Flower shape and nectar provision
Flower pollination is also aided by the very shape of the flower, and the way in which insects come into contact with its sexual parts (the carpels and stamen). For example, even within the bee families, the shapes, sizes and weights of the bees vary, as do the tongue lengths.
Whilst honey bees have quite short tongues for sucking up nectar, some of the bumblebees have long tongues, meaning they may target deep, tubular shaped flowers. For example, with their furry, roundish bodies, they are ideal pollinators for foxgloves, their coats being efficient catchers of pollen as they make their way up inside the flowers.
Flowers have different nectar re-fill rates - yes, once the nectar is taken by one insect, the flower may replenish the nectar ready for the next passing insect. This helps to ensure that a plant can be visited more than once, increasing its chances of pollination.
However, insects may cheat the plant!
In cases where short tongued bumblebees cannot get at nectar stores in the base of flowers, they may bite a hole, and access the nectar in that way. This is called ‘nectar robbing’. The hole may then be visited by other insects also keen to take the nectar, as the nectar supply is replenished. This is called ‘secondary robbing’.
Opinions vary, but some state that flower pollination is not necessarily hindered, because the flower may still be targeted by other bees that are engaged in gathering pollen, rather than nectar.
On the other hand, flowers may cheat insects too!
The Bee Orchid (Ophyrys apifera) is believed to have evolved to emulate the appearance of the female bee of the species required to pollinate it. The male bee lands on the female with the intention to mate. In his attempt, the orchid is pollinated. The bee, however, is disappointed!
Orchid pollination is not only carried out by bees. Certain beetles such as the beetle Strangalia maculata , are also able to assist in orchid pollination, as they can efficiently access the complex flower structures of some wild orchids.
Buzz about bee net
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