It is often disputed whether an insect population as a general concept is beneficial or detrimental to a gardener, however this subject cannot be decided with a simple black/white frame of mind. Like their micro equivalent bacteria, there are types and species of creepy crawlies that can be either devastating or redemptive of any green space.
All the species mentioned here will be recognizable and that is chiefly why they've been selected, their banality, particularly in the case of those detrimental species, is what often disguises them as a neutral force in the garden.
Probably the most immediately recognizable on our list is the Ladybird, whose name derives from the moniker given Mary of Nazareth, whose personage was oft depicted draped in a red spotted cloak, whose seven blemishes symbolized her corresponding joys and sorrows. These gorgeous insects act as the perfect countermeasure against one of the villains on our list, Aphids, who form a large part of the beetle’s diet. In the pupal stage alone it is not uncommon for a ladybird to consume upwards of four hundred of these plant lice and over five thousand in an average life cycle. However, there are certain procedures to attend if you are to successfully attract this species to your garden, first of all your choice of pesticides can have an adverse effect on their propogation, so be careful what you use. Also, an artificial supplement known as ‘wheast’, a combination of whey and yeast can be applied to your space to nourish growing larvae. You can make your own version by mixing 1 part sugar to 1 part yeast in water to make a paste, which can then be painted onto stakes among your planting. Or you can make a looser mixture and simply spray it onto plants. Planting such as Achillea(Yarrow) and Daffodils will also provide enticing pollen.
Charles Darwin once of spoke of the Earthworm as being of the most significant organisms in the history of the world, describing it as nature's version of the soil plough, while immeasurably older and more efficient. Never will you find a greater aid to the quality of your soil then this fisherman's aid. The Earthworm operates on a symbiotic basis with its environment i.e. the greater the quality of the soil and the better tended it is, the greater the population of worms and in turn the greater the quality will remain. Thus it is important to serve these creatures appetites as a means of satisfying your gardens. First of all we must understand how the Earthworm survives. Its respiration is conducted entirely through its skin, rather than through lungs like us humans and to thrive they need, moisture and oxygen. Therefore, a well-drained, moist soil that is turned regularly will guarantee a healthy population. Also, while composting and mulching may seem obvious tricks for benefit of the plants themselves, the tunnels an Earthworm creates will provide greater pockets of oxygen and thus a more efficient means by which bacteria can break down this organic material.
Similarly to their striped friends, the bees, butterflies are an excellent vector of pollination. In a previous article we outlined how important it was to aid the continued growth of our native butterfly species due to the adverse conditions they'd been faced with in the past summer. However it is not only flower propagation that makes this insect important - over one third of the world's food supply is pollinated by natural vectors. Also the butterfly provides a source of food for numerous bird species that along with the aesthetic of the insect itself add exciting colour and movement to your green space.
Einstein is quoted as saying that "If the bee disappears from the surface of the earth, man would have no more than four years to live." And this is due to their critical role as the primary pollinator on our planet. From the largest crops to the smallest bloom, no other insect can lay claim to such widespread or efficient propagation. As such, there is no doubt that a population already resides in your garden, however there are measures that can be taken to ensure, in their state of decline, that this presence continues. Aside from a healthy supply of pollen rich plants, bees require a local water source to multiply, preferable one placed away from sources of intrusive noise like lawnmowers. A small pond or fountain amid the more remote areas of your garden would suit this role perfectly.
For a long time this creepy crawly has been on the receiving end of much stigma due to its presentation on the silver screens of yesteryear. However, it is the very aspect that sealed this creature as a menace, that also confirms it as one of the greatest assistants a gardener could employ. The same predatory instinct that saw so many grind-house heroes laid low, can be put to work on the winged afflictions of your leaves and petals, consuming, as it does, many of our garden pests. Unfortunately, arachnids are primarily attracted to dry, tranquil places and so an English garden cannot hope to yield a huge amount! However, hopefully their mention here will help dispel the myths of fear and aversion that surround them, and pay the dues that spiders really deserve.
One of the most common pests in any English garden, these slimy critters are known for the destruction they cause to any foliage they can reach. However, there are other methods of their repulsion aside from expensive artificial aids. The most important thing you can do is use nature against itself i.e. in the approaching winter months it’s important to rake over your top soil, thus exposing larvae and egg clusters to the threat of frost. Keeping the garden clear of fallen leaves and plant matter also reduces places for slugs to hide. Slugs also have many natural predators, foremost of which is the Hedgehog. As they are shy creatures by nature, the best way to attract them initially is a healthy portion of dog food but to make them stick around you'll have to invest in a habitat that suits them. To this end we recommend a waterproof box, insulated with hay and camouflaged by leaves which if successful will provide you not only an effective solution to your arthropods but a cute addition to the family. If hedgehogs are out of the question then another effective predator is the group known as Rove Beetles, which includes the most commonly known ‘Devil’s Coach Horse Beetle’. They can be catered for with a series of perspex lined, pebble filled trenches into which the slugs will become trapped for the beetles lunch. A hedgehog house should be constructed to dimensions of eighteen inches length, twelve depth and six width while beetle trenches should be about half those measurements.
Aphids aka Greenflies or Blackflies are a species of parasitic insect that are notorious for the destruction of foliage and flower alike. They have been mentioned already as one of the Ladybirds primary food sources, however there are a number of other species that will incorporate this pest into their diet if properly encouraged. The most fool proof way to ensure these predators presence is through the liberal planting of nettles, when sited next to those flowers worst afflicted they will attract a local population of nettle Aphids which, as their name suggests, will only attack the nettle itself while attracting plenty of less discriminate insects to regulate theirs and their counterparts’ population. We would highly recommend this method over the use of pesticides or waterborne protection as one annoying habit of an Aphid afflicted leaf is to curl inward, thus protecting the insect from outward dusting of insecticides.
The trick with Grasshopper control is in early intervention - by catching the infestation early you halt the population growth before it become unmanageable. They are a particular nuisance to vegetable crops, mostly targeting baby carrots, onions and lettuce. One method involves something of a phyrric victory by way of providing a strip of lush grass to divert the hopper from the rest of the garden, this will also localize the entire population making them an easy target for predatorial birds and insects. However as stated earlier, it is important to undertake these countermeasures as soon as possible because, once the hopper has a foothold, then no method will be effective except to wait for the cold season that wipes them out annually.
A Caterpillar infestation is a result of butterflies laying eggs on the leaves of the afflicted plant, a non-chemical means of preventing is to use a horticultural fleece to cover the plants and halt butterflies access to them. Unfortunately, they have a long laying season that can last from early spring to autumn and the indiscriminate fleeces will also prevent other beneficiary species from reaching the plant. Another method is to move the afflicted plant to an enclosed site such as a greenhouse and then to flood the space with Trichogramma brassicae, a species of wasp that targets caterpillar eggs. If that is not possible, you can just use the old-fashioned method of picking them off the plants manually!
10. Viburnum Beetle
This little monster has recently topped the RHS most wanted list in terms of garden pests, partly due to its destructive capacity, but mostly due to its lack of treatment protocol. The majority of the defoliation this creature causes is during the larvae stage wherein the hatchlings are far too numerous to effectively clear by hand. Thus chemical methods are the only viable ones, once inspecting infected Viburnum for signs of the larvae, spray the plant with deltamethrin or cyhalothrin. This treatment is best utilized in the mid spring months when the larvae do the majority of their damage. There are organic options, however these have proved nigh ineffective against matured beetles.
And so as our roster of friends and foes draws to a close, remember the tips given here on avoiding the latter and do your best next year to attract the former. The one comfort of the oncoming cold weather is that caterpillar and slug are far more susceptible to it than we are!