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Uptake of liquid from wet surfaces by the brush-tipped proboscis of a butterfly.

Lee SC, Lee SJ - Sci Rep (2014)

Bottom Line: This study investigated the effect of the brush-tipped proboscis of the Asian comma (Polygonia c-aureum) on wet-surface feeding.The liquid-feeding flow between the proboscis and the wet surface was measured by micro-particle image velocimetry.The film flow that passes through the sensilla styloconica region shows a parabolic velocity profile, and the corresponding flow rate is proportional to the cubed length of the sensilla styloconica.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang Gyeongbuk, Republic of Korea [2] Center for Biofluid and Biomimic Research, Pohang University of Science and Technology, Pohang Gyeongbuk, Republic of Korea.

ABSTRACT
This study investigated the effect of the brush-tipped proboscis of the Asian comma (Polygonia c-aureum) on wet-surface feeding. The tip region of this proboscis was observed, especially two microstructures; the intake slits through which liquid passes into the proboscis and the brush-like sensilla styloconica. The sensilla styloconica were connected laterally to the intake slits in the tip region. The liquid-feeding flow between the proboscis and the wet surface was measured by micro-particle image velocimetry. During liquid feeding, the sensilla styloconica region accumulates liquid by pinning the air-liquid interface to the tips of the sensilla styloconica, thus the intake slit region remains immersed. The film flow that passes through the sensilla styloconica region shows a parabolic velocity profile, and the corresponding flow rate is proportional to the cubed length of the sensilla styloconica. Based on these observations, we demonstrated that the sensilla styloconica promotes the uptake of liquid from wet surfaces. This study may inspire the development of a microfluidic device to collect liquid from moist substrates.

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Morphological structure of the proboscis of the Asian comma (Polygonia c-aureum).(a) Coiled proboscis with sensilla styloconica (yellow) (b) Image of the cross-section that passes through the center of the coiled proboscis. Fc. food canal; Dl. dorsal linkage; Vl. ventral linkage; Ss. sensilla styloconica. (c) Sagittal images of the area near the tip. (Modification of the dorsal linkage coincides with the appearance of sensilla styloconica).
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f1: Morphological structure of the proboscis of the Asian comma (Polygonia c-aureum).(a) Coiled proboscis with sensilla styloconica (yellow) (b) Image of the cross-section that passes through the center of the coiled proboscis. Fc. food canal; Dl. dorsal linkage; Vl. ventral linkage; Ss. sensilla styloconica. (c) Sagittal images of the area near the tip. (Modification of the dorsal linkage coincides with the appearance of sensilla styloconica).

Mentions: We identified the structural characteristics of the proboscis used to uptake liquid from wet surfaces through synchrotron X-ray micro-CT. 3D reconstruction images of the proboscis and its cross-sectional images were generated. The proboscis of the test butterfly was coiled (Fig. 1a); thus, several cross-sections of the proboscis were observed and their morphological characteristics were analyzed (Fig. 1b). The proboscis was composed of two galeae that were linked dorsally and ventrally to form a food canal between them4 (Fig. 1b). The widths of the two galeae and of the food canal were relatively constant, with the exception of the tapered tip region12. The decreased galea width in this region is offset by the elongated sensilla structure known as the sensilla styloconica, which is observed laterally (Fig. 1b). The overall external width of the proboscis is thus maintained. The cross-section of the proboscis is flat with a wide dorsal side as in Fig. 1b, and its aspect ratio is approximately 3.37:1. In addition to this wide cross-sectional area, the proboscis displays a projecting dorsal linkage structure (Fig. 1b). To determine the morphological characteristics of the tip region, the formations of the inlet structure and of sensilla styloconica were examined in detail. The sagittal cross-section images indicate that the dorsal linkage near the tip is shaped like a curved turbine blade (Fig. 1c). This morphological feature leaves intake slits between the curved linkage structures (Figs. 2a, b). The dorsal linkage structures overlap well and function as the roof wall of the food canal along the rest of the proboscis4 (Figs. 2a, b).


Uptake of liquid from wet surfaces by the brush-tipped proboscis of a butterfly.

Lee SC, Lee SJ - Sci Rep (2014)

Morphological structure of the proboscis of the Asian comma (Polygonia c-aureum).(a) Coiled proboscis with sensilla styloconica (yellow) (b) Image of the cross-section that passes through the center of the coiled proboscis. Fc. food canal; Dl. dorsal linkage; Vl. ventral linkage; Ss. sensilla styloconica. (c) Sagittal images of the area near the tip. (Modification of the dorsal linkage coincides with the appearance of sensilla styloconica).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4221773&req=5

f1: Morphological structure of the proboscis of the Asian comma (Polygonia c-aureum).(a) Coiled proboscis with sensilla styloconica (yellow) (b) Image of the cross-section that passes through the center of the coiled proboscis. Fc. food canal; Dl. dorsal linkage; Vl. ventral linkage; Ss. sensilla styloconica. (c) Sagittal images of the area near the tip. (Modification of the dorsal linkage coincides with the appearance of sensilla styloconica).
Mentions: We identified the structural characteristics of the proboscis used to uptake liquid from wet surfaces through synchrotron X-ray micro-CT. 3D reconstruction images of the proboscis and its cross-sectional images were generated. The proboscis of the test butterfly was coiled (Fig. 1a); thus, several cross-sections of the proboscis were observed and their morphological characteristics were analyzed (Fig. 1b). The proboscis was composed of two galeae that were linked dorsally and ventrally to form a food canal between them4 (Fig. 1b). The widths of the two galeae and of the food canal were relatively constant, with the exception of the tapered tip region12. The decreased galea width in this region is offset by the elongated sensilla structure known as the sensilla styloconica, which is observed laterally (Fig. 1b). The overall external width of the proboscis is thus maintained. The cross-section of the proboscis is flat with a wide dorsal side as in Fig. 1b, and its aspect ratio is approximately 3.37:1. In addition to this wide cross-sectional area, the proboscis displays a projecting dorsal linkage structure (Fig. 1b). To determine the morphological characteristics of the tip region, the formations of the inlet structure and of sensilla styloconica were examined in detail. The sagittal cross-section images indicate that the dorsal linkage near the tip is shaped like a curved turbine blade (Fig. 1c). This morphological feature leaves intake slits between the curved linkage structures (Figs. 2a, b). The dorsal linkage structures overlap well and function as the roof wall of the food canal along the rest of the proboscis4 (Figs. 2a, b).

Bottom Line: This study investigated the effect of the brush-tipped proboscis of the Asian comma (Polygonia c-aureum) on wet-surface feeding.The liquid-feeding flow between the proboscis and the wet surface was measured by micro-particle image velocimetry.The film flow that passes through the sensilla styloconica region shows a parabolic velocity profile, and the corresponding flow rate is proportional to the cubed length of the sensilla styloconica.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang Gyeongbuk, Republic of Korea [2] Center for Biofluid and Biomimic Research, Pohang University of Science and Technology, Pohang Gyeongbuk, Republic of Korea.

ABSTRACT
This study investigated the effect of the brush-tipped proboscis of the Asian comma (Polygonia c-aureum) on wet-surface feeding. The tip region of this proboscis was observed, especially two microstructures; the intake slits through which liquid passes into the proboscis and the brush-like sensilla styloconica. The sensilla styloconica were connected laterally to the intake slits in the tip region. The liquid-feeding flow between the proboscis and the wet surface was measured by micro-particle image velocimetry. During liquid feeding, the sensilla styloconica region accumulates liquid by pinning the air-liquid interface to the tips of the sensilla styloconica, thus the intake slit region remains immersed. The film flow that passes through the sensilla styloconica region shows a parabolic velocity profile, and the corresponding flow rate is proportional to the cubed length of the sensilla styloconica. Based on these observations, we demonstrated that the sensilla styloconica promotes the uptake of liquid from wet surfaces. This study may inspire the development of a microfluidic device to collect liquid from moist substrates.

Show MeSH