The adult wasp emerges from a hole in the back of the aphid mummy. The wasps are tiny and difficult to see. This wasp can give effective control provided that the use of pesticides harmful to the wasps are either avoided or are carefully targeted to avoid hitting the wasps when they are in the mobile adult stage. Pesticide use in the rose area would need to be carefully controlled so that it is compatible with the use of beneficial organisms in the rose areas. This insect will be seasonal causing more problems in mid to late summer.
Damage is seen as silvering of the foliage and distortion of growing points and flower buds.
The underside of leaves may be covered with the excreta of the insect which is like brown tar droplets. There are no effective specific biological controls and thus control can be difficult to achieve. Thrips are preyed upon by ladybirds and lacewing but the control achieved is not great enough in plague situations. Control should be achieved via the use of Dipel. This will not affect the other beneficial organisms recommended for control of these pests.