible differential persistence of toxins in the environment may explain our inability to detect a toxicological response to Bti in treated sites. The evidence for positive selection occurring at several genomic regions suggests a first step towards Bti resistance in natural mosquito populations treated with this bio-insecticide. Furthermore, this signal was detectable using genomic tools before any toxicological evidence for resistance could be identified.

In the present study, four populations of the same field mosquito species, Ochlerotatus cataphylla, were sampled over the Rhone-Alpes region (France), and their respective sensitivity to the organophosphate temephos and the bacterio-insecticide Bacillus thuringiensis var. israelensis (Bti) was measured. The results obtained in toxicological tests showed significant differences in the larval sensitivities of the four populations for both insecticides. These differences appeared to be related to the activity of the three main families of detoxifying enzymes: Cytochrome P450 monooxygenases, glutathione-S-transferases (GSTs), and esterases. All three enzyme families were significantly overexpressed in the less susceptible larval population, and after multiple regressions, GSTs and esterases came out as the most explicative variables of the larval sensitivity. Considering these results and the chemical history of the sites in terms of insecticide treatments, the hypothesis of cross-effects of insecticides leading to resistance acquisition to Bti in field organisms emerges.

Photons with energies above 6 MeV can be used to detect small amounts of nuclear material inside large cargo containers. The method consists in using an intense beam of high-energy photons (bremsstrahlung radiation) in order to induce reactions of photofission on actinides. The measurement of delayed neutrons and delayed gammas emitted by fission products brings specific information on localization and quantification of the nuclear material. A simultaneous measurement of both of these delayed signals can overcome some important limitations due to matrix effects like heavy shielding and/or the presence of light elements as hydrogen. We have a long experience in the field of nuclear waste package characterization by photon interrogation and we have demonstrated that presently the detection limit can be less than one gram of actinide per ton of package. Recently we tried to extend our knowledge to assess the performance of this method for the detection of special nuclear materials in sea and air freights. This paper presents our first results based on experimental measurements carried out in the SAPHIR facility, which houses a linear electron accelerator with the energy range from 15 MeV to 30 MeV. Our experiments were also modeled using the full scale Monte Carlo techniques. In addition, and in a more general frame, due to the lack of consistent data on photonuclear reactions, we have been working on the development of a new photonuclear activation file (PAF), which includes cross sections for more than 600 isotopes including photofission fragment distributions and delayed neutron tables for actinides. Therefore, this work includes also some experimental results obtained at the ELSA electron accelerator, which is more adapted for precise basic nuclear data measurements.

International audience; The ability of mosquito larvae to tolerate toxic compounds (temephos, Bacillus thuringiensis var. israelensis, toxic vegetable leaf litter) was examined on a laboratory larval strain of Aedes aegypti L. Bioassays and detoxifying enzyme activity measurements were performed to compare tolerance/resistance capacities. The possibility of a functional plasticity of detoxifying equipment was investigated through experimental determination of the inductive effect of each xenobiotic within a given generation. In the same way, the selective effect of a toxic leaf litter was also investigated along successive generations. Results revealed that differential cytochrome P450 monooxygenase, esterase, and glutathione S-transferase activity levels correlated with the bioassay results. Both induction and selection increased larval tolerance to the xenobiotics used and increased the levels of larval detoxifying enzyme activities.

International audience; Invasive mosquitoes are economic and sanitary concerns especially in Europe and America. Most work has emphasized the role of resistance [Berrada, S., Fournier, D., Cuany, A., Nguyen, TX, 1994. Identification of resistance mechanisms in a selected laboratory strain of Cacopsylla pyri (Homoptera: Psyllidae): altered acetylcholinesterases and detoxifying oxidases. Pesticide Biochemistry and Physiology 48, 41-47; Hemingway, J., Hawkes, N.J., McCarroll, L., Ranson, H., 2004. The molecular basis of insecticide resistance in mosquitoes. Insect Biochemistry and Molecular Biology 34, 653-665] to insecticides. Compounds acting on larval sensitivity to insecticides are not well studied and their action remains poorly understood. Among several residual chemicals in ecosystems, particularly in wetlands, we identified a possible interaction of an herbicide on larval resistance to an insecticide. Our work contributes to the global control of mosquito populations by identifying possible pathways of resistance to insecticides of these vectors. Resistance or tolerance to insecticide treatments might contribute to successful invasion by mosquitoes. Here we report an ecotoxicological approach to test the hypothesis of an indirect effect of atrazine on mortality of an invasive vector. A brief contact (48 h) between Aedes aegypti mosquito larvae and atrazine led to a modification of larval sensitivity to an insecticide: using atrazine as an inducer led to a decrease in the mortality of larvae treated with Bacillus thuringiensis var. israelensis (Bti). (c) 2006 Elsevier Ltd. All rights reserved.

International audience; The response of mosquito larvae to plant toxins found in their breeding sites was investigated by using Aedes aegypti larvae and toxic arborescent leaf litter as experimental models. The relation between larval tolerance to toxic leaf litter and cytochrome P450 monooxygenases (P450 s) was examined at the toxicological, biochemical and molecular levels. Larvae pre-exposed to toxic leaf litter show a higher tolerance to those xenobiotics together with a strong increase in P450 activity levels. This enzymatic response is both time- and dose-dependent. The use of degenerate primers from various P450 genes (CYPs) allowed us to isolate 16 new CYP genes belonging to CYP4, CYP6 and CYP9 families. Expression studies revealed a 2.3-fold over-expression of 1 CYP gene (CYP6ALI) after larval pre-exposure to toxic leaf litter, this gene being expressed at a high level in late larval and pupal stages and in fat bodies and midgut. The CYP6ALI protein has a high level of identity with other insect's CYPs involved in xenobiotic detoxification. The role of CYP genes in tolerance to natural xenobiotics and the importance of such adaptive responses in the capacity of mosquitoes to colonize new habitats and to develop insecticide resistance mechanisms are discussed. (c) 2006 Elsevier Ltd. All rights reserved.

BackgroundMalaria was endemic in the Rhône-Alpes area of eastern France in the 19thcentury and life expectancy was particularly shortened in Alpine valleys. This study was designed to determine how the disease affected people in the area and to identify the factors influencing malaria transmission.MethodsDemographic data of the 19thcentury were collected from death registers of eight villages of the flood-plain of the river Isère. Correlations were performed between these demographic data and reconstructed meteorological data. Archive documents from medical practitioners gave information on symptoms of ill people. Engineer reports provided information on the hydraulic project developments in the Isère valley.ResultsDescription of fevers was highly suggestive of endemic malaria transmission in the parishes neighbouring the river Isère. The current status of anopheline mosquitoes in the area supports this hypothesis. Mean temperature and precipitation were poorly correlated with demographic data, whereas the chronology of hydrological events correlated with fluctuations in death rates in the parishes.ConclusionNowadays, most of the river development projects involve the creation of wet areas, enabling controlled flooding events. Flood-flow risk and the re-emergence of vector-borne diseases would probably be influenced by the climate change. The message is not to forget that human disturbance of any functioning hydrosystem has often been linked to malaria transmission in the past.

International audience; The mosquito-borne arbovirus Zika virus (ZIKV, Flavivirus, Flaviviridae), has caused an outbreak impressive by its magnitude and rapid spread. First detected in Uganda in Africa in 1947, from where it spread to Asia in the 1960s, it emerged in 2007 on the Yap Island in Micronesia and hit most islands in the Pacific region in 2013. Subsequently, ZIKV was detected in the Caribbean, and Central and South America in 2015, and reached North America in 2016. Although ZIKV infections are in general asymp-tomatic or causing mild self-limiting illness, severe symptoms have been described including neuro-logical disorders and microcephaly in newborns. To face such an alarming health situation, WHO has declared Zika as an emerging global health threat. This review summarizes the literature on the main vectors of ZIKV (sylvatic and urban) across all the five continents with special focus on vector competence studies.

International audience; Background: The diapause of Aedes albopictus is maternally induced by photoperiod and initiates at the pharate larvae stage in eggs. This pre-diapause results in enhanced survival eggs during the winter. This study aims to disentangle the effects of photoperiod and diapause on embryonic developmental time and egg size in A. albopictus. A temperate strain capable to perform diapause and a tropical strain unable of diapause were reared at 21°C with long-(LD) and short-day (SD) lengths. Four distinct traits were studied on embryos and eggs were measured at the end of embryogenesis.Results: The chronologies of embryo development for both strains were influenced by maternal photoperiod, especially in the temperate strain in which the development of SD eggs took longer than LD eggs. The delay increased gradually in the temperate strain, and reached up to 38 h at the end of embryogenesis. The kinetics of embryogenesis differed among the temperate and the tropical strains, each one of the 4 studied traits showing differences. For example the serosal cuticle was secreted precociously in the tropical strain. Egg width and volume are influenced by the maternal photoperiod and the strain  photoperiod interaction. For both strains, larger eggs were laid by female reared under SD when compared to LD.Conclusions: The influence of several maternal effects was demonstrated in this study. The diapause process modifies greatly the length of embryogenesis in the temperate strain, whereas the maternal photoperiod has a direct influence on egg size and embryogenesis regardless of the strain considered. These findings provide useful data on chronology of embryonic development for integrative biology studies of egg pre-diapause stages.

This meeting report presents the outcomes of a workshop held in Bangkok on December 1st 2014, where the following challenges were discussed: the threat of resistance to artemisinin and artemisinin-based combination therapy in the Greater Mekong Sub-region (GMS) and in Africa; access to treatment for most at risk and hard to reach population; insecticide resistance, residual and outdoors transmission. The role of operational research and the interactions between research institutions, National Malaria Control Programmes, Civil Society Organizations, and of financial and technical partners to address those challenges and to accelerate translation of research into policies and programmes were debated. The threat and the emergency of the artemisinin resistance spread and independent emergence in the GMS was intensely debated as it is now close to the border of India. The need for key messages, based on scientific evidence and information available and disseminated without delay, was highlighted as crucial for an effective and urgent response. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-0802-4) contains supplementary material, which is available to authorized users.

International audience; Background: Indoor spraying of insecticides and the use of insecticide-treated bed nets are key strategies for national malaria vector control in the central highlands of Madagascar. During the year 2013, malaria outbreaks were reported by the National Malaria Control Programme in the highlands, including the district of Ankazobe. Methods: Entomological trapping was carried out in April and May 2013 and in March 2014, using human landing catches, collection of mosquitoes resting in stables and in houses by oral aspirators, and Centers for Disease Control and Prevention light traps. Detection of Plasmodium in mosquitoes was carried out on head and thorax of anophe-line females by ELISA, CSP and PCR (Plasmodium falciparum, Plasmodium malariae, Plasmodium vivax, or Plasmodium ovale). Human biting rate (HBR), sporozoite index and entomological infection rate (EIR) were calculated for Anopheles funestus, Anopheles arabiensis, Anopheles mascarensis, and Anopheles coustani. Results: In Ankazobe district, the presence of malaria vectors such as An. funestus, An. arabiensis and An. mascaren-sis was confirmed, and a new and abundant potential vector, An. coustani was detected. Indeed, one individual of An. funestus and two An. coustani were detected positive with P. falciparum while one An. mascarensis and four An. coustani were positive with P. vivax. For An. coustani, in March 2014, the EIR varied from 0.01 infectious bites/person/ month (ipm) outdoors to 0.11 ipm indoors. For An. funestus, in April 2013, the EIR was 0.13 ipm. The highest HBR value was observed for An. coustani, 86.13 ipm outdoors. The highest sporozoite rate was also for An. coustani, 9.5 % of An. coustani caught in stable was sporozoite positive. Conclusion: The implication of An. coustani in malaria transmission was not previously mentioned in Madagascar. Its very high abundance and the detection of Plasmodium coupled with an opportunistic feeding behaviour in villages with malaria cases supports its role in malaria transmission in Madagascar.

International audience; Background: Madagascar is a malaria-endemic country with an increase in cases in recent years. In vector control using insecticide, a susceptible strain is necessary to evaluate insecticide efficacy, either for spraying or on nets. The susceptibility of Anopheles arabiensis from Antananarivo, Madagascar to two organophosphate, three pyrethroid, two carbamate, and one organochlorine insecticides was investigated. Since 2010, An. arabiensis strain has been maintained away from insecticide source during 110 generations with optimal insectarium conditions. Methods: Bioassay were performed on adult mosquitoes to assess the susceptibility of An. arabiensis to insecticideimpregnated papers (malathion 5 %, fenitrothion 1 %, deltamethrin 0.05 %, permethrin 0.75 %, alphacypermethrin 0.05 %, bendiocarb 0.1 %, propoxur 0.01 %, and DDT 4 %) following World Health Organization Pesticide Evaluation Scheme guidelines. Bioassay using Center for Disease Control bottle tests were also used to detect mortality. Molecular assay were carried out to detect the presence of knock down resistance (kdr) mutation using PCR techniques. Results: Anopheles arabiensis is fully susceptible with 100 % mortality to malathion, fenitrothion, deltamethrin, permethrin, alphacypermethrin, bendiocarb, propoxur, and DDT. No kdr gene was detected using PCR method. Conclusion: The strain An. arabiensis maintained in the insectarium of Institut Pasteur de Madagascar is a fully susceptible strain and can be used for insecticide evaluation.

International audience; The large and recent migrations of the main vector of the Chikungunya virus, Aedes albopictus, raise questions about the epidemiological impact of possible microevolutionary changes in new territories. Quantitative traits are suitable to detect such changes as induced by environmental adaptations, local competition and founder effects. Using landmark-based geometric morphometrics, we compared the size and shape of 22 populations (1572 females) of Ae. albopictus. The collection sites covered five countries around the world, with special emphasis on Asia, which is assumed to be the origin of the vector. Some collections came from places where an important epidemic outbreak of Chikungunya has recently occurred.Quantitative comparisons were based on 18 anatomical landmarks on the wing. To contrast geographic and possible interspecific shape variation, close species were introduced in the sample, namely five Aedes riversi and nine Ae. flavopictus from Japan. The three species had similar size, but they were clearly separated by shape.Within Ae. albopictus, there was general agreement on size variation with the available climatic data. Shape variation was less related to climatic data than to either geography or a known itinerary of past territorial expansion. Thus, two main clusters were distinguished by wing shape variation: the first one composed of the Southeast Asian sample, the second one grouping Japan, Florida, Hawaii and the Reunion Island samples.The Southeast Asian countries, assumed to be at the origin of the geographic expansion of the mosquito, had similar wings and constituted a distinct group where localities clustered into northern and southern localities. Contrasting with this homogeneous group, very distant localities such as United States (US) and Japan shared a common shape pattern. The US Ae. albopictus samples (Hawaii and Florida) were indeed very similar to the Japanese samples, with Florida behaving exactly like a northern Japanese locality, close to Tokyo and Yokohama. Shape proximity among these distant areas could be explained by a common and relatively recent ancestor, as generally suggested in the literature. The three Reunion Island samples conformed a group external to the Southeast Asian countries, loosely connected to the remaining localities.Thus, areas where recent epidemics took place, the Reunion Island and the southernmost localities of Thailand, did not cluster together, but represented separate groups.In sum, the size of the wing was apparently under the influence of climatic factors, while its shape could contribute information on species and geographic differences. Apparent departures from expectations based on geography were explained by known past and present migratory routes. These patterns of shape variation were compatible with genetic drift, suggesting microevolutionary changes probably induced by the expansion of the Ae. albopictus mosquito.