Root Aphids are like a returning thief in the night that continuously steals the life and vigor of your cannabis plant. Since they attack the root, they eat away at your dear plant unbeknownst to you. At first you may notice some signs like stunted growth and droopy yellow leaves. This may lead you to think you have a nutrient deficiency but it you will have to dig a bit deeper (pun intended) to find the true source of your plant's problem.
Fungal infections and dead spots
Where the Root Aphids have chomped on your marijuana roots it leaves the plant susceptible to fungal infections and dead spots. You will have to inspect your plants closely to see if Root Aphids are your problem. These tiny buggers are only about 1mm small; so be sure to be wearing your up-to-date prescription glasses when looking for them. They come in various colors as their colors change depending on what they eat or their maturity. Their colors can range from yellow, red, green, and sometimes black and brown. If you are having a difficult time distinguishing whether or not the bug you're spotting is a Root Aphid, then look for a white, waxy material on your plant's roots that the aphids secrete. This is a sure tell sign that they've infested your plant.
Pear-shaped bodies and "tail pipes"
Root Aphids have pear-shaped bodies and "tail pipes" at the end of their abdomen. At a later life cycle they can be mistaken for fungus gnats. These adaptable bugs can have varying life cycles. During the growing season they reproduce asexually. During the winter time, the female Root Aphids lay their eggs in the soil. During warm months the female will attach the eggs to leaves and stems where the hatchlings will fall to the ground and bore into the root. Once an infestation gets bad enough the night thieves move higher up the stem continuing to steal your plant's life. Once they have killed off a plant, they will develop wings to find a new plant to attack.
Ants around that area
Another tip of how you can detect if your outdoor cannabis plants are under attack by Root Aphids is if you notice a lot of ants around that area. Ants and Aphids have a "I scratch your back, you scratch mine" kind of deal. Ants will escort Aphids between plants, protecting them from predators. In return, the Aphids secrete a sugary substance that the ants like to feed on.
If you suddenly get an infestation of these creepy crawlies then you must be wondering where the hell these little bastards came from. Most often than not, they came from commercial soil. Therefore, you should only buy clean soil! Growers talk, so before you purchase soil ask around if any brand is being rumored to be infested with Aphids.
Now, if you've reached past the point of being able to prevent Root Aphids and they're already munching away at your crop you should try to kill them with these methods. Beneficial nematodes can work very well to control Root Aphids. You are basically buying microscopic, non-segmented roundworms that kill many pests like Aphids. You can buy nematodes at many garden centers. Nematodes are a biological and natural way to kill root aphids within a couple days and they are harmless to people, animals, and plants. Fill up a spray bottle with water and put in the correct amount of nematodes as stated on the nematode package. Water the soil around your cannabis plant and spray the mixture onto the soil around the plant that is infested with the Root Aphids. The nematodes will go into the soil and kill the pests in 24 to 72 hours. This will give you protection for months.
Another great natural insecticide is pyrethrum; it's made with chrysanthemum flowers. It's toxic to Root Aphids along with other harmful garden bugs. However, it's safe to use around people and pets. All you have to do is spray the insecticide on the soil around the infested plant. Water the plant so that the pyrethrum sinks into the soil. Within hours the pests will start to die. Wait for 12 hours until you water the plant again. You can spray your plants with pyrethrum every 2 or 3 weeks.
Neat and tidy grow space
An infestation of Root Aphids are a horror to have. Preventing them is the best way to go. Keep a neat and tidy grow space and be wary of commercial soils.