NE Sailboat wrote:
...mosquito's the size of turkeys...
...[make] companionway sliding screens...

I've done this twice: boat 1 on Great Lakes: when way offshore in an
insect hatch, you know where all the little corpses go:-)
boat 2 in SW New Zealand, it's sandflies dn there, serious bad news.

both companionway openings approx 2ftx1ft high.

1. black walnut varnished, bronze screen from (I think) Jamestown Distributors,
once frame assembled and fitted to boat, we routed out a suitable groove on the face.
pressed in the screen with a suitable tool, covered with 1/2 round walnut facing
approx 1/2 inch wide, tacked on w/ little bronze nails. Mucho work.

2. sandwich 2 layers 1/2 inch ply, synthetic fabric screen from Mitre10==Builders'Square
layer one screwed onto layer two thru the screening, w/ ss wood screws: ply
painted white. Not as beautiful: much less work.

lovely consequence is watching the little buggers clambering around on the outside,
you on the inside w/ ack-ack handy: flying insect spray.