How "normal" is this level of phobia?

[stopgap]

DS1 is 2.8 years old. He is currently receiving occupational therapy for a couple of small physical delays (catching up quickly) as well as sensory stuff. He has no diagnosis, as such, but was deemed fine and in no need of ABA or speech therapy.

He doesn't do well in large groups. We've known that for a while. He will become every anxious and start falling over a lot, becoming increasingly nervous, to the point he demands to go home after five minutes. But his latest phobia is flies and bees. We had to abandon an outing to a friend's the other day as he practically screamed and quivered for an hour, due to bees in her garden. The tiniest fly coming into our house will set him off, to the point he's shaking, crying, screaming and utterly distraught. He's also started hand flapping again (something he did a lot as a baby) when he's very overwhelmed in these kinds of situations.

It does seem extreme in comparison to other kids his age, but thought I'd gather opinions here.

I think it depends on how well he settles once the threat is gone. How quickly did he calm one he was inside/in the car?

I have an fear of 'flying things with stings' that can be quite acute and probably worsening. For me, I think it's rational (if they sting it hurts) and I calm instantly once it's gone.

This is in no way based on any actual knowledge or expertise, but just my observations of my DS (who has a fairly severe dog phobia alongside diagnoses of sensory processing disorder, anxiety, and ASD) and my gut feelings:

I think in my DS' case the phobia stems partly from sensory problems (particularly fear of loud unexpected noise - dog barking - and touch - dog brushing up against him /licking), partly from his terror of the unpredictable, which stems from his anxiety generally and his need to control; and partly provides a focus for his anxiety which is otherwise generalised and unfocused.

I don't know if any if that makes any sense or rings any bells?