There are many types of organic spider mite control methods. I will try and list all that I can find but I personally have not tried all of these.
Horticultural Oils such as that extracted from the neem tree, are excellent alternatives to non-organic compounds when you want to kill spider mites. One must be wary, however, of the ingredients used to produce the horticultural oil purchased because historically horticultural oils have been derived from petroleum rather than vegetable oils. But change is coming.
Horticultural oils used to kill spider mites should be applied during the day during warmer periods to ensure quicker evaporation, thus reducing the chances of damaging the plants. Plants that are noticeably under water stress should not be sprayed with oils.
Insecticidal soaps are rather mean way to kill mites. Derived from organic soaps like Castile soap, insecticidal soaps kill mites and other plant pests by compromising their cellular integrity, causing cells to rupture and die. In other words, insecticidal soaps dissolve the spider mite from the inside out, slowly turning them into mush. The usual recipe is about 2-3 drops of castile soap for every quart of water. There are premixed commercial applications available online if you don’t feel you have the experience necessary to mix your own insecticidal soaps.
Neem oil does work, but the way it works is different from other insecticides. Neem is not an instant, knock down, kill everything pesticide. Neem oil affects insects in many different, ingenious and subtle ways.
How neem oil messes with the insects’ brains and bodies
Neem oil has many complex active ingredients. Rather than being simple poisons, those ingredients are similar to the hormones that insects produce. Insects take up the neem oil ingredients just like natural hormones.
Neem enters the system and blocks the real hormones from working properly. Insects “forget” to eat, to mate, or they stop laying eggs. Some forget that they can fly. If eggs are produced they don’t hatch, or the larvae don’t moult.
Obviously insects that are too confused to eat or breed will not survive. The population eventually plummets, and they disappear. The cycle is broken.
How precisely it works is difficult for scientists to find out. There are too many different active substances in neem oil, and every insect species reacts differently to neem insecticide. Neem oil does not hurt beneficial insects. Only chewing and sucking insects are affected. It is certainly fascinating.
Like real hormones, neem oil insecticide works at very low concentrations, in the parts per million range. A little neem oil goes a long way.
But this is not something that happens over night. People use neem oil as an insecticide, and expect everything to die instantly, because that’s what they are used to from chemical poisons. When that does not happen they conclude neem insecticide does not work.
How neem oil deters chewing and sucking insects
There is a nice story that demonstrates how grasshoppers react to neem oil insecticide. It goes something like this:Someone did an experiment. It involved two jars, two leaves, and two grasshoppers. One leaf was sprayed with a chemical insecticide, and one with neem oil. The two grasshoppers were put in the two jars, with one leaf each.
The first grasshopper ate the leaf and died almost instantly. The grasshopper with the neem oil covered leaf did not touch the leaf and lived. At least for a few days. Eventually it starved to death.
Neem stops insects from eating the plants.
Part of this action is due to to the hormone like action of neem oil that I explained above. Insects “forget” to eat after they’ve been in contact with even traces of neem oil.
But it is also the presence, the mere hint of a smell of neem oil, that seems to be enough to keep leaf eating insects away. Neem oil can be very powerful as an anti-feedant and insect repellent.
This anti-feedant property is one of the most often advertised and lauded properties of neem oil insecticide. However, the hormonal effects I described above are even stronger.
Neem oil as an insect deterrent works well against grasshoppers and leafhoppers, but all other insect pests are controlled mostly through the hormone action.
The subtlety of the hormonal effects, and the fact that they may take days or weeks to manifest, makes people overlook them. Ill informed gardeners seek instant gratification, i.e. lots of dead insects immediately, rather than a balanced environment in the long run.
It’s a shame, because the hormonal effect is where the real power of neem oil lies. It’s the key to neem oil being an effective insecticide and good for the environment at the same time. It’s also important to understand this effect to use neem oil insecticide correctly.
Neem oil works from inside the plant
Many insecticides break down quickly. They wash away with rain, or when irrigating, or the sunlight destroys them. You either have to spray all the time, or you have to spray something that’s so stable that it stays around forever. That means the chemical builds up everywhere and eventually poisons everything, including you.
Neem oil breaks down very quickly, too. It is especially susceptible to UV light. But neem oil is also a systemic insecticide. That means you can pour it on the soil (not pure neem oil of course, you use a dilution or extract) and the plants absorb it. They take it up into their tissue, and it works from the inside. A leaf hopper may take a couple of bites, but that’s it.
However, this does not work for all insect species. The neem ingredients accumulate in the tissues deeper inside the plant. The phloem, the outermost layer, contains hardly any. A tiny aphid feeds from the phloem, it can not penetrate deep enough to get a dose of neem. But any leaf hoppers, grass hoppers or similar chomping insects will be incapacitated quickly.
People eat neem leaves to cleanse the blood, stimulate the liver, and boost the immune system. So we certainly don’t need to worry about a bit of neem inside our lettuce leaves. To me this is a much more attractive option than having poisonous foulicides build up in my garden.
Neem oil suffocates insects
Many gardeners use white oil (plain mineral oil) or even olive oil to combat soft bodied insects like aphids, thrips or whitefly. The oil coats the bugs and they suffocate. Neem oil insecticide does that as well. But it’s more like a little bonus on top of everything else it does.
It can be a hazard, though. Of course there is no difference between suffocating good or bad bugs. Oil suffocates anything. So this aspect can harm beneficial insects!
Neem oil and beneficial insects
Neem is non toxic for beneficial insects. The main reason is that insects need to ingest the neem oil to be affected, and beneficial insects don’t eat your plants. But you can still kill beneficial insects if you smother them with neem oil, so please be careful.
Beneficial insects are most active during the day. The best time to spray neem insecticide is very early in the morning, so the spray can dry before the good insects become active. Also a good time is the late afternoon or evening. Once the spray has dried it does not harm your bees, ladybugs, lacewings, predatory mites and wasps etc.
Which contains abamectin as the active ingredient, is an effective insecticide/miticide for many different mite species and is typically recommended for control of mites both indoors and outdoors. The active ingredient, which occurs naturally, is derived from the soil microorganism, Streptomyces avermitilis. Avid is labeled for control of twospotted spider mite, European red mite, carmine spider mite, Southern red mite, spruce spider mite, cyclamen mite, broad mite, and rust and bud mite. The product can be used to control mites in greenhouses, shadehouses, on field-grown ornamentals, Christmas tree plantations, and woody ornamentals. Avid is a contact and translaminar miticide. Translaminar is a term that refers to insecticides/miticides that penetrate the leaf tissue and form a reservoir of active ingredient within the leaf. Avid generally provides up to 28 days of residual activity. The label rate for all mite species is 4 fl oz per 100 gal. Avid is active on the mobile life stages of mites, with no activity on eggs. Although the insecticide/miticide is slow acting, treated mites are immobilized after exposure.
M-pede is a commercial insecticidal soap based on potassium salts of naturally derived fatty acids. M-Pede acts on contact by disrupting the pest’s cuticle and breaking down cell membranes resulting in rapid death of the target insect or mite. M-Pede is generally effective on larval, nymphal and adult life stages. M-Pede effectively controls many soft-bodied pests, but is low in toxicity to non-target organisms. M-Pede is an excellent organic alternative to conventional insecticides.
Common Rose Pests Controlled:
Aphids, Bristly Rose Slug, Earwigs, Rose Leaf Hoppers, Tent Caterpillars, Scale, Thrips, Mites & Whiteflies.
M-Pede is an excellent organic alternative to conventional insecticides for the control of the insects listed above and others on fruits, vegetables, herbs, and ornamental plants.
Rate & Combinations:
2.5 ozs. per gallon of water. M-Pede can be combined with insecticidal oil to broaden the target spectrum. M-Pede’s fast knockdown activity in addition to its excellent wetting properties make it an ideal tank mix partner for other insecticides.
Botanical Insecticide, Miticide, and Nematicide
AzaMax is a natural product with a broad spectrum of pest control and broad plant applications. AzaMax is made from special Azadirachtin Technical extracted using patented extraction technology from Neem, a tree known for it’s innumerable benefits. AzaMax contains Azadirachtin A&B as active ingredients and more than 100 limonoids from it’s special technology. The special feature of AzaMax is that it does not use hard chemical solvents and uses food grade formulation ingredients. AzaMax is licensed in all 50 states.
AzaMax is an antifeedant and insect growth regulator and controls pests through starvation and growth disruption. AzaMax effectively controls spider mites, thrips, fungus gnats, aphids, whiteflies, leaf miners, worms, beetles, leafhoppers, scales, mealy bugs, nematodes and other soil borne pests. Best of all, AzaMax can be applied up to the time or day of harvest. The product is exempted from residue tolerance, thus there is no harmful residue on veggies, fruits, herbs and flowers etc. Truly, AzaMax is a product of Nature in tune with Technology
Other Methods of Treatment
is another organic method of Spider Mite control. Be careful though I have seen diatomaceous earth at certain large chain stores that had poison in it. I don’t understand the logic behind that myself. Diatomaceous earth is Made from the finely ground fossils of prehistoric fresh water diatoms. Diatomaceous earth kills common household and garden pests like slugs, beetles and countless others. It also works great in the house on cock roaches, ants etc. Some insects actually eat diatomaceous eat which is extremely fatal.
One method I have not tried yet is CO2. If you have a sealed room, you can take a co2 tank, dry ice or a (co2 fire extinguisher if it’s a small room). Flood the room till you get in the 5000-6000ppm range and it will kill everything except the plants, they will love it! As I said, I have not tried this method but some people say it works well and if you don’t have a sealed room you can take bags and cover your plants and co2 them one at a time using a co2 fire extinguisher. Dry cleaning garment bags would work well. WARNING this method is very dangerous, when you fill the room with enough co2 to kill any bugs, it will also kill you! Filling the rooms with CO2 removes any oxygen! Make sure you take all necessary precautions to avoid death! Make sure you have help to watch you and make sure you are safe! Ventilate well before entering when done.
Either way is fairly expensive, Getting a co2 tank can cost as much as $600.00. If you get a regulator, that is another $250.00 to $300.00 and enough fire extinguishers to do the job could cost you several hundred dollars depending on how many plants you have!
- Soap & Water – Mix a dilute solution of non anti-bacterial dish soap and water, and spray (fine mist) the leaves of your plant, particularly the underside where the mites like to live. May require multiple applications depending on how well you can cover each individual leaf of the plant. Make sure to rinse off the leaves with plain water 20 minutes after spraying in order to prevent the soap from clogging up the stomata on the leaves, which will stunt plant growth if not cared for.
- Soap & Water Plus Version 1 – Gather 1/4 cup baking soda, 1/2 cup apple cider vinegar, 1 tablespoon lemon juice, 2 drops dish detergent & 1/4 teaspoon epsom salt. Take one cup of hot water to dissolve epsom salts and pour into a clean 2 liter container with the rest of the ingredients. Add water to fill to 48 ounces (a 2 liter bottle will be 3/4 full) and shake well. Put into a spray bottle and cover your soil/medium with plastic. With the lights off, mist the plant all over concentrating on the underside of leaves. Wait 20 minutes and sprits off with clean fresh water, shaking as much water off the plant as you can. Solution is alkaline and rinsing is important in order to remove mites and eggs, and to prevent the solution from burning the plant leaves. Test on a small portion of the plant and wait 24 hours to observe before dousing the whole thing. If you see plant damage, dilute with more plain water and test again.
- Soap & Water Plus Version 2 – Gather 1/2 cup baking soda, 1 cup vinegar, 3 tablespoons lemon juice, 2 drops dish soap, mix and dilute with plain water to 40 fluid ounces. Use in the same manner as Version 1. Shown to work both indoor and out, with success on spider mites, thrips, aphids, clover mites, grass gnats and mosquitoes.
- Soap & Water Variations – Since all plants will have varying degrees of sensitivity to these sprays, you can try to create your own by mixing water with a small amount of dish soap, as well as garlic, cinnamon, clove oil and lemon juice.
- Rubbing Alcohol – This poisonous liquid can kill mites and evaporate relatively quickly in order to reduce harm to plants. Varying degrees of success have been reported with solutions ranging from 1:3 (light) to 1:1 (strong) ratios of rubbing alcohol to water.