Psyllid or Lerp insects
Colour - Yellow or brown
Body - Up to 4 mm. Oval. Flat. Soft.
Wings - Transparent. Wing-span 6 mm
Mouthparts - Stylet. Sucking. Near rear of head.
Antennae - Very small. 3-10 segments.
Eyes - 2. Compound.
Legs -Very small. Feet (Tarsi) have 4 segments.
Head - fused to thorax.
Thorax - 3 segments.
Abdomen - Eight pairs of spiracles on underside. Segments ill defined
Egg - brown, ovoid. Less than 0.5 mm long.
Habits - Scales are formed on the leaf and the nymph feeds below the scale. These may be of various sizes and shapes.
Usually 5 stages (instars). Look quite different to the adults.
Often orange. They move when the leaf is tapped.
Eggs hatch to produce nymphs that are active form May to November. Adults appear in summer and lay batches of 50-100 eggs.
Habitats:Origin and History:
Severe defoliation of trees may result from lerp insect attack. The nymphs shelter under the lerp scale and suck sap from the leaf. This often causes a reddening or browning of the leaves.
Death of trees may result after a number of severe attacks.
Management and Control:Insecticides provide reasonable control especially if applied at the first sign of attack. Valuable trees may be stem injected.
For stem injection, mix 10 mL dimethoate400 with 10 mL water. Drill 12 mm diameter holes angled downwards at 45 degrees about 25 mm deep into the sapwood at 100 mm spacings around the trunk and about 250 mm above ground level. Inject 3 mL of the dimethoate mix into each hole. Plug the holes with putty a few hours later to prevent decay
Related Species:Aphids, various 'bugs', leafhoppers and scales are sometimes confused with Lerps.
WADA. Insects and Allied Pests of Extensive Farming. Department of Agriculture - Western Australia Bulletin No. 4185. p87.
Acknowledgments:Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.