Lerps or Psyllids: are sap-sucking insects similar to aphids. The better known aphids are mobile whilst immature Lerps are sedentary. Most Aphids species are introduced and common garden pests. About eight species are said to be endemic.
Lerps, in their immature stages, cover themselves with a protective scale-like covering. This covering is a sweet, carbohydrate secretion from the insectís anus.
These lerp-scales are often intricate and beautifully shaped. The scales, and their protected insects, in the photos were found on the leaf of one of our Eucalyptus sideroxylon. The left photograph shows the leaf and Lerps whilst the right is a magnified view of an individual scale. This illustrates the beautiful, sculptured appearance of the scale. Notice that the majority of Lerps have constructed their scales over the veins of the leaf to gain access to the sap.
The species is probably Spondyliaspis eucalypti. This Lerp occurs throughout Australia and is sometimes massed on Eucalypt foliage. Our Lerps were only on a couple of leaves. Under extreme conditions Lerp infestations may lead to Eucalypt defoliation.
Aboriginal people made a sweet drink by collecting Lerp-scales and soaking them in water.
Some biological control is exerted by Pardalotes and other birds feeding on the sweet Lerp-cases.
The adult Lerp is a small, winged insect with a soft body.