PEST

NAME
Citrus Gall Wasp
Bruchophagus fellis

ORDER
Hymenoptera

FAMILY
Eurytomidae

Description of the Pest
The small wasp is black and up to 3mm long.
It lays its eggs in the new stems of a plant where the white legless larva develops, up to 4mm long.


Gall on the young stem of a citrus

Life Cycle
This insect has a Holometabolouslife cycle, i.e. it has alarvaland a pupal stage.
The wasp lays its eggs during spring. The larvae hatch and begin to feed eventually the larvae pupate within the gall and the adults emerge late winter to early spring. It normally infests the same plant or one near by due to its poor flying capabilities. The female can lay up to 120 eggs within 24 hours of leaving the gall. There is one generation a year.

Distribution of the Pest
In Australia found on the eastern states and south Australia. It is native to Australia.
It can also be transported to other areas physically, as in contaminated stock or on cut plant material.

Vacated galls are peppered with small holes.

Period of Activity
Throughout summer the larvae grows and affects the surrounding cell walls of the plant, creating galls in which it lives.

Damage Caused
The larvae in the stems stimulate excessive cells to develop. The stems have a lumpy appearance. This can reduce the plants growth and reduce fruit yields. There can be hundreds of individual larvae in a gall.

Susceptible Plants
All citrus varieties are prone to attack including common lemon and grapefruit. It also feeds on the native finger lime Micro citrus australiasica

Control

Cultural
During late winter cut off the infested stems, before the adults emerge (when holes appear in the stems the adults are emerging).       Place the pruning into a sealable bag. Avoid distributing and dispose of infested stock.
There is no chemical control that is effective.

Biological
A native parasitic wasp Megastigmus spp are available to reduce the pest population.

Note
It is your responsibility by law to read & follow the directions on the label of any pesticide

Monitoring
A non-toxic sticky trap that attracts the wasp, which is then stuck fast and dies, is available.

Amendments by B. Sonsie Dip Hort Sc Burnley