The legalization of cannabis in Canada has resulted in increased clone sharing through large LPs, Micros, ACMPRS and home growers. This transition in the cannabis market resulted in the cannabis aphid (Phorodon cannabis) becoming a wide scale problem amongst growers. Upon introduction, eradication of this pest with current available tools is exceptionally difficult. Health Canada regulations restricts the use of commonly used aphid insecticides that are key for aphid control in other crops. 
If the cannabis aphid enters your garden space, it will typically come in on clones imported from another growing facility. Inspection of clones is vital as aphids inconspicuously hide on the stem, under a leaf or in the growing tip. In addition, because cannabis cultivation has grown with outdoor gardens and neighboring facilities, the cannabis aphid can spread by its winged form, through windows, doors or by people. As a result, aphid prevention strategies are crucial when implementing an Integrated Pest Management (IPM) Program.
Once they enter the facility, soon after you will begin to notice things like leaf curl, plant stunting, or honeydew excrement. If left untreated, major economic damage will occur because of direct bud contamination by aphid, aphid exoskeletons, sooty mold (encouraged by honeydew excrement) and viruses/viroids vectored by these sap-feeding insects.
Rigorous exclusion protocols are effective at preventing the cannabis aphid from entering your facility. Exclusion strategies will include rigorous inspection of new material, quarantining, scouting, as well as implementing clean room processes and clean up procedure. This will minimize economic, health, and environmental risks to your crop.
On Arrival:
- Most importantly, avoid importing clones if possible and do not import more than you can inspect.
- After the first screening, do a preventative dip treatment with insecticidal soap, horticultural oil or a bio-insecticide.
- Move the clones to a quarantine room.
- Keep them in this room for at least 2 weeks to observe potential aphid development.
- Upon completing quarantine, intensive scouting should occur weekly.
- Check stems and undersides of leaves. Scan for all signs of honeydew and aphid exoskeletons (aphid shedding).
- Do not rely on sticky cards for early aphid detection. This only detects aphids very late in the infestation period.
Best Practices:
- Install air curtains on overhead doors. This prevents aphids hitching a ride into your facility on worker clothing or hair.
- Screen any air intakes in your growing facility to prevent outside aphid introduction.
- Ensure personnel wear hairnets, booties and coveralls when entering the growing space
Bio-control is typically out of the question for preventing the cannabis aphid because of the return on investment. When strictly practicing the exclusion program listed above, it is highly unlikely you will develop an aphid infestation. Therefore, bio-control agents are unnecessary unless you identify the cannabis aphid in your facility.
A few things can help when scouting a cannabis crop. Most importantly a hand lens of about 10X magnification, this is an important tool for a grower or scout who wants to identify an insect in their establishment and make an informed decision on what to do next. We sell two different kinds of hand lenses, our Metal Magnify Lens w/ Scale and our Plastic Magnifying Lenses. Both will help you locate, magnify and identify common pest species, including the cannabis aphid
Our Monitoring Starter Kit, which comes with a field guide, a magnifying lens, a Horiver Grid Yellow Pack and a Koppert Pen will also help you locate, magnify, identify and keep track of pest pressure in your crop. The field guide along with the lens will aid you in identifying an unknown pest, as it gives you dedicated space for your notes.
In conclusion, exclusion strategies are the best way to prevent a cannabis aphid from entering a facility. If strictly practiced, you will be able to avoid the introduction of unwanted pests, as well as decrease money spent on unnecessary bio-control agents. In turn, your crop will thank-you by providing you with a clean, smokeable, aphid free harvest.
Monitoring Starter Kit – Retail Koppert Canada
Plastic Magnifying Lens – Retail Koppert Canada
Metal Magnify Lens w/ Scale – Retail Koppert Canada
Please see our Cannabis protocol here for product application rates if you find the cannabis aphid in your crop: Cannabis – Retail Koppert Canada
Here is another blog post on Cannabis pests, quickly touching on the Cannabis and Root Aphids: Do you think you’ve got Cannabis Pests? – Retail Koppert Canada