Aphids are small, soft-bodied insects of the family Aphididae, about 1-3 mm long, that feed on phloem sap through a needle-like stylet. Most have two tube-like cornicles at the rear. Indoors, females give birth to live young without mating, so a colony can double in days. Several species use cannabis, including the cannabis aphid (Phorodon cannabis) and the generalist green peach aphid (Myzus persicae).
In practice
Signs are colonies on leaf undersides and stems, white cast skins, sticky honeydew, and the black sooty mould that grows on it. Ants farming honeydew are a strong clue outdoors. Heavy feeding curls and yellows leaves, and some aphids carry plant viruses. Standard tools are parasitic wasps such as Aphidius colemani, predators such as lacewing larvae and ladybirds, and soft contact sprays such as insecticidal soap in veg only. Honeydew and cast skins on buds are a quality problem, so act early. Check what is registered for cannabis locally.
Don't confuse with
- Whitefly nymphs: flat, scale-like and fixed in place on the leaf underside.
- Root aphid: lives on roots, rarely seen on foliage until late.
- Mealybugs: covered in white waxy fluff.
The plant's living transport tissue that carries sugars, amino acids, hormones and mobile nutrients from leaves to roots, buds and other growing parts.Phorodon cannabis, an aphid that feeds mainly on cannabis and hemp, colonising leaf undersides and buds and leaving honeydew and cast skins in flower.An infectious particle of nucleic acid in a protein coat that replicates inside plant cells; on cannabis, often insect-spread and incurable once infected.Tiny parasitic wasps of the genus Aphidius that lay eggs inside aphids; the larva kills the host from inside, leaving a swollen tan mummy.Predatory beetles of the family Coccinellidae, such as Hippodamia convergens, whose adults and larvae eat aphids and other soft-bodied pests.Potassium salts of fatty acids sprayed to kill soft-bodied pests such as aphids, mites and whitefly nymphs on contact by disrupting their cell membranes.Aphids that colonise roots and the crown below the medium surface, on cannabis chiefly the rice root aphid (Rhopalosiphum rufiabdominale), causing slow, unexplained decline.Soft-bodied sap-sucking insects of the family Pseudococcidae, covered in white waxy filaments, that hide in stem joints and roots and excrete honeydew.Insects of the family Chrysopidae, mainly Chrysoperla species, whose larvae are general predators of aphids, thrips, mite eggs and young caterpillars.
