## 5 Conclusions and Challenges for Future Research  
This study provided three main results achieved through the employment of the Larvasonic device against _Ae. aegypti_ young instars: (i) both the distance from the source of acoustic waves and the exposure time significantly affected mosquito larval mortality; (ii) the efficacy of the Larvasonic device was high even in the field over various _Aedes_ breeding sites; and (iii) we did not detect negative impacts on the non-target copep species _M. formosanus_, which is of interest for providing additional biological predatory control of mosquito larvae. The application of this method is particularly suitable for small urban and peri-urban water bodies where young instars of _Ae. aegypti_ may develop at high densities. Therefore, the size of the experimental setup can be increased in future applications and research to assess the efficacy of this tool in large-scale real-world scenarios. Our laboratory and field studies suggest that an ultrasound-based technology has a good potential for future applications for mosquito larval control. Therefore, can be considered among integrated vector management tools to manage mosquito-borne diseases in an ecofriendly way.  
As recommended by the World Health Organization in 2005, tests with new products and technologies should follow standard methodologies and should be carried out mainly with third and fourth instar mosquito larvae. In relation to the field experiment, another important factor affecting the efficacy of this tool is the volume of water at breeding sites, as already stressed in earlier researches [5]. Depending on the volume of water in the container, the effect can vary, thus decreasing larval mortality. Another factor is the timing of mortality after larval exposure in respective treatments. In addition, field tests should be carried out at larger scale.  
The applied technology should be improved to minimize side effects on non-target species in aquatic ecosystems. In this framework, further research is still needed to assess the impact of the Larvasonic device on other aquatic non-target organisms. In addition, future _in situ_ applications could include ultrasonic devices integrated in a remotely operating vehicle with a function similar to a vacuum cleaner. Furthermore, artificial intelligence could integrate signals of a laser sensor that would automatically detect and target mosquito larvae and pupae. This application would successfully manage mosquito populations, reducing environmental pollution and non-target effects of still widely used chemical insecticides.  
[PERSON] conceived and designed the experiments. [PERSON] performed the laboratory experiments. [PERSON], [PERSON], [PERSON], and [PERSON] performed the field experiments. [PERSON] and [PERSON] analyzed the data, prepared the figures, and wrote the original draft. [PERSON] contributed reagents, materials, and analysis tools. [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON] and [PERSON] contributed to formal analysis, data curation and reviewed/edited the manuscript. All authors have read and agreed to the published version of the manuscript.  
The authors are grateful for financial support from the Ministry of Science and Technology (MOST) of Taiwan through grant no. MOST 104-2611-M-019-004, MOST 105-2621-M-019-001, MOST 105-2918-I-019-001, MOST 106-2621-M-019-001, MOST 107-2621-M-019-001 and MOST 108-2621-M-019-003 to [PERSON], as well as the grant no. MOST 104-2811-M-019-005, MOST 105-2811-M-019-008, MOST 107-2811-M-019-004 and MOST 108-2811-M-019-504 to [PERSON]. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.  
We appreciated the innovation and kind technical assistance of [PERSON] (New Mountain Innovations, NY, USA), who developed the Larvasonic device. Finally, we thank [PERSON] for his assistance in manuscript submission.  
The authors declare no conflict of interest.