For the moment, no resistance to Bti has been observed in mosquito but it is crucial to develop other candidate larvicides to fulfil the range of effective and environmental-friendly control tools. However, its effectiveness is limited by many biological and environmental factors: sunlight, amount of organic matter, larval density and depth of breeding sites 15. israelensis ( Bti), a natural soil bacteria selected for its exclusive pathogenic action on some species of Diptera 14. temephos, pyriproxyfen, diflubenzuron), the biological larvicide recommended against urban Aedes larvae is derived from Bacillus thuringiensis subsp. The control of urban Aedes larvae is extremely complex to implement because of the diversity and multitude of larval habitats, which are made up of small, and usually cryptic, water containers 13. mosquitoes such as adult traps, lethal ovitraps, autodissemination stations, release of insects with dominant lethality (ridl), sterile insect technique, incompatible insect technique 12 but larval control remains essential and is systematically included in any integrated control strategy. Many innovative approaches are being developed to control Aedes sp. Pyrethroids are the most widely used chemical insecticides in the world but their intensive use has led to the selection of pyrethroid resistant mosquitoes worldwide 8, 10, 11. The application of insecticides can be problematic because of their high environmental and human health toxicity 3, 4, 5, 6, their general toxicity to non-target insects 7, and the insecticide resistance of target mosquitoes 8, 9.
This is mainly practiced by controlling adult mosquito populations through spatial treatments, in emergency situation, using pyrethroid-based chemical insecticides and by controlling larvae through physical suppression of breeding sites or larvicides. In the absence of vaccine or antiviral therapy for the majority of these diseases, vector control is the main strategy to prevent their spread. In the context of globalization and the movement of goods and people, these emerging vector-borne diseases are now present on almost every continent 1, 2. aegypti (the yellow fever mosquito), are particularly invasive species that proliferate in tropical and temperate urban environments and are the main vectors of dengue, chikungunya, yellow fever and more recently Zika viruses. Thus, although even if Aedes albopictus densoviruses could be powerful biocontrol agents used in the management of urban Aedes populations, our results also call into question the use of single viral isolate as biocontrol agents.Īedes albopictus (the tiger mosquito) and Ae. In addition, we also found significant intra-specific variation in infection and mortality rates.
Under laboratory conditions, Aedes albopictus densovirus 2 appeared more virulent for the different strains of Aedes aegypti tested than for those of Aedes albopictus. The two Aedes species were different in terms of susceptibility to viral infection. In this study, we compared infection and mortality rates induced by the Aedes albopictus densovirus 2 in different strains of Aedes albopictus and Aedes aegypti mosquitoes. However, knowledge on the extent of inter- and intra-specific variations in the susceptibility of Aedes mosquitoes to infection by different densoviruses remains insufficient.
Numerous studies have focused on evaluating the potential of different densoviruses species as biological control agents. Alternative control methods, such as the use of mosquito-specific entomopathogenic viruses should be explored. Insecticide resistance and environmental toxicity risks hamper the effectiveness of chemical control against these mosquito vectors. Urban Aedes mosquitoes are vectors of many viruses affecting human health such as dengue, chikungunya and Zika viruses.
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