Review: Improving our knowledge of male mosquito biology in relation to genetic control programmes.

The enormous burden placed on populations worldwide by mosquito-borne diseases, most notably malaria and dengue, is currently being tackled by the use of insecticides sprayed in residences or applied to bednets, and in the case of dengue vectors through reduction of larval breeding sites or larviciding with insecticides thereof. However, these methods are under threat from, amongst other issues, the development of insecticide resistance and the practical difficulty of maintaining long-term community-wide efforts. The sterile insect technique (SIT), whose success hinges on having a good understanding of the biology and behaviour of the male mosquito, is an additional weapon in the limited arsenal against mosquito vectors.

Reproductive strategies of Aedes albopictus (Diptera: Culicidae) and implications for the sterile insect technique.

Male insects are expected to optimize their reproductive strategy according to the availability of sperm or other ejaculatory materials, and to the availability and reproductive status of females. Here, we investigated the reproductive strategy and sperm management of male and virgin female Aedes albopictus, a mosquito vector of chikungunya and dengue viruses. The dynamics of semen transfer to the female bursa inseminalis and spermathecae were observed.

The roles of kairomones, synomones and pheromones in the chemically-mediated behaviour of male mosquitoes.

Despite decades of intensive study of the chemical ecology of female mosquitoes, relatively little is known about the chemical ecology of males. This short review summarizes the current state of knowledge of the chemicals that mediate male mosquito behaviour. Various trophic interactions including insect-plant, insect-host, and insect-insect responses are emphasized.

Effects of irradiation, presence of females, and sugar supply on the longevity of sterile males Aedes albopictus (Skuse) under semi-field conditions on Reunion Island.

Background: The development of the sterile insect technique (SIT) for reducing populations of Aedes albopictus (Skuse), (the vector of Chikungunya and Dengue fever), was studied in Reunion Island. For some mosquito species the sterilization process and mating activity may alter male survival. Most previous studies were carried out in the laboratory and may inadequately reflect the field situation.

The sterile insect technique for controlling populations of Aedes albopictus (Diptera: Culicidae) on Reunion Island: mating vigour of sterilized males.

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.

Evidence of multiple inseminations in the field in Aedes albopictus.

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.

Abiotic and biotic factors associated with the presence of Anopheles arabiensis immatures and their abundance in naturally occurring and man-made aquatic habitats.

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.

Vegetation cover and long-term conservation of radioactive waste packages: the case study of the CSM waste disposal facility (Manche District, France).

The CSM is the first French waste disposal facility for radioactive waste. Waste material is buried several meters deep and protected by a multi-layer cover, and equipped with a drainage system. On the surface, the plant cover is a grassland vegetation type.

Spatial and temporal distribution patterns of Anopheles arabiensis breeding sites in La Reunion Island--multi-year trend analysis of historical records from 1996-2009.

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.

Laboratory selection for an accelerated mosquito sexual development rate.

Background: Separating males and females at the early adult stage did not ensure the virginity of females of Anopheles arabiensis (Dongola laboratory strain), whereas two years earlier this method had been successful. In most mosquito species, newly emerged males and females are not able to mate successfully. For anopheline species, a period of 24 h post-emergence is generally required for the completion of sexual maturation, which in males includes a 180° rotation of the genitalia.

Ubiquitous water-soluble molecules in aquatic plant exudates determine specific insect attraction.

Plants produce semio-chemicals that directly influence insect attraction and/or repulsion. Generally, this attraction is closely associated with herbivory and has been studied mainly under atmospheric conditions. On the other hand, the relationship between aquatic plants and insects has been little studied.

Long-term evolutionary stability of bacterial endosymbiosis in curculionoidea: additional evidence of symbiont replacement in the dryophthoridae family.

Bacterial intracellular symbiosis (endosymbiosis) is well documented in the insect world where it is believed to play a crucial role in adaptation and evolution. However, although Coleopteran insects are of huge ecological and economical interest, endosymbiont molecular analysis is limited to the Dryophthoridae family. Here, we have analyzed the intracellular symbiotic bacteria in 2 Hylobius species belonging to the Molytinae subfamily (Curculionoidea superfamily) that exhibit different features from the Dryophthoridae insects in terms of their ecology and geographical spanning.

How human practices have affected vector-borne diseases in the past: a study of malaria transmission in Alpine valleys.

Background: Malaria was endemic in the Rhône-Alpes area of eastern France in the 19th century 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.

Methods: Demographic data of the 19th century were collected from death registers of eight villages of the flood-plain of the river Isère.

Do herbicide treatments reduce the sensitivity of mosquito larvae to insecticides?

Invasive mosquitoes are economic and sanitary concerns especially in Europe and America. Most work has emphasized the role of resistance [Berrada, S., Fournier, D.

Response of Aedes aegypti (Diptera: Culicidae) larvae to three xenobiotic exposures: larval tolerance and detoxifying enzyme activities.

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.