If your temps and light distance are in range, how's your humidity? Also where are you located (no details, just region/state)? I live in a pretty cold area, upper midwest, and never seem to have any problems with pests in the winter, so unless you're in a warmer area I'd say no, doesn't look like bugs to me.
If your humidity is a bit high, it could be the same problem that I've been having with leaf fungus, which I've been battling for a few months now. It actually killed off my previous grow, 30 seedlings succumbed to this, and now I've been using anti-fungal sprays and probiotics as well as keeping the humidity below 40% rH. Here's some pics:
In this you can see some of the advanced stages where the edges turn yellow and then become necrotic as the fungus does its worst damage (eventually the whole leaf will turn yellow/brown and die).
Here you can see a slightly different look - these spots started out as small dots and then spread, but the combination of feeding probiotics and keeping the humidity low can stop it from spreading. But it's just waiting and if I stop the probiotics or allow the humidity to get to high, they'll get worse.
In this pic you really need to zoom in to see some of the small specks, (and no they are not bugs, just looks like it, lol) but they're all over this leaf. Again if I keep things within range this stops spreading. The main problem is during feedings because I'm running Hempy buckets, a DTW system, the humidity can spike up and I can see the difference the next day.
Another example, it does seem to like to start at the edges sometimes, and in the examples where there appears to be leaves that look chewed on, that's just because I've accidentally broken off the dead material inspecting the leaf. I know some are going to chime in about how it looks like this deficiency or that, but this is appearing only on certain leaves, old and new, randomly throughout the grow, and from my past xp, I'm certain that it's nothing to do with any deficiencies as I have my nutrient spectrum fairly well dialed in for some time now.
I discovered a great anti-fungal spray, it's call Serenade, you can find it on Amazon, it's organic and contains Bacillus Subtilis, which has done wonders to control this stuff (way better than my xp with copper based sprays). There's good science behind how this stuff attacks fungal infections AND boosts your plants immune system. I've also been feeding heavily with double doses of GH Subculture B and M. The Sub B actually contains B. Subtilis as well which is great to know, and of course the Sub M has beneficial mycorrhizal organisms that also help keep your plants healthy.
Finally had to dish out a couple hundred $$ to get a good dehumidifier because I needed to get the rH under control and fast, but I could probably use an even bigger one imo cuz like I said it still can't keep it completely under control at feeding time. But keeping the lower canopy clean and clear and using plenty of ventilation also helps, and if you have fungus gnats you'll need to get those little buggers under control too (I use Gnatrol for this). Also cutting off damaged parts of leaves and removing from the grow room asap is a good practice cuz these are vectors for spreading more fungal spores. Hope this info helps ;?D