Over the past 6 years of growing orchids in my apartment I've realized that my main enemy is spider mites, with the occasional scale and mealy bug every so often. I've tried diy 'natural' remedies, neem/azamax, imacloprid. All of these have drawbacks which were not very compatible with indoor use.
soap/oil/isopropyl emulsions
pros:
-effective on spidermides and other soft body insects
-relatively non-toxic to use indoors
-cheap
cons:
-requires regular and regimented applications to rid plants of mites
-non-systemic
-improper detergent type or concentration can cause phytotoxicity
neem oil /azamax
pros:
-systemic
-fairly cheap
-relatively non-toxic to use indoors
cons:
-smells terrible and may cause divorce if used indoors
-over-application can cause root burn or phytotoxicity
-requires regular and regimented applications to get rid of spider mites
-leaves an oily residue if using neem oil
imidacloprid
pros:
-very persistent systemic
-fairly cheap
-works on pretty much every bug
cons:
-toxic to humans, pets other animals
-persistent if not exposed to UV
-supporting the global insect collapse
-basically dont be an idiot and use it indoors
None of these methods were satisfactory to me, they either caused phytotoxicity if used too often, smelled bad or were just too toxic to use indoors. Turns out that a couple of products- primarily marketed towards organic cannabis growers who need to pass stringent testing on the product for residues finally have solved my pest problem. I'm hoping to get the word out to other primarily indoor orchid growers because I haven't seem them suggested and after almost 2 years of testing I feel confident in suggesting application regimes that I have observed to not kill my plants and have greatly reduced the pest burden on my collection. Even better they smell great, evaporate fast and leave minimal residues.
Products:
method 1 pps
Method 1 pps – Growth Efficiency Technologies
lost coast plant therapy
Lost Coast Plant Therapy in 12 & 32 ounce, 1 and 2.5 gallon sizes.
Both products have a similar approach but differ slightly in their formulation- they are emulsions of peppermint oil or additional essential oils. There is a lot of research on peppermint oil as an insecticide so in case you think that this is some hippy dippy crap you can read the research yourself here:
Google Scholar. Each product has their own angle on utilizing the insecticidal and fumigant qualities of peppermint oil- lost coast plant therapy contains soybean oil for increased insect suffocation, and method 1 pps contains rosemary essential oil and the ester of isopropyl alcohol which offers additional insecticidal properties.
Either way both products have solved my indoor pest problems in a way that is suitable for my pets, me and most importantly my wife. Not only do they have both contact killing ability and mildly systemic insecticidal properties, both products evaporate fast and can be sprayed in excess and at any time of the day without phytotoxicity** AND make your home smell like peppermint. Tough pests like russet mites may require a more concentrated solution and/OR you an add 1 oz/gallon 91% isopropyl. Not only that but the essential oils also possess some fungicidal and antibacterial properties.
here are some regimes that I have tried with great success on my orchids and houseplants. USE DISTILLED OR RO/DI WATER TO MAKE YOUR SPRAY.
removing spider mites:
spray until all surfaces are dripping
apply every 3 days for 2 weeks
scale/mealy:
spray all surfaces until dripping
root drench if root mealies are suspected
repeat weekly for a month
killing thrips:
spray until all surfaces are dripping
apply every week for a month
if thrips are in media a root drench can be applied with no damage to roots
killing fungus gnats:
gnats will die on contact with spray
soak media with working strength solution
I have not tested on other orchid pests because these are what lives around me. I know that caterpillars, leaf hoppers may require stronger solutions to kill them according to the maker of lost coast plant therapy.
** dont spray over 85f
Anyways just hoping to get the word out to others who may have similar constraints and indoor orchid collections. Its hard to get away from regular spraying without using something really toxic like imidacloprid and these products are the most effective and least toxic insecticides I've found. I think most people would be surprised at how effective a bi-weekly spraying program is at reducing their overall pest burden even if they don't notice an active infestation. Spider mites are pretty much everywhere and even if you don't see them out of control there is a good chance you have some in your collection especially in the heart of winter with low humidity.