“These silkworms are working out so well, we
might have to increase our colony tenfold next time!” Mark
exclaimed after I told him how much our chicks relished the test
caterpillars I’d tossed their way.



“Good idea,” I
replied.  “But we have to increase our mulberry planting
first.”  And that begged the question — which variety or
varieties should we be focusing on?

Although they’re not
large enough to provide many leaves for our miniature livestock
this year, we actually have five mulberry varieties on the farm at
the moment, so I decided to test them all.  The silkworms had
already reached their fifth instar, at which point they’re able to eat tougher leaves,
so I tried to select nearly-mature leaves from all the trees at
roughly the same toughness level.  (Younger leaves are always
preferred by the silkworms, but some of the trees didn’t have any
young leaves available and I didn’t want to mess up the experiment
by using young leaves from some trees and old leaves from others.)



I labeled each leaf
with a pen mark and placed one of each variety on top of the
silkworms, trying to cover approximately the same number of
caterpillars with each leaf.  After about twenty minutes, I
photographed the results:





The Paper
Mulberry (Broussonetia papyrifera)
was slightly more palatable than my previous experiment suggested, but this was definitely the silkworms’ least
favorite offering.  I gave this species a D for silkworms.



(As a side note, I
didn’t take a picture but I did try out a Chicago Hardy Fig leaf
in a previous taste test.  The theory is that figs are in the
same family as mulberries and osage oranges, both of which
silkworms will eat, so figs might be similarly edible.  Our
caterpillars did lightly taste the fig leaf, but soon moved on to
the mulberries, suggesting that figs probably wouldn’t even work
in a pinch the way Paper Mulberries might.)

I had guessed Oscar’s
Mulberry (Morus alba) would be the tastiest of the selection
since the leaf felt less rough and more tender than other
varieties’ leaves of the same age.  And the silkworms did
enjoy this offering, but I’d say they rated it more of a B+ than
an A.

Silk Hope (Morus
alba x M. rubra) also seemed to be a B+ offering, which is actually better
than I thought the variety would do from what I’ve recently learned about its history.

Moving on to the
A-grade mulberries, the Illionis Everbearing (Morus
alba x M. rubra) tree I’ve been feeding to the silkworms since the beginning
of their lives was well received.  Notice how the silkworms
have eaten over half of the leaf in the twenty minutes alloted to
the experiment!

And now for the
surprise grand-prize winner — a random rootstock mulberry! 
Two of the Illinois Everbearing Mulberries we put in a few years
ago died back to the ground due to neglect, and what popped back
up was clearly not the named variety.  Our mulberry source reports this is Morus alba variety Tatarica, and I’m now considering letting these trees grow for the silkworms rather than grafting a more tasty variety on top.




I want to repeat this
experiment a few more times to ensure the location of the leaves
within the bin didn’t impact the results, and I’d also like to
test some of our native Red Mulberries once I track down a
source.  Finally, when we hatch our second batch of
silkworms, I want to run a taste test on much younger caterpillars
to see if they’re more or less picky at that age.  But for
now, I’ll leave you with a video showing the speed with which a
19-day-old silkworm chows down on a new leaf.  Inspiring,
isn’t it?