Welcome to the forum...
After reading your post I located numerous claims that PEX tubing can be damaged by the Western Conifer Pine Bug, these claims were made on everything from Plumbing Forums to Wikipedia, and all of those claims were made citing a single study listed below:
Damage to common plumbing materials caused by overwintering Leptoglossus occidentalis (Hemiptera: Coreidae)
Sarah L. Bates 1
Department of Entomology, New York State Agricultural Experiment Station, Cornell University, 630 West North Street, Geneva, New York 14456, United States of America
1 Present address: BIOCAP Canada Foundation, Queen’s University, 156 Barrie Street, Kingston, Ontario, Canada K7L 3N6
Would you care to add any information, pictures, correspondence with Uponor, etc. regarding the damage to your home and the plumbing system?
I would expect that damage by a pest in the home would not be covered by any manufacturer of wiring or, plumbing materials, but rather the expectation would be that the home is kept past free to avoid damage. A similar instance would be if a rodent gnawed through the insulation on wires or, gnawed through a plastic pipe the expectation would be that you keep the rodents from entering the home and exterminated them if their presence was noted. I would not expect a manufacturer to assume any product liability.
That said, I find this interesting and would appreciate any additional information you may have on the subject.
One of the things I would be very interested in is any additional information on what would make one home more vulnerable than others, any thing that would attract them to a home, where the damage occurred and if there is any location in a home that is more vulnerable. One of the things plumbers try to do is use the right material in the right location to avoid the possibility of failure. Any additional information you can provide will be appreciated.