Introduction
Cannabis is a versatile plant that thrives in climatic conditions. It is not just popular among humans, but birds, moles, squirrels, and even pests and insects love to binge on cannabis harvest both indoors and outdoors. Common cannabis pests and diseases threaten plant health and productivity in cultivation settings.
So, you must be extra careful as common cannabis pests and diseases await to steal your harvest potential. But fear not, green thumb! This guide will help you to look for the signs of cannabis pest infestation, so you can keep your hemp healthy and flourishing.
Common Cannabis Pests And Diseases Affecting Your Plant
Before we proceed, let us take a quick look at the lists of pests and viruses that affect your marijuana plants, so you can better understand the challenges posed by common cannabis pests and diseases. Uncover the challenges faced by cannabis growers as they navigate common cannabis pests and diseases, and explore effective strategies to protect their precious plants.
Common Cannabis Pests:
- Aphids (Green Peach Aphid, Potato Aphid, Cannabis Aphid, Cotton Aphid, Rice Root Aphid)
- Thrips
- Leaf Miners (Liriomyza trifolii, Liriomyza sativae)
- Mealy Bugs
- Red Spider Mites
- Whiteflies (Bemisia tabaci)
- Fungus Gnats
- Caterpillars (cabbage loopers, inchworms, armyworms, hornworms)
Common Cannabis Diseases:
- Leaf Septoria/ Yellow Leaf Spots
- Bud Rot/ Mold (Botrytis cinerea)
Cannabis Viruses:
- Hop Latent Viroid (HLVd)
- Lettuce Chlorosis Virus (LCV)
- Cannabis Cryptic Virus (CCV or CanCV)
- Tobacco Mosaic Virus (TMV)
Navigating the world of cannabis cultivation presents unique challenges, especially when contending with common cannabis pests and diseases. Growers must remain vigilant and proactive in their efforts to safeguard their valuable plants.
Also Read: Where to grow Cannabis- Indoor or Outdoor?
List of Most Common Cannabis Pests
Identifying and treating common cannabis pests and diseases is essential for maintaining the health and vitality of your cannabis plants, especially considering the threat posed by common cannabis pests and diseases such as aphids, fungus gnats, leaf miners, spider mites, inchworms, caterpillars, and thrips.
Also Refer to: What Tools and Equipment Do You Need To Grow Cannabis?
Here is the list of common cannabis bugs that you find in Canada and how you can combat them naturally:
1. Aphids
Aphids are tiny sap-sucking creatures in various colors like black, green, yellow, etc., and can quickly form large colonies. They weaken plants by sucking nutrients from the leaves and transmitting diseases. Check for distorted leaves, such as curling and sticky sap, that lead to mold fungi formation, ultimately decreasing photosynthesis activity. The most common ones among cannabis are the Green Peach Aphid, the Potato Aphid, the Cannabis Aphid, the Cotton Aphid, and the Rice Root Aphid.
Solution:
As per Canadian National Pest Management Association CNPMA, Regularly inspect your cannabis, especially the undersides of leaves. Get some ladybugs or aphids, Coleman, as they are natural sustainable predators of aphids. You can also use neem oil spray or insecticidal soap to disrupt their growth cycle. However, always follow the instructions and test on a small area first to avoid harming your plants.
2. Thrips
Thrips are slender insects, about 1-1.5 millimeters long, with fringed wings. They come in various colors, including yellow, black, or brown, and suck on plants causing brown discoloration. They destroy chlorophyll, and in severe cases, leaves fall off prematurely. They reproduce quickly in warm and dry conditions. The plant dies if not treated early.
Solution:
Maintain good airflow. Use natural DIY neem sprays, insecticide soap, or predatory mites like Amblyseius Cucumeris, or Nematodes to combat thrips.
3. Leaf Miners
Are you tired of those white blotches or the serpentine tales? On the underside of cannabis leaves, these tiny bugs lay eggs. Some common leaf miners are Liriomyza trifolii and the Liriomyza sativae. The larvae burrow into the leaf tissue, creating winding tunnels as they feed to become adult flies. By prematurely yellowing leaves, they cause heavy damage to plants.
Solutions:
Maintain good airflow in your grow area. Use spinosad as the best organic pesticide for cannabis. You can also introduce parasitic wasps like Diglyphus isaea to help control leaf-miner populations naturally. In light infestations, manually remove the affected leaves to eliminate the larvae.
4. Mealy Bugs
Mealy Bugs are soft-scale insects covered in sticky wax flour whitish powder that cause plant heavy damage. Some are pathogenic, while some are oviparous, viviparous, or ovoviviparous. Find white, cottony wax clusters on your cannabis plants’ stems, leaves, and nodes to find out.
Solutions:
Regularly clean your grow tent and introduce predators like Anagrus pseudococci, cryptolaemus montrouzieri, ladybug, or lacewings to control mealybug populations. You can also opt for organic sprays and insecticides. Also, if detected early, remove them manually with a cotton swab dipped in rubbing alcohol.
5. Red Spider Mites
Red spider mites are tiny reddish-orange eight-legged mites that live beneath the leaves and suck plants’ sap, leaving tiny yellow dots that turn brown over time. If left unnoticed, the whole plant is stunted and gets sick. They reproduce quickly in warm conditions, and females can lay eggs for up to seven days.
Solutions:
Maintain humidity between 50-65% and use a humidifier. Opt for predatory mites like Phytoseiulus persimilis and Amblyseius swirskii. Always pick healthy clones or seeds and provide proper nutrients to resist pest infestations.
6. White Fly/ Whiteflies
White fly, also known as Bemisia tabaci, is a 1/12-inch long winged insect that feeds on plant sap, similar to aphids, and promotes mold growth. They may look harmless, but when disturbed, they will readily take flight in a white cloud, as a female may lay dozens of eggs beneath the leaf. They contaminate plants with viruses like Begomoviruses.
Solutions:
Initiate beneficial insects like ladybugs, lacewings, or parasitic wasps like macrolophus pygmaeus, as these are effective agents to kill white flies and other bugs. You can also use Diatomaceous Earth DE, a powder made from algae that dries out the bodies of insects.
7. Fungus Gnats
Fungus Gnats are another small pesky insects that are a headache to cannabis growers in Canada. They are dark-colored flies with long legs and wings. They resemble mosquitoes but are much smaller. They lay eggs in the soil, especially compost of wood and chips. It stuns growth and damage roots.
Solutions:
As they are root feeders, kill the larvae to stop their growth. Stop overwatering and use beneficial nematodes like Steinernema feltiae or neem oil in your soil. To prevent them, use mosquito bits, and cinnamon as a topper.
8. Caterpillars
Caterpillars love to eat cannabis leaves and cause significant damage to the plants, reducing yields and leaving behind holes, ragged edges, and frass. Many caterpillar species eat cannabis leaves, but popular ones are cabbage loopers, inchworms, armyworms, and hornworms.
Solutions:
Bt (Bacillus thuringiensis) spray is a popular organic option, also, caterpillar sprays and spinosad are effective remedies to target caterpillars. You can also plant mint or basil as companion plants to keep them at bay as it remits strong scents.
Also Read: Troubleshooting Guide
Most Common Cannabis Diseases
Cannabis, like other plants, can fall victim to diseases. Common ones include fungal issues like bud rot (Botrytis cinerea) and leaf septoria, both causing discoloration and stunted growth. Here are they:
1. Leaf Septoria/ Yellow Leaf Spots
Leaf Septoria also known as Septoria leaf spot, is a fungal disease that can affect various plants, including cannabis. It thrives in warm, humid environments with extended periods of leaf wetness. The circular or oval leaf spots on older leaves start at the lower part and progress upwards may enlarge causing leaves to turn yellow and eventually drop.
Solutions:
Maintain good airflow, and use a drip irrigation system to minimize leaf wetness. You can also use fabric grow bags. Use organic fungicides containing copper or DIY garlic spray.
2. Bud Rot/ Mold
Have you noticed that your plant looked sick overnight and smelled unpleasant? It is because of mold that is growing inside the bud. Upon opening it, you’ll see a white mold that is Botrytis cinerea, a common fungus found in soil and air.
Solutions:
Regularly check the growing area, and maintain humidity and airflow. Provide ample light and decrease the water schedule. Also, use copper or neem oil as natural disinfectants.
Common Cannabis Plant Viruses
Unfortunately, cannabis is susceptible to a few sneaky viruses. These can be tricky because they don’t always cause noticeable symptoms. Here are the most common Cannabis viruses and their symptoms and how you can combat them:
1. Hop Latent Viroid
Hop latent viroid (HLVd) is a single-stranded RNA pathogen causing significant concern for both hop and cannabis growers worldwide. It lacks a protective protein coat and relies entirely on its host plant for survival. It spreads readily through contact with infected plant sap via tools, equipment, or workers’ hands. It causes Dudding, a common phenomenon used for stun growth, loss of potency, flavor, and reduced yields. HLVD root testing is necessary to know if the plant has this virus or not.
Solutions:
Always buy mother plants from reputed sellers who have checked for the HLVD virus. Practise sanitary practices, and cleanliness and isolate plants with unusual development.
2. Lettuce Chlorosis Virus
Lettuce Chlorosis Virus (LCV) is a plant-based RNA pathogen that infects lettuce crops in Southern California regions but also affects cannabis plants. When cannabis crops are affected, it leads to interveinal chlorosis, leaves turning yellow as plants fail to absorb sunlight. It causes stun growth and potential leaf loss, with low terpene profiles ultimately causing reduced yields.
Solutions:
See, these are viruses, and you need to test them. Always use certified clones and check for symptoms like brittle, pale, rolled leaves. Protect your plants from whiteflies, vectors for LCV. Isolate or removing plants with viruses is all you can do to save the other plantations.
Also Read: Why Are My Cannabis Leaves Turning Yellow?
3. Cannabis Cryptic Virus
Cannabis Cryptic Virus, CCV or CanCV is a double-stranded RNA virus that infects hemp. It is called a cryptic virus because, unlike other viral infections, CCV exists within the plant without causing noticeable symptoms. While initially thought to be harmless, some studies suggest a possible link between CCV and certain conditions like the hemp streak virus. However, more research is needed to confirm a cause-and-effect relationship.
Solutions:
As the research is limited, CCV is usually transmitted via seedlings, so it may get transferred in the next generations. It is known as vertical transmission, so try to get seeds through reputed sites and maintain good hygiene practices in the growing area.
4. Tobbacco Mosaic Virus TMV
Tobacco Mosaic Virus, as the name says, this virus was first discovered in tobacco plants. It can affect over 100 plant varieties leading to pale light and dark green mottling on leaves, necrosis, twisted curled leaves, and uneven stripes accompanied by stunted growth and discoloration. It may feel sticky.
Solutions:
While TMV occurs less in cannabis hygiene practices in the grow room can help prevent the introduction of TMV, just like with other pathogens.
Also, refer to: Can You Clone Autoflower Cannabis Plants?
FAQs
1. What are the symptoms of the Cannabis Plant virus?
The symptoms of the cannabis plant virus vary depending on the virus and cannabis strain. Symptoms include stun growth, leaf discoloration, brittle leaves, deformed leaves, and reduced trichome production, depending on what issues you have.
2. Is neem oil safe for Cannabis Plants?
Neem oil can be a safe and effective organic option for controlling common cannabis pests and diseases. But keep a few things in mind, like diluting neem oil, testing on small areas, avoiding heat, etc. It is organic, but using it safely depends on you.
3. How to get rid of Cannabis Bugs and Viruses?
Unfortunately, there’s no single solution to remove cannabis bugs and viruses. However, different approaches may reduce pest pressures and minimize the impact of viruses. Preventing the spread of cannabis disease is possible with early detection, organic pest control, and maintaining good hygiene.
Conclusion
If you are dealing with these problems, be vigilant because building a healthy cannabis garden to resist pests and disease starts with early detection. By prioritizing hygiene, using certified disease-resistant seeds or clones, and creating an environment optimized for plant health, you can significantly reduce the risk of problems, including common cannabis pests and diseases.
Regularly inspect your plants and be prepared to take swift action if you notice any signs of pests or diseases. There are many online retailers, gardening stores and mail-order suppliers in Canada for cannabis pest control management.
Important Note: When purchasing beneficial predators in Canada, ensure the supplier complies with the Canadian Food Inspection Agency’s (CFIA) regulations for the import and movement of biological control agents.
Feel free to contact us if you need expert advice!
