Biological Control of Green Vegetable Bug (Nezara viridula) with the egg parasitoid Trissolcus basalis

Trissolcus has long been recognised as the major egg parasitoid of GVB and can have a significant impact of GVB numbers especially late in the season.

Unfortuneately, this is often too late for growers who are forced into spraying for bugs well before this time which further delays the build up of natural populations of parasitoids.

We started working towards supplying parasitoids for GVB mid 2015. This has been a labourious process but is starting to pay off.

Initially a small culture of GVB was established in order to produce GVB egg masses rthat are placed in the field to catch Trissolcus wasps. We were able to do this in November 2015 in the Bundaberg area.

We now have the cultures going really well and are now taking orders for Trissolcus.

By releasing mass reared Trissolcus early in the season or in the life of the crop we believe the build up will be greatly accelerated. This will take the peaks off bug numbers and give a bit more time to decide whether spraying is needed or not.

Releases in the autumn are also likely to reduce the overwintering populations of GVB in the vicinity.