Aphids
Definition: Aphids are soft-bodied, pear-shaped insects, usually green, black, or gray and roughly 1/25 to 1/8 inch long, that cluster on stems and leaf undersides to suck cannabis sap. They reproduce rapidly without mating and excrete sticky honeydew, which attracts ants and can grow black sooty mold on leaves.
How Aphids works
Female aphids can give birth to live young without mating, so a colony can multiply quickly in warm weather. When a colony gets crowded, winged adults appear and fly off to start new ones.
Warning signs
- Clusters of small insects on stems, new growth, and the undersides of leaves.
- Curled, puckered, or yellowing leaves.
- Sticky, shiny honeydew on leaves below a colony.
- White shed skins scattered on leaves.
- Ants marching up stems, which often farm aphids for their honeydew.
Two species to know
The cannabis aphid feeds on leaves and stems and can be hard to spot because it blends in. The rice root aphid lives in the root zone, especially in indoor and hydroponic grows, and often goes unnoticed until plants decline. Check around the stem base and drainage holes if plants struggle without an obvious cause.
Control options
- Blast colonies off with a strong spray of water during veg.
- Treat persistent colonies with insecticidal soap or another aphid-labeled product, applied per the label and within your state’s input rules.
- Release beneficial insects: green lacewing larvae, the parasitic wasp Aphidius colemani indoors, or lady beetles outdoors.
- Control ants, which protect aphids from predators.
Like thrips and spider mites, aphids often hitch a ride on new clones, so quarantine is the cheapest prevention. Avoid spraying buds in flower.