Pests in marijuana crops: Aphids

How to tell if your marijuana plant has aphids

Aphids are easy to detect with the naked eye. In addition, thanks to their high reproductive capacity (a female can release 30 to 100 larvae per day), they are usually grouped in clusters of tens and even hundreds of individuals. These are the symptoms that you should look out for to know whether your marijuana plant is infected.

• Presence of aphids: this is the most evident sign; you'll find them in colonies, under the leaves and on the stalks.
• Leaves with a sickly appearance: yellow, withered and dry.
• Honeydew: as the infection advances, a kind of honeydew appears which is secreted by these parasites. This honeydew can cause the appearance of the fungus commonly known as sooty mold.
• Presence of ants: aphids and ants have a symbiotic relationship in which the ants benefit from the honeydew produced by the aphids and in turn these receive the protection of the ants against some predators. So pay special attention if you see lines of ants around your plant, as it could be a sign that you have an aphid infestation.

You must be particularly alert for these signs in spring, as it is the most favourable period for the appearance and reproduction of this pest. These are the conditions that can cause the appearance of aphids:

• High temperatures
• Dry ambient conditions
• Excess fertiliser

How to prevent Aphids

Like with all pests and diseases that can affect your marijuana crop, the secret to avoid them is through prevention. Here are the measures you should take:

• Cleanliness: Remove decomposing vegetable waste matter. Change clothes before going into the indoor grow room.
• Fumigate your plants occasionally with natural insecticides:

1. Neem oil
2. Insecticidal soap
3. Nettle spray
4. Horsetail

What to do if your marijuana crop is infested with aphids

• Eliminate them manually: when the aphids are adhered to the plant they do not move, so it's easy to squash or remove them with your fingers. You can do it with gloves or with a sponge soaked in Neem oil.
• Introduce predator species: below we list a series of natural predators that you can introduce in your crop to keep the infestation of aphids at bay:

1- Chysoperla or lacewigs: when these insects are adults they feed on nectar, pollen or the honeydew excreted by aphids, but during their first stage of life, when they are larvae, they feed on aphids. They are therefore a good tool. Release about 20 per plant and repeat the process once a month.

2- Parasitic wasp Aphidius matricariae.

3- Ladybirds: these are effective for eliminating aphids, but the catch is that they are fatally attracted by HID lights, so their use is not recommended for grow indoor crops.

• Verticillium lecanii fungus: very effective against aphids.
• Spraying: spray the plants with pellitory two to three times at intervals of five to ten days.