Leaf miners have been around in European crops since the last decade of the 20st century.
If you’ve ever seen any long, discolored furrows on your plants’ leaves, you’ve probably had leaf miners.
Keep reading and we’ll tell you how to identify, prevent and get rid of these common insects in urban and greenhouse grows.
What are Leaf Miners?
Many different insects fall under the term of leaf miners due to the way that they damage plants. There are currently two known leaf mining insects that attack cannabis, known as:
- Phyllocnistic Citrella, a type of moth.
- Liriomyza Spp Subspecies, cannabis, trifolii, broniae etc., a type of fly.
These species, when in their larvae state, create tunnels in your plants’ leaves, feeding off of the layers of leaves with less cellulose. From the outside, the empty parts will look like furrows or paths along your plants’ leaves.
Leaf miners are not likely to ruin your plants, but they will end up slowing your plants’ growth down, especially during the first few weeks.
They’re much more common in outdoor grows as well as greenhouses compared to indoor grows. If you find the larvae fast enough it’ll be quite easy to get rid of them.
How to Detect Leaf Miners
During the larvae state, when they’re making tunnels through the leaves, it’s quite easy to find them. If you see a small brown dot at the end of the tunnel or furrow, that’s the larvae.
In their adult state they can be harder to detect; you’ll need to use coloured traps in order to trap adults and make them easier to detect.
How to Prevent Leaf Miners
- Make sure not to go overboard using growth fertilizers; excess nitrogen in your plants can attract leaf miners and other types of insects.
- Use preventive products such as Cannacure, Protect, or Leaf Coat; these products are designed to create a thin protective film around your plants’ leaves, which makes it hard for leaf miners to attack them.
- Yellow and blue sticky traps are quite useful when it comes to getting rid of adult flies and leaf miners, as well as for identifying them.
- You should also use products rich in silicon such as Silicate, Rhino Skin, Vitalize etc. These additives can increase your plants’ strength and resistance, giving them a much tougher skin.
How to Get Rid of Leaf Miners
If you only have a few miners you can simply squish them; the larvae is always at the end of the furrow. Depending the stage your plants are in, you may want to simply remove the leaf; if you remove it, don’t leave it in your grow.
If the infestation has gotten bad, you can use natural pyrethrins such as Spruzit, which also gets rid of other insects such as white flies, spider mites, aphids and more. Spruzit contains rapeseed oil and pyrethrin, which degrade under the sun.
We recommend combining insecticides with anti-stress products that can stimulate your plants natural reaction to stress such as Regulator or Revive.
Before Handling Insecticides…
- Read the instructions and manufacturer’s recommendations.
- Use protective material.
- Make sure to respect the indicated safety period and follow all necessary steps to get rid of the containers and residues.
- If you have any questions, get in touch with our team of professionals.
At La Huerta Grow Shop we recommend protecting your cannabis plants using environmentally friendly, bio products.