Merian’s new approach to scientific illustration is demonstrated in this watercolour of the life cycle of the Achilles Morpho Butterfly (Morpho achilles). Unlike her predecessors, who had arranged the different life stages in a row, Merian produced an elegant naturalistic composition, which nonetheless shows the caterpillar, green chrysalis (at centre left), and adult butterfly with wings both open and closed.

Merian meticulously showed the insects she depicted at exact life size. Her breeding of butterflies and moths led her to realise that individual species were dependent on particular food plants, and she was careful to show these in her illustrations.
Because of her understanding of the relationship between plants and insects she has been described as the first ecologist.