If you have the right conditions (a closed space with enough bugs to feed the troops) you can use auxiliaries. I won't go further as I don't have the experience nor the conditions prerequisite.
Then you have two "liquid" organic way to fight: oil and soap/alcohol.
You can spray a light
oil on your plants (colza, olive), some mix it with water and soap. Some use the neem oil which is a traditional helper in India (I don't, it has active substances in it I don't like).
All the oil treatments are effective but have bad sides:
- Neem can smell…
- you have to remove the oil a day or two later
- it won't go everywhere
Then there's
soap/alcohol.
You can use
soap in water (1-2 teaspoons/liter), i've used it and didn't find it very effective. It's better to use organic soap (note, what we call "savon noir" in France) (sold for gardening, but organic liquid soap without perfumes and additives is the same stuff). In emergency, dish soap can do.
Alcohol:
- any can do, but prefer isopropyl if you can find some. It is no metabolized hence harmless. If you have only access to Cooper from drugstores or methylated spirits (90+°), go on, just apply the following point if necessary.
- it should be 70° used pure on cotton wool else dilute the alcohol so that it reach 70°. A more concentrated alcohol can harm cells.
- be aware that some thin leaves may not like it much.
- you can bathe roots with alcohol (to do with roots already wet). I've done it for hybrid phals using 1 teaspoon/liter of less. Others bathe in alcohol a few minutes then wash them under water which may be more sensible, especially with non isopropyl alcohol.
If you have only 90° alcohol available, you can make 70° alcohol by mixing 470g of 90° with 110g of water to obtain half a liter of 70°.
Alcohol is the best to kill the bugs, so here is the winning formula. It mays not solve all issues, but it can contain an invasion quite well. It goes further than oils too. I've used it thoroughly since january.
Mix 1 teaspoon of soap, 2 to 3 teaspoons of alcohol (70°) with one liter of water. After a thorough alcohol chasing of bug, spray the plant. You can do so every 2-3 days if needed.
And last,
cinnamon !
Cinnamon is an effectice acaricide, bactericide… and with alcohol is great to fight the mealy beasts.
Leave a tea bag full of 3 good teaspoons of cinnamon powder for 24 hours inhalf a liter of isopropyl alcohol (you can use Cooper etc. as long as it's titled 70°.)
Note: don't spray this on buds and flowers, and avoid roots.