10yr old gas a fear of Wasps and other flying insects

Hi looking for advice.  Our boy is 10 yrs old dual diagnosis autism and adhd.  He is very articulate and bright  but socially likes to be on his own even at school.   For the last year he has developed a fear/phonia of wasps and other flying insects.  It’s getting worse and we can’t get him outdoors    We get him to school but runs into class then refuses to leave the room until it’s  home time.  
I’ve put insect screens on windows as he was refusing to let me open windows. He screams and runs when sees anything flying is hysterical and  he is highly vigilant, searching for them.   He was almost run over last week.  I was parking the car and a wasp landed on the outside of the windscreen, he opened the door and jumped out as car whilst it was moving ran into road a neighbour was coming into street and had to hit her breaks.    He was trembling with fear.  He has an interest in bugs, animals and sea life and loves reading books about them.  Can tell you everything about bugs but isn’t helping his fear.    It is impacting on his health and as a family we are becoming isolated as can’t take him anywhere.   

he attends CAMHS re adhd meds and I’ve mentioned it when he attends clinic. they need to close windows in the room whilst he is thee but no advice being offered.   I feeL he needs support from specialist re this as I fear we will get to point whereby I won’t get him out the house even for school.  We had to come home from our holiday early as he refused to leave hotel. 

Any advice appreciated and sorry for long post.