Issue |
Apidologie
Volume 34, Number 1, January-February 2003
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Page(s) | 1 - 10 | |
DOI | https://doi.org/10.1051/apido:2002049 |
DOI: 10.1051/apido:2002049
Nectar sugar content: estimating standing crop and secretion rate in the field
Sarah A. CorbetDepartment of Zoology, Downing Street, Cambridge CB2 3EJ, UK
(Received 13 May 2002; revised 25 July 2002; accepted 9 August 2002)
Abstract
Field techniques for sampling and measuring the standing crop and secretion
rate of nectar are described, in order to clarify some discrepancies and omissions
in existing reviews of nectar measuring techniques. Slender microcapillary tubes
(a fresh one for each sample) are recommended for withdrawing nectar, and a hand
held sucrose refractometer, capable of operating with very small fluid volumes,
is used for measuring concentration. Potential errors due to the presence of solutes
other than sucrose, or to temperatures other than the calibration temperature,
are discussed. I consider how measurements of secretion rate are affected by reabsorption
and by the nature of the bags used to exclude nectarivores.
Key words: standing crop / nectar concentration / secretion rate / microcap / refractometer / sucrose / glucose / fructose / amino acids / nectarivore
Correspondence and reprints: Sarah A. Corbet
e-mail: sacorbet@stloy.u-net.com
© INRA, EDP Sciences, DIB, AGIB 2003