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whiteflies with their eggs

Whiteflies on Cannabis Plants: Identification and Cure

When cultivating cannabis, you constantly need to protect your crop from diseases and pests. A common issue among growers is finding whiteflies on their weed plants. 

While there are various ways to prevent creepy crawlies from infesting your crops, sometimes they overcome these barriers. In some cases, you might not even notice that they’re there until your cannabis shows symptoms of distress. 

So, how do you eradicate a problem you don’t even know you have? 

By keeping a keen eye on your marijuana crops. Note any changes and try to identify the cause. If it’s whiteflies on your cannabis, take action immediately. 

Are you ready to learn all you need to know about these common garden pests? 

Let’s jump right in.

What are whiteflies? 

Before we discuss how to get rid of white bugs on your weed plants, you first need to know what they are. 

These minuscule insects look similar to moths, but they’re only 0.02–0.08 in long. Do you see how tiny they actually are?

a picture shows the actual size of a whitefly
This pic shows the actual size of a whitefly

Despite their name, these bugs aren’t always white. Some have a grey appearance. These cannabis pests have a waxy textured powder that coats their wings and bodies.

adult whiteflies can be recognized by their waxy wings
Adult whiteflies can be recognized by their waxy wings

The insects are related to mealybugs and aphids, also commonly found in greenhouse environments.

Why do whiteflies want to infest plants from cannabis seeds

The simple answer is that the environmental conditions in your grow room are ideal. A whitefly on a cannabis plant suckles nutrients from the underside of the leaves and lays its eggs there. At the images below, you can see what whiteflies eggs look like.

whiteflies eggs can be identified as tiny white bubbles on a cannabis plant
Whiteflies eggs can be identified as tiny white bubbles on a cannabis plant

They remain in this region for most of their lifecycle, which is why an infestation isn’t easy to detect. These flies go through several phases of maturity, and adults can live as long as 40 days in ideal conditions.

These insects can lay up to 400 eggs that hatch within a week and feed off your crops immediately. 

Aside from depriving your crops of nutrients, whiteflies on weed plants can cause other significant issues. These bugs extract more nutrients than they can digest and excrete the excess as sticky honeydew.

whiteflies body covered with sticky powder substance
Whiteflies body covered with sticky powder substance

This substance serves as a growth medium for specific pathogens like black mold, impacting the process of photosynthesis. Honeydew also attracts other insects, including ants. The introduction of new creepy crawlies affects the predators of whiteflies. 

an image of honeydew from a whitefly
An image of honeydew from a whitefly

How to identify whiteflies on cannabis

Regardless of growing indoor cannabis seeds or outdoor varieties, keep an eye out for these pests. It may take a while for you to identify them if you’re not actively looking for cannabis whiteflies. 

Sometimes you may notice small moth-like creatures fluttering around. In many cases, growers only see the leaves turning yellow.

Leaves turning yellow
Leaves turning yellow due to whiteflies infestation

Another symptom of an infestation is white spots on top of the leaves. These markings are the result of bugs piercing the underside for nutrients.

small bugs look like moths on weed
small whiteflies look like moths on weed

A simple way to check if your weed crop harbors these unwanted tenants is by gently shaking the plants. Mature whiteflies fly off when they detect movement. 

There are alternatives if the idea of hundreds of tiny waxy creatures flying around is too much to bear. Check for small white bugs on the weed plants by looking under the leaves. You may notice clusters of 30–40 circular eggs.

whiteflies under a cannabis leaf
whiteflies with their eggs under a cannabis leaf

How to get rid of whiteflies on weed

While it’s best to take preventative measures if you’ve already got an infestation, get rid of them quickly. The last thing you want is whiteflies during flowering, which could affect the bud quality. 

Below, you can see a weed plant attacked by whiteflies. The infestation got out of control! The pests are practically glued to the plants and it is hard to wipe them off.

a weed plant attacked by whiteflies
A weed plant attacked by whiteflies from all sides

So, how do you get rid of them?

There are multiple ways, but natural methods are the best way to approach the issue. Certain chemicals can damage your marijuana plants or kill whitefly predators.

Here are five ways:

Temperature change

One of the most natural options is to drop the temperature slightly. These small white bugs on weed plants thrive in warm conditions. 

A cooler environment of around 68℉ can help reduce the infestation. Make sure that it’s not a drastic drop that affects your crop. Ensuring that there’s adequate ventilation in your grow area is also helpful.

Pruning 

Trimming excess foliage benefits your marijuana crops in many ways. It helps direct nutrients to more vital parts of the plant and makes for healthier buds. Other advantages include the prevention of mildew and mold while improving air circulation around the plant. 

When you have cannabis whiteflies, there’s bound to be some yellow, damaged leaves. Prune them and discard the trimmings immediately. Trimming helps you get rid of some of the eggs and nymphs.

Hosing 

This method works best paired with pruning. Hose your plants with a fair amount of pressure to remove bugs from the leaves. 

The eggs can be challenging, but persistent hosing does the trick for eliminating whiteflies on weed plants

Predators

Another method of eradicating these pests is outsourcing the task to natural predators

Introduce creatures like lacewings and ladybugs to your growing environment. Soon you won’t see any more whiteflies on your cannabis plants. These insects also keep other pests at bay without damaging your crop.

ladybugs help get rid of whiteflies on marijuana
ladybugs are beneficial insects which help get rid of whiteflies on marijuana

Organic insecticides

There are several commercial insecticides available, but the chemicals they contain can harm your plants. Some bugs also develop a resistance against them. Your best bet is to select an organic product.

Various natural oils, soaps, and sprays can help you remove whiteflies from weed crops. 

Neem oil is a firm favorite as it can suffocate insects. An effective technique involves blending this product with dish soap and applying it to the bottom of the leaves. 

Some growers opt for a DIY oil, water, and cinnamon solution. Choose from: 

  • Canola oil 
  • Soybean oil
  • Eucalyptus oil 
  • Cottonseed oil 
  • Rosemary oil 

This method is excellent for those cultivating outdoor cannabis seeds. To apply, mist your crops with the solution.

an organic alternative to pesticides: bug blaster
An organic alternative to pesticides: bug blaster from i49

A plant protectant like bug blaster is another organic alternative and doesn’t harm your crop.

How to prevent the infestation

The easiest way to maintain a healthy marijuana crop is to take precautionary measures. Knowing what attracts whiteflies to your cannabis is the first step in this process. 

Dry, hot weather makes your plants more susceptible to insect attacks. Make sure your crops are hydrated well. 

Another culprit is nitrogen. It’s one of the essential macronutrients that marijuana crops need to flourish. However, it also attracts these pests. If you supplement your plants, be observant of any signs of infestation so you can end it early. 

Some growers use reflectors to repel the insects. Foil and CDs are cheap options in this regard. Alternatively, fill your grow space with other plants that help keep whiteflies away from your weed.

Crops that fit this profile include:

  • Basil 
  • Chinese carnations 
  • Marigolds
  • Ornamental tobacco 
a healthy marijuana plant
A healthy marijuana plant

Taking care of a cannabis crop is a labor of love; when pests invade, the risk of damage is high. The best way to nurture your plants is to take preventative measures before any threat. 

Observe your crops and note any changes in their development. If you discover an infestation of whiteflies on your weed, act quickly to get rid of it. There are various ways to do this, so select the best option for your situation.

AUTHORED BY: Douglas Kester Mr. Kester came to i49 with a wealth of experience. He’s worked in the cannabis industry for more than ten years. As a growing expert at i49, Doudlas finds it hard to choose a favorite strain. Instead, he regards each one as unique and full of potential. Douglas finds it rewarding to experiment with specific cultivars and cross-breed to discover a new one. He strongly believes in sharing the benefits of marijuana with as many people as possible to avoid any misconceptions about the herb. Mr. Kester creatively produces information based on what he’s learned and his experience obtained by implementing what he knows. i49 is proud to have Douglas as part of the team.

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