Dear Greg,

I don't know how much help this will be, but one superstition mentioned
in T.S. concerns the ticking of a death-watch:

  “Next the ghastly ticking of a death-watch in the wall at the bed’s
head made Tom shudder.  It meant that somebody’s days were numbered.”

What Tom was hearing was a death-watch beetle in the family Anobiidae.
They like seasoned wood, furniture or timber. It emits a ticking sound
in its burrow by bobbing its head up and down, tapping the wood in
search of a mate.  In an active house, this ticking goes unnoticed,
drowned out by other noises. In a house stilled by the prospect of
death, this ticking would bring itself to notice.  Ergo, the
superstition.

I can't tell you about the Doodlebug superstition, but I can tell you
that the Doodlebug is a larval antlion, myrmeleon immaculatus. It finds
a nice piece of sandy or loose soil and begins to walk backward in a
circle.  As it goes, it dips its head into the ground and flings sand
out of the circle.  Eventually, a cone-shaped pit is formed two or three
inches across.  When it is satisfied that the pit is ready, the antlion
wiggles into the sand with only his mandibles sticking out waiting for a
hapless ant to fall in.

I am a Twain enthusiast and free lance writer.  In doing a little
research on T.S., I came across the above information.  In one of those
"what-ifs" of creative writing, I wrote "Getting the Bugs Out of Tom
Sawyer."  The principle character is an entomologist whose favorite book
is Tom Sawyer, not because of its rich characterization, but because of
the fascinating insect life contained therein.  The entomologist is
shamelessly modeled after Simon Wheeler, and, like Wheeler, he corners a
listener with an absurd, rambling monologue detailing  interesting
trivia about houseflies, tumblebugs, doodlebugs, etc.

I  had planned to offer it for publication, but realize the narrow
audience I targeted, primarily Twainians and entomologists.  If anyone
in the Forum would like a copy of the manuscript, email me and I'll send
it out.  If anyone knows of a publication that would be receptive to a
piece like that, let me know.  I might pull it off the shelf and dust it
off.
Thanks,
John Evans