A number of the insects found in the garden, although of rather an alarming appearance, are great friends to the gardener. They are often entirely carnivorous, living on aphides and other small pests. Below are a few particulars of some of the most common, all of which should be allowed to carry out their good work and not destroyed on sight, like.
The honey bee is a wonderful worker, and, of course, is a most welcome visitor to the garden. Without his visits practically no seed would develop on some plants, as it is on his body that the pollen is taken from flower to flower to effect fertilization. The only member of this family that is inclined to be destructive is the leaf-cutting bee but as he only disfigures the leaves, and is easily caught, he does not represent a very great menace. Bees should therefore be treated with courtesy, especially when the fruit blossoms are open. The gardener must avoid the use of poison sprays such as lead arsenate at this critical time.
Most ground beetles are carnivorous, living on slugs, grubs and maggots of all kinds. The most familiar are: The Tiger Beetle, a rich emerald green, with orange stripes, about ½ in. in length. It covers the ground at a great pace, but, of course, flies as well, and is very difficult to catch. As it does no harm this does not matter. Carrion Beetles which are yellow, with a black patch on the thorax, and two on each side of the wing covers about 1/2 in. long. Both the larvae and the beetles feed on carrion, also on snails and slugs. Burying Beetles, black with broad orange bands, often an inch long. They also are scavengers, living on dead birds, moles, fish, frogs, etc.
These are entirely insectivorous and should not be mistaken for millipedes, which are very harmful. The centipede is flat and yellow, and has a large number of legs. It runs very fast with a slightly crab-like movement. Millipedes are almost black in colour, rounded in shape and when touched roll into a ball. The millipedes move slowly—a fact which applies to most of the insects that are vegetarian, and therefore harmful. Having no need to catch their food, they approach it in leisurely fashion.
Devil’s Coach Horse or Cock-tail Beetle
This is a narrow black beetle which has a habit of raising its head and tail in a rather threatening manner when touched, hence its name. It feeds on slugs, and otherpests.
These wonderfully beautiful flies, too well known to need description, are insectivorous, and live entirely on minute insects. They have no sting, although they are often called “Horse Stingers.”
The larvae live almost entirely on aphides, and therefore destroy large quantities. There are several varieties. The common ones seen hovering over rose trees and fruit trees are easily recognizable.
There are thousands of varieties of this particular insect which varies in size from that of a midge to about 2 in. across the wings. They have long thin bodies and very long legs. They hunt for caterpillars of all kinds, and lay their eggs in the bodies of their victims. The grubs hatch out and feed on the caterpillars, thus killing off large numbers of them. Cabbage caterpillars are a favourite victim.
This is another very beautiful insect, with 4 large gauzy wings, and a thin bright green body. On account of its brilliant golden eyes it is sometimes called the Golden-eyed Fly. It is mostly found near water, and lays its eggs under leaves, each one being attached by a thin silken thread. The lame sucks the juices from aphides (green-and black-fly).
Ladybirds, sometimes called Cow Ladies
These live almost entirely on green-fly, and are found on rose trees and other plants subject to this pest. There is no need to describe them, as even the youngest and most amateur gardener knows this charming little spotted beetle.
Spiders feed on insects of all kinds, and are so well known there is no need to describe them.
Wasps (small varieties and Hornets), in spite of the fact that they eat into fruit, are really beneficial. They remove the wings from ordinary house flies, and take the bodies home to their young. They eat grubs in large quantities. Thus hornets and small wasps not only clear the garden of pests, but also fight disease-carrying flies that invade the house.