|MadSci Network: Zoology|
Hi Emily, The following care sheet should give you all the information you need to know in order to take care of your Wooly Caterpillar. There are over 140,000 species of Butterfly and Moth (Lepidoptera) in the World. They represent some of the largest and most beautiful insects to some of the smallest and most easily over-looked (unless you're an Entomologist). Caterpillars are the main feeding stage in the life cycle of butterflies and moths, and are one of the best "Creepy Crawly" Pets around. OBTAINING CATERPILLARS Caterpillars of many different moth and butterfly species can be obtained by post from many good entomological suppliers (a list of these can be found in the Links Section). However, many excellent caterpillars can be found by searching plants or bushes around you homes during spring and early summer. When you find a caterpillar remove the plant stem that it is feeding on and place this is a suitable carrying vessel (eg. Jam Jar or Sweet jar - with a lid!). WARNING: Do not try and pick up the caterpillar with your fingers as they are quite delicate and many possess hairs or secretions that are extremely irritating to your skin - collecting the stem they're on is much safer. Never take lots of caterpillars from a particular site, five is probably a maximum and the number taken depends on the size of enclosure you have prepared at home before collecting the caterpillars. It is also very important that you record the type of plant the caterpillar was found on and also take some stems to put in the enclosure at home. If you find a caterpillar wandering along the ground then it is either searching for a food plant or looking for somewhere to pupate. If it is small then it is best not to collect it unless you know the exact species of caterpillar and the plant that it feeds on. NOTE: there are many, many species of small green caterpillar and unless you know exactly which one it is then it is likely to starve to death because you can't provide it with the correct foodplant. HOUSING This very much depends on the size of your caterpillars and how big they grow - you may need to re-house your pets as they get larger. Normally a tall sweet jar will be ideal, drill some small (ie smaller than the caterpillars) holes in the lid (Get an adult to help you) and place the stems of the food plant in a small jar full of water. It may be a good idea to block the top of the small jar with cotton wool to stop your pets climbing in and drowning. If your caterpillars are very small then you can use a block of oasis (a type of hard green sponge used for flower arranging) soaked in water and with the stems pushed into it. Once the foodplant is placed in the larger jar then you can gently introduce your caterpillars - again using the stem they are sitting on. It is also an idea to place a twig in the large jar so that should the caterpillars fall of the stems they can climb up the twig back to their foodplants. Where you keep the cage is very much up to you and the type of caterpillar you are keeping. If you have a tropical species which you ordered from a supplier then it is best to keep them indoors and they may even require more specialised conditions (consult your supplier). If you found your caterpillar outside your house then you can keep your cage outside however you must be very careful that it will not blow over in the wind or fill with water when it rains. You should spray the cage lightly with water once a day or so, however avoid large quantities of condensation forming on the inside of the container. Caterpillars can easily drown in condensation, remember that to caterpillars, a blob of water is very much like a lump of syrup the size of a small car is to us ie: very sticky and difficult to escape from. FEEDING The majority of caterpillars are herbivores (ie they eat vegetation) although many will become cannibals if not given enough foodplant. Aside from cannibalistic tendencies some caterpillars will kill and eat caterpillars of other species of moth and butterfly and it is best to keep them singularly (eg Anthocharis cardamines - Orange Tip Butterfly). Caterpillars are extremely particular of what they will eat. Every caterpillar species has a particular type of plant (or family of plants) that it is associated with. Caterpillars will only eat very specific plants, which is why you MUST remember what plant you collected the caterpillar from - it is a good idea to identify the plant from a book or collect and press a stem for reference as your caterpillar grows. As your caterpillars grow they will require more and more food so it is a good idea to make sure you have a good supply of the foodplant before contemplating keeping the caterpillar. Remember that the larger the caterpillars get the more they will eat. Caterpillars increase in size by moulting so don't be concerned if you see some with small bits of their old skin still attached. As soon as most of the foodplant has been eaten or if it starts to wilt you must change it for fresh leaves etc. The replacement food should be exactly the same plant as before otherwise your caterpillar may not eat it, it is also a good idea to wash the foodplant thoroughly before giving it to you pets. I cannot stress enough how important it is that you feed your caterpillar the correct foodplant. If a caterpillar does not feed on it's specific foodplant then it may not feed at all and starve to death or will eat the plant but will never complete it's lifecycle and become a butterfly or moth. PUPATION As I'm sure you all know caterpillars must pupate as a chrysalis or pupae before becoming a butterfly or moth (Imago). During the pupation almost all of the caterpillar's body is broken down and the resulting 'nutrient soup' rebuilt into the body of the adult insect. When the caterpillars are full-grown they should be provided with suitable pupation sites. Butterfly caterpillars should be given stems and branches from which to suspend their pupae. Moth caterpillars producing subterranean larvae should be provided with a thick layer a damp peat, other larvae should be provided with foliage or bark depending on the species. If you are unsure of your caterpillar's requirements it is best to present them with a choice of pupation sites. Pupae that have formed during the spring or early summer may be left where they have been formed and should hatch within a few weeks. Pupae that have formed during the autumn will over winter and should be removed from the cage and stored to prevent them drying out or going mouldy. The pupae should be placed in layers of peat in small sealed containers; these should be kept in a cool but frost-free place until the following spring. In spring the pupae should be slightly embedded into a layer of peat or placed between the grooves of a sheet of corrugated cardboard. They should be misted with water occasionally to produce a humid atmosphere and this can be used to induce the emergence of adults. EMERGENCE When the adults are about to emerge you should place a number of twigs and stems in the emergence tank. The twigs are required by the butterflies and moths to climb up before expanding and drying their wings. If no suitable supports are available then your butterflies and moths will have deformed wings and be unable to fly. If you collected your caterpillars from the wild then you should release the emerged adults (or Imagos) in the same area as you collected the caterpillars. When releasing butterflies and especially moths (during the day) make sure that they are released in a fairly secluded area so as not to immediately fall prey to birds. If you obtained you caterpillars from an entomological supplier and they are not a species native to your country or area you could try and breed them to produce another generation of insects. Information on breeding butterflies and moths will be available from the supplier of the caterpillars and from a number of AES Publications. I wish you luck rearing your caterpillars but remember that if you've collected them from the wild then return the adults to the wild so there will be more caterpillars next year. Copyright K.Pitts 1997 This Caresheet may be printed and freely distributed however it must be distributed in its entirety and remains Copyright to the authors and the AES Bug Club. This Caresheet may not be distributed for money or as part of a publication (electronic or otherwise) for which people must pay unless express permission is gained from the Author and/or AES Bug Club - see Contact Section. The Caresheet reflects the particular techniques used by the author to rear the relevant invertebrate however other techiniques may also be suitable. http://www.ex.ac.uk/bugclub/ Thanks for taking the time to send in a question to the Mad Scientists Network June Wingert Baylor College of Medicine Houston, Texas
Try the links in the MadSci Library for more information on Zoology.