6 April 2001
Volume 9: no. 1
There have been questions about catching and rearing moths, so I thought we'd feature the LUNA moth in this issue. Much of what is said here will apply to most of the large moths.Moths are often called the `butterflies of the night' because they generally are more active during at night. Moths are just as exciting and often as beautiful as their daytime cousins - the butterflies and skippers. They too belong to the Order Lepidoptera, which actually means scaly wings. Luna moths have feathery antennae with the female's being thinner than the male. Some moths have thread-like antennae which is straight with no adornments. Butterflies and skippers have a knob at the end of their antennae and the skipper has a hook on the end of the knob. A number of the moths feed much like butterflies and skippers by taking nectar from flowers, but many of the larger moths have reduced or missing mouthparts, thus do not feed at all as adults. Luna moths fall into this group. They are called the Giant Silkworm Moths and are from the family Saturnidae.
All Lepidoptera undergo complete metamorphosis including an egg, caterpillar(larva), pupa and adult. Some moth species will have 2 to 3 broods per year, while others only have one. There are even a few which require multiple years to complete the life cycle. Moths generally hibernate in a particular stage, for example the giant silkworm group hibernates as pupae encased in silken cocoons. Some moths, like sphinxes (tomato hornworm), pupate and overwinter in the soil, others overwinter as caterpillars feeding on available green plants during warm periods then becoming dormant during cool periods. Still other Lepidoptera pass the winter as eggs and quite a few hole up in a crack or crevice as an adult. Because of its hibernation habit may be one of the reasons we see LUNAs in the early spring.
|The drawings to the left by Robert Dirig depict a typical Lepidoptera life cycle.|
If you are interested in `ranching' some of your catch, it is important to learn to identify the sexes. Female moths are usually heavier bodied than males and have less flowery (plumose) antennae. Most moths captured will already have mated, so we need not be overly concerned about catching and holding both sexes. Some female moths look completely different from their male counterpart. This is called sexual dimorphism. The Luna moth has seasonal dimorphism, meaning that the midsummer brood will look different from the early spring ones.
A brown paper bag makes and ideal egg laying (oviposition) chamber. Simply place the female moth in the bag and close it up as shown. Eggs will be glued to the inside of the bag and can be harvested simply by cutting the area of the bag where they were placed. Some moths may drop their eggs into the bottom of the bag. When you have a couple of dozen eggs, release the female or pass her on to another `rancher' or collector. Remember most of the moths only live about a week. Each species is different but eggs will hatch is 3- 14 days. There are some species which have only one generation per year, so those eggs may have to be held for a year. Eggs will usually darken immediately before hatching. Hatching chambers may be made by simply placing the cut out paper in a plastic box with a tight fitting lid. Wait until after hatching before adding any food! Check the eggs daily and be prepared to transfer them to your food source within 24 hours of hatch. The small larvae will not starve during the first 12 hours, but do need to be fed within 24 hours. Do not punch holes in the box or the lid. Add absorbent paper to the bottom of the box along with the leaves of the host plant. Keep boxes out of direct sunlight. Do not overcrowd your caterpillars. You can start out with 8 or 10 in a crisper box as shown, but as they grow, they should be separated out so that no more than 3 or 4 are in a box. This will lessen the chance of diseases and competition for food. Keep plenty of fresh food in the box at all times. It is probably not a good idea to add water. The leave will provide enough moisture for the critters. The feeding of your insect livestock can really get to be a chore, so some `ranchers' take their livestock outside and hold them in sleeve nets on host plants. The caterpillars may have to be transferred to new food, but not nearly as often. Be sure and check the leaves closely before caging the caterpillars on them as there may be predators lurking in the foliage waiting to pounce on the livestock. Direct sunlight and too much moisture are often enemies of growing catepillars.
After the caterpillars have finished their last molt and are ready to pupate, they will begin to visibly fatten and change. Some Lepidoptera actually spin a silken cocoon in which they complete their development and transformation, others form a naked or bare pupa. The pupae on the left are examples of 11 different pupae. Number `l' is a drawing of a Luna Moth pupa. Care of the pupae is very important, for even though we call it the `resting stage' the critter is making some pretty drastic changes during the time it is confined in the small immobile shell. If the pupae are handled many of them wiggle quite violently. Luna moth pupae tend to be quite active when handled. Freshly spun cocoons should be left in the open air for about a week to allow it to dry and harden. Moths may emerge from the cocoon in 10 to 28 days after pupation. Late fall pupae should not be forced by keeping them indoors. If they are left out doors they will most likely not emerge and can be saved until next spring. Some people have successfully stored pupae in the refrigerator for overwintering. Frost free units will dehydrate the critters and kill them, so be careful. When you are ready for the adults to emerge the pupae should be placed in a roomy space so that emergence can occur. A box with a screened section sitting outside in a protected place, i.e. a screened in porch would be an ideal place to place pupae in preparation for emergence of the moths. Bare pupae as below should be wrapped loosely in tissue and stored in the larval holding box. You can then place peat moss over the top of the pupae. Hold the box in a cool place until ready for emergence. Place strips of cheese cloth along the lip of the box so moths can crawl up on them. Once it warms up pupae will emerge.
The interest is increasing in the 4-H Linnaean Games. We have a number of schools which have expressed interest in local competitions for the buzz-board game. It's a lot of fun, and with the 4-H connection, there are some prizes. The NEW Manual will be out in photocopy form shortly and will be submitted for official publication shortly thereafter. It will provide the prospective teams with their study materials. We'd really like to encourage the formation and participation of both junior (age 8-13) and senior (age 14-18) teams from each county. The Mid-South Fair has added 4-H Linnaean competition to our 4-H Day activities for 2001. We will name a REGIONAL JUNIOR and SENIOR 4-H LINNAEAN Champion in 2001.
Camp is almost full. We have a limit of 40 young people this year and at my last count have 30 applications, already. If you are going to be an entomology camper in 2001, you'd better act NOW! I've enclosed a form but want everyone to know we will hold closely to our limits and it will have to be first come, first served with camp.
It is also time to refurbish insect collections and get ready for adding new specimens. Boxes, pins and other information are available through your extension office. Just have them contact us at MSU and we can help to supply what you need.
Most of the material and all the graphics were adapted from the extension booklet Growing Moths by Robert Dirig, New York State College of Ag and Life Sciences, Cornell, NY. 4-H members Guide M-6-6, 1975.
June 2-5, 2001
Sorry, but we are no longer taking applications. Please try again next year.