What is the favorite food of the bug?

Answer 1

Maple tree seeds are the favorite food of boxelder bugs.

Specifically, the insect in question (Boisea trivittata) favors the seeds of the boxelder tree (Acer negundo). Maple tree species (Acer spp) produce many distinct, fibrous, winged seeds which are called samaras. Boxelder bugs tend not to do the equivalent of defoliate trees -- and they control maple tree populations -- but they are considered pests because of their great numbers.