Care Guide Series 2:
Butterflies and Moths
Care Guide 2.2:
Saturnid Moth Overview
Written by Mark Nelson
The Saturnid moths are an incredible family within the order Lepidoptera (Butterflies and Moths). A number of the species found in this family are some of the largest in the world. Colours and patterns vary a huge amount from one species to another. One trait they often share is eye spot mimicry, and many species have remarkable see through scales that form small 'windows' allowing one to see right through their wings. The adult moths are incredibly short lived as a result of having reduced mouthparts to the point where they are no longer able to feed! The lifespan of an adult Saturnid moth is between 7-10 days. During this time the males will locate and mate with females who will then lay up to several hundred eggs. Their caterpillars are also large and beautifully coloured with amazing tubercles which in some cases are covered in spines to defend them against predators. Many but not all species produce a silken cocoon to protect their pupae while metamorphosis takes place.
Caring for cocoons / pupae
When caring for Saturnid moths, the care of the cocoon / pupae is much more specific for each species than caring for butterfly pupae. It is therefore much more important to understand the specific requirements of the species that you are dealing with. Here are a few general tips just to get you started.
Cocoons can be hung using a hook or paperclip - see picture below
It is vital to ensure that when hanging the cocoons that you do so very carefully, if you pierce the pupae inside this will be fatal to the developing moth.
When hanging cocoons, be sure that there is nothing surrounding the cocoon that will prevent the moths wings from spreading once it emerges.
Make sure the enclosure / emerging case being used is maintained at the correct humidity and temperature for that species.
We do this by lightly misting the cocoons daily
While misting the cocoons we also check them for signs of disease and parasites (see our pupae health checking guide)
All our cocoons are slightly cut open at one end or down the side, this makes it much easier to check them.
African saturnid pupae
There are a number of african suturnids that we sometimes have available which do not produce cocoons. Instead when the caterpillars are ready to pupate they burry underground and pupate several feet below the ground where they are less likely to be dug up by predators. These pupae experience alternating seasons of very extreme weather. It may be extremely hot and dry for several weeks followed by intense rainfall.
In order to mimic this we place them in a container full of a sand soil mix and burry the pupae with the head facing upwards.
We keep the enclosure at around 28 degrees C
Caring for Saturnid Moths
Hatching, Mating and Egg care
Once the moths emerge they will slowly pump up their wings and find a place to sit until their wings dry. This is usually on the cocoon from which they have just hatched. Most of the saturnids we supply are active at night time so as it gets dark they may begin to fly around. So make sure once they have dried you move them very carefully to their enclosure (See our video guide below).
As they only live a very short amount of time (between 7 and 10 days) one of the hardest parts about breeding these moths is getting a male and female to emerge at the same time! This is a very unlikely possibility if you have only started with a few cocoons. I have lost count of the amount of times I have done this and the males emerge and die before the female has even emerged or visa versa. So now when it comes to starting up breeding projects with saturnid moths I personally prefer to have at least 10 pupae to start with to give yourself a good chance of getting a male and female at the same time..
When a pair does eventually emerge within the same time period, the female will usually sit quite still producing pheromones to attract the male. The male then has the tricky job of locating the female which for some species takes a lot longer than others. When the male does finally locate the female they will mate. So long as both are healthy and fertile the female should begin to lay lots and lots of eggs!
In the mean time we prepare a petri dish(this is where we will house the eggs once they have been laid). Cut a piece of kitchen towel to fit the bottom of the petri dish - simple as that!
The females are usually pretty hap hazard about where they lay their eggs, Sometimes they will lay on the food plant but some will lay on the side of the enclosure and we have also found eggs laid on the water bottle that is supplying water for our food plant cuttings. Once the female lays we leave the eggs for a day or so to allow them to dry as they can be extremely delicate when they have just been laid. Once dried we gently remove them and place them in the petri dish we prepared. Each batch of eggs we collect goes into its own petri dish. This way we can date them and have an idea of when they will hatch. Each day we open up the petri dish just a tiny bit and breath into the dish before closing it again. This will create the required humidity to allow the eggs to develop and hatch. The required temperature will depend on the species but our greenhouse is maintained at 26 degrees C during the day and 18 degrees C at night which seems to suit the species we keep (Attacus, Samia, Actias, Argemma).
We check the eggs daily and as soon as they begin to hatch we place a couple of leaves of the species food plants inside the petri dish as this is where we keep the larvae until they reach the second instar, provided they dont become too overcrowded. Once they shed their skins for the first time we gently transfer them using a fine paint brush to a larger container. An icecream tub or takeaway food container works really. They close securely without leaving gaps. You will need to pierce a few small holes in the lid for ventilation but the holes must be very small or the tiny caterpillars might escape. Larger holes will also create too much ventilation - we dont want them drying out!
Replace the food plant when necessary and as frass (Caterpillar poop) begins to build up in the bottom of the container then they will need a clean. The easiest way which provides the least ammount of stress to the caterpillars, is to set up a new container and then move the caterpillars across. Then the old container can be cleaned and reused next time.
As the larvae grow we increase the size of the containers. They will require more and more food the larger they get some species depending on the number of caterpillars you have produced may need cleaning out daily!
When the caterpillars reach their final instar they will eventually stop eating and will begin to wander around their enclosure. We continue to ensure there are fresh leaves available, as many species use the leaves to help construct their cocoons.
Here is a link to a site written by Bart Coppens which contains many excellent care sheets on a number of Lepidoptera including a number of Saturnid Care sheets
Thank you for reading! If you have any questions please feel free to send us a message via our contact us page!