Nonfiction: Nabokov Theory on Butterfly Evolution Is Vindicated, an article by Carl Zimmer in NYT.

A male Acmon blue butterfly (Icaricia acmon). Vladimir Nabokov described the Icaricia genus in 1944

For a Russian, Nabokov’s best entomological theory is formulated in poetic form:

Нет, бытие – не зыбкая загадка.
Подлунный дол и ясен и росист.
Мы – гусеницы ангелов; и сладко
въедаться с краю в нежный лист.

Translation of the highlighted lines, by Brian Boyd and Dmitry Nabokov:

We are the caterpillars of angels; and sweet
It is to eat from the edge into the tender leaf.

[With thanks to muriel]