How to know if you have aphids?
Aphids are large enough to be identified with the naked eye. They often take on the hue of the plant they are chewing on, so when discovered in cannabis crops they are typically light to dark green. It is most common to find them crawling up the stalks of young plants at the first outset of an infestation. They move at a leisurely pace but you can prod them with a small stick like a toothpick or wooden skewer and they will run away.
As cannabis aphids develop, they progress through four instar phases. As they grow they will molt their exoskeleton and the sheds can be observed on the dirt at the base of the plant. The sheds can be identified with the naked eye and are a sure sign of a rising infestation.
Why be concerned about aphids?
Aphids feed on the sap inside the leaves and stems of a cannabis plant. Very little cosmetic damage occurs when they feed, however, over time the loss of fluids will ultimately stunt the growth of the plant. Each feeding site becomes a potential point of infection as aphids can carry diseases such as Fusarium and Pythium from a sick plant to a healthy one. In addition, after an aphid feeds it will secrete a sticky, sweet honey dew. This substance attracts ants and often turns into black sooty mold that will ruin mature product. The ants will also act as defenders for the aphids from their natural predators.
The aphid characteristic that is most concerning is their unique breeding abilities. Not only are they one of the few insects that can birth live young and/or eggs, a single female aphid can carry multiple generations at a time. The females can reproduce asexually and eggs can survive dormancy periods of 4-5 months.
How can I mitigate an aphid infestation?
Chrysopa Carnea also known as a green lacewing, is a natural predator of cannabis aphids. The Chyrsopa larvae are ravenous and have been labeled the aphid lion. The larvae are very effective for cleaning up aphids in cannabis crops. If using the eggs, they need to be placed in a distribution box as broadcast methods have been shown to yield very low hatch rates. The chrysopa eggs on cards have been specifically created with cannabis growers in mind and are a clean and easy way to treat a crop. The cards are small and light and can be hung on very small plants. The eggs will hatch after a few days and ravenous larvae will emerge.