Cochineals are one of the most annoying and damaging insects that could attack any marijuana cultivation. This small yet dangerous parasite can turn into any grower’s worst nightmare, whether it’s cannabis plants or any other plant that they’re growing. But don’t panic. However strong these insects can be, there’s always something we can do to defend our plants and stop them from spreading.
It's true that cochineals are one of the most common pests attacking cannabis plants. That's undeniable. But there's a series of effective preventive and reactive measures that will allow our plants to show their full potential. In many respects, they're very much like bedbugs and aphids. In fact, all three of them belong to the order of Hemiptera (Rhynchota). Their power lies in their ability to hide, making them hard to detect unless the leaves and branches are thoroughly examined.
What do they look like?
There's a world of cochineal species, but the mealybug and the brown soft scale insect are the ones that put a major threat to us. Most commonly found outdoors, they can attack and feed on any kind of plant, including cannabis plants.
The brown soft scale insect is the most common pest in marijuana cultivation, usually attacking the stems. These small insects, measuring no more than 4 mm, are characterized by their dome-shaped aspect. It's as if they were equipped with a shield that protects them from some insecticides.
Mealybugs, or "cotonet" in Spanish, for their part, owe their name to their cotton-like texture. The most common species of mealybugs are the citrus mealybug (Planococcus citri) or some other Pseudococcus mealybugs. Adult insects are about 3 mm long. Male mealybugs have lots of wings that allow them to fly around easily. Depending on the species, female mealybugs can lay from 50 to 500 eggs that they later protect with a powdery wax layer. A curious thing: after the egg-laying, they die.
When the eggs hatch, the newly-born cochineal set out to find a safe place for sucking the sap of our plant. Mealybugs need warm temperatures to live. If it's over 65°F, they can live up to 3 months, for it's in dry and hot environments that they thrive.
Their favorite spot, near the internode
They love hiding in the internodes of the plants yet they can also be found on the backside of the leaves, on the stems and near the roots. They feed on sap by inserting their suction beak into the cracks on the leaves' surface, with a special liking for the most hidden parts of the plants, the ones with less exposure to light, because it's in areas with little moisture and ventilation that they feel more at ease.
Early detection is key. So keeping an eye on all the changes in your plants is paramount. One of the most evident signs of cochineal presence is the appearance of a sweetened liquid known as honeydew. This substance attracts not only fungi but many other insects such as ants. If you happen to see some of them wandering around, it may be an indication of cochineals on your crop. Other symptoms are the yellowing of leaves, strong defoliation and the loss of strength as a result of having their vital sap sucked.
Keep them at bay using natural remedies
Given their preference for hot and dry environments, it's during summer that they thrive. So the best way to keep them away is to make sure they're properly watered and the growing environment is as clean as possible. Alternatively, you can clean the infected part with plenty of water and expose it to the sun in order to create a hostile environment for the parasite.
White oil or tea oil have also proved to be really effective in keeping cochineal at bay. Spray it on the leaves to create a repellant coat. It's a mechanical system that affects neither the environment nor the people. The only drawback is that it can't be used during summertime for the layer wouldn't let the leaves breathe and plants would end up dying.
The use of natural predators is, and has always been, one of the most effective ways to fight pests. Coccinellids (Coccinellidae), also known as ladybugs, are found all over the world, with over 4,500 different species, and make the best allies. Usually found in plants infested with their preys, they're natural predators of insects and mites, such as aphids or cochineal, both of which pose major threats to cannabis plants.
If we succeed in attracting their presence, cochineals will stay far from our plants. It's true, though, that nowadays ladybugs can be directly purchased from nurseries specialized in biological pest control. With them, and most particularly with the seven-spotter lady beetle (Coccinella septempunctata), great results can be obtained. However, it's far better if the ladybug decides to show up spontaneously or it's reproduced right in our crop. Don't use pesticides if they could somehow interfere with this kind of microfauna.
Or standard treatments
If natural remedies fail to succeed, you can always use limonene-based products. Limonene is a natural terpene extracted from lemon peel oil responsible for the zesty aroma found in them. The market is full of pest control insecticides. All you have to do is pick a good one and stick to the manufacturer's dosing instructions.
With an adequate treatment, cochineals shouldn't be so hard to beat. It's important to remember, though, that prevention is better than cure, so you'll be better off using preventive products that could protect your plants from any possible attacks.
One of the most effective ones is neem oil. No wonder it's one of the most commonly used pesticides and fungicides by cannabis growers all over the world. Besides, it's fully organic, meaning neither the plant nor the environment will be badly affected by its use. By spraying your plants once a week with it, the active chemical azadirachtin will block the respiratory tract of the little invaders. It is to be mixed with the irrigation water.
Another way to effectively get rid of cochineal is by mixing alcohol and water in equal parts. When soaked with this mix, the shell of brown soft scale insects will dry out and come off very easily.
If any of your plants' parts have been in any way damaged, the best thing you can do it cut it off and get rid of it. Remember that weak or sick plants are more likely to suffer serious pest attacks, so make sure they stay healthy during the whole growing process. And don't forget that prevention is always better than cure.