Bibliography: leaves 95-104. / Beetles pollinate over 80% of all flowering plants and feed on the two most common floral rewards, nectar and pollen. Pollen is nutritionally very valuable, being a rich protein and carbohydrate source. However, the hard and highly resistant outer wall (exine) of the grain is an obstacle that pollen-feeders must overcome in order to benefit from the pollen's nutritious protoplasm. There are a variety of mechanisms that pollen-feeders may use to deal with the exine. Collembolans secrete exinase that breaks down the wall, but other pollen-feeders do not produce this enzyme. Pollen-feeders that are unable to ingest grains may either pierce the grain and suck out the contents (thrips and biting-flies) or cause the grain contents to leach out an imbibe the leachate (butterflies and the eucalupt nectar fly). Pollen-feeders that can ingest the grains (bees, syrphid flies, rodents, marsupials, bats and birds) may use osmotic shock, pseudo-germination, exudation, microbial digestion or enzyme penetration to gain access to the protoplasmic contents. Further study is needed to define the details of these methods and whether they are all in use.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uct/oai:localhost:11427/6106 |
| Date | January 2000 |
| Creators | Johnson, Shelley |
| Contributors | Nicolson, Sue W, Tets, Ian G van |
| Publisher | University of Cape Town, Faculty of Science, Department of Biological Sciences |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Master Thesis, Masters, MSc |
| Format | application/pdf |
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