Orchard Swallowtail Life Cycle

The Orchard Swallowtail Butterfly is a regular guest in our garden, and it's always a pleasure to see them. What I wasn't aware of, until today, is just how striking the larvae are ... in my opinion - even more beautiful than the adult, certainly more interesting.

It's easy to encourage these guys into the garden - just plant some lemon trees and leave the insecticides in the shed. There'll be more than enough fruit produced even with a few Caterpillars on board.

Late Stage Instar

Defensive Posture, displaying bright pink osmeterium

Note what could be parasitic wasps on this Larvae as it begins to pupate 

Complete: The blob on the leaf, (bottom right) is its discarded skin

Yet another chrysalis

close up of the osmeterium

The osmeterium is a fleshy organ found in the prothoracic segment of larvae of Swallowtail butterflies including Birdwings. This organ emits smelly compounds believed to be pheromones. Normally hidden, this forked structure can be everted (turned inside out) when the caterpillar is threatened and is used to emit a foul-smelling secretion containing terpenes (the primary constituents of the essential oils of many types of plants and flowers)i. These chemicals vary from species to species.

Interestingly I noticed the smell, but it wasn't foul at all - actually it smelled sweet and quite pleasant ... course my olfactory sense could be going the same way as my vision lol!

Take care