Laura Soresinetti

Mosquitoes are vectors of numerous pathogens that pose significant threats to human and animal health, making their monitoring crucial for effective disease control. Environmental DNA (eDNA)–based approaches enable the detection of multiple organisms in their habitats without the need for morphological identification. However, they require strict and extensive protocol optimization. In this study, we focused on the need for novel monitoring strategies, particularly ones capable of overcoming the limitations of traditional methods. Given the central role of water in the life cycle of mosquitoes, we explored whether eDNA collected from aquatic habitats could provide an effective tool for mosquito detection and taxonomic identification. Specifically, we aimed to evaluate whether an eDNA‐based approach can reliably detect multiple mosquito species and accurately discriminate among them under different community compositions. To this end, we developed and validated a protocol for an eDNA‐based detection and identification method for mosquito monitoring. First, we assessed its performance by conducting laboratory experiments on samples containing nine different combinations of larvae from five mosquito species. eDNA occupancy analysis revealed varying species‐specific detection probabilities, with Aedes albopictus showing the highest detection rate and Aedes koreicus the lowest. Overall detection probability was high at moderate to high larval densities (5 to 50 ind/L), whereas it decreased at 0.5 ind/L, indicating reduced sensitivity at very low larval concentrations. Then, we collected 165 water samples from three types of field locations and assessed the influence of ecological variables, including land use and site type, on mosquito detection probability. Our results indicate that eDNA represents a promising tool for mosquito monitoring, particularly in contexts where larval densities are not extremely low, and may support its future integration into vector surveillance and control program.

Background: Aedes koreicus is a mosquito species native to East Asia which has recently invaded several countries in Europe. In Italy, this mosquito was first detected in the North-East in 2011 and is now widely distributed in the entire northern part of the country. The development of specific genetic markers, such as microsatellites, is necessary to uncover the dispersal routes of this mosquito from its native areas and, eventually, to plan future control interventions. Methods: Available raw sequences of genomic DNA of Ae. koreicus were screened in silico using BLASTn to identify possible microsatellite-containing sequences. Specific primer pairs were then designed, and their efficiency was determined through polymerase chain reaction (PCR) on 32 individuals of Ae. koreicus collected in Italy. PCR conditions were optimised in three multiplex reactions. Genotyping of individual mosquitoes was performed on both single and multiplex PCR reactions. Finally, analysis of intra-population variation was performed to assess the level of polymorphism of the markers. Results: Mosquito genotyping provided consistent results in both single and multiplex reactions. Out of the 31 microsatellite markers identified in the Ae. koreicus genome raw sequences, 11 were polymorphic in the examined mosquito samples. Conclusions: The results show that the 11 microsatellite markers developed here hold potential for investigating the genetic structure of Ae. koreicus populations. These markers could thus represent a novel and useful tool to infer the routes of invasion of this mosquito species into Europe and other non-native areas. Graphical

Background: Post-translational modifications of histones constitute a dynamic process impacting gene expression. A well-studied modification is lysine methylation. Among the lysine histone methyltr...

The Asian tiger mosquito, Aedes albopictus, has become one of the most important invasive vectors for disease pathogens such as the viruses that cause chikungunya and dengue. Given the medical importance of this disease vector, a number of control programmes involving the use of the sterile insect technique (SIT) have been proposed. The identification of chemical compounds that attract males can be very useful for trapping purposes, especially for monitoring the makeup of the male population during control programmes, such as those involving the use of the SIT. Twenty-eight chemical compounds from different chemical classes were evaluated using a dual-port olfactometer assay. The compounds included known animal, fungal and plant host volatiles, and components of a putative Aedes aegypti pheromone. Many of the compounds were repellent for male mosquitoes, especially at the highest concentration. One compound, decanoic acid, acted as an attractant for males at an intermediate concentration. Decanoic acid did not elicit a significant response from female mosquitoes.