ETYMOLOGY
from straddle (with the legs astride)
EXAMPLE
“…If he even seen a straddle-bug start to go anywheres, he would bet you how long it would take him to get wherever he was going to, and if you took him up, he would foller that straddle-bug to Mexico but what he would find out where he was bound for and how long he was on the road. …”
From: The Notorious Jumping Frog of Calaveras County,
By S. L. Clemens (Mark Twain), 1867
Lexicophilia 