Complex sentence: It hides the nymph from the view of predators and parasites, it insulates against heat and cold, thus providing thermal control and also moisture control; without the froth the insect would quickly dry up.
Split into simpler sentences: It hides the nymph from the view of predators and parasites, it insulates against heat and cold, thus providing thermal control and also moisture control. Without the froth the insect would quickly dry up.