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Getting to know your Beneficial Insects |
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Published in Organic Gardening Magazine - August 2006 |
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Gardening
organically affords many benefits to both ourselves and the environment, and
all organic gardeners recognise the advantages that gardening with nature
brings. The
active encouragement of beneficial insects and their canny employment around
the garden not only helps to remove pest species in a natural and efficient
way but also maintains the balance of wildlife in the garden environment,
making it less likely that any one species will increase enough to overwhelm
another or cause problems to crops.
But we are gardeners and not entomologists and sometimes a little
help is required to sort the good from the bad, especially if you are new to
organic gardening.
Amongst all the insects and other invertebrates in your garden, there
are a few worth getting to know better, as they form the backbone of the
useful army of natural predators. |
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Beetles
Where beneficial insects are concerned, the ladybird is perhaps the best known. Fortunately this little beetle is easy to like, its bright red wings dotted with black making it a familiar and much loved garden insect. But most beetles have an important role in the garden. Many eat dead or decaying plant material, including wood, and therefore help to recycle waste garden material, increasing soil fertility. Some of the larger ground beetles, including the very handsome violet ground beetle, eat slugs so are useful predators if your garden suffers from an excess of these creatures. These insects are generally found sheltering under vegetation, logs and stones, in fact anywhere they might find their prey. But our favourites beetles, the ladybirds, can be found in almost any part of the garden. There are over forty different species in this country, but several are declining and are now quite rare. Ladybirds are particularly welcome in gardens as they and their dark grey larvae will eat large quantities of greenfly and blackfly, scale insects and whitefly. It has been estimated that an adult ladybird will eat up to 100 aphids a day. Encouraging them can be simply a matter of making sure that you have a few aphids around (easy for most of us) but ladybird homes and ladybird attracting chemicals are now available to keep these beetles in your garden where they are needed. Perhaps the most effective way of ensuring that they are available where you want them is to make sure that they have somewhere safe to spend the winter. Special ladybird homes will do this, or you can make your own with bundles of hollow plant stems pushed under a hedge or into dense vegetation around the garden. Most importantly, always wait until March or even April (depending on where you live) before tidying up all your herbaceous plants. Ladybirds and many other small useful creatures will spend a safe winter sheltering in the dead flower stalks or under piles of leaves. When they emerge in the first warm days of spring they will be just where you need them and over several winters their numbers will increase. Like all wild creatures, population numbers naturally have good and bad years, but surviving the winter is an adult ladybird’s most difficult life task. They have few natural predators so increasing survival rate through the winter by ensuring shelter for them is the most positive thing you can do to help them. |
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Solitary
bees In
recent years solitary bees have become better recognized for the fantastic
job they do pollinating fruit and vegetables.
The vast majority of bee species that we see in the garden are
solitary bees; they do not live in large social colonies in the way that
honeybees do and can be found in a variety of habitats.
Many solitary bees species are garden dwellers and the small red
mason bee is one that many gardeners are now actively encouraging.
These are very effective pollinators and good to have around if
children use your garden, as they virtually never sting.
They can be out and about at much lower temperatures than the
honeybee and pollinate at a rate of 15 to 20 flowers per minute, almost
twice the honeybee’s rate.
Red mason bees occur naturally in most gardens and as well as
planting a selection of good nectar and pollen producing flowers in your
borders for them you could also include a nesting box.
Again it is not necessary to buy a special home for them as you can
make your own with hollow plant stems and stalks of varying diameters. Other
types of solitary bee will also use these homemade nest homes, especially
some of the species of leaf cutter bee, which also pollinate for us. |
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Hoverflies Apart
from bees there are plenty of other beneficial flying insects that we can
encourage, and hoverflies must be top of the list. These small striped
insects are sometimes mistaken for tiny wasps, but their quick darting
flight and ability to hover over the flowers they are visiting distinguishes
them from wasps which have a more lazy way of flying.
Hoverflies are complicated insects – many mimic other insects
including honeybees, bumblebees, wasps and flies and sometimes it is
difficult to identify a hoverfly for this reason.
As mainly pollen feeders, hoverflies help to pollinate the flowers
they visit, the adult insects seeking out flowers with easy access.
These helpful insects can be encouraged by any flower where the
stamens and their pollen grains are obviously visible, including well-known
attractants such as the poached egg plant and baby blue eyes, but also many
types of poppy, hardy geranium, some golden rods, even open flowered
Dahlias, so there is plenty of choice.
There are 266 species of hoverfly of all sizes in Britain and like
the ladybirds some are in decline.
Again, like the ladybirds, these harmless creatures have larvae that
eat aphids, making them essential insects to have around in any garden or on
the allotment.
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Wasps Few
of us like wasps, for obvious reasons!
However, the common wasp is a great predator, taking large numbers of
caterpillars back to the nest to feeds its young.
Many other small invertebrates are also eaten by the larvae, but the
adult insects are fond of all sorts of sweet things including the nectar of
certain flowers, those of ivy being a favourite.
There is little need to do anything to actively encourage wasps –
as tireless hunters they will find their prey with ease. Lacewings Lacewings
are familiar to most of us, the most common type having delicate green wings
with a fine tracery of veins.
We may find them tucked away somewhere in the garden in the winter
months or even inside the house as, like moths, they are attracted to light.
Like many insects they need to hibernate through the winter and may
choose a pile of logs, a crack in a wooden fence, thick vegetation or gaps
in your window frames to find some protection from the elements.
Like ladybirds and hoverflies they also eat aphids and a bug home
with a variety of nooks and crannies will aid their survival. Those
of us who prefer to garden organically are well aware of the beneficial
wildlife that can make our gardening easier and more enjoyable.
These insects are just a few of the legions of creatures that are out
there, helping us as they go about their business, maintaining a balance
that can only be achieved in this most natural way. |
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© Text and photographs Jenny Steel 2007 |
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