How to raise silkworms

In a previous post, I
wrote about the potential of feeding
silkworms to chickens. 
But how do you raise them?



Although you can buy
commercial feed for silkworms, those who want to create a sustainable
system will first need to plant or track down a mulberry tree. 
Silkworms don’t eat as adults, and the caterpillars live entirely on
fresh mulberry leaves, preferably white or black mulberries.  I
haven’t found information on how many silkworms you can raise on the
leaves of one tree without damaging it, so I’ll have to report on that
after a season of experimentation.  In the meantime, I’ve scoped
out a few additional sources to supplement my young Illinois
everbearing mulberry
if I run short.



Your next step is to find a
source of silkworm eggs.  There are several different varieties of
silkworms, but I’ve opted to buy so-called Peace Silkworms since the
adults of this variety are able to break free of their cocoons and
breed naturally.  Many other varieties have been bred to optimize
silk-production and have such thick cocoons that the adults perish
inside.  I’m going to try out Aurora Silk, where you can buy 200
silkworm eggs for $30 with free shipping.



Once your eggs arrive,
you can keep them in a ziplock bag in the fridge for up to a few months
to delay hatch.  When your mulberry tree is well leafed out, take
the eggs out of the fridge and leave them at room temperature in a box
or on a tray.  It should take about a week for your eggs to hatch,
and you’ll know they’re nearly there when you see dark rings forming on
the eggs.  Just before the eggs hatch, layer some mulberry leaves
underneath for the caterpillars to eat, then put a clear lid with some
air holes on your tray to hold moisture in the leaves without
suffocating your insects.



Silkworms are voracious
eaters of mulberry leaves, with various sources recommending topping
off their feed once to three times per day.  When you do so, be
sure to supply fresh mulberry leaves with no water on them — young
caterpillars, especially, can drown in drops of dew.  Every other
day or so, clean out the old leaves (perhaps using mesh trays so that
the caterpillars can crawl up into the fresh leaves without your help).



Chickens are supposed to
like silkworms best when they’re less than two inches long, but the
insects will keep growing up to three inches.  At that size, about
one month after hatching, the silkworms stop eating and
turn yellow — your cue that they’re ready to move on to the pupation
phase.  Take out any remaining mulberry leaves and place the
bottom half of a egg carton in the silkworm habitat, providing about
one egg cup per caterpillar.  It’s best to try to save at least
twenty caterpillars to reach this stage if you want to keep the cycle
going.



Within three days, the
silkworms should have spun cocoons, and three weeks later they will
emerge as flight-less moths.  Provide paper towels or another type
of bedding and the female moths will mate and then lay 200 to 500 eggs
apiece.  If you want to raise another batch right away, just put
the eggs in a container and wait for them to hatch in a week, or move
them to the fridge to store until the mulberry leaves are flush again.