Hey guys, I recently noticed that there are some insects flying and sitting on my Carmona. Is this a threat and should I do something about it or it's just a healthy natural thing? Check the attachment please
Second thing is that in recent 40 days when it got colder, some of the leaves started to get yellow and fall, but the tree still grows new shoots and leaves, and also it had only one flower in the recent month (there are blossoms but most of them just won't bloom), is this normal for the season or there is a problem?
It's my first winter with my bonsai and I'm a bit too nervous, thanks in advance for your helps.
Additional information :
I live in Tehran, Iran. In fall and winter it's 3 to-3 C outside but I kept inside temperature at 15 C or slightly higher.
I reduced feeding from per two weak to per month (since it's fall season)
I also attached some pictures of overall look and some yellow leave
If there is anything you need to know let me know.

Sorry my photos were'nt uploaded for some reason here they are

That looks like drosdophilia to me. If that is what it is, they are no threat to your tree.