## 1 Introduction  
Mosquitoes (Diptera: Culicidae) transmit several of the most relevant life-threatening infectious diseases worldwide, including malaria, different types of encephalitis, lymphatic filariasis, West Nile virus, chikungunya, yellow fever, as well as Zika and dengue virus [1; 2; 3; 4; 5]. Recently, chikungunya and Zika virus emerged as two mosquito-borne viral diseases of major public health concern [6; 7; 8]. They are vectored by _Aedes aegypti_ (L.) and _Aedes albopictus_ (Skuse). Besides, a Flaviivirus (Flaviviridae) mainly transmitted by the mosquito _Ae. aegypti_, is causing dengue fever, with significant human morbidity and mortality worldwide [9; 10; 11]. Annually, there are about 390 million humans infected with the dengue virus, with 96 million cases resulting in about 21,000 deaths. This worrying scenario urgently requires the development of effective measures for mosquito control [12; 13]. The recent Zika virus outbreaks in many states of Brazil as well as on Pacific islands provide challenging examples [14; 15; 16]. In Brazil, Zika virus was ranked as one of the most serious public health issues, registering about 1.6 million cases in 2015 [17]. Mosquito vector control has the potential to reduce the impact of several mosquito-borne diseases [18; 19]. Notably, since no effective vaccines against _Aedes_-vectored arboviruses are currently available, the control of vector populations at breeding sites remains crucial in urban and adjacent areas. Chemical insecticides are largely used for the management of mosquito populations, but they can be toxic to humans and non-target organisms, as well as for the environment [20]. They also led to the rapid development of insecticide resistance [21]. This situation demands new and safe mosquito control agents to reduce environmental and human health concerns [22; 23; 24]. In this study, we evaluated the efficacy of the Larvasonic apparatus based on ultrasound technology against _Ae. aegypti_ larval instars developing in diverse aquatic breeding sites in Taiwan. Indeed, since _Ae. aegypti_ widely exploits rather small water containers for oviposition and larval breeding, common in urban areas, it represents a suitable target for the Larvasonic device that was developed for acoustic transmission under water. Ultrasound-based devices are used for other purposes, including microbiological control in aquaculture facilities, and for water treatment of ornamental water bodies and reservoirs [25]. Ultrasound was tested at strikingly different conditions on aquatic organisms, and effect studies are available from the earliest days of anti-mosquito ultrasound use [26]. It was observed that ultrasound can cause ruptures and bubbles that damage animal tissues. Tissue effects by cavitation are related to the duration, intensity, and frequency of acoustic waves [27]. The available ultrasound literature was already discussed by [PERSON] [28] in 2010, who applied ultrasound for algal control in a park pool of Austin, Texas, USA. Before that, ultrasound was used for wastewater treatment [29], as well as for anti-bifouling strategies in marine applications [30]. Concerning young instar management of mosquitoes, lower frequencies (20-50 kHz) are generally more effective in killing mosquito larvae than higher frequencies (\(>\)100 kHz), although the latter more efficiently produce free reactive radicals [31]. In another application, ultrasound-based technology was applied in the characterization of tissue and to evaluate animal carcass quality for human consumption. For instance, [PERSON] et al. [32] measured the intramuscular fat content using spectral analysis echo signals emitted by ultrasound treatment (at \(\sim\)3.5 MHz). In pigs, backfat thickness and the length of the musculus longissimus, as well as fat thickness of the back was measured using an ultrasound scanner (at 3 MHz), as a prediction of meat quality [33]. In poultry, breast muscle thickness, as determined by ultrasonography (at 7 MHz), was shown to provide a reliable measurement of meatimess [34].