Populations of Aphids are starting to really take off this spring on greenhouse and outdoor ornamentals. They are loving the softer tissue from this cool spring. Usually aphids are not life threatening to woody plants, but they can stunt growth and they are unsightly to consumers.
Green peach aphid (Myzus persicae) is one of the most common species on outdoor ornamentals. Aphids are sucking insect pests that cause stunting, malformation and coat plant surfaces with their white cast skins and honeydew. They also attract ants and wasps. (Photo: Charlotte Thomson, LO Nursery Scout)
This spring we are also seeing Cherry aphids (Myzus cerasi) on several species of deciduous flowering shrubs in the nursery, especially Prunus sp. (Photo: Lynette Elliot)
And back again, with cool springs being their favorite, the Black Bean Aphid (Aphis fabae). (Photo: Charlotte Thomson, LO Nursery Scout)
Usually aphids are not life threatening to woody plants but they can stunt growth. Various insecticides are registered to manage aphids in outdoor production nurseries including Beleaf, Endeavor, Forbid, Kontos, Tristar and Trounce/Pounce/Ambush/Maki. In greenhouses insecticides include Endeavor, Intercept and Enstar EW.
Don’t forget to monitor for natural predators and parasites, aphids have several. In amongst the populations of aphids, our students found these amazing predators, Syrphid Fly Larvae feeding on aphids. The Syrphid fly larvae resemble larvae, but you’ll notice they do not have a head capsule. They are headless maggots, they are fly larvae (head is on the left). They pierce and suck the juices out of aphids. Check our jen.llewellyn on Instagram for a cool Syrphid fly larva video!
Where populations aren’t immediately economically damaging, commercial biological control (e.g. Aphidius, Aphidoletes) may provide excellent management when introduced on a regular basis. Biocontrol suppliers include Biobest, Koppert, Plant Products and Canadian Hydrogardens.
Much of the content for the ONnurserycrops blog comes from our two wonderful students: (left) Kaitlin Creighton, OMAFRA Summer Field Technician (right) Charlotte Thomson, LO Nursery Scout