Ok, please do not try this without checking it out first. Here is my story. I had this problem more then once. The first time I got these crawly threadlike things in my soil (ie. Last summer), I ended up throwing out my Thanksgiving Cactus. So last November, I purchased a few more Thanksgiving Cactus from the supermarket. I noticed those pesky tiny fruit flies/knats flying around my plants. ( they usually lay their eggs in the soil ) Well that was it! I mixed a combo of rubbing alcohol and water and sprayed the surface of the dirt on my newly purchased plants really well. I have knat/fruit fly traps all over...ie.. Near each plant. For the first time since the Fall, I recently saw the first little bugger and put out my traps. I may do my alcohol/ water spray again. But this is risky. It did not kill my plants, but it can kill them if you overdo this. Proceed at your own risk. Best to try to control this problem. I do not think you can completely avoid it if you have live plants in the home. They LOVE organic soil and there may be unhatched eggs in the organic soil you buy at the garden center to transplant your thanksgiving cactus into a new pot in the Spring. So far I have NOT transplanted anything. Nor have I fertilized anything. These tiny fruit flies/knats come in through screens or with your groceries/fruit that you buy at your local supermarket. They can even come up out of the drain in your sink! I have added photos of these traps. They work well so far for me. You can purchase them at Home Depot or True Value Hardware.

Mikes the bug is a wolly mealy bug. The plant is in a pot I assume.......maybe post in on the citrus forum as there are a lot of people there that grow in pots. I have 15 citrus in the ground and have never seen leaves do that so I would just be guessing at the cause. Here is a link that might be useful: Citrus forum

The green lacewing eggs are on slender stocks; I had some on my kale. I wanted to watch them hatch so I put the leaves in a cup of water. When I looked at the leaves I saw no caterpillar. When I wasn't looking a caterpillar hatched I guess or grew from a little one and ate a good portion of one leaf. When I see damage, I sometimes image it is a whole bunch of caterpillars. One can do a lot of damage in just a few days and grow from tiny to good sized in no time.

Ians, not really controversial. Most people think of insects who are vigorous predators as beneficial but I don't. SOME are quite specific into what they will devour and can be trusted in my gardens, lol. But others, such as the Robber Fly and Praying mantid will grab anything that moves. That goes for Dragonflies, too! I've watched one grab a bee in the air while in mid flight! Mantids will literally hide underneath a flower head in order to snatch the bees that come to visit. And if you ever see a strange pile of butterfly wings under a flower, you'll know that a praying mantis has been there. Just the wings, not the whole insect. I keep an eye out on my hummingbird feeder, too. But, they also go after the pesky things too, like Japanese beetles. It just doesn't seem to balance out in my gardens. If only they would attack aphids, lol.