Mechanics of nectar feeding in the orchid beeEuglossa imperialis: pressure, viscosity and flow
| Autor: | Brendan J. Borrell |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Sucrose
Suction Viscosity Physiology Proboscis Euglossa imperialis Feeding Behavior Bees Aquatic Science Biology Biomechanical Phenomena chemistry.chemical_compound Animal science chemistry Insect Science Botany Pressure Animals Nectar Animal Science and Zoology Molecular Biology Ecology Evolution Behavior and Systematics Pressure gradient Ambient pressure |
| Zdroj: | Journal of Experimental Biology. 209:4901-4907 |
| ISSN: | 1477-9145 0022-0949 |
| DOI: | 10.1242/jeb.02593 |
| Popis: | SUMMARYThe orchid bee Euglossa imperialis sucks nectars through a slender proboscis. I tested how nectar properties influence this suction pressure and whether ambient air pressure sets the upper limit for suction feeding. Nectar intake rate was measured as a function of sucrose concentration (5-75% w/w),nectar viscosity (2-80 mPa s), and ambient pressure (101-40 kPa). Intake rate declines from about 1.2 μl s-1 to 0.003 μl s-1 as sucrose concentration increases from 15% to 65% sucrose. When sucrose concentration is held at 25% while viscosity increases from 2 to 80 mPa s,intake rate declines. When viscosity is held at 10.2 mPa s (the viscosity of 50% sucrose) while sucrose concentration increases from 5% to 50%, intake rate remains constant. Intake rate was limited by a reduction in ambient pressure at all nectar concentrations. Assuming a rigid proboscis, the Hagen-Poiseuille equation suggests that suction pressure increases with viscosity from 10 kPa at 5% sucrose to 45 kPa at 65% sucrose. However, because intake rate declined by the same fraction under hypobaria (40 kPa) at all sucrose concentrations,the euglossine bee proboscis may be better described as a collapsible tube:expanding or collapsing depending on the flow rate, the pressure gradient along the proboscis, and circumferential forces imposed by the proboscis walls. |
| Databáze: | OpenAIRE |
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