Longwing Butterfly Eggs

In News by Robin Snieder

Longwing butterflies (Heliconius sp.)
 All butterflies hatch from an egg! Butterfly eggs in general are quite small, sometimes even smaller than the head of a pin. They come in a wide variety of colours and shapes, however, and some butterfly eggs look a lot like a colourful tiny diamond or gem. Longwings are a tropical group of butterflies from Central and South America and are locked in an arm’s race with the host plant on which they lay their tiny yellow eggs. A female butterfly lays one egg at a time, after carefully selecting a leaf or stem of a passion vine (Passiflora sp.). A single caterpillar can devour a passion vine, so a female wants to spread out her eggs over many plants so the caterpillars don’t eat themselves out of the house and home. This means many female longwings are constantly searching for many passion vine on which to lay eggs. As you can imagine, a plant doesn’t want to be eaten by any animal, so passion vines have developed a strategy to create small structures on their stems that mimic the longwing butterfly egg. A female, when inspecting the plant for other eggs laid before her, may sense these and be fooled into thinking the plants are already too crowded with pre-existing eggs and fly on to find another plant! If an egg is laid successfully on a plant, it only takes a few days to hatch into a tiny caterpillar (larvae).