The continuous expansion of exotic Aedine mosquito species potential vectors of pathogens into new areas is a public health concern. In continental Europe, the surveillance of these mosquitoes is hindered by the simultaneous presence of three main invasive species (i.e.,Aedes albopictus,Ae.japonicus, andAe.koreicus). Standard low-cost surveillance methods (i.e., the deployment of oviposition traps and count of eggs under stereoscopic microscope) fail to distinguish the eggs of the different species. Identification of eggs by molecular methods is costly and time consuming and prevents measuring the density of invasive species and detecting early new invaders. Here we tested whether certain species could be identified by the patterns on the exochorionic membrane of their eggs. In a first step, we examined Aedine eggs of the three mentioned invasive and one indigenous (i.e.,Ae.geniculatus) species with a high-resolution stereomicroscope and we identified each egg by MALDI-TOF mass spectrometry. In a second step, we submitted images of the eggs to 60 entomology experts and non-experts and tested their ability to distinguish among the species after an initial short training. The results obtained were consistent. Participants did not encounter difficulties in determiningAe.albopictusandAe.geniculatus, while they had more difficulties in distinguishingAe.japonicusfromAe.koreicus. In general, the quality of the exochorion seemed to play a more important role than the expertise level of the rater. The feasibility to differentiateAe.albopictusfrom the other two invasive species is a significant achievement, as this is currently the most problematic species at the level of public health in Europe. Due to the presence of multiple invasive species that might prevent the correct quantification of mosquito population densities using standard surveillance methods and due toAe.aegyptithreat, it is recommended to optically determine also other species.

The sterile insect technique (SIT) is considered a promising and environmentally sustainable tool for controlling Aedes albopictus. While current guidelines address its implementation in moderately large and partially isolated areas, evidence from small, fully urban and spatially connected environments remains limited. In 2025, we evaluated SIT in two municipalities in southern Switzerland, releasing sterile males in small (≈12 ha), non-isolated urban areas representing contrasting operational contexts within ongoing integrated vector management programs. Entomological responses were assessed using a spatial, distance-based framework integrating ovitrap-derived egg abundance and hatching rates from treated and surrounding zones, alongside adult female monitoring. Following releases, egg abundance declined within treated areas relative to surrounding zones, with model-based peak reductions of approximately 57% in Ascona and 67% in Losone. Egg hatching rates were also lower within treated areas, with estimated reductions of approximately 9% and 22%, respectively. For both indicators, spatial analyses revealed gradual distance-dependent patterns rather than abrupt boundary effects. No consistent pattern was detected for adult female abundance, likely reflecting limited sampling intensity. The spatial and temporal responses observed across the two study sites suggest that SIT may contribute to modifying local reproductive dynamics of Ae. albopictus even in small, non-isolated urban areas under operational conditions.