Growing cannabis is relatively easy, the plants only require basic things to grow: water, light, a soil rich in nutrients and an airy space. However, plants have enemies that can kill them if they are not detected in time. These are the pests.
Cannabis is not a desirable plant for all insects but there are some that find it appetizing. These cannabis pests can often be found in pot cultivation conditions, such as exterior growing, where there are no barriers to keep them out.
Among the pests, the most common insects that may attack your plants are: the whitefly, red spider, mealybug, thrips and caterpillars.
The cannabis grower must be prepared to identify these pests quickly and take the correct measures to eradicate them in order to protect the plant and avoid loss. What follows is information to help you detect pests threatening the health of your cannabis plants before it’s too late.
Whitefly: Actually white or yellowish white, these are very small insects (1-1.5 mm) but have a reproductive capacity of up to 500 eggs by a single female. Additionally, under favorable conditions, each insect can live up to 55 days. They are easy to see with the naked eye and when moving or shaking your plant they may fly away. They also leave circular marks on the front of the leaves as well as small, recognizable eggs. They feed on the sap of your plant and leave behind a harmful sticky residue called honeydew.
Although this pest does not kill your cannabis plant, they do weaken it and reduce the quality of your buds and contribute to the growth of fungi.
This fly is a worldwide pest in agriculture and since it reproduces quickly, sometimes when we notice them it is because the plant is already infested. It is best to try to prevent them with the use of potassium or neem soap. You can also use fly traps which are sticky and yellow or blue in color.
As a treatment against the infestation try not to use chemical elements. Instead, it is preferable to use biological insecticides or fight the flies with natural predators. For example, some species of bedbugs are specifically useful to combat whiteflies.
Red spider: These are undoubtedly one of the most difficult pests. They are small red or brown mites capable of quickly weaving webs. They reproduce easily and can kill your crop in just days. Although they are found both indoors and outdoors, they tend to be more aggressive indoors. They reproduce by settling on the front of the leaves and feeding on the plant, leaving pale yellow spots. The spots do not affect your plant much, however, by weaving their webs around the buds, they prevent photosynthesis and weaken the plant, leading to its death.
This pest is easy to detect but difficult to kill. The best strategy is prevention which, like the whitefly, can be achieved with potassium or neem soaps or by letting their predators live in the plants. Some of the red spider’s natural enemies are mantises, ladybugs and lacewing spiders. If you see any of these predators in your crops allow them to do what they do, they are your friends.
Mealybugs: These insects inhabit the stems and branches of plants and leave a trail of honeydew where they pass. They feed on sap, weakening and delaying your plant’s growth and flowering. Their suction injects toxins into the plant and can transmit viruses. The trail of honeydew that they leave can also encourage the growth of fungi.
Although they are not difficult to identify, they are difficult to fight. Once spotted, do not waste any time. Their reproduction is fast and accelerates in high temperatures. They are more common in outdoor crops planted in the ground or in a pot.
To combat them you can use adhesive plants. Provide your plant with silicon that thickens the skin, making it difficult for the mealybug to feed on it. During the growth phase you can remove them manually with an object such as a blade. You can also use potassium soap or pharmacy bought rubbing alcohol by applying it to a piece of cotton and then wiping down the branches.
Biological insecticides that contain organic pyrethrin are another option to help you with these destructive insects. Constant care and attention is the most important thing, you have to be vigilant and not let your guard down.
Thrips: Thrips are winged insects that, instead of flying long distances, use their wings to help them jump from leaf to leaf. Cylindrical and elongated in shape, they are yellow, brown or black in color with light banding. They are one of the most common pests in the cultivation of marijuana. You may find them when you move the leaves in the upper parts of your plants, mainly the leaves of the stems toward the tops. They are biting insects but they do not secrete honeydew. Their bites are visible and leave yellow spots on the leaves of plants, very similar to those of the red spider.
They are common outdoors and in greenhouses although they can also appear in indoor crops. These insects thrive in humidity and the higher the humidity, the greater their reproduction. The use of ventilation for indoor crops or outdoor planting with enough space between crops helps to control humidity.
These insects weaken the plant. During the growth phase they could stop advancement or cause the plant to lose vigor. During the flowering phase they generate stress that slows the plant down and decreases the production of buds.
To combat this pest it is important to combine a biological insecticide with products that stimulate the natural defenses of the plants and help control the stress that they go through. Like many pests, they have natural predators that can help you fight them as well.
Caterpillars: These are butterfly larvae that develop around spring and summer, during the growth and flowering stage of cannabis. They are voracious and can quickly kill your plant. Upon reaching the pupal stage, caterpillars need to eat as much as they can to generate energy for their transformation into butterflies. They only have a short time to feed so they feed ferociously. It is more common for them to appear in the flowering stage of your plants, settling in the buds and rotting them from the inside out, leaving holes and droppings.
Although they are easy to identify with the naked eye due to their large size, they cause great damage as they arrive just when the plant is almost ready to harvest.
They have a ravenous appetite and without control can destroy your entire harvest. They bite the leaves and buds, break the stems, dry them out or rot them due to the infection of their droppings that facilitates the growth of fungi.
To recover your plants it is necessary to apply specialized insecticides and remove the droppings, pupae and remains of dead caterpillars. Check your plants constantly to make sure that you have eradicated the caterpillars and use natural products to help them regain their strength. Bathe the leaves with rapeseed oil to suffocate any eggs that may remain there.
Remember that the best way to avoid pests is to constantly monitor your plants. Every 3 to 5 days take a look at them and note any changes that have occurred such as yellow leaves, spots, honeydew, marks or anything that indicates that they are having a problem. Before carrying out any treatment it is important to identify the cause of the changes and if they are due to a pest. There are treatments that are effective for some pests but for others they are a waste of time. However, there are some things that can help in every situation like changing to diatomaceous soil. Remember to use biological insecticides and employ the use of natural pest predators to avoid harming your plant while controlling the pests. Once you’ve managed to get rid of a pest your plant should continue to grow as normal. If it struggles to continue growing, an algae extract can be used to help it regain its vigor.