PEST
 
   NAME
     Leafblister Sawflies
     Phylacteophaga species.
 
   ORDER
     Hymenoptera
 
   FAMILY
     Pergidae

Description of the Pest
There two commonly seen Leafblister Sawflies are (Phylacteophaga eucalypti) and (Phylacteophagafroggatti) which have simular feeding habits and life cycle.
Generally the larvae of the leaf blister sawflies are segmented and up to 6mm long; feeding on the inside of the leaf where they are only visible if the blistered leaf cuticle is removed.  Adults are sawflies, 5mm long that live for about one week.

		  Blister on Acacia longifolia

Appearance and Distribution of the Pest
Appears both coastally and inland, in temperate areas of Eastern Australia.

Life Cycle
The complete lifecycle takes 6 weeks in the warmer months; longer during winter. The sawfly has a complete metamorphosis, with 4-8 generations each year. Females lay eggs in slits that they have made in the leaf veins. The leaf swells around the eggs, forming galls. Larvae feed between the leaf surfaces, causing blistering. The larvae pupate within the blister.
These insects have a Holometabolous life cycle, ie. When metamorphosis is observed during the pupal stage.

Period of Activity
Damage occurs during the warmer months. Young plantations, or trees stressed by drought, are particularly susceptible during these times.

Damage Caused
Mining between the upper and lower leaf surfaces causes blisters, giving a brownish burnt appearance. Heavy infestations may defoliate the plant and repetitive attacks can lead to dieback. The sawfly does not lay eggs above heights of 4m, thus mature trees are unlikely to be seriously damaged. The appearance of the host plant becomes unsightly after an infestation with disfigured leaves.

Susceptible Plants
There are many species that are attacked including Acacia and Eucalyptus species, juvenile foliage is commonly attacked particularly (E. grandis, E. Saligna, E. botryoides & E. robusta, Eucalyptus tereticornis).

Callistemon species, Lophostemon confertus and Buckinghamia celsissima are also susceptible to attack. 

Cultural Control
Remove and destroy infested leaves or seriously damaged plants. Mature plants are unlikely to suffer serious damage, unless under stress.

Biological Control
No effective biological controls are known, although natural predators such as parasitic wasps and small birds eat many larvae.

Chemical Control
Systemic pesticides may be sprayed if the blisters are small and the larvae are active - otherwise, chemicals have a limited role.
Note
Always read the label for registration details and direction of use prior to application of any chemicals.