Aphid banker plants Rhopalosiphum padi

The most common example of banker plants for greenhouse IPM systems is the use of cereal plants for aphid parasite rearing. These plants are used to sustain populations of grain aphids which in turn host the parasitic wasp Aphidius colemani. The grain aphid is not able to survive on crops such as capsicums, eggplants, cucumbers or roses but is an excellent host for Aphidius wasps.

Growers place barley or wheat plants infested with cereal aphids through the greenhouse. Aphidius wasps are then released onto the banker plants so that a breeding colony of Aphidius can be established within the crop, even when there are no pest aphids present. Banker plants need to be replaced or new plants added every 4-6 weeks. Suggested rate is 1 banker per 1000m².

• Grow your banker plants (barley, corn, wheat) prior to planting your new crop. The cereal will germinate within 7 days
• Infest with grain aphids when plants are 25-50mm high and let aphids breed for one week
• Place bankers throughout the new crop, either in pots or in the soil, and introduce parasitoids. Place near doorways and on ends of rows where it is easy to find and look after the bankers
• Aphids on bankers become parasitised. A new generation of wasps develop which fly into the crop looking for new pest aphids to parasitise