Sunday 29 March 2015

Life cycle of the Oleander Hawkmoth (Daphnis nerii)

My aunt has several Desert Rose (Adenium obesum) plants in her garden. When I realised there were Oleander Hawkmoth (Daphnis nerii) caterpillars feeding on them, I decided to observe and keep a photographic record of the different stages of their lives and their activities.

Having them in an easily accessible place not too far from home was very convenient for me. I visited the plants every few days to take snapshots, hoping to eventually capture the winged adult emerging from the pupal case.

The photos in this post were not of the same individual. They were taken over a few months. As a newbie to butterflies and hawkmoths at that time, it did not cross my mind that birds and other animals would prey on the subjects I was photographing. Some of the caterpillars died when they were a few days old, other bigger ones just disappeared. But I was very happy to have witnessed a few of them turn into adults.


Day 1. Eggs were laid mostly singly on the underside of
leaves and flowers of the host plant.

Day 4~5. The very young caterpillars ate the flowers too!
At least 50% of them do not make it past this stage.

Day 5~6. Most hawkmoth caterpillars have a horn at the
rear end. It was still thin and long at this stage.

Day 11. As it grew, the eyespots near the head became
more prominent.

Day 15~16. Notice how the thin and long tail had become a
bulbous stump. The folds of skin on the body allowed for
growth. At this stage, it was about 7 to 8cm long.

Caterpillars have tiny hooks at the base of the so-called false
legs. They help the caterpillar in walking and climbing.

Caterpillar poop. Every single piece has the same structure,
regardless of size.

Day 17~19. It had grown to about 10cm and was very round
and fat. It was an eating machine, consuming about 1 leaf
every 25 minutes!

Day 20. When ready to pupate, it looked for a safe hiding
place among the leaf debris at the base of the plant. The body
started to shrink. Unlike butterflies, moths would spin silk
around themselves before transforming into a pupa.

Day 23. Pupation was complete. The pupa would wriggle
violently if touched.


Day 32. The pupal case had darkened, especially the wing
case. The patterns of the wings can be seen.

Day 33. The adult emerged from the pupal case.

It immediately climbed up the plant. It was out of the case
and up the plant in less than 2 minutes. The wings were
small and wet and it was not ready to fly yet.

It took about 45 minutes for the wings to be fully pumped
with fluids. It stayed like this for another 4 hours before I
decided to call it a day. It was gone the next morning.

Milky liquid left in the pupal case.


HintTo witness this amazing metamorphosis,

1. you must be willing to sacrifice the looks of your plants. The caterpillars eat a lot and can make your plants go bald by the time they turn into pupae. However, you will be well rewarded with softer new leaves very quickly.

2. it is advisable to throw a mesh or something similar over your plants to prevent the caterpillars from becoming bird food. In my case, I secure the base too to prevent nocturnal predators from climbing up the plant because I have had pupae disappear too!

UPDATE

Thanks to a reader of this post, Klaus Schoenwiese, I got to know of a North American species which looks very similar to this moth. At first glance, you would have thought that they were the same.

Pandora Spinx moth in NY. Photo taken by Klaus Schoenwiese.

This one does not have the dark banding and spot on the edge of the wings nearest to the head. Thank you, Klaus!