The Life Cycle of the Red Admiral
The Red Admiral can be found in the temperate regions of North America, Europe and Asia. It spends the winter in warm southerly regions such as Florida or the Mediterranean and then migrates north in Spring.
It is an easy species to breed, starting from eggs or young caterpillars any time between March and September. The green eggs are laid singly on the food plant - Nettle or Pellitory. They are very tiny, less than 1mm, and strongly ribbed. After 4-5 days the caterpillar has developed and may be seen inside the eggshell. It has a blackish head and cream body when first hatched. This darkens as the caterpillar develops after the first moult.
Using silk the caterpillar joins leaves together to make a resting tent, often going outside for yet another feed. In this way it quickly develops through a total of 4 instars (stages). A fully grown caterpillar is nearly black with a prominent yellow splash on the side of each segment.
The fully grown caterpillar hangs downward in the shape of a letter J and turns to a chrysalid, often often possessing beautiful green and gold highlights. This normally takes place within a leaf tent (which has been opened for the photograph).
In due course, usually in the morning, the butterfly emerges and expands its wings.
Whilst the time to develop from young caterpillar to butterfly varies with temperature - the warmer the faster - the typical timespan at 20 deg.C (70 deg.F) is 5 weeks.
Preparing Potted Plants for use in Cages
Much pleasure and knowledge can be gained from watching the development of butterflies. Three factors normally promote good results:
1/ Good healthy plants
2/ The avoidance of predators
3/ The right temperature and humidity conditions
Start by potting up younger plants using pest and weed free potting compost. Covering the holes in the base of the pot with a pad of thin fibre-mat or a similar porous material stops pests from entering but still allows free passage of water and air.
A wide range of pests and parasites including woodlice, weevil larvae, slugs, beetles, centipedes, earwigs, ants, and spiders can accumulate on the plant or in the soil, perhaps because the plant was left unsleeved or because it was necessary to use a soil other than potting compost. These pests can dealt with by totally immersing the pot, soil and plant in water for two days before introducing the larvae. Most unwanted visitors drown or float off and can easily be hand picked. Aphids can be killed by using an insecticide spray as directed, but not with larvae present. Be careful when selecting your insecticide - many will still kill larvae several weeks after application.
To ensure the health of the food plant, clip off old growth, water regularly and feed with liquid fertiliser to encourage the growth of new young leaves which most larvae prefer. If the plant is completely consumed it is possible to put a cut plant in a water jar in your insect cage. The neck of the jar should be blocked off using a wad of cotton wool, to prevent the larvae entering and drowning.
Keeping an appropriate temperature and humidity are important. Natural outside conditions are usually best for British butterflies. Some species, such as downland types, thrive in good sunlight. Others, for example woodland species, require shade. Under greenhouse conditions or on a sunny indoor windowsill, very hot and dry conditions may be created which can quickly kill larvae which expose themselves. If in doubt, it is safest to choose light but shaded situations.
Please note that these hints should be regarded as general guidance and do not guarantee breeding or rearing success. For common sense ethical guidelines about rearing butterflies and other excellent supporting information, please see Steven Cheshire's 'British Butterflies' site.
Enjoy caring for your butterflies and happy rearing!
A Butterfly Rearing Project for Children
What will we learn ?
Raising butterflies is a great project for the summer holidays that the kids will enjoy - and so will Mum and Dad! It will help children gain an insight into the biology and conservation of the natural world through direct observation and hands-on experience. It will also teach them to responsibly care for living and growing things.
Collecting eggs or caterpillars, looking after them and watching them change into butterflies can also be linked in the classroom to elements of the English National Curriculum relating to science. These include but are not limited to:
Scientific Enquiry (KS1 & KS2)
Life Processes and Living Things (KS1 & KS2)
Practical and Enquiry Skills (KS3 & KS4)
Organisms and Health (KS4)
BEWARE! Raising butterflies can be highly addictive and you could get hooked...
What do I need ?
Many internet sites now offer a complete kit where you can buy the butterfly eggs, cage and food in one package. Whilst these kits are popular, Insectopia don't support this approach for two main reasons. Firstly the caterpillar food that comes with the kit is nearly always processed and artificial (for example food paste) - this does not give anyone a real feel for the link between the caterpillar and its natural habitat. Secondly, eggs from kits will be from captive bred sources, and releasing butterflies from these sources can introduce harmful genetic weaknesses into the wild population.
The items you need to make your own butterfly rearing kit are:
* A collecting tub (a clean plastic food container is ideal)
* Gardening gloves
* Scissors or secateurs (to cut the food-plant when collecting eggs or caterpillars)
* Butterfly eggs OR 6-12 caterpillars
* Paper towel
* Small jar or milk bottle
* Cotton wool
* Plant clippings, OR potted food-plant(s)
* Plant sprayer (that produces a fine mist)
* Butterfly cage
Insectopia butterfly cage options:
To house 1 - 3 caterpillars:
EITHER - Bug cage
OR - 07ZL Free standing flowerpot frame & zipped sleeve - long
To house 4 - 6 caterpillars:
EITHER - Hanging cage - regular + support rods
OR - 10Z Free standing flowerpot frame & zipped sleeve
To house 7 - 12 caterpillars:
EITHER - Hanging cage - large + support rods
OR - 16Z Free standing flowerpot frame & zipped sleeve
OR - Tabletop cage
Stage 1: The Egg
Butterflies are insects, and start off their lives as an egg. Butterfly eggs themselves vary enormously depending on the species of butterfly that laid them. They can be round, oval or cylindrical, smooth or ribbed. The only thing they all have in common is that they are very small - around 1-2mm which is about the size of a pin head. Sometimes if you look very hard, you can see the caterpillar curled up inside the egg.
Start your butterfly raising experiment by going on safari in your own back garden, or local park. Why not make a day of it, and take a picnic to eat before you go on your hunt? Butterflies usually lay their eggs on the stems or leaves of plants. You may need to search on several plants before you find any eggs, so don't give up if you don't find your eggs straight away. As nettles are a popular food plant for many species, don't forget to take some sturdy gardening gloves so you don't get stung.
Once you have found your eggs, cut off the leaf or section of plant and place it carefully in your collecting tub. Don't collect any more eggs than you need for the size of your habitat. Please take care of your eggs - they are living creatures - so don't leave them in the heat of the day, and take them home to their new habitat as soon as you can. When you get home, remove the section of the plant with the eggs and put it on a piece of damp, but NOT wet, paper towel in the bottom of your butterfly cage with the eggs on the top. Keep checking the paper towel at least daily to ensure it is kept moist.
You will need to make sure that you have some of the same type of plant available at home for the caterpillars to eat when they come out of the eggs. NEVER collect eggs (or caterpillars) if you are not certain which food plant they eat, or if you cannot get supplies of their food plant.
NOTE: If you don't want to start at the egg stage you can collect caterpillars on your garden safari instead. Don't collect more than 6 caterpillars from any one place. When collecting caterpillars, again cut off the leaf they are eating. DO NOT pick them up with your fingers as they are delicate and many also have hairs or secretions that can irritate your skin. You must also ensure that they have food to eat while you are moving them to their new temporary home, and are not left in direct sunlight which can kill them.
Stage 2: The caterpillar
When the butterfly eggs have developed for long enough they hatch into caterpillars. This usually takes about 1 week from the date the eggs were laid. Another name for a caterpillar is larva (plural larvae). Pretty much all caterpillars do is eat and grow bigger. If you get too many caterpillars hatching out then the rest can be released back where you collected the eggs. Make sure they are placed safely on the correct food plant otherwise they will starve.
Caterpillars are fussy eaters! Each type of caterpillar will only eat certain types of leaves. For this reason, the adult butterfly will have laid her eggs on the right plant, so that when the egg hatches, the caterpillar can begin eating straight away. First they eat the egg shell, and then they start to eat the food plant. Caterpillars don't need to drink, they get all the water they need from the leaves they eat, however it is helpful to lightly mist your cage with a plant sprayer once a day.
It is very important that you have a good supply of food for your caterpillar - the same type of plant that the eggs were laid on. If you do not have enough food, or if you have the wrong food, then your caterpillars will starve and die. If you have several caterpillars then you may need to renew your food plant quite often.
You can either use a plant potted in garden soil, or a sprig of cut plant in water in a jar or milk bottle. If you are using a milk bottle or jar, plug the top with cotton wool to make sure that the caterpillar can't fall in and drown. To renew your food plant, simply place the new food next to the old and the caterpillars will crawl across. If you remove the old food plants, check carefully that there are no caterpillars left on them.
Put your caterpillars and cage in a safe spot, not in full sun or next to a working radiator. Listen carefully - can you hear the caterpillars munching ?
Unlike humans, caterpillars do not have bones. Instead they have an external skeleton - an 'exoskeleton'. The exoskeleton encloses them like our skin and also supports them like our bones. Because their exoskeleton cannot stretch, caterpillars grow by shedding this skin each time they get too big for it. Underneath the old exoskeleton is a brand new, bigger one. This process is called moulting and will happen several times.
Stage 3: The chrysalis or pupa
Once your caterpillar has grown big enough, usually after a week or two, then it will become a chrysalis. The caterpillar settles itself at the top of your cage or the underside of a leaf in a 'J' shape and holds on using a ring of hooks at its tail end. Then the caterpillar's skin splits, falling to the ground along with its old head, revealing the chrysalis which formed underneath.
The chrysalis does not eat, and whilst it looks as if it is sleeping, it is still very much awake. Try not to disturb your chrysalis - some species if disturbed will twitch and wriggle which is a defence against predators! Inside the chrysalis the caterpillar is undergoing enormous changes, a huge change in appearance called metamorphosis which leads to the final stage of the butterfly's life cycle.
Continue to lightly mist your cage with a plant spray once a day.
Stage 4: the adult butterfly or imago
It usually takes 7-10 days for the chrysalis to finish its metamorphosis. Butterflies often come out or 'emerge' from their chrysalis in the morning, and if you are very lucky you will see the chrysalis split and wriggle around like mad for about 15 minutes before the butterfly crawls out.
When it first emerges, the butterfly's wings are small and soft because they were squashed inside the pupa. The first thing the butterfly will do is rest on a leaf or stem of the food plant, so make sure that there is somewhere it can perch. It will then pump blood into its wings so they expand and can be used for flying. If no plant stems are available for the butterfly to perch on its wings will not expand properly and will be deformed, meaning the butterfly will not be able to fly.
Enjoy watching your butterflies emerge, but please release them as soon as possible back into the wild and certainly no later than 24 hours after emerging. Butterflies should always be released in the same place that the eggs or caterpillars were originally collected from. Butterflies need to feed on nectar to thrive and survive, and the best way to do this is to allow them to find a natural source of food. The ideal time to release is when it is warm, dry and not too windy, and you should release in a secluded area so your butterflies are not immediately caught and eaten by birds.
In this final stage of the butterfly's life it will be looking for a mate so that it can reproduce and lay eggs. The butterfly life cycle will then start all over again.
Watching your butterflies fly away is not only a satisfying experience but there is also an important lesson to be learned - most creatures are happiest living free, in their own wild environment.