The Hewitson's Olivewing (Nessaea hewitsonii) is a species of butterfly

Butterfly

A butterfly is a mainly day-flying insect of the order Lepidoptera, which includes the butterflies and moths. Like other holometabolous insects, the butterfly's life cycle consists of four parts: egg, larva, pupa and adult. Most species are diurnal. Butterflies have large, often brightly coloured...

 of the Nymphalidae

Nymphalidae

The Nymphalidae is a family of about 5,000 species of butterflies which are distributed throughout most of the world. These are usually medium sized to large butterflies. Most species have a reduced pair of forelegs and many hold their colourful wings flat when resting. They are also called...

 family. It is common in a broad range of the Amazon basin

Amazon Basin

The Amazon Basin is the part of South America drained by the Amazon River and its tributaries that drains an area of about , or roughly 40 percent of South America. The basin is located in the countries of Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, and Venezuela...

including the eastern slopes of the Andes mountain range. It is found in high evergreen tropical forest, semi-deciduous tropical forest, and riverine forest.

The length of the wings is 33–40 mm for males and 36–41 mm for females. The upperside of the males is dark brown, with bright sky blue diagonal bands on the forewings and blue markings on the hindwings.

They are fast flyers and fly in an erratic fashion. They may land suddenly on leaves or on the
ground if decaying fruit is present. They are also attracted to human perspiration.

Subspecies

• Nessaea hewitsonii hewitsonii (from Colombia, Ecuador and Peru eastward into the Amazon valley, and south to Rondonia, Brazil)
• Nessaea hewitsonii boliviensis Jenkins, 1989 (Bolivia and southern Peru)