Experimental analysis of the blood-sucking mechanism of female mosquitoes

Abstract

SUMMARYPioneering studies have been conducted to reveal the functional characteristics of the two-pump system of the female mosquito. Mosquitoes are equipped with two pumping organs located in the head: the cibarial (CP) and the pharyngeal (PP) pumps. To analyze the functional relationship of these pumps during the blood-sucking process, micro-particle image velocimetry (PIV) and synchrotron X-ray micro-imaging were employed. The two pumps were found to be well coordinated with a phase shift () and time shift () but to have distinct functions in the liquid-sucking process. The first pump (CP) starts to expand first, and then the second pump (PP) expands in advance with a time shift () before the first pump (CP) begins to contract, playing a key role in improving pumping performance. The systaltic motion of the two pumps works systematically in a well-coordinated manner. In addition, the pumping performance of blood-sucking female mosquitoes is demonstrated to be superior to that of nectar-eating male mosquitoes. Intake flow rate is maximized by reducing the relaxation time of the CP and increasing the pumping frequency. Supplementary material available online at

Effect of fluid viscosity on the liquid-feeding flow phenomena of a female mosquito

“…To record flow images at the one-quarter location of the food canal from the tip, about half of the cuticle was stripped off using keen-edged forceps. After this treatment, the food canal became translucent (Kim et al, 2011a).…”

“…In our previous study using the synchrotron X-ray imaging technique (Kim et al, 2011a), the pumping process was divided into three phases. In contrast to the present study, the PP expansion was not divided into two phases.…”

“…Kikuchi and Mochizuki visualized the blood flow around the proboscis tip and measured the electrical signals generated from the pump muscles located in the mosquito's head (Kikuchi and Mochizuki, 2011). Kim and colleagues visualized the systaltic motion of the two pumps using a synchrotron X-ray micro-imaging technique (Kim et al, 2011a). Kim and colleagues visualized the three-dimensional morphological structure of the pump system of a female mosquito using synchrotron X-ray microscopic computed tomography (Kim et al, 2012).…”

“…Pappas also showed that the two pumps are out of phase in the initial contraction, but then change to a more in-phase behavior (Pappas, 1988). Kim and colleagues visualized the systaltic motion of the two pumps in detail using a synchrotron X-ray imaging technique and found that the two pumps work systematically with a certain phase shift (Kim et al, 2011a). In the present study, the temporal volume variations of the two pump chambers of female mosquitoes were estimated according to experimental information acquired from in vivo flow measurements.…”

Experimental analysis of the liquid-feeding mechanism of the butterfly Pieris rapae

“…These advanced imaging techniques have been recognized as effective for studying liquid-feeding insects (Westneat et al, 2008;Kikuchi and Mochizuki, 2011;Kim et al, 2011a;Monaenkova et al, 2012). We analyzed the dynamic motion of the cibarial pump and the corresponding ellipsoidal model.…”