Pollination, the transfer of pollen from the male anthers to the female stigma, is vital to enable fruit and seed to be produced, and it is these fruits and seeds that form a large part of the human diet. Pollination can be achieved by various means. Many of our important food plants are pollinated by the wind, including wheat, barley, oats, rye, rice etc. Many trees are also wind pollinated, including oak, ash, beech and the conifers. Some plants are self-fertile and don’t require insect help, such astomatoes, though yields may be better with help. Trees such as apple, pear, plum, cherry etc. are NOT wind pollinated but rely on insects as do a great many other plants including many food plants and wild flowers. It is one of the marvels of evolution that insects have evolved to do this. In return, the insects are offered nectar and pollen as a food source. In the UK there are several types of insects that perform this task for the large number of species of flowering plants that depend on them. [In other countries birds, bats, lizards and other species also play a part] In the UK the list includes Bees, both honey bees and wild bees, Hover flies, Wasps, Butterflies and moths and beetles
BEES There are over 250 species of bee in the UK. Divided into social bees that live in groups and solitary bees. All are excellent pollinators and all differ in details like the length of their probiscus [the tongue] and their agility which determine which flowers they are most suited to pollinate. If you have been to recent talks and films you are now well informed about bees.
HOVER FLIES These are flies and therefore have just one pair of wings, unlike bees which have two pairs. They resemble bees in that they are black and yellow/whitewhich helps them ward offpredators. Adults eat nectar and pollen whilst pollinating the flower. Their larvae gorge themselves on aphids, a very useful trait to the gardener. Hoverflies love poached egg plants.
WASPS The body of a wasp is not so hairy as that of a bee so pollen does not cling to their bodies so readily. Their hair is finer, but they do still play a role in pollination. They also eat a variety of garden pests, so think twice before killing them. They do a lot of good.
BUTTERFLIES Butterflies are less efficient than bees at transferringpollenas they are perched on long legs so that they do not pick up so much pollen on their bodies. They feed on nectar and prefer flowers they can easily land on i.e. those with flat open blooms and those that have clusters of small flowers. They have good vision but a week sense of smell.
MOTHS Some moths fly in the day time, but many species fly at night. To attract night flying moths for pollination the flowers need to be white or pale and scented such as night scented stock or evening primrose. Moths have an excellent sense of smell.
BEETLES These were probably the first pollinators before bees evolved! There about 100 pollinating species in the UK and theseare found on open flowers such as magnolia and cow parsley.
IN CONCLUSION All these insect pollinators have different adaptations for feeding from flowers and prefer different types of flowers. They fly at different times of the year and in different conditions and some of them are general pollinators and some only pollinate specific plants. Therefore it’s best to encourage a wide range of pollinators to visit our gardens and to encourage bio diversity in plants and insects.
SO WHAT CAN WE DO? All of the above have different requirements so we should try to grow a LARGE VARIETY of flowering plants. Include those that have different flower shapes and colours and those that are a good nectar source. The RHS has a list of plants, ‘PERFECT FOR POLLINATORS’ on their website.
Set up a NECTAR CAFÉ in a sheltered spot in your garden ensuring the plants you select provide flowers throughout the year to provide a nectar source for pollinators. Avoid double flowers and some modern varieties which have little nectar. ‘ Cottage garden’ plants are best. Don’t forget shrubs such as buddleia, flowering currant and winter flowering honeysuckle which extend the flowering season. Plant each variety in groups or drifts so they are easier for pollinators to detect
Set up a BUG HOTEL for hibernating insects and don’t be too tidy in the garden. A pile of dead leaves and a wood pile left undisturbed can provide a place to overwinter. Leave a patch of nettles and dandelions and don’t cut the lawn too short so that daisies and other wild flowers can bloom. Info on bug hotels here.
DON’T USE PESTICIDES and allow natural predators to do their bit.
FIND OUT MORE about this subject by looking on the internet. It is a fascinating topic. Look at www.buglife.org.uk , www.butterfly-conservation.org www.rhs.org.uk and search for ‘Plants for pollinators’
Grow some pollinator plants for the PLANT SALE on 12th May and buy more [different ones] for your Nectar Café. These will be marked by a special Bee logo.
Since writing this article a couple of other points have come to light:
- Traces of neonicotinoids have been found in plants purchased from garden centres, even though these are labelled ‘pollinator friendly’ The only way to avoid this is to buy from an organic nursery or to grow your own. The exception is B&Q, who have pledged all their flowering plants are grown without pesticides from February 2018. Source, article in the Independent, May 13 2017 and Horticulture Week, August 22 2017
- According to the charity BUGLIFE British waterways are increasingly contaminated by neonicotinoids from the use of flea and tick treatments on dogs which them play in rivers and streams, as well as washing pet bedding. Source, Natural Health News article, Jan 22 2018
Neonicotinoids include: IMIDICLOPRID, ACETAMIPRID, THIACLOPRID, DINOTEFURAN, NITEMPYRAM, THIAMETHOXAM, CLOTHIANIDIN
Bridget Woollen