Series 3 of 4:
Encarsia, Eretmocerus, Aphidius And Aphidoletes
Aphid Parasitoid,
Not Hatched.
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Aphidius sp. commonly used in the greenhouse are Aphidius colemani and Aphidius ervi. These parasitic wasps are an effective tool when it comes to aphid control. Both are great searchers and can find aphid spots when colonies are small. The type of aphids you have in your greenhouse will determine what type of
Aphidius you should use.
Aphidius will arrive to you in a vial with vermiculite or buckwheat carrier and the
Aphidius will be in the form of a "mummy" (a parasitized aphid or cocoon). They should be released throughout the greenhouse or in a banker plant system for preventative use. For existing aphid spots
Aphidius should be released directly in and around the spot.
The banker plant system is potted cereal (monocot) inoculated with cereal aphids.
A. colemani can begin to parasitize these aphids to provide a constant production of aphid parasites. If monocots are being grown for production, banker plants are not recommended as the cereal aphids may become an issue.
Aphidius colemani is used to control melon (or cotton) aphids and green-peach aphids.
Colemani will begin to mate and then parasitize aphids a day after emerging from the mummy. An adult female can lay about 300 eggs in her adult life. After the egg is laid in the aphid host, it can take from several up to 14 days before the adult
A. colemani emerges, depending on temperature. Prevention is key! Introducing on a banker plant system is a great way to build up a parasite population
before aphids become a pest in your crop.
Aphidius ervi is larger than A. colemani and can control larger aphids such as foxglove (=glasshouse potato in Europe) and potato aphids. The life cycle of A. ervi is similar to that of A. colemani.
Aphidoletes is a gall midge that will fly and search out many species of aphids and deposit eggs in the colony. After 2-3 days (depending on temperature) the eggs hatch and the larvae begin feeding on the aphids. Aphids are consumed only by the larval stage; this stage can last up to 14 days. It also has a bonus of killing more aphids than it actually eats. The adult Aphidoletes will survive on the honey dew excreted from the aphids. Aphidoletes should only be used from March through September to prevent diapause; if artificial lighting is available, they can be used year-round.
Aphidoletes are shipped in a vermiculite carrier in the pupal stage. Piles of the mixture should be introduced in and around aphid spots. This is one of the most efficient and cost effective predators.