Smallholders should befriend beneficial insects such as lacewings. We tend to spend time worrying about insects that might be a threat to our crops, livestock, pets, gardens or ourselves. However, there are insects which we should encourage, because they prey on other insects that are pests.
Lacewings are just such a family of predators and the Yellow, Green and Brown lacewings are the most common.
Green Lacewings
The green lacewing, sometimes known as the golden-eyed lacewing, has long delicate antennae, a slender greenish body, golden- or copper-coloured eyes, and two pairs of similar veined wings. It is worldwide in distribution and flies near grasses and shrubs.
Adults have elongated bodies reminiscent of dragonflies, but they have four wings which each have many veins, which give them the netlike or “lace” appearance.
Larvae have different body shapes and are similar in appearance to ladybug larvae but have very large mandibles. Several families are found within the order, but most of the pest controllers are located within the Chrysopidae family.
Green lacewings have a 3 cm body and their wings have no markings.
Yellow Lacewings
Ceratochrysa antica are yellow and slightly larger than the green lacewing. Wings also have no markings. Chrysemosa jeanneli are smaller than the green lacewings with grey bodies and grey wings. They have a distinctive black spot on the mid hind margin of their wings, which meet up when their wings are at rest.
Lacewings lay their pale green oblong eggs on the tips of threadlike stalks attached to plants. The immature lacewings hatch within a few days. Lacewing larvae are reddish cream in colour and are tapered in shape. They have distinct legs, and have prominent mouth parts used to consume their prey. After about two weeks of continuous feeding, the larva spins a silken, pearl-sized cocoon on the underside of a leaf and remains in the pupal case approximately two weeks before emerging as an adult.
Some of the adults of this family of insects live on nectar or pollen and it is the larvae that are voracious hunters. As with many other pest predators, they will be attracted to areas with lots of prey species. They feed on will feed on aphids and other soft-bodies insects such as mites, scale, leafhoppers, thrip and mealy bugs, as well as spider larvae, insect eggs and caterpillars.
Hungry Larvae
The larvae are voracious, attacking other insects of suitable size, especially soft-bodied ones, other insect larvae and insect eggs. When they touch a potential prey object, the larvae grasp it. Their upper jaws are hollow and inject a digestive secretion into the prey. The organs of an aphid can be dissolved by this in 90 seconds.
Some lacewing larvae hold debris (including the bodies of their victims) on their backs with hooks or bristles. This camouflage allows the lacewing larva to surprise its victims and also protects it from enemies.
So the lacewings play an important role in maintaining the balance of bio-diversity on our plots.
To read about other insects and wild life on smallholdings click here.
To receive all our notices and each edition of SA Smallholder register here.