Wax worms are the larvae or caterpillars of the wax moth. They are a pest in beehives and can sometimes be obtained from a beekeeper when they have infested a hive. There is a greater wax moth (Galleria mellonella) about 1 inch and a lesser wax moth (Achroea grisella) about 1/2 of an inch in size. Their larvae grow to about l-1h in. and 3/4 in. respectively, before they pupate. The greater wax moth appears to be easier to be cultured.
The larvae are raised in shallow, plastic storage boxes with a large metal fly screen window in the lid to allow for good air circulation. A useful sized container is 12 x 7 x 4 inches high (1 gallon or 4.4 1). The opening in the lid should be as large as practical, but by leaving a good rim for gluing in the screen with a hot glue gun. The hatching container should have very fine screen while the rearing container can have metal fly screen. The food medium is filled about one inch deep into the container and larvae are added. They mature in the growing container until pupating.
For the hatching container we can use small, round steel screens, which are sold for fuel funnels, to be glued into the lid of a smaller the hatching container approximately 10 x 6 x 2 in. high plastic storage box. The larvae are kept in these hatching containers until they have grown to a size too large to pass through fly screen, and then the contents are transferred to rearing containers described above.
A piece of paper towel is used to line the hatching container and a 3/4 inch layer of food medium is added with a small piece of tissue placed on top. The eggs are spread on the tissue paper. This allows us to monitor the hatching
of the eggs. The egg cases become transparent when the invisible (to the naked eye), minute larvae hatch and migrate to the food medium. It may take two to three weeks before they become evident in the culture, so be patient.
Wax moths and their larvae prefer darkness and warmth. This can be useful in keeping the tiny, young larvae in the container by placing a light source above it and at the same time give warmth to the culture. (See "brooding cabinet" below).
All screens must be metal since the larvae will chew through plastic fly screen in short order when they run out of food or approach the pupating stage. A well populated culture will generate a surprising amount of heat on its own, hence the great need for ventilation. The optimal rearing temperature is 27-29 °C.
More food may have to be added, depending on the number of larvae. The larvae grow rapidly once they reach a certain age and begin to wander around on the surface just before pupating. If food is short in supply the larvae will also begin to wander around in the container and out of the container if they find an opening. The fully grown larvae like to pupate under the lid near the vent opening. If too many larvae block the air screen, then some need to be removed. 30 moths are sufficient to generate thousands of eggs for the next generation. Food shortage will trigger premature pupation and smaller bodied moths might hatch. The emerging moths do not require special feeding, since they will begin to mate and lay eggs immediately and perish within about 2 to 3 weeks. The eggs are deposited in small patch-
es near the lid of the container. The greater wax moth lays up to 800 eggs (the lesser moth up to 300) eggs. The moths try to deposit the egg masses in tight cracks and use the margin between the lid and the top rim of the plastic container to deposit their eggs there in strips. The strips of egg masses can be scraped off with the fingernail or the back pocket knife and divided up for several new cultures. Several batches of eggs can be harvested from the same container for several days.
The cycle from egg to egg is about 6- 7 weeks at 28 °C and up to 3 months at room temperature. By propagating starter cultures at various temperatures, we can achieve a staggered effect, to have a more continuous supply of larvae.
One must manage the cultures responsibly, to prevent any unnecessary escapes of the insects, so as not to cause unnecessary bee hive and bumble bee nest infestation. Both moth species do, however, occur in the wild and invade bumble bee nests and honey bee
hives. Fortunately the insects can be cultivated year around like mealworms. Larvae can be taken at different times depending on the size of food animal desired. By keeping maturing cultures at lower temperature the metamorphosis is delayed, which extends the harvesting and storage time.
The author developed a simple and suitable food medium as follows: mix by volume 5 parts of poultry starter with 2 parts mixed baby cereal, 2 parts of wheat bran and 1 part wheat germ. Warm up 3 parts of "liquid" honey in a hot water bath to about 35°C and mix the dry ingredients with the honey to produce a moist crumbly texture. It is best to use a plastic pail or large bowl and a sturdy wooden spoon to mix the ingredients. Unused mix can be stored for a long time. "Liquid" honey is usually less expensive and sold in bulk containers for baking, etc. This type of honey is best suited since it does not crystallize as quickly, turning the medium into a solid mass. Larvae can not feed on dry solid food mixes. To avoid this, glycerin can be added by stirring it into the heated honey at a ratio 1 to 10 parts of honey. The dry ingredients can be changed in proportion. The honey is really the key component and the primary food source to the larvae. It is better to have the mix on the moist side than on the dry side by increasing the honey component. High levels of wheat bran are questioned by some due to the potential effect of binding calcium in the food chain.
An older formula is as follows: 250 g honey, heated to 35 °C; 250 g glycerin; 1 pkg. beer yeast, dissolved in 1 tablespoon lukewarm water with 1/z teaspoon of sugar; 100 g wheat germ; 100 g powdered skim milk; 750 g wheat bran; 250 g oat meal. Mix the warm honey and glycerin together. Mix the dry ingredients and add the liquid ingredients. Knead the mix until it becomes a moist crumbly mass.