Mosquito Protection through Screen Doors

※ We used a 18 × 18 mesh screen, as used in standard screen doors.
Experiments were carried out in collaboration with the National Institute of Infectious Disease.

Mosquito Invasion Experiment

The most commonly seen mosquitoes are Culex pipiens (house mosquitos) and Aedes albopictus (tiger mosquitos). They have a body length of around 5mm, therefore just looking at the apertures in screen doors will tell you that they are not capable of passing through the screen. We carried out experiments to determine whether or not properly closed screen doors are able to prevent the entry of mosquitoes.

Experimental Outline

First of all, we created a wind flow from point A to a mouse at point B, thus carrying mouse odor to point C. Mosquitoes were then released at point C, following which they headed for the mouse odor at point B. The effectiveness of an insect mesh was tested by spreading it over the mouse cage at point B.

Results

Normal Screen Door 18×18 mesh

No	Number of Mosquitoes	Mosquitoes that Managed to Invade
1	41	0
2	43	0
3	40	0
4	42	0

Upon starting the experiment, all the mosquitoes made for the source of the mouse odor at point B. The mosquitoes reached the mesh and clung to the mesh surface, however they were not able to pass through, thus they initially flew back and forth between the point of invasion and the mesh, then settled on the surface of the mesh and on walls. The experiment was carried out four times, and on no occasion did the mosquitoes pass through the mesh. It was clear from this experiment that, with the exception of cases in which there are rips or screens are left slightly open, it is not possible for mosquitoes to pass through the mesh, as mosquitoes do not attempt to enter by widening gaps in the mesh.