Breeding case: Acherontia atropos
Acherontia atropos, Linnaeus (1758), the death’s-head hawkmoth, is a member of the Sphingidae family (Lepidoptera, Bombycoidea). It is distributed across southern Europe and throughout Africa. This species has a migratory behavior, flying north during the warm season and returning southward when cold is coming.
Acherontia atropos is one of the most loved species by Lepidoptera amateur breeders. Why? Because the caterpillars are beautiful eating machines, they grow very large and heavy. In addition, adult moths pair and lay eggs easily. As adults, they can live up to two months and their thorax shows the skull which made them a celebrity among moths. Oh right, the moth squeaks in an adorable but loud way! These features should already be enough to give them a chance.
Rearing and breeding Acherontia atropos is quite easy, making them suitable for beginners too.
We collect the eggs from the female’s cage daily and store them in standard 80x15mm Petri dishes. Upon hatching, which takes from 4 to 9 days depending on temperature, we transfer the young caterpillars to new Petri dishes containing some Ligustrum leaves. We use Ligustrum because it’s a valuable host for them, is an evergreen plant and stays fresh for a long time in water after being cut. By the way, many more host plants can be used, like Fraxinus, Eunomyous, Datura and other Solanaceae. Caterpillars can switch from one host species to another with ease. For example, our last generation was reared on Ligustrum ovalifolium until early L5, when we started feeding them on Fraxinus with amazing results.
The caterpillars reach full size in about 4 weeks, even 3 with high temperatures! As they go through L1, L2 and L3 we keep moving them to bigger containers and when they reach L4, we use our 40x60cm rearing cages. It’s important to always provide them with fresh food, prolonged starvation or wilted host plants could lead to the onset of diseases and sometimes even to cannibalism. Provide good airflow to the larvae throughout all the process, that’s the main reason why we choose the mesh cage in later instars. Rearing cages provide enough space for the larval stages in which animals start to consume huge amounts of food. Remember that Acherontia atropos likes a dry and clean environment, thus never spray the caterpillars with water and remember to clean their droppings daily.
At the end of the last larval instar (the fifth instar, which is called L5), starts the wandering phase in which caterpillars will look for the right place to pupate. Acherontia atropos is an underground pupator, which means that the caterpillars don’t spin a cocoon among the leaves but drop from the host plant and start wandering on the ground, looking for a place to burrow and pupate. Fully grown L5 caterpillars show orange markings along the dorsal side as soon as they’re ready to pupate, making it easy to distinguish between growing and full grown ones.
When we spot L5 caterpillars wandering, we move them one by one to small transparent plastic boxes, which size is approx. 10x10x8cm. Boxes are filled with slightly moist wood chips. To this purpose, you can use pretty much every kind of substrate, sphagnum moss or peat. We choose wood chips as it’s cheap and environment-friendly, while sphagnum moss and peat are way less sustainable. We put one wandering caterpillar in each (small) plastic box, because they can get stressed if there is competition for space. Too many caterpillars wandering in the same box will walk on each other and waste a lot of energies fighting for the best spot to pupate. In crowded conditions, the risk of one wandering caterpillar breaking the pupal chamber of another one is always high, resulting in malformed/non-viable pupae.
After the caterpillars are inside we close the boxes with the lid and put them in a closet in the dark, which we found makes them burrow quicker. Remember to ensure the lid is close, because they’ll try to escape in any way during this phase.
One benefit of using transparent boxes is that we can clearly see when the caterpillars undergo pupae formation, which is an amazing process to follow. The newly formed pupa is yellowish and will develop a dark brown colour by the days. Do not disturb the pupae for at least 3-4 days after they’re formed, they’re still soft and hardening so you could break or damage them easily.
We pick them one week after pupae formation, this way we’re sure that they are hard enough to be handled. We move them in the bottom of our rearing cages, both on top of kitchen paper or on a thin layer of moist wood chips, waiting for the adults to emerge.
Here the game restarts and you can try achieving adult pairing. Let the fun begin again and again!!!
How to take care of the adults is a completely different story. Adults, in the wild, steal honey from bee-hives. In captivity you’ll need to feed them with a honey-water 1:3 solution. Adults need to be fed by hand and to do so we use a stingless syringe in which we add the honey-water solution, making a new one every 2-3 days to avoid fermentation. We feed the adults starting on the 2nd/3rd day after emergence and, since then, every two days.
When attempting to feed them, make sure to grab the adults firmly, don’t be afraid to do so, they’re very very resistant and we assure you it’s not harming them at all. We use a thin toothpick to unfold their proboscid in the syringe. You will hear them squeaking the first times you feed them, but once they “understand” it’s feeding time, they’ll be very calm and easy to handle. Using a scaled syringe helps us knowing how much they’ve actually eaten. Some large females can eat up to 3,5/4ml every 2 days…that’s almost a full syringe and and half! Being well fed is crucial for this species, which may not pair without it and won’t lay any eggs if too weak or starved.
In order to make them pair, you should leave both sexes together in the same cage by the night. If all went good, you will find the couple still together the morning after. After adults have split from each other, separe the males from the females and add some host plant branches into the female’s cage. From now on, always during the night from dusk to dawn, females will lay eggs both on the cage’s mesh and the host plant. We noticed that members of the Solanaceae family trigger egg laying in a more efficient way compared to Ligustrum.