|
Insects are the most important biotic pollinators of flowering plants. Different animals are sensitive to different wavelengths of light, most insects are able to see well beyond the frequencies of visible light (to humans) into the Ultra Violet. It is these higher frequencies that attract insects most, the colours in the visible spectrum are not hard indicators of likely pollinators but they can still help indicate pollinator types. So as not to exclude potential pollinators most plants take a generalist approach to attracting pollinators, not specialising too much in morphology. Many others have some degree of adaptation which may favour certain types of pollinator over others. A few, particularly among orchids go all out & can commit to even a single species of pollinator. Perhaps the most frequently cited example of pollinator specialisation is the Madagascan orchid Angraecum sesquipedale which possesses incredibly long narrow spurs to the flower at the bottom of which resides the nectar. In 1862 Charles Darwin published a work on orchid specialisation for pollinators in which he examined this flower, after much experimentation he concluded that to effect pollination of the flower & for the pollinator to get its nectar reward it would require a moth with a 35cm long proboscis. Many dismissed this as fanciful at the time but in 1903 the moth which did the job was dually found. You can read more here: http://en.wikipedia.org/wiki/Angraecum_sesquipedale |
|
Bees: Respond to generally showy flowers, especially keen on flowers rich in nectar, though sometimes frequenting those offering a reward of pollen instead of nectar. Yellow & Blue flowers are particularly popular; many have markings guiding the bee to the reward visible in Ultra Violet wavelengths of light. Bees are absolutely vital to our survival in their role as pollinators for many of our food crops & internationally bees, both wild typed like our familiar bumble bees & commercially raised honey bees are in drastic decline. There seems to be several factors combining to cause this decline including disease, parasitism, climate change & insecticide use. By offering as many plants attractive to bees as possible in your garden you can do your bit to help your local bee population. Good bee plants include: Aquilegia, Brunnera, Caltha, Doronicum, Eryngium, Fuchsia Geranium, Hemerocallis, Iberis, Jasione, Kalmia, Lamium, Monarda, Nepeta, Olearia, Primula, Quercus (oaks, like chestnuts provide pollen rather than nectar), Rudbeckia (Rhododendron provide tons of nectar for bees but many varieties make the bees ‘drunk’), Salvia, Thymus, Ulex, Verbascum, Weigela, Xanthorrhoea, Ypsilandra & Zinnia, X,Y & Z wasn’t easy to come up with! |
|
Butterflies: Prefer pink & lavender flowers often strongly scented with long narrow tubes to allow the butterflies to get their long tongues down to the ample nectar. A few good butterfly plants are: Buddleja, Calendula, Echinops, Eupatorium, Echinacea, Hebe, Kniphofia, Lavandula, Mentha, Sedum & Verbena. |
|
Moths: Not major pollinators in the North of Scotland, hawk moths particularly have quite a lot of flowers evolved to suit them. Generally flowers for moths are large open, creamy or white, often sweetly or musky scented in the evening. They are usually pollinated on the wing & are nectar-rich to support the hawk moths active life-style. |
|
Flies: There are huge numbers of flies in multitudinous varieties, there a many generalist types that take advantage of any available food source & this makes them very frequent pollinators of flowers particularly of non-specialised flowers. Their ubiquity makes them important pollinators in more extreme environments like alpine regions where there aren’t the range of different specialised pollinators. Many plants also use trickery to attract to attract pollinators & particularly flies. Some flowers will produce chemicals that mimic fly pheromones to attract male flies which will then crawl all over the flower covering themselves in pollen, the plant hopes the fly will then go to another flower of the same species, falling for the same trick again & shed some of its pollen on the stigmas of the second flower. Another common method of duping flies used by plants is to make a flower appear to the fly to be a rotting animal. These flowers are often red or brown in colour & mottled & put out an irresistible scent of corrupting meat. A great many aroids (family Araceae) are pollinated by flies, e.g. Arum, Arisaema, Dracunculus, Lysichiton & the huge & slightly pornographic Amorphophallus titanium. The worlds largest flower is the Indonesian fly-pollinated parasite Rafflesia arnoldii, it is sometimes called the ‘corpse plant’. |
|
Other types of insects act as pollinators in some plant species. Beetles pollinate many Magnolias, amongst the oldest of flowering plants, as such beetles were amongst the first flower pollinators. European wasps (the normal black & yellow kind people try to swat on sight) adore Angelica gigas. Figs require certain species of small wasps to pollinate their flowers, there was an excellent BBC Natural World documentary on the symbiotic relationship between the African sycamore fig & its pollinator wasp Ceratosolen arabicus & their impact on the wider environment. No doubt will be repeated sometime on the Beeb or on one of innumerable satellite channels. |
|
Plants and Their Insect Pollinators |
|
Passiflora mollissima the ‘Banana Passionfruit’ frequented by heavy weight bumble & honey bees in warmer climates. |
|
Buddleja 'Lochinch' with its narrow tubed highly scented nectar-rich flowers has attracted two red admirals. |
|
Yucca gloriosa is entirely dependant for pollination on the yucca moth whose caterpillar also eats nothing but yucca seeds. |
|
Home Page Catalogue Links Background Information on: Coastal Gardening Hedges & Windbreaks Rabbits & Your Garden Some Useful Gardening Books 5 top plants for different situation What is Gondwana & why it should concern you Back to Wildlife Gardening Page |