Thursday, November 20, 2008

Bees, pollination & parasites

I had to read an article out of my Ecology lecture text and then write about it so I figured I'd just blog about it as well. Mutualism exists between flowering plants and their pollinators-bees. Plants benefit from this relationship in that they greatly increase their chances of reproduction. The chances of having their pollen grains fertilize another flower are much more probable if they rely on a pollinator like the bee who moves among many flowers in a short amount of time, rather than simply relying on the unpredictability of the wind for reproductive purposes. Flowering plants invest a substantial amount of energy in pollen production and so by utilizing bees as a vehicle for carrying out pollination they are increasing their energy efficiency. The bees benefit by extracting nectar from the flower and then internally converting it into honey (“a high quality energy store”). Once the bees inadvertently pick up the pollen grains, they may consume the highly nutritious grains which are rich in proteins and oils.

A host-parasite relationship exists between bees and two mite species: Varroa and Tracheal. The cost to the host (bees) is their mortality and fitness. The Varroa mite benefits from the relationship by deriving sustenance from the internal fluid of the bee. The Tracheal mite derives nutrition from its host’s body, but also uses this medium as a site for reproduction. Due to varying levels of exposure to the parasites, different host species have developed differing levels of resistance. Often, the more time a bee species is exposed to a parasite, the more likely it is able to develop resistance to the pest and survive if attacked.

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