Pollen digestion in flower-feeding Scarabaeidae : protea beetles (Cetoniini) and monkey beetles (Hopliini)

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.

Grantor dc:publisher.institution

Department of Biological Sciences

Year dc:date.issued

2000

Author dc:creator

• Johnson, Shelley

Advisors dc:contributor.advisor

• Nicolson, Sue W
• Tets, Ian G van

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/11427/6106

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/6106