1.Comparison of the effectiveness of BG-trap mosquito traps using carbon dioxide versus BG-lure attractants
JIN Shu-qing ; FAN Jian ; CAO Hui ; GAO Qiang ; LENG Pei-en
China Tropical Medicine 2022;22(10):954-
Abstract: Objective To compare the mosquito trapping effect of BG-trap mosquito trap using carbon dioxide versus BG-lure attractant under filed conditions. Methods In August and September 2020, two areas were set with a distance of 100 m. Two sites were set at each area, and one mosquito trap BG trap was set with a distance of 5 m. Each site was set with different flow of CO2 and different amount of BG-lure attractants. The BG-trap mosquito traps on the same area would exchange positions every other day. The mosquitoes captured by each mosquito trap was collected and classified. and the species, sex and number of mosquitoes captured were recorded and counted. Results The densities of Aedes albopictus captured by BG+/CO2-and BG-/CO2+were 14 and 31, and that of Culex pipiens pallens were 2 and 16, respectively. The differences were statistically significant (Aedes albopictus, t=-2.675, P<0.05; Culex pipiens pallens, t=-4.873, P<0.05). With BG-lure attractant, the females of Aedes albopictus and Culex pipiens pallens in the CO2+group were 2.6 (25/9.5) and 12.0 (12 /1) times higher than those in the CO2-group, and the differences were statistically significant (female Aedes albopictus, t=-4.119, P<0.01; female Culex pipiens pallens, t=-4.592, P<0.01), suggesting that the most important attractant to female mosquitoes is CO2. With BG-lure attractant, the male Aedes albopictus in the CO2+ group was 3.0 (12/4) times higher than that in the CO2-group, and the difference was statistically significant (male Aedes albopictus, t=-3.284, P<0.01). Without BG-lure attractant, female Aedes albopictus and female Culex pipiens pallens in the CO2 + group were 1.8 (18 / 10) and 15.5 (15.5/1.0) times higher than those in the CO2-group, and the difference was statistically significant (female Aedes albopictus, t=-2.868, P<0.05; female Culex pipiens pallens, t=-5.259, P<0.05). Without BG-lure attractant, the male Aedes albopictus in the CO2+group was 2.0 (9.0/4.5) times higher than that in the CO2-group, with a statistically significant difference (t=-2.508, P<0.05). With CO2, Aedes albopictus and Culex pipiens pallens in the BG + attractant group were 1.4 (43.5/31) and 0.78 (12.5/16.0) times higher than those in the BG-attractant group, and the differences were not statistically significant (Aedes albopictus, t=-0.943, P>0.05 ; Culex pipiens pallens, t=0.709, P>0.05). Without CO2, Aedes albopictus and Culex pipiens pallens in the BG + attractant group were 1.0 (14/14) and 2.0 (2.0/1.0) times higher than those in the BG + attractant group, and the differences were not statistically significant (Aedes albopictus, t=-0.500, P>0.05; Culex pipiens pallens, t=-1.000, P>0.05). Without BG-lure attractant, the densities of female Aedes albopictus captured by adding 0, 1 and 2 parts of dry ice were 10, 17.5 and 18 respectively, and the difference was statistically significant among the three groups (F=3.942, P<0.05). The densities of female Culex pipiens pallens captured were 1, 13 and 18 respectively, and the difference was statistically significant among the three groups (F=13.881, P<0.05). However, there was no significant difference between the capture of female Aedes albopictus and female Culex pipiens pallens by adding 1 part of dry ice and 2 parts of dry ice (female Aedes albopictus, t=0.112, P>0.05; female Culex pipiens pallens, t=-0.540, P>0.05). Without CO2, 10, 10, 9.5 and 1, 1 and 1.5 female Aedes albopictus and Culex pipiens pallens were captured by adding 0, 1 and 2 portions of BG-lure attractants, respectively. There were no significant differences between the three groups (female Aedes albopictus, F=0.120, P>0.05; female Culex pipiens pallens, F=0.477, P>0.05). Conclusions In the monitoring of BG-trap mosquito trap, the mosquito trapping effect of CO2 is better than that of BG-lure attractant. When the same monitoring effect is obtained, the use of CO2 (100 mL/min) can save the use cost.
2.Environmental management and mosquito control
Pei-En LENG ; Qiang GAO ; Hong-Xia LIU
Shanghai Journal of Preventive Medicine 2016;28(10):687-692
With global warming, mosquitoes and mosquito-borne diseases are spreading rapidly in many regions across the world and producing substantial morbidity and mortality.According to recent studies, mosquito population structure, density and distribution in urban environment are under dynamical changes with continuous urbanization and the consequent environment changes.Surface sewers and under-ground catch basins are becoming major mosquito breeding habitats. Population structure in surface sewers varies with the environment, Aedes albopictus is the dominant species in residential areas.Charac-terized with high population density and mobility, residential areas are easier for mosquito-borne disease spreading, so more attention should be paid to Aedes albopictus control in urban residential areas.Increased underground garages and subway traffic generated new breeding habitats and over wintering sites for mosquitoes in urban environment, control measures should be taken for such environments, since urban underground spaces are always the transit hub of vehicles, which may facilitate the spread of mosquito and its vectored virus, particularly, Culex molestus, Aedes albopictus and Culex tritaeniorhynchus can all be found breeding in underground catch basins.Frequent reports of Culex tritaeniorhynchus breeding in urban surface and underground environment suggest that Culex tritaeniorhynchus is gradually adapted to the new urbanized habitats, which may produce great effect for mosquito population structures in urban environment.Breeding habitats management is the most effective measures for mosquito control, qualified mosquito surveillance can help understand the fluctuation of mosquito species and provide timely warning, at the same time, regular risk assessment for mosquito-borne disease is essential for disease control and prevention.
3.Laboratory study on chain-killing efficacy of four gel baits
Yao LIU ; Pei-en LENG ; Hong-xia LIU ; Jin-qiu XU ; Jiang ZHU ; Ming-qiu FAN ; Yi-bin ZHOU
Shanghai Journal of Preventive Medicine 2020;32(12):996-
Objective To study the first-time killing efficacy and the chain-killing efficacy of four gel baits against
4.Selection and risk assessment of resistance to pyriproxyfen in Culex pipiens pallens
Hong-Xia LIU ; Pei-En LENG ; Jin-Qiu XU ; Yao LIU
Shanghai Journal of Preventive Medicine 2015;27(9):533-536
[ Objective ] To assess the resistance risk of Culex pipiens pallens to pyriproxyfen in Culexpipiens pallens, to predict the rate of resistance development and to provide the reference for scientific and rational application of insecticides. [ Methods ] The resistance strain was developed by group selection, and the realized heritability ( h2 ) of Culex pipiens pallens resistance to deltamethrin was estimated by Tabashnik's method. [ Results] The resistance of Culex pipiens pallens to pyriproxyfen had increased by 5.69-fold after 12 generations of indoor breeding, and the h2 of Culex pipiens pallens to pyriproxyfen was 0.02, indicating that a relatively risk of resistance development. [ Conclusion] The results indicate that Culex pipiens pallens has resistance risk to pyriproxyfen, so the application of the insecticide must be scientific and rational.
5.Surveillance of cockroach population and evaluation of control effects in households from 2017 to 2019 in Jiading District of Shanghai
Shao-hua WANG ; Zheng-rong WU ; Teng-fei DONG ; Qiao-yan WANG ; Wei FANG ; Pei-song ZHONG ; Pei-en LENG ; Ming-qiu FAN ; Hong-xia LIU
Shanghai Journal of Preventive Medicine 2020;32(12):1001-
Objective To learn the population and infestation rates of cockroaches from 2017 to 2019 in Jiading District of Shanghai, to evaluate the effect of cockroach termination in household, and to provide information for cockroach control. Methods Cockroaches were controlled by dinotefuran baits and clean-up in households.Sticky trap and visual method were employed for density monitoring in farmers markets, supermarkets, hotels, restaurants, hospitals, and residential areas.Visual method was used in households before and after using the insecticide. Results Sticky trap result showed the room infestation rate was 3.24%, mean adhesion rate was 3.29%, the density was 0.06 per board, and the density peak appeared in May.Rate of invasion and density decreased year by year.