Carnivorous Plants/Thrips and Sarracenia
Winter starts here in two days where I live at Tolga at 757 meters altitude near Cairns.
With my thrip invested Sarracenia, do you think it would be a good idea to cut ALL the leaves and pitchers of them including the older green growth now as the plants are mainly dormant. I would leave the younger shoots that are not infested if there are any. I am just wondering if cutting off all the older green growth as well could set the plant back in the coming growing season because I heard that the plant should have some green growth left on as a nutrient source for the plant. However, removing all the older green growth would get rid of more of the thrips which are probably on this green growth. It is also much quicker to remove all the leaves than only selecting the dead leaves.
I also received an email from a large carnivorous plant nursery that said: "The best treatment to use is Yates Success, this is an extract from bacteria that is lethal to thrips, not much else works."
Another friend said "Spinosad fixed the problem". They look promising and have low toxicity and are similar ingredient. See http://www.epa.gov/pesticides/chem_search/reg_actions/registration/fs_G-4674_01-
What do you think of these, and do you have any suggestions how to get rid of thrips without having to use very toxic chemicals?
I would certainly keep some healthy leaves to ensure the plant has an immediate method of obtaining sunlight after dormancy.
So far as control of insect pests, I typically do not have many issues with that and rarely use chemical controls. I have not used the methods you displayed. The main thing to ensure is that any chemical controls are not soap or fat based and/or add fertilizers to the soil.
If looking for less artificial methods to manage pests, you can clip the leaves back, just leaving a few inches of the most healthy for the spring, and then immerse the entire plant and pot in a bucket of water for 24-48 hours, take it out and let it set for a day, then immerse it again for 24-48 hours. Many bog plants like Sarracenia are occasionally waterlogged and will not be harmed by this, however; insects will drown if they do not remove themselves from the plant.
After you have taken the plant out of the bucket of water the second time, you can use a chemical control as well to ensure that the thrips are all killed off. Make sure that you use distilled, rain, or reverse osmosis water in the bucket.
If you prefer a more natural chemical control, you can use Neem oil. While not instant or as thorough as insecticides, it does tend to kill off insects slowly and keep them from wanting to remain near the sprayed plants. You could spray Neem oil on your plants after the water immersion treatment. To kill off any remaining larvae in the soil, you can use mosquito dunks dissolved in water and water your plants with it as shown in this site: https://4hydroponics.com/post/control-thrips-in-your-garden.
Good luck with getting rid of those thrips. They are notoriously difficult to kill off.