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The
Gloworm
6 April
2001
Volume 9: no. 1
2001
has begun with a great deal of interest in insects, both
collecting and rearing the critters. It seems that the
ground hog may not have seen his shadow, for spring and even
summer temperatures have arrived . Insects are moving. Crane
flies and moths are seen around lights in good abundance
most nights and some have reported seeing Lunas and Royal
moths, already. We are also seeing some bugs and beetles
crawling around, so it's getting time to get
started.
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.
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The drawings to the left by Robert Dirig depict a typical Lepidoptera life cycle. |
Interest
in catching Luna moths is generally pretty high about this
time of year because this is generally when they are
abundant. One of the easiest ways to catch Luna moths is to
use a blacklight and a sheet. Remember that Lunas and other
large moths overwinter as pupae and that they also feed on
hickory, walnut and other forest hardwoods. So set up near
some of these larger trees and see what comes in. The moths
often do not come in quietly, but flutter through the leaves
and limbs on surrounding trees. The light seems to drive
them crazy. The moths will also come to other lights and can
often be seen in the early morning resting on the walls of
buildings near a security light, but much of the adventure
comes with setting the lights out and then monitoring them
during the night. Different types of moths fly at different
times of the year, thus if one kept the light out most of
the spring and summer the selection of insects coming to the
sheet would vary greatly. The light is an excellent way to
obtain stock for rearing moths and for increasing the
quality of your collection, as well. Another way to catch
moths is by baiting, but remember that regal moths, giant
silkworm moths, some sphinxes and most tiger moths do not
feed as adults. Baits may be made using molasses or sugar
and mixing with fruit. Beer is often added to the mix. It is
then cooked (brought to a boil). The bait is `painted' onto
a tree trunk - usually the host plant for the critter being
sought. This site is then monitored during the hours of dusk
to full darkness. Underwing moths are particularly
susceptible to this method in late summer on humid nights.
Butterflies will also visit the `bait stations' during the
day time.
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.
Happy Bugging,
Michael
Williams
Extension
Entomologist
4-H
Entomology Camp 2001 at Holmes State Park
June
2-5, 2001 
Camp
is full!!!
Sorry,
but we are no longer taking applications. Please try again
next year.
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