The cannabis aphid (Phorodon cannabis) is an aphid that specialises on Cannabis sativa. Wingless forms are pale green to yellow, often with faint darker stripes, and about 1-2 mm long. It became a widespread hemp pest in North America after hemp production expanded in the late 2010s. Like other aphids it reproduces rapidly by live birth.
In practice
Colonies form on leaf undersides and stems and, by late season, inside flowers. Damage is mostly contamination rather than yield loss: honeydew, sooty mould and white cast skins stuck in buds make the crop look and test poorly. Outdoors it can overwinter as eggs on plant debris; indoors it rides in on clones. Scout leaf undersides weekly, and use parasitic wasps (Aphidius species), lacewings and ladybirds as the backbone. Soap or oil sprays are for veg only. Check what is registered for cannabis locally.
Don't confuse with
- Green peach aphid: a generalist with many hosts; looks similar and needs a closer look at the head tubercles to tell apart.
- Rice root aphid: lives on roots, not foliage.
- Thrips larvae: slender and fast, with no cornicles.
Small soft-bodied sap-sucking insects of the family Aphididae that cluster on stems and leaf undersides, excrete sticky honeydew and multiply rapidly by live birth.The single botanical species, in the family Cannabaceae, that covers all hemp and drug-type cannabis; "L." credits Linnaeus, who named it in 1753.Hemp is cannabis grown for fibre, seed or other uses and, in many laws, defined as Cannabis sativa with no more than 0.3% THC by dry weight.Tiny parasitic wasps of the genus Aphidius that lay eggs inside aphids; the larva kills the host from inside, leaving a swollen tan mummy.Insects of the family Chrysopidae, mainly Chrysoperla species, whose larvae are general predators of aphids, thrips, mite eggs and young caterpillars.Predatory beetles of the family Coccinellidae, such as Hippodamia convergens, whose adults and larvae eat aphids and other soft-bodied pests.Bag appeal is how good flower looks in the bag or jar, frost, colour, density and trim, which sells cannabis but does not measure its quality.Aphids that colonise roots and the crown below the medium surface, on cannabis chiefly the rice root aphid (Rhopalosiphum rufiabdominale), causing slow, unexplained decline.Systematic, regular inspection of plants, traps and roots to detect pests and disease early, identify them correctly and record numbers for decisions.
