每日吃瓜

Hi everyone!
So I'm pretty new to bonsai-I have a juniper and a ficus ginseng so far. Lately I've been noticing some strange insect that looks like fruit flies around my ginseng, and a week or so ago I began to notice that the trunk feels papery and thin to the touch, it seems like parts of it are totally hollow. They are not mushy or rotted, just thin, dry, and bendable. What is happening, and what should I do?
Thank you so much!!!
Farah (she/her)

The small flies is fungus gnats.

if the roots have become soft, it is due to excessive watering