Why it's totally FUCKED these spider mites. Is it a worse problem is different parts of the country/world? I totally thought I had them in check, but then BAM they came back. Here's something I cut and pasted, but use this method before I have to result to harsh chemical shit..
Water Management
Adequate watering of plants during dry conditions can limit the importance of drought stress on spider mite outbreaks. Periodic hosing of plants with a forceful jet of water can physically remove and kill many mites, as well as remove the dust that collects on foliage and interferes with mite predators. Disruption of the webbing also may delay egg laying until new webbing is produced. Sometimes, small changes where mite-susceptible plants are located or how they are watered can greatly influence their susceptibility to spider mite damage.
I have always used the hose to spray the plants down, but after a point in flowering it's harder to keep them from burning and other stuff. Here's some more cut & paste from another college research study.
Rubbing Alcohol
Light infestations restricted to one or a few plants can usually be treated with household products. When possible, immediately isolate infested plants from others to prevent the mites from moving amongst them. Probably the most popular home remedy is to spray plants with a mixture of isopropyl (rubbing) alcohol and liquid mild dish detergent, such as Ivory. Do not use other alcohols, such as ethanol or methanol, as these will penetrate the plant tissues and cause considerable damage! The concentration of the isopropyl seems to make little difference, the common 70% concentration available in stores is satisfactory. Alcohol treatment is effective against all the life stages of mites, except eggs.
A potential problem with alcohol treatment is the rapid evaporation of alcohol causing cooling of plant tissues. Especially with air movement that increases evaporative cooling, this chilling may over-cool tissues and create zones of dead cells that can become necrotic with bacterial or fungal infection. On warm days or in a breeze consider blotting residual alcohol with a tissue instead of permitting it to evaporate off the plant. Alcohol and detergent solutions can also damage delicate buds and blooms, so caution is urged for prized plants.
Repotting is not very effective against mites. However, with an extreme infestation it may be worth repotting a plant as eggs and resting adults may be in the growing media.
Horticultural oil, neem oil, mineral oil, and insecticidal soaps are readily available, inexpensive, and effective against mites. Oil solutions smother the mites so a complete coverage of all sprayed plants is essential. These oils are mixed with water and usually a plant-safe detergent or commercial spreader-sticker should be used for enhancing the effectiveness of the oil. The main caution with these oil solutions is that they should never be applied to plants on hot days (>85ºF/29ºC) or in direct sunlight, as to prevent burning of tissues. Leave the plant in shade until the application has dried. Some plants or parts, such as buds and blooms, are sensitive to oils so due care and consideration is urged.
Insecticidal soaps are usually solutions of a synthetic pyrethrin and potassium salts of fatty acids, otherwise known as soaps. Pyrethrins are synthetic analogs of pyrethrum, the natural extract from certain Asteraceae, particularly certain species of Chrysanthemum. Caution is urged with so-called “safe” insecticidal soaps as some plants are sensitive, particularly tender new tissues. Piperonyl butoxide is a common enhancer of pyrethrins but can cause allergies in some people and may affect plants, too. Some non-orchid ornamentals will drop leaves and abort flowers when sprayed with insecticidal soaps, so again caution is urged with prized orchids.
Because the life cycle of mites is so short and there are overlapping of generations, to bring a serious problem under control you may need to do treatments every 1-3 weeks. The time period between control efforts will depend upon the growing conditions, especially temperature: greater frequency in a warm greenhouse, less inside a house. As with any pest, persistence is a key to success and correlating the control method to the mite species is important for effective management. Cultural conditions are a key to managing mite populations.
Insecticides and Acaricides
Persistent populations of mite or infestation in many plants usually demand the need for synthetic pesticides. Mites are unrelated to insects and most common insecticides are not effective against mites. Pesticides designed for mite control are called miticides or acaricides. There are few miticides specifically registered for use on orchids, but there are many miticides Miticide formulations not labeled for ornamental plants are often mixed with solvents that aide in the application of the active ingredient for specific purposes. These solvents, not necessarily the miticide itself, often produce phytotoxicity and may seriously damage or kill plants. Thus, never use any chemical that is not specifically labeled for ornamental plants. for ornamental plants in general and several are available as inexpensive home-and-garden solutions.
Common insecticides are not effective against mites, though some do have some weak suppressive action, but will kill mite predators. Acephate (Orthene), malathion, and disulfoton (Di-syston) are labeled for mites but are not very effective. Resistance by mites to pesticides is a serious problem and is in part due to the excessive use and weak action from common insecticides. Dimethoate, diazinon, and chlorpyrifos were recently removed from the market in the U.S. for non-commercial applications due to excessive and careless use causing some serious health and environmental problems.
There are many miticides available for ornamental plants, but some are not tested on orchids, and others are generally too expensive or otherwise not readily available for the small-collection grower. Effective miticides for ornamental use include avermectin (Avid), bifenthrin (Talstar), dienochlor (Pentac), fenbutatin-oxide (Vendex), and fluvalinate (Mavrik). Fenbutatin-oxide is mixed with acephate and sold in home-and-garden formulations. Avermectin is probably the least toxic of these chemicals to people and pets.
Of course, always follow label directions and never exceed the minimum recommended concentration given in mixing directions! Recommended solutions are based on extensive testing for selected pests and plants. Orchids are sensitive to many chemicals, particularly under direct sunlight or high heat, and while certain species may not react to a given formulation others may, so your own testing on plants before general application is recommended.
Home orchid keepers that need to apply miticides during inclement weather need special care for applications. If you cannot spray out of doors, place your plant(s) inside a large plastic bag (remove the bag after the spray has settled!) and let the plant ventilate where the fumes will not be wafted around the house or work area.
Final Considerations
Heavy infestations of mites, especially on many plants may require extensive control methods. Since the damage done by mites is permanent, constant management of the population more effective than control of a major infestation. On the extreme side if you have a plant showing signs of severe change or general decline from mites you may have to seriously consider destroying that plant, as the likelihood of rejuvenating that plant may not justify the expense and effort of continued treatments. Too, destruction of a sick plant can be used to justify the purchase of a new and healthier plant!
If you are battling mites for long periods of time (e.g., >2 months) and have been using the same miticide then you likely developed a resistant population of mites. Remember the short generation times of mites. The best resolution to this is to change methods and chemicals frequently; that is do not use the same chemical mix more than 3-4 times sequentially. After isolating infested plants give them a thorough application of something different from what you have been using. Resistance is not a problem with alcohol, oils, and soaps as these suffocate or dessicate the mites.
Generally, never use a miticide not labeled for ornamental plants. Be thorough. Prophylactic use of miticides is tempting but does little good as it is a waste of chemical and money, and allows resistant mites to develop.
I hope this can help someone. We are at war these bastards!! I need to bring in the troops!!
