How to kill spiders on your marijuana plants
Spiders are perhaps the most damaging invaders for your marijuana plants. Regarded as arachnids rather than insects, spiders have eight legs and no antennae… They are extremely difficult to see with the naked eye. Spiders make their homes on the underside of leaves and will spin a silky web as a way to protect their colony and eggs. If you see beautiful white connections between the leaves, you are lucky you have mites ... But in both cases, these pests must be exterminated, or your growing medium will go by the wayside ...
Vegetable cell devourers
Spiders have small "teeth" with which they can puncture a single plant cell and extract the chlorophyll needed for photosynthesis in all plant life. The eggs hatch in three days with the mite becoming sexually mature in just five days… This means they can reproduce at a rapid rate, causing significant damage to your crop.
Because they reproduce quickly, spiders have the potential to cause major damage to your marijuana plants. A mature female can literally produce millions of offspring in a month.
Uncontrolled mite infestation can cause extensive crop damage and / or failure. By following the planting practices mentioned below, you can discourage mite infestation.
How to kill spiders on your marijuana plants
Organic compost and mulch added to the planting site deters these microscopic warriors from invading your marijuana plants by encouraging the presence of predatory mites which feed on the destructive mites.
Ladybugs also feed on mites. They can be purchased online, but will more than likely fly away once they no longer have a food source available to them. You can see the sudden appearance of ladybugs if mites are present and can save you the trouble of finding or even buying them. Mother Nature works like this!
Already have mites?
If, despite taking preventative measures, you still see evidence of mites, water your plant with a hard stream of water three mornings in a row. The water pressure will kill insects and their protective tissue, causing them to fall to the ground and debilitating their movement. They will no longer be able to reach the leaves and will starve to death.
Reinforce all cleaning measures, and separate infected plants from each other. Everything must be done to stop the plague, so that it does not spread. Remove more than 50% affected leaves and throw them away… Avoid touching other parts of the plant or other plants during this process.
And for indoor growing, create a hostile environment by reducing the temperature to 16 degrees and increasing the humidity. Do not hesitate to sprinkle your leaves with cold water. You can also remove them by hand using a small sponge. Spiders thrive in high temperatures, and will die from the cold. Dispose of the bag in your garbage, away from the growing medium.
The red spider in the indoor culture
In an indoor culture, there are no predators like there can be in natural ecosystems. Crops are particularly prone to the expansion of this species, during months when the heat is high, especially summer.
Spider mites, the most famous species of which is the weaver spider mite (Tetranychus urticae), are formidable pests that can parasitize plants. Their presence can be detected by the appearance of small white spots on the leaves which then turn yellow and dry out completely.
Different products on the market can be effective once the invasion is widespread.
- Neem oil : Neem oil is obtained from the seeds of a tree growing in India. Its insecticidal, acaricidal and bactericidal properties are no longer to be proven. However, it remains prohibited for sale in France as a phytosanitary treatment, including organic.
- Black potassium soap : Black soap is made with potassium salts and a natural fatty substance, a vegetable oil (generally linseed and / or olive oil). It is commercially available in liquid form or in a soft paste. For use in the garden, it is advisable to take liquid black soap because its use is easier. Two to three applications with five to ten day intervals will be necessary.
- Pyrethrum oil : Pyrethrum is a plant insecticide extracted from dried chrysanthemum flowers. This insecticide is also called Dalmatian pyrethrum (Tanacetum cinerariifolium). It is a good natural miticide to be applied two or three times leaving a five day interval between each application.
Natural predators of spider mites
There are different types of predatory mites on the market, the best known are:
- Amblyseius californicus: Predatory mite of the red spider
- Feltiella acarisuga: predator of the red spider
- Macrolophus caliginosus: predatory bug nymphs against red spider
- Phytoseiulus persimilis: Predatory mite of the red spider
There are also home-made systems, do-it-yourself repellents to fight against this scourge, in particular. Spread onion skins at the base of your crop, or administer an infusion of ferns diluted with water (to be applied in early spring). Absinthe infusions (sic!) Mixed with sodium silicate are effective (sprinkle the species in spring and autumn).
And if you have the patience and care for your plants. Use a cotton swab soaked in alcohol (pharmacy) diluted at 50% with water, and wage war under the underside of the leaves ... The system is off-putting because it will be necessary to repeat the operation every week until the end of your culture.