The terms recto and verso are often used to refer to written text. The term has been around since ancient manuscripts on the earliest form of papyrus paper made in Egypt.  Today it can be used to describe the front and back of a single sheet of paper or the right-hand and left-hand page of an open book or pamphlet.

This term is also used in early illustrations and collections of entomology, the study of insects.

When viewing an insect with it's wings spread and mounted open you will see it positioned in the frame one of two ways:

Recto - the top or inside of the specimen is displayed for view
Verso - the bottom or underside (outside) of the specimen is displayed for view

Take a closer look....can you imagine the wings folded and the butterfly is resting on the stem of a plant? This a the verso view. Often times this side will resemble colors to help camoflauge in a grouping of flowers or blend in the dark shade of the rainforest. When it is flying a colorful side may call attention to a potential mate or coloring may disappear into the foliage of the forest,  grasses of the open landscape or the blue of the sky. Think about the colors in nature and see if you can figure it out with a bit of research.