Figure 1.
Taxis boxes experimental design.
Two taxis boxes placed 1 m away from the stimulus/treatment that is: a human or human and a coil. Mosquitoes were introduced in the middle chamber of each taxis box and the stimulus/treatment was changed each day to determine the effect on orientation of mosquitoes.
Figure 2.
Point source experimental set up.
These experiments were conducted in the semi – field tunnel. In the control, two coils were placed on one side of the human. The distance between the coils and the human was changed each day to determine the protective distance of coils. Coils were not used in the control. Mosquitoes were released inside the tunnel and they were left to acclimatize for 10 minutes and then the human started collecting mosquitoes that landed on the bare feet.
Figure 3.
Experiments were conducted in the semi – field tunnel. A coil was placed equidistant on either side of the human. The distance was changed each night to determine the protective distance. Coils were not used in the control. Mosquitoes were released inside the tunnel and left to acclimatize for 10 minutes and then the human started collecting mosquitoes.
Figure 4.
Dose response of mosquitoes to Transfluthrin coils with a human using taxis boxes.
Horizontal histogram presenting the percentage proportion of mosquitoes activated, attracted and repelled by control (no stimulus) and treatments: human alone, human + blank coil, human +0.015% Transfluthrin coil, human +0.030% Transfluthrin coil, human +0.045% Transfluthrin coil) in the taxis boxes. The table includes percentage proportions and their confidence intervals.
Table 1.
The odds ratios and proportion of activated and attracted mosquitoes in taxis boxes placed 1 meter away from different doses of mosquito coils and a human.
Table 2.
The proportion of biting mosquitoes in the presence of 0.03% Transfluthrin coils placed as a point source at different distances.
Table 3.
The proportion of biting mosquitoes in the presence of 0.03% Transfluthrin coils creating a ‘bubble’ around the user.
Figure 5.
The effect of Transfluthrin coils on blood feeding behavior of mosquitoes in a Peet Grady chamber.
Mosquitoes were exposed to different doses of Transfluthrin coils inside a Peet Grady chamber and later offered blood meals at different time intervals. The proportion of blood fed mosquitoes was compared between different doses and the control that had no coil. The proportion of blood fed mosquitoes was significantly lower than the control in all treatments after 25 minutes (a) and 1 hour (a). At 12 hours only 0.03% Transfluthrin coils significantly (b) reduced feeding compared to the control while after 24 hours there was no significant difference between all treatments and controls (c).
Table 4.
The proportion of mosquitoes that blood fed at different time intervals following exposure to different doses of Transfluthrin coils inside a Peet Grady chamber.
Figure 6.
The effect of Transfluthrin coils on blood feeding behavior of mosquitoes in a Semi-Field Tunnel.
The proportion of blood fed mosquitoes after they had been exposed to mosquito coils in the semi-field tunnel is presented in the two graphs. The graph on the left indicates caged mosquitoes and the one on the right indicates free flying mosquitoes. In the left graph the proportion of blood fed mosquitoes was significantly lower in the treatment compared to the control after only after 1 hour. In the right graph, the proportion of blood fed mosquitoes was not significantly different between controls and treatments at all times.