The parasite Aphidius ervi occurs in most parts of Europe and has been introduced in North America, Argentina, New Zealand and Australia. It looks very much like the related Aphidius colemani, but it is twice as big. Aphidius ervi also has a black, slender body with brown legs and long antennae. Its bigger size is logically related to the fact that it parasitizes bigger aphid species.

Parasitation also occurs similarly as with Aphidius colemani. Once the female has found a suitable host, she bends her abdomen under her legs and injects an egg in the aphid with her ovipositor. During the first days after parasitation, as long as the egg stage takes, the aphid keeps on eating and secreting more honeydew. Adult aphids keep on reproducing progeny. Then the Aphidius ervi larva starts eating the larva from the inside, and modifies it consequently to a golden-yellowish-brown mummy. Finally, a new adult parasitic wasp leaves the mummy through a round hole.

The total development time of Aphidius ervi takes 26 days at 14°C (57°F), 13.5 days at 20°C (68°F) and 12 days at 23.6°C (75.5°F). A female lays about 350 eggs in a life time, of which most are laid during the first 5 to 7 days, at a rate of about 55 eggs per day. Aphidius ervi has a very good searching ability. Also at lower temperatures the parasitic wasps still fly well. Just like other aphid parasites the presence of Aphidius ervi can cause such a panic in an aphid colony, that some aphids fall down.

Aphidius ervi is mainly used for control of the potato aphid and glasshouse potato aphid in greenhouses. The parasitic wasp is applied in crops such as tomato, sweet pepper, eggplant, gerbera, rose, cucumber, strawberry, bean, etc. Thanks to its good searching ability, Aphidius ervi is also suited for preventative weekly introductions of 0.05-0.1 wasps/m².

Usually, Aphidius ervi is released as soon as the first aphids appear. It is therefore important to detect hot spots on time and to act immediately. Aphidius ervi is then introduced weekly at 0.5-2 wasps/m² in and around hot spots until a balance is reached. Discuss the possibilities with your technical advisor.

Beginning infestations can be controlled in combination with the gall midge Aphidoletes aphidimyza. More advanced infestations can be treated with the lady birds Adalia bipunctata and Harmonia axyridis or with the selective pesticide pirimicarb (Pirimor, Rapid, ZZ Aphix, ...).

Aphidius ervi is presented in tubes per 100 adults. The parasitic wasps are released in the lower part of the crop.

Aphidius ervi can be stored briefly at 6-8°C (42.8-46.4°F).

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