I got this ficus bonsai about a month ago from Walmart. When I first took it out of the decorative pot I noticed about 5 little orange worms at the bottom and I immediately let it sit outside for a few days, scraped off the top inch of soil, and sprayed it with insecticide. It is growing a lot of new leaves, and the new leaves seem to be healthy. But, starting about two weeks ago, some of the lower leaves started browning. I cut these brown leaves off, but then more turn brown. I'm not too sure what I'm doing wrong here, but this is my first bonsai. It gets bright indirect sunlight for about 4-5 hours a day, humidity is average household humidity (maybe a little bit higher, I have a humidifier but its at least 3 feet away), temperature is around 75-80°F. I also noticed that some of the smaller leaves at the base of the plant have turned crispy and fallen off. I do not move the plant very often, at least I try not to. I maybe move it like once every week and a half or so just to water it but then I put it right back. As for watering, I water it when the top inch or more is dry. Back to the bug issue, I noticed that one of the leaves that fell off had a shiny substance on it, which is always concerning, but I have inspected the plant and I see no bugs. Any thoughts on what I might be doing wrong?
- UPDATE -
I am worried it is starting to get worse...the leaves are now spotted and seem to be browning a lot quicker. I am worried it is a fungal issue. 
