Great silkworm dieoff

I learned a lot about
silkworm
management during weeks 1.5 to 2.5 of our first batch’s
life.  In fact, the information is enough for two or three
posts, but my mother helped me see that not everyone thinks
caterpillars are as adorable and fascinating as I do, so I won’t
turn this into the silkworm blog.

The big news is that
I accidentally killed off two-thirds of my colony through
mismanagement.  I’m not quite sure what did it, but the
possibilities include:

1. Heat.  The
   silkworms fared well the first day when the temperatures in our
   trailer got up into the 80s, but the dieoff occurred on the
   second hot day.  So maybe it was just a delayed
   reaction?  (In case heat was the culprit, I moved our
   silkworms to the cool of the barn the next day.)
2. Tough leaves.  I’ve
   been very carefully picking only the mulberry leaves that are
   still pale green and slightly crinkly from youth, but I thought
   our caterpillars might be old enough to try slightly tougher
   leaves.  It’s quite possible the old leaves were hard to
   eat, the heat dried them up prematurely, and our silkworms
   dehydrated as a result.
3. Cat flea medicine. 
   I put that scary
   flea medicine on our cats right before picking mulberry
   leaves on the morning of the die-off.  However, I’m 95%
   sure I didn’t get any of the chemical on my hands, and I think I
   washed my hands after applying the flea medicine and before
   picking the mulberry leaves.  But the reaction of our
   caterpillars was so extreme, I suspect this might have been the
   problem.

No matter what the
cause, the silkworms stopped eating and even started running away
from the mulberry leaves in search of better digs.  Here’s
where the sawdust
on the bottom of the bin became problematic — it was
awfully tough to pick tiny caterpillars off the sawdust, and the
sawdust tended to cling to their bodies even after I put them back
on the leaves.  Probably sawdust isn’t the greatest idea for
the bottom of a silkworm bin.  (In retrospect, I don’t think
any sort of bedding is necessary.)

In more-pleasant
caterpillar news, I ran a taste test to see whether our silkworms
prefer our Illinois everbearing mulberry leaves or some paper
mulberry leaves my mom brought over when she came to
visit.  I alternated each type of leaf, then came back a
couple of hours later to see which ones the caterpillars had moved
onto.  It was a nearly unanimous vote for the Illinois
everbearing, although, again, the reason is a bit uncertain. 
Even though I picked the youngest, least-wilted leaves from Mom’s
supply, the paper mulberries had been off the tree for hours while
the Illinois everbearing were fresh-picked.  Plus, I think
it’s possible silkworms could learn a certain variety of mulberry
and want to stick with it — aren’t all youngsters picky eaters
who want what’s familiar?  I’ll run another taste test with
homegrown paper-mulberry leaves at some point, but for now will
stick to our Illinois everbearing mulberry.

In a way, it was a
blessing in disguise that we lost so many of our silkworms during
the great dieoff because our one mulberry tree was running itself
ragged trying to keep up with the caterpillars’ appetites.  A
week later, even the smaller population of silkworms was starting
to eat us out of house and home.  So I decided it was time to
prepare for the
chicken taste test suggested by one of our readers by
freezing a dozen silkworms every couple of days.  Next week
at this time, I might have results to share with you, so stay
tuned!