At the NEVFC conference "Dubois Agrinovation" had a display of "ProtekNet" insect netting. The nets are woven out of UV treated (5 yr) "fishing line", and have different hole sizes, the ones I am looking at are 1 mm X . 85 mm or 1.9mm X 0.95 mm. They can sew them into 36' wide pieces. The price is high, ~$1300 for a 36' X 328' roll which I would cut into 10 nets so $130 per net. Light transmission of 87%, 95% porosity.

The official hole size for SWD exclusion is 1mm X 1mm or less, but I pulled up the original paper and the 1.9mm X 0.95mm excluded 99% or so of the SWD, so it should be sufficient economically.

SInce we already bird net the trees I was thinking of just putting the insect netting over the bird netting as the fruit starts to ripen. The bird netting would protect the insect net from the tree branches.

So, if you could save 10lb of fruit per tree at $3.50/lb, and move the net from early to later ripening varieties on a 3 week schedule, they could pay for themselves the first year.
Since the pesticides which are effective against SWD and stink bugs all have significant PHI's and are costly the savings would be even greater.

What we don't know is how the nets would effect brown rot and whether you can spray thru the net. Will the nets increase humidity to much? will the rain plug the holes in the net preventing drying off? The nets increase the temp inside by a couple of degrees, reduce time to harvest, and may reduce color according to the article (which was on blueberries).

So I am asking your opinions, or if you know of someone who has tried this.

Eric

I once tried to use shade cloth to see if it would keep birds off of peach trees. It was a 50% UV cloth (allowed 50% sunlight). The biggest problem with peaches was that they were noticeably less sweet with the shade cloth.

The other problem was that it was hard to keep on the tree. It was a big piece of shade cloth, and I tried to keep it weighted down, but the wind always wanted to take it off. Unlike bird netting (which hooks on the shoots) the shade cloth was smooth enough it would blow off easily.

I tried the shade cloth on some trellised blackberries (for bird control). I tied the cloth to the trellis, so it stayed on better. But it caused another problem. The cloth caused the blackberries to get too hot. It cooked the berries under the cloth.

The holes on your netting are bigger, and look like they will release more heat (and probably stay on the trees better).

I guess my question, would it be enough to control SWD? I've noticed non-SWD fruit flies love to remain under the canopy of fruit trees (where it's shaded). If enough SWD could get through or under the net, would they have their own protected environment under the tree?