It was reported that there was no significant difference in the capture efficiency of light traps among the three kinds of mosquitoes widely distributed in China, Cx. quinquefasciatus, Ae. Albopictus and An. sinensis in laboratory tests. . Cx. Quinquefasciatus is stipulated as tested insects by Chinese National Standard Laboratory Efficacy Test Methods and Criterion of Public Health Equipment—Electronic Trap for Mosquitoes and Flies. In this study, Cx. Quinquefasciatus was also chosen to evaluate the capture efficiency of five light traps.
The ultraviolet light of all five household mosquito traps had a wavelength range of 390-400nm, which conformed to the standard ultraviolet light range. According to the Pearson correlation coefficient, the correlation coefficient between the ultraviolet light wavelength of the five mosquito traps and the mosquito capture rate in the laboratory was subtle (P > 0.05). Therefore, the ultraviolet light wavelength was not a significant factor influencing the difference of capture rate in the selected mosquito traps. In the study of David P Tchouassi, the attraction preferences of blue(430nm), green(570nm), red(660nm) and ultraviolet(390nm) light to mosquitoes were compared, and the results showed that blue and green light in visible light have relatively higher mosquito trapping efficiency than others. B M Costa-Neta’s research also supports that LED mosquito traps equipped with green(520nm) and blue(470nm) light have higher trapping efficiency. However, Alongkot Ponlawat's research shows that the traps that emit ultraviolet light (10-400nm) are better than green(490-570nm) and red(620-780nm) light, which is completely opposite to the results of previous studies. In the study of Emmanuel P. Mwanga, the effect of UV (364nm) LED mosquito trap is equal to or better than CDC incandescent lamp, and the indoor effect is better than outdoor. The mosquito traps in this study have a relatively small range of ultraviolet light and does not involve research in the visible light band. Follow-up will expand the ultraviolet light band and select the blue and green light in the previous research conclusions for the next step.
In this study, the fan speed and laboratory capture rate exhibited a linear relationship according to Pearson correlation coefficient analysis on the air suction efficiency of the mosquito traps, which showed that fan speed might be a crucial factor influencing the mosquito capture performance of the traps (P < 0.05). Other researchers also tested the effect of different fan speeds against the performance of the trap in capturing mosquitoes. The result showed that 1.7 m/s was the ideal suction rate to obtain a higher capture rate and lower damage to the bodies of captured mosquitoes. In our study, mosquito trap 5 had the highest capture rate with an air suction rate of 2m/s. And the mosquitoes captured did not show critical damage to their bodies. Therefore, we guess that the mosquito capture performance can be enhanced by appropriately increasing the air suction rate, but whether this conclusion can be drawn remains to be further studied.
Mosquito trap 5 and trap 1 had the highest mosquito capture rates during the laboratory and field tests. This may be due to their shape and structural design, which were different from the other three mosquito traps (Fig. 2). Trap 5 and trap 1 have inclined upward-opening entries, which means they can capture mosquitoes from 360° around the top, whereas the entries of the other three traps are located at the middle (Fig. 2B), where the airflow into the entries is parallel and thus there is a smaller capture area. The capture area might be one factor influencing the mosquito capture rate.
National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention reported that the mosquito species in residential areas in 2018 was mainly Cx. quinquefasciatus, accounting for 60.25% of the total; in 2019, the species of mosquitoes in residential areas were Cx. quinquefasciatus Mainly 57.73%, followed by Anopheles sinensis, Cx. tritaeniorhynchus, and Ae. albopictus, which accounted for 20.27%, 12.22%, and 2.29%, respectively. In the greenhouse experiment of this study, the 5 kinds of mosquito traps caught the most mosquito species were Cx. quinquefasciatus, accounting for 51.76%, followed by Ae. albopictus (25.29%). The capture of Cx. quinquefasciatus is roughly in line with the national survey and monitoring in the past two years. The population density of Ae. albopictus is higher than the national total, which also reflects one of the reasons for the frequent outbreaks of dengue fever in Guangxi in recent years, which may be caused by the increasing population density of Ae. albopictus.
Mosquito trap 5 and trap 1 had a relatively high capture rate of mosquitoes, which was significantly higher than that of the other three traps. Further, the difference was particularly significant in the capturing of Cx. quinquefasciatus. The total effective radiation of mosquito trap 5 exceeded the standard quite a bit, and its air suction rate was also the largest, which may be the reason for its high capture rate.
Mosquito trap 1 achieved high capture efficiency under the premise of product compliance and should be an excellent choice among the five mosquito traps for household use that we evaluated.
There were few studies on the capture rate of mosquito traps for household use. This study tested the product parameters of five popular mosquito traps, the capture rate in the laboratory and the capture rate in a field test and preliminary data obtained, which provided research and development ideas for improving the performance of mosquito traps marketed for household use in China.