PEST
 
   NAME
     Leaf Hopper (General)
     Various Leaf Hopper Species
 
   ORDER
     Hemiptera
 
   FAMILY
     Eurytomidae

Description of the Pest
Generally hopper grows up to 15mm in length, with “A”-shaped folded wings that give it a characteristic triangular cross-section. The adults often have bright coloured markings and the nymphs conjugate in colonies.   Adults can fly but will hop away immediately if disturbed and both nymphs and mature hoppers have piercing and sucking mouth parts.

The Passion Vine Hopper (Scolypopa australis) has clear triangular wings that have brown margins and black bands. The nymphs are wingless and white with tufts of hair on the end of the abdomen. 

The Green Leaf Hopper (siphanta acuta) looks triangular with its steeply folded wings and can grow to 10mm long. The adults are generally a solitary feeder but the nymphs congregate on shoots.

Appearance and Distribution of the Pest
The adults and nymphs are present throughout the year in tropical to warm temperate regions and are dispersed by flying.

Life Cycle
These insects have a Hemimetabolous life cycle, ie. When the immature nymphs resemble the adults.
Females deposit eggs in slits they make in the bark or on the leaves of the host, and several generations may appear annually on the same plant.

   Egg and Nymph   

Damage Caused
Nymphs and adults are gregarious, and both stages may be found on host plants at the same time. If large numbers attack young new growth, sucking sap from leaf petioles and young stems, the host plant may become stressed. Severe infestations may weaken and eventually kill the plant with dieback and distorted leaves. 

The nymphs exude a sweet secretion, which is attractive to ants that attend and protect the colony. The honeydew also causes sooty mould to occur as a secondary problem. Some species produce toxic saliva that kills the effected plant tissue; other species carry plant viruses.

Susceptible Plants
Most Eucalyptus, Acacia and Casuarina species are attacked by a variety of leafhoppers. Many other Australian native and ornamental plants are attacked. 

Acer species are attacked by the leaf hopper (Alebra albostriella) which lays eggs under the bark causing minor swelling. Acer platanoides is particularly venerable. 
 
Callistephus and Aster species are attacked by the Leaf Hopper (Macrosteles fascifrons) that generally causes little harm to the plant but transmits Yellow Disease, a viral infection.

Fern species are attacked by several types of leaf hopper, particularly the Passion Vine Hopper (Scolypopa australis). New fronds become deformed or misshapen as the insect sucks the sap causing dead patches to appear.

Parthenocissus species are attacked by the Green Leaf Hopper.

Rosa species are attacked by the Rose Leaf-hopper (Edwardsiana rosae), nymphs feed on the underside of leaves causing white blotches.

Sorbus aucuparia is attacked by the Japanese Leaf Hopper (Orientus ishidae) which causes the leaves to form a brown blotches with yellowish margins.

Cultural Control
Improving the culture of the host species may assist in maintaining vigorous growth, to minimise shock from infestations. It may be possible to remove them by hand, from young trees, using a small butterfly net if you are lucky.

Biological Control
Controlled by natural predation and the Green Leaf Hopper causes little harm and control is unnecessary. 

Chemical Control
Under normal circumstances, it is impractical and unnecessary to treat mature trees however, hoppers on young plants may be treated with a contact insecticide. 
Note
Always read the label for registration details and direction of use prior to application of any chemicals.