Experiments on blood-sucking mechanism of a female mosquito*

The blood-sucking phenomena of a female mosquito were investigated experimentally At first, the velocity fields of blood-sucking flow inside the proboscis of a female mosquito were measured consecutively using a micro particle image velocimetry (PIV) system The velocity signals of the blood-sucking flow in the proboscis show a periodic pulsatile flow pattern and the spectral analysis of the velocity waveform exhibits a clear peak at 6.1 Hz. The blood flow inside the proboscis has a parabolic profile, similar to that of a Hagen-Poiseuille flow. In addition, the synchrotron X-ray micro-imaging technique was employed to visualize the dynamic movement of the two pumping organs (cibarial pump and pharyngeal pump) inside the head of blood-sucking using iodine solution as a contrast material. The temporal variation of the two pump organs of a female mosquito was found to be superior, compared to that of a male mosquito. In addition, we found the functional relationship of the two pumps operating in a systematic manner with a small phase difference.