1 wasp / 1 m2.
Most crops can be infested with aphids. Damage is caused in three ways: sucking plant sap when feeding, excretion of honeydew leading to sooty mould and some species can transmit plant viruses leading to distortion and disfigured plant growth. Biological control with parasites, predators and fungal pathogens are available depending on crop and environmental conditions. There are a large number of aphid species and identification can be important when parasitic wasps are to be used. Depending on the species there can be alternate plant hosts. Winged forms develop under conditions of high density to migrate to alternate hosts. Resistance to some insecticides is a serious issue with some species.
Activity / Control
It has a slightly different host range to A. colemani and includes Ovatus crataegarius (mint aphid). The adult wasp inserts its egg into the aphid, a parasite larva develops killing the aphid, producing a characteristic goldenbrown papery 'mummy' An adult parasitic wasp later emerges through a round hole on the mummified aphid. The adult wasps also feed as a predator on aphids, killing one or more each day.
Use at the first sign of aphids or better, as an early season preventative.
Aphidius matricariae is effective against Myzus persicae nicotianae (tobacco aphid) and Myzus persicae persicae (peach potato aphid) and Ovatus crataegarius (mint aphid).
Has a side effect on cotton aphid.