06/01/16 1:00pm. sighted two very large aircraft 1 flying due east to west 2nd due north to south. Both off white, not markings side or botto. I could see someting red on upright tail fin, not able to identify marking. Both planes were releasing white plumes from the REAR of the plane not from the engines on the wings. Planes looked to be much larger than the largest transport plane I saw at USAF Travis air force base, Ca. Sighted 9 other chem trails released earlier. After 3.5 hrs) I could still see outline of where releases took place. The UFO part of this report is the unkn planes orgin and the unkn release from the rear of these planes. Also, maybe unrelated or not the previous Thurs I saw many long white spider looking webs drifting past my home. Picked one that landed with a stick, touched it, not a web! Material looked like a soft plastic type material. Appeared to be in slim spikes sticking all over, didn't loose shape when touched???? Not like your normal UFO sightings but very strange none the less. Thank You for your time.